Compass

COMPASS, Release 2003.5

Training Manual

© 2001, 2002, 2003 by Landmark Graphics Corporation

Part No. 157605 Rev D 2003.5 July 2003

ii COMPASS Training Manual Landmark

© 2001, 2002, 2003 Landmark Graphics Corporation

All Rights Reserved Worldwide

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Phone:713-839-2000

Help desk: 713-839-2200

FAX: 713-839-2401

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Note

The information contained in this document is subject to change without notice and should not be construed as a

commitment by Landmark Graphics Corporation. Landmark Graphics Corporation assumes no responsibility for any

error that may appear in this manual. Some states or jurisdictions do not allow disclaimer of expressed or implied

warranties in certain transactions; therefore, this statement may not apply to you.

Landmark COMPASS Training Manual iii

Contacting Support

Landmark operates a number of Technical Assistance Centers (TACs).

Additional support is provided through district support offices around the world.

If problems cannot be resolved at the district level, Landmark’s escalation team

is called to resolve your incidents quickly.

Support information is always available on the Landmark Graphics Support

internet page.

Technical Assistance Centers

North America (Houston, Texas)

713-839-2200 or toll-free 1-877-HELP-LGC

7:30 am - 5:30 pm CST/CDT

Monday - Friday, excluding holidays

Fax: 713-839-2168

Email: [email protected]

South America (Houston, Texas)

713-839-3405

7 am - 5:00 pm Local Time


Fax: 713-839-3646


United Kingdom (Leatherhead)

44-1372-868686



Fax: 44-1372 868601


Europe and Africa

44-1224-778500

24 hour support including weekends and holidays

**NOTE: 24 hour support is for DIMS only. WellPlan,

Compass, and Profile are supported business hours: 8 a.m. - 6

p.m. Local Time, Monday - Friday, excluding holidays.

Telephone: +44-1224-778500


Middle East and North Africa

9712-676-1745

Fax: 9712-672-5924

Support Mobile Phone: 971-50-551-7273


iv COMPASS Training Manual Landmark

Asia Pacific International

61-8-9481-4488 or

toll-free 1-800-448-488

8:30 am - 5:30 pm Local Time

Monday-Friday, excluding holidays

Toll-Free Numbers:

10-800-6100-253 (China)

001-803-61284 (Indonesia)

00531-61-0021 (Japan)

1800-803-687 (Malaysia)

0800-400-555 (New Zealand)

1800-1611-0207 (Philippines)

00308-61-0046 (South Korea)

0080-61-1350 (Taiwan)

001-800-611-2784 (Thailand)


Bangladesh, Brunei, India, Pakistan, Vietnam

61-8-9481-4488


District Support Offices

Argentina (Buenos Aires)

54-11-4812-5888 or toll free 1-800-800-5263


Monday-Friday, excluding holidays

Fax: 54-11-4812-9777


Australia

1800-448-488


Australia (Melbourne)

61-3-9820-2486



Fax: 61-3-9828-5365


Australia (Perth)

61-8-9481-4488 or toll free 1800-448-488



Fax: 61-8-9481-1580


Brazil (Rio de Janeiro)

55-21-3974-4000 or toll free 000-814-550-3785

8 am - 5 pm Local Time



Chile (LAO TAC, Houston, Texas)

800-201-898

7 am - 5 pm CST/CDT


Fax: 1-713-839-3405


Landmark COMPASS Training Manual v

China

10-800-6100-253


Colombia (Bogota)

571-326-4000 and 571-326-6710

or toll free 1-800-915-4743



57-1-326-4000 or 57-1-326-6710

Fax: 57-1-326-6717


Ecuador (Quito)- Halliburton Office

593-2261-844 ext 146



Fax: 593-2246-1835


Egypt (Cairo)

20-2-517-3095

(ask for Landmark Technical Support)


Local Business Days, excluding holidays

Fax: 20-2-353-2608


India (New Delhi)

91-11-622-1885



(c/o Samit Enterprises)

Fax: 91-11-647-9246

Indonesia

001-803-61284


Indonesia (Jakarta)

62-21-526-5555 or

toll-free 001-803-61284



Fax: 62-21-526-6555


Malaysia

1800-803-687


Malaysia (Kuala Lumpur)

60-3-2164-1121 or toll free 1800-803-687



Fax: 603-2164-1135


Mexico (LAO TAC, Houston, Texas)

52-52083533 and 52-52083868

or toll free 011-888-438-1296

8 am - 6 pm CST/CDT


Fax: 52-55147646


vi COMPASS Training Manual Landmark

New Zealand

0800-400-555


Nigeria (Lagos)

234-1-262-0765




Fax: 234-1-262-0769

People's Republic of China (Beijing)

86-10-6465-4501 or toll free 10-800-6100-253



86-10-6465-4502 or 86-10-6465-4503


Peru (Lima)- Halliburton Office

0800-51634




Russia (Moscow)


7-095-755-8300

7 am - 5 pm CST/CDT


Fax: 7-095-755-8301

Trinidad (LAO TAC, Houston, Texas)

1-888-438-1296

7 am - 5 pm CST/CDT


Fax: 1-713-839-3405


United Arab Emirates (Abu Dhabi)

9712 676 1745

Fax. 9712 672 5924


Support Mobile is 97150 551 72 73

8:30am - 5pm Local Time, Saturday-Wednesday,

excluding holidays

Out of office hours support provided for DIMS only,

call Support mobile number.

United Arab Emirates (Dubai)

+971-4-331-3142




Fax: 971-4-331-5837


United Kingdom (Aberdeen)

44 (0)1224 778500

8:30am - 5pm Local Time, Monday-Friday, excluding

holidays

Fax. 44 (0)1224 778555


Out of office hours support provided for DIMS only,

call above number and request Oncall Support.

Landmark COMPASS Training Manual vii

Helpful internet links are shown below.

Venezuela (Caracas)

58-212-9530774 or toll free 0-800-526-3627



Fax:58-212-9523845


Vietnam (Ho Chi Minh City)

84-8-910-1901



Fax: 84-8-910-1902

Name Website Address

Landmark Graphics home page http://www.lgc.com

Landmark Graphics FTP Site ftp://ftp.lgc.com

Oracle home page http://www.oracle.com

FLEXlm license management software

home page

http://www.globetrotter.com/flexlm.htm

Microsoft SQL Server home page http://www.microsoft.com/sql/default.asp

Adobe Acrobat Reader http://www.adobe.com

Microsoft MSDE http://www.microsoft.com/sql/default.asp

viii COMPASS Training Manual Landmark

Landmark COMPASS Training Manual

July 2003 Contents ix

Contents

Contacting Support ............................................................................................................. iii

Introduction ....................................................................................................................... 19

What is COMPASS? .................................................................................................... 19

Modules ................................................................................................................. 21

Who Should Use COMPASS ...................................................................................... 23

Licensing and Installation ............................................................................................ 25

Licensing ................................................................................................................ 26

The Engineer’s Data Model (EDM) Database .................................................. 27

Overview............................................................................................................................. 27

Logging In To the Database................................................................................................ 28

Starting COMPASS ..................................................................................................... 28

Describing the Data Structure............................................................................................. 29

Associated Components ............................................................................................... 31

Associated with Designs: ....................................................................................... 32

Associated with Cases: .......................................................................................... 32

Copying and Pasting Associated Items .................................................................. 33

Rules for Associating Components ........................................................................ 33

Common Data ..................................................................................................................... 35

Data Locking....................................................................................................................... 36

How Locking Works .............................................................................................. 36

Concurrent Use of Same Data By Multiple Users .............................................................. 38

How the Well Explorer Handles Concurrent Users ..................................................... 38

Same User on Same Computer .............................................................................. 39

Multiple Users, Different Computers .................................................................... 39

Reload Notification ...................................................................................................... 39

Simultaneous Activity Monitor (SAM) .............................................................................. 41

Importing and Exporting Data ............................................................................................ 42

Importing Data into the EDM Database ...................................................................... 42

Importing EDM Well Data from Another Database .............................................. 42

Importing a DEX File Into the Database ............................................................... 43

Exporting Data From the EDM Database .................................................................... 44

Exporting Data in XML Format ............................................................................ 44

Exporting Well Data in DEX Format .................................................................... 45

Wellbore Planner Import / Export ............................................................................... 46

Wellbore Planner Import ....................................................................................... 47

Wellbore Planner Export ....................................................................................... 48

DIMS for Windows Survey Import ............................................................................. 48

Well ........................................................................................................................ 48

COMPASS Training Manual Landmark

x Contents July 2003

Sidetrack ................................................................................................................ 48

Tool Mappings ....................................................................................................... 48

Using Datums in EDM ....................................................................................................... 50

Definition of Terms Associated With Datums ............................................................ 50

Project Properties ................................................................................................... 50

Well Properties ...................................................................................................... 50

Design Properties ................................................................................................... 52

Setting Up Datums for Your Design ............................................................................ 52

Changing the Datum .................................................................................................... 53

Using the Well Explorer .............................................................................................. 57

Overview............................................................................................................................. 57

Introducing the Well Explorer ............................................................................................ 58

Well Explorer Components ......................................................................................... 59

The Tree ................................................................................................................. 59

Associated Data Components ................................................................................ 60

The Recent Bar ............................................................................................................ 60

Displaying/Sizing the Well Explorer and Recent Bar ................................................. 60

Positioning the Well Explorer ...................................................................................... 61

Tracking Data Modifications ....................................................................................... 61

Drag and Drop Rules ................................................................................................... 62

Well Explorer Right-Click Menus ............................................................................... 63

Working at the Database Level .................................................................................... 63

New Company (Database Level) ........................................................................... 64

Instant Plan (Database Level) ................................................................................ 64

Instant Survey (Database Level) ............................................................................ 64

Well Name (Database Level) ................................................................................. 65

Wellbore Name (Database Level) .......................................................................... 65

Lithologies (Database Level) ................................................................................. 66

Import (Database Level) ........................................................................................ 67

Search (Database Level) ........................................................................................ 67

Refresh (Database Level) ....................................................................................... 68

Expand All (Database Level) ................................................................................. 68

Collapse All (Database Level) ............................................................................... 68

Working at the Company Level ................................................................................... 68

Open (Company Level) ......................................................................................... 69

New Project (Company Level) .............................................................................. 69

New Attachment (Company Level) ....................................................................... 69

Paste (Company Level) .......................................................................................... 69

Rename (Company Level) ..................................................................................... 70

Delete (Company Level) ........................................................................................ 70

Export (Company Level) ....................................................................................... 70

Search (Company Level) ....................................................................................... 70

Survey Tools (Company Level) ............................................................................. 70

Properties (Company Level) .................................................................................. 81


July 2003 Contents xi

Using the Company Properties > Wellbore Types Tab ......................................... 88

Expand All (Company Level) ................................................................................ 89

Collapse All (Company Level) .............................................................................. 89

Working at the Project Level ....................................................................................... 89

Open (Project Level) .............................................................................................. 90

New Site (Project Level) ........................................................................................ 90

New Attachment (Project Level) ........................................................................... 90

Copy (Project Level) .............................................................................................. 91

Paste (Project Level) .............................................................................................. 91

Rename (Project Level) ......................................................................................... 91

Delete (Project Level) ............................................................................................ 91

Export (Project Level) ........................................................................................... 91

Search (Project Level) ........................................................................................... 91

Targets (Project Level) .......................................................................................... 91

Lease Lines (Project Level) .................................................................................. 92

Properties (Project Level) ...................................................................................... 92

Expand All (Project Level) .................................................................................... 96

Collapse All (Project Level) .................................................................................. 96

Working at the Site Level ............................................................................................ 96

Open (Site Level) ................................................................................................... 97

New Well (Site Level) ........................................................................................... 98

New Attachment (Site Level) ................................................................................ 98

Copy (Site Level) ................................................................................................... 98

Paste (Site Level) ................................................................................................... 98

Rename (Site Level) .............................................................................................. 98

Delete (Site Level) ................................................................................................. 98

Export (Site Level) ................................................................................................. 99

Search (Site Level) ................................................................................................. 99

Unlock (Site Level) ................................................................................................ 99

Templates (Site Level) ........................................................................................... 99

Properties (Site Level) ........................................................................................... 104

Expand All (Site Level) ......................................................................................... 107

Collapse All (Site Level) ....................................................................................... 107

Working at the Well Level ........................................................................................... 108

Open (Well Level) ................................................................................................. 109

New Wellbore (Well Level) .................................................................................. 109

New Attachment (Well Level) ............................................................................... 110

Copy (Well Level) ................................................................................................. 110

Paste (Well Level) ................................................................................................. 110

Rename (Well Level) ............................................................................................. 110

Delete (Well Level) ............................................................................................... 110

Export (Well Level) ............................................................................................... 110

Search (Well Level) ............................................................................................... 110

Properties (Well Level) .......................................................................................... 111

Expand All (Well Level) ........................................................................................ 115

Collapse All (Well Level) ...................................................................................... 115


xii Contents July 2003

Working at the Wellbore Level ................................................................................... 115

Open (Wellbore Level) .......................................................................................... 116

New Plan (Wellbore Level) ................................................................................... 116

New Actual Design (Wellbore Level) ................................................................... 116

New Survey (New Wellbore) ................................................................................ 117

New Attachment (Wellbore Level) ........................................................................ 117

Copy (Wellbore Level) .......................................................................................... 117

Paste (Wellbore Level) .......................................................................................... 117

Rename (Wellbore Level) ...................................................................................... 117

Delete (Wellbore Level) ........................................................................................ 117

Export (Wellbore Level) ........................................................................................ 117

Import DIMS Surveys (Wellbore Level) ............................................................... 118

Targets (Wellbore Level) ....................................................................................... 118

Properties (Wellbore Level) ................................................................................... 118

Working at the Design Level ....................................................................................... 120

Open (Design Level) .............................................................................................. 122

Edit (Design Level) ................................................................................................ 123

View (Design Level) .............................................................................................. 123

New Survey (Design Level) .................................................................................. 123

New Attachment (Design Level) ........................................................................... 123

Paste (Design Level) .............................................................................................. 124

Rename (Design Level) ......................................................................................... 124

Delete (Design Level) ............................................................................................ 124

Export (Design Level) ........................................................................................... 124

Import (Design Level) ........................................................................................... 124

Casings (Design Level) .......................................................................................... 124

Formations (Design Level) .................................................................................... 125

Reports (Design Level) .......................................................................................... 126

Properties (Design Level) ...................................................................................... 126

Concepts ............................................................................................................................. 133Overview............................................................................................................................. 133

Accessing Online Documentation ...................................................................................... 134

Using the Main Window..................................................................................................... 135

Using the Well Explorer .............................................................................................. 135

Status Window ....................................................................................................... 136

Viewing Preferences .............................................................................................. 137

Browser Window ................................................................................................... 137

Locked Data Items ................................................................................................. 138

Concurrency Control .............................................................................................. 138

Data Viewer ........................................................................................................... 139

Recent Bar or Recent Selections List .................................................................... 139

Using the Menu Bar ............................................................................................................ 140

Using Toolbars.................................................................................................................... 142

Using Status Bar ................................................................................................................. 143


July 2003 Contents xiii

Accessing the Online Help ................................................................................................. 144

Finding Information in Help ........................................................................................ 145

Frequently Asked Questions ........................................................................................ 145

Configuring Units ............................................................................................................... 146

Planning Module ............................................................................................................. 149Overview............................................................................................................................. 149

Defining Targets ................................................................................................................ 150

Using Targets ............................................................................................................... 150

Target Geometry .......................................................................................................... 150

Accessing the Target Editor ......................................................................................... 151

Using the Target Editor ................................................................................................ 152

Using the Target List ............................................................................................. 152

Defining the Target Geometry ............................................................................... 153

Defining Drilling Targets ....................................................................................... 158

Using the Target Viewer .............................................................................................. 159

Target Landing Point Adjust ................................................................................. 159

Creating a Plan.................................................................................................................... 160

Naming the Plan and Defining the Depth Reference Point ......................................... 160

Specifying the Tie-On Point ........................................................................................ 160

Defining the Survey Tool Program .............................................................................. 162

Specifying the Vertical Section ................................................................................... 163

Using the Plan Editor .......................................................................................................... 164

Accessing the Plan Editor ............................................................................................ 164

Plan Grid ...................................................................................................................... 166

Selecting the Planning Method .................................................................................... 166

Using the Plan Method Window .................................................................................. 166

Using the Plan Editor Toolbar ..................................................................................... 167

Adding a Plan Section .................................................................................................. 168

Deleting a Plan Section ................................................................................................ 168

Editing the Plan Grid ................................................................................................... 168

To Highlight Plan Sections in Views (plots): ........................................................ 169

Incremental Measured Depths ............................................................................... 169

Viewing the Planned Surveys ...................................................................................... 170

Planning Methods ............................................................................................................... 171

2D Directional Well Planning ...................................................................................... 172

Slant Well Design .................................................................................................. 172

S-Well Design ........................................................................................................ 173

3D Well Planning ......................................................................................................... 176

Build/Turn Curves ................................................................................................. 176

Dogleg/Toolface Curves ........................................................................................ 178

Build-Turn vs. Dogleg-Toolface ............................................................................ 181

Optimum Align ...................................................................................................... 182

Hold Tool ............................................................................................................... 187

Thread Targets ....................................................................................................... 188


xiv Contents July 2003

Nudge ..................................................................................................................... 192

Project Ahead ......................................................................................................... 192

Applied Walk Rates .............................................................................................. 193

Using the Plan Optimiser .................................................................................................... 195

Torque and Drag Calculations ..................................................................................... 196

Load Cases ............................................................................................................. 197

Plan Optimizer Editor .................................................................................................. 198

Using the Optimizer Tabs ...................................................................................... 199

Buttons and other Features .................................................................................... 205

Grid Manipulations ...................................................................................................... 207

Grid Columns ......................................................................................................... 207

Tubular Catalog ..................................................................................................... 208

Plan Optimizer Viewer ................................................................................................ 209

The Graphs ............................................................................................................. 209

Planning and Anti-Collision ............................................................................................... 212

Planning Reports................................................................................................................. 213

Planning Report Options ........................................................................................ 214

Anti-Collision Module................................................................................................... 215Overview............................................................................................................................. 215

Specifying AntiCollision Analysis Parameters................................................................... 216

Error Systems ............................................................................................................... 217

ISCWSA ................................................................................................................ 217

Cone or Error ......................................................................................................... 219

Scan Methods ............................................................................................................... 219

3D Closest Approach ............................................................................................. 220

Traveling Cylinder ................................................................................................. 220

Trav Cylinder North ............................................................................................... 221

Horizontal Plane .................................................................................................... 221

Comparing the Scan Methods ................................................................................ 222

Traveling Cylinder Scan and Near-Perpendicular Intersections ............................ 223

Warning Types ............................................................................................................. 224

Error Ratio ............................................................................................................. 224

Depth Ratio ............................................................................................................ 225

Rules Based ............................................................................................................ 225

Error Surfaces .............................................................................................................. 225

Elliptical Conic ...................................................................................................... 226

Circular Conic ........................................................................................................ 226

Combined Covariance ............................................................................................ 227

Including Casings ........................................................................................................ 228

Selecting Offset Designs for Anticollision Analysis .......................................................... 229

Anti-Collision Offset Designs ..................................................................................... 229

Specifying Anticollision Interpolation Intervals and Other Settings ........................... 231

Analyzing Results ............................................................................................................... 232

Using Live Graphs ....................................................................................................... 232


July 2003 Contents xv

Using the Live Graph Toolbar Buttons .................................................................. 232

Example Anti-Collision Analysis ................................................................................ 235

Spider View ................................................................................................................. 236

Viewing Casing Tunnels ........................................................................................ 237

Ladder View ................................................................................................................ 238

To set up a Ladder Plot: ......................................................................................... 239

Optionally .............................................................................................................. 239

Equivalent Magnetic Distance .............................................................................. 242

Separation Factor View ............................................................................................... 242

Reduced Error Bars with Depth ............................................................................. 243

Traveling Cylinder View ............................................................................................. 244

To set up a Traveling Cylinder Plot ....................................................................... 245

Optionally .............................................................................................................. 245

3D Proximity View ...................................................................................................... 251

To set up a 3D Proximity graph: ............................................................................ 251

Interactive Scroll Bar ............................................................................................. 251

Reports ................................................................................................................................ 254

Ellipse Separation Report ............................................................................................ 254

To set up a data scan report: .................................................................................. 255

Definition of sections: ............................................................................................ 255

Error Ellipse Report ..................................................................................................... 257

To set up an ellipse survey report: ......................................................................... 258

Survey Module ................................................................................................................. 263Overview............................................................................................................................. 263

Defining New Survey Properties ........................................................................................ 264

Naming and Specifying General Information About the Survey ................................ 264

Specifying the Tie-On Point ........................................................................................ 266

Specifying User Defined Tie-On Points ................................................................ 267

Specifying Tie-On Points From Wellhead ............................................................. 267

Specifying Tie-On Points From Survey ................................................................. 267

Validating Survey Data ................................................................................................ 268

Managing Survey Data ....................................................................................................... 269

Using the Survey Editor ............................................................................................... 269

Using the Survey Editor Tool Bar ............................................................................... 271

Interpolating Surveys ............................................................................................. 271

Project Ahead ......................................................................................................... 273

Survey Data Quality ............................................................................................... 280

Input Validation ..................................................................................................... 281

Importing Survey Data ................................................................................................. 282

Survey Types ......................................................................................................... 283

Analyzing Survey Data ....................................................................................................... 285

Using Varying Curvature ............................................................................................. 285

Using the 2D Varying Curvature Graph ................................................................ 286

3D Varying Curvature graph ................................................................................. 287


xvi Contents July 2003

Using Graphs to Analyze Survey Data ........................................................................ 288

Max / Min View ..................................................................................................... 289

Analysis Graphs ..................................................................................................... 289

Plotting Multiple Surveys ...................................................................................... 290

Relative Instrument Performance .......................................................................... 292

Survey Reports.................................................................................................................... 294

Survey Export ..................................................................................................................... 295

Export File Format ................................................................................................. 295

Plots ....................................................................................................................................... 299Overview............................................................................................................................. 299

Comparing Live Graphs and Wall Plots ...................................................................... 299

Live Graphs ............................................................................................................ 299

Wall Plots ............................................................................................................... 300

Using Live Graphs .............................................................................................................. 301

Accessing Live Graphs ................................................................................................ 301

Live Graphs Common to All Modules .................................................................. 301

Live Graphs in the Survey Module ........................................................................ 301

Live Graphs in the Anticollision Module .............................................................. 301

Customizing Live Graphs ............................................................................................ 302

Using the Live Graph Toolbar Icons ..................................................................... 305

Legend Box ............................................................................................................ 306

Using the 3D View ............................................................................................... 306

Using the Vertical Section View .......................................................................... 307

Using the Plan View ............................................................................................. 308

Using the Wall Plot Composer ........................................................................................... 309

What is the Wall Plot Composer? ................................................................................ 309

Accessing the Wall Plot Composer ............................................................................. 309

Examining the Wall Plot Composer Components ....................................................... 310

What is an Object? ................................................................................................. 310

What is a Sub-Object? ........................................................................................... 311

Setting Up the Wall Plot Composer Page .................................................................... 311

Using the Toolbars ....................................................................................................... 312

Using the General Toolbar ..................................................................................... 313

Using the Object Toolbar ....................................................................................... 314

Using the Layout Toolbar ...................................................................................... 316

Working With Wall Plot Composer Objects and Sub-Objects .................................... 318

Adding an Object to the Wall Plot ......................................................................... 318

Adding an Art Object to the Wall Plot .................................................................. 318

Selecting an Object(s) on the Wall Plot ................................................................. 319

Selecting a Sub-Object(s) Within an Object on the Wall Plot ............................... 319

Moving an Object(s) or Sub-Object(s) on the Wall Plot ....................................... 319

Deleting Object(s) or Sub-Object(s) ...................................................................... 320

Resizing an Object(s) or Sub-Objects(s) ............................................................... 320

Placing Object(s) and Sub-Object(s) Relative to Each Other ................................ 321


July 2003 Contents xvii

Aligning Object(s) and Sub-Object(s) on the Page ............................................... 321

Editing Style, Thickness, and Color ...................................................................... 321

Exporting Selected Objects .................................................................................... 321

Designating an Object’s Properties as the Default Setting .................................... 322

Setting an Exact Graph Size .................................................................................. 322

Embedding Images on a Plot ................................................................................. 322

Changing Object Properties ......................................................................................... 322

Changing XY Graph Properties ............................................................................. 323

Changing Traveling Cylinder Graph Options ........................................................ 324

Changing 3D Graph Options ................................................................................. 325

Changing Data Boxes Graph Options .................................................................... 326

Changing Geological Columns Graph Options ..................................................... 326

Changing North Arrow Options ............................................................................ 326

Changing Legend Options ..................................................................................... 327

Changing Text Box Options .................................................................................. 327

Changing Picture Options ...................................................................................... 327

Changing Rectangle, Polygon, or Ellipse Options ................................................ 328

Changing Line, Segmented Line, Curved Line, or Arrow Options ....................... 328

Using Wall Plot Composer Right-Click Menus .......................................................... 328

Wall Plot Composer Files ............................................................................................ 329

Tools ...................................................................................................................................... 331Overview............................................................................................................................. 331

Geodetic Calculator ........................................................................................................... 332

The Calculator .............................................................................................................. 332

Geodetic System, Datum and Map Zone ............................................................... 332

Results .................................................................................................................... 333

Geomagnetic Calculator ..................................................................................................... 334

Using the Site Optimizer..................................................................................................... 337

Site Optimizer .............................................................................................................. 339

Targets ................................................................................................................... 339

Design Constraints ................................................................................................. 339

Site Centre .............................................................................................................. 340

Optimiser Viewer ......................................................................................................... 341

Results .................................................................................................................... 341

Theory ................................................................................................................................... 343Overview............................................................................................................................. 343

Introducing Directional Drilling ......................................................................................... 344

Origins ......................................................................................................................... 344

Early Means of Directional Control ............................................................................. 346

Oriented Drilling .................................................................................................... 346

Survey Measurement ............................................................................................. 347

Modern Directional Drilling ........................................................................................ 348


xviii Contents July 2003

Mud Motor ................................................................................................................... 350

Measurement Systems ................................................................................................. 352

Measurement While Drilling ....................................................................................... 353

Emerging Technologies ............................................................................................... 356

Coiled Tubing/Underbalanced Drilling ................................................................. 356

Multi-Laterals ........................................................................................................ 357

Rotary Steerable Systems ...................................................................................... 359

Geo-Steering ................................................................................................................ 361

Survey Calculation Methods............................................................................................... 364

Calculation Methods .............................................................................................. 366

Geodesy .............................................................................................................................. 368

System .......................................................................................................................... 368

Datum ........................................................................................................................... 368

Map Zone ..................................................................................................................... 369

US Stateplane Coordinate System 1983 ................................................................ 369

Universal Transverse Mercator .............................................................................. 369

UK National Grid ................................................................................................... 371

Geomagnetism .................................................................................................................... 372

Geomagnetic Main Field Models ................................................................................ 373

Factors that Influence Declination ......................................................................... 374

True, Grid, and Magnetic North ......................................................................................... 377

True north .................................................................................................................... 377

Grid north ..................................................................................................................... 377

Magnetic North ............................................................................................................ 377

Drillers Target Algorithm ................................................................................................... 380

References ......................................................................................................................... 383

Landmark COMPASS Training Manual 19

Chapter

Introduction

What is COMPASS?

The Computerized Planning and Analysis Survey System (COMPASS)

is a comprehensive software tool designed for use in directional well

design by either oil companies or directional contractors. COMPASS

for Windows is a tool that enables you to quickly and accurately plan

wells and identify potential problems at the earliest possible stage.

All of the features for complex well trajectory design, monitoring and

analysis are included. The list of features include survey & planning

methods, torque-drag optimization, anti-collision plotting with traveling

cylinder and ellipse of uncertainty.

COMPASS is designed to increase the efficiency and cost-effectiveness

of directional well planning and wellbore monitoring by providing an

easy-to-use interface and numerous other features. COMPASS enables

fast and accurate well planning and identification of potential directional

drilling problems at the earliest possible stage.

COMPASS enables you to:

� Design the shape of wellbores using the Planning Module.

� Calculate the shape of wellbores using the Survey Module.

� Calculate positional uncertainty and wellbore separation using the

Anti-Collision Module.

� Create hardcopy plots using the Wallplot Composer Module.

� Display results using various online graphics and hardcopy reports.

� Construct a data repository for storing deviation data that can be

linked to other data models.

The following technical features ensure that COMPASS is the most

comprehensive software of its kind available today:

1

Chapter 1: Introduction

20 COMPASS Training Manual Landmark

� Based on Landmark’s EDM database to provide seamless

integration with other Landmark Drilling software products such as

WELLPLAN, DIMS for Windows, StressCheck, and CasingSeat.

� Integration with Landmark’s OpenWorks applications, including

Wellbore Planner

� ODBC-compliant databases

� A logical, context-designed data model

� A consistent, easy-to-use interface

� Flexible units handling

� Comprehensive, context-sensitive online help written by engineers

� Comprehensive live graphical output

� Multi-component, customizeable plots with Wallplot Composer

� Formatted customizeable reports with ASCII file options

� Integrated planning and analysis work flow complemented by live

graphic updates

� Support for multiple depth datums per site

� Integration with industry-accepted Geodetic, Geomagnetic, and

Survey Tool Error models

� Customizeable survey tool error models

� Definition of targets with different geometry types

� Project Ahead and Varying Curvature Survey Analysis tools

� An easy-to-use planning tool with numerous 2D and 3D planning

solutions

� Improved horizontal well support with multiple target threading

� Curved Conductor/Slant rig support with configurable well

reference point.

� Multiple Anti-Collision Scan Methods and Graphical Outputs



� Detailed Positional Uncertainty Error Surface Geometry calculation

and reporting

Modules

COMPASS consists of three main modules integrated by a host of

supporting features and an underlying data structure.

Survey

The Survey module calculates a Wellbore’s trajectory. Compass

considers a survey to be a set of observations made with a single survey

tool in the same tool run. Data can be entered in a spreadsheet or

imported and processed using industry-standard calculation methods.

The resulting survey files can be edited, printed or analyzed. Surveys

may be spliced together to form a definitive 'best path' using a tool

interval editor. Special provisions are made for Inertial and Inclination

only surveys. Survey provides an advanced "project ahead" from survey

station to target, formation or well plan.

Two methods enable you to assess survey data for incorrectly entered

survey data or bad readings from the survey tool. Input Validation will

isolate bad survey data as soon as it is entered. Varying Curvature

isolates incorrect survey station data by highlighting their inconsistency.

Survey analysis graphs are available that produce comparison plots of

survey and plan data for a number of different variables.

COMPASS survey data can be referenced to any number of user-

defined datums and can include a number of canned or custom formatted

report layouts that you can send to an ASCII file. You can also export

survey data to a raw survey file or output it to a number of canned or

custom export file formats.



After you enter data, you can do the following:

� Perform point interpolations for any number of Measured or True

Vertical Depths, Inclination or Azimuths.

� Use the Project Ahead tool to compare the wellpath’s current

trajectory against a proposed target or plan.

� Perform Free Projections to a proposed MD or TVD using an

entered Build & Turn rate, Dogleg & Toolface, or by constructing a

trend using a number of existing survey observations.

Planning

Use the Plan Editor to design the shape of proposed wellbores. The

Planning environment has an interactive editing worksheet allowing the

user to build up the well trajectory in sections. There are many different

plan sections available for each section and they can be based on 2 or 3

dimensional Slant or S Shaped profiles or 3 dimensional dogleg/toolface

or build/turn curves. Alternatively the plan can be imported or entered

directly into the spreadsheet line by line. At each stage of well planning,

the user can see the Wellbore graphics dynamically update as changes

are made. The user may re-visit, insert or delete any section of a plan and

the whole plan will be recomputed.

The Wellbore optimizer integrates torque drag analysis into the

planning module. It will determine the best combination of trajectory

design parameters that lead to the minimum cost, anti-collision or torque

and drag solution. Planned designs which are 'un-drillable' by colliding

with other Wellbores or exceeding the drill strings tension, torque,

buckling, side force or fatigue limits are indicated.

Different plan methods are supported:

� Slant Well and S-Well designs are available to plan a well within a

vertical section.

� In 3D, you can construct plans using Build & Turn curves for

rotary-drilled sections or Dogleg/Toolface curves for steering tool-

drilled sections.

� You can also use additional tools such as Optimum Align, which

enables steering to be minimized to certain user-selected parts of

the well; Thread Targets, which automatically constructs a plan

through two or more targets using various plan types; and the



Landing Calculator, which enables a plan to intersect a target plane

along a given azimuth.

� For long hold sections, a plan can be corrected for anticipated Walk

Rates through certain formations.

Anti-Collision

Anticollision can be used to check the separation of surveyed and

planned Wellbores from offset wells. Anticollision provides spider

plots, ladder plots, traveling cylinder, and printouts of well proximity

scans. Any anticollision scans may be run interactively with planning,

surveying or projecting ahead. All anticollision calculations are

integrated with Wellbore uncertainties that are shown on graphs or

reported as separation ratios. Warnings may be configured to alert the

user when the Wellbores converge within a minimum ratio or distance

specified by company policy.

Available Plots:

� Travelling Cylinder View: Wellpath separation referenced from

either high side of the well or high side + current well azimuth.

� Ladder View: MD vs. wellpath separation

� Separation Factor View: MD vs. Separation Factor

� 3D Proximity View: 3d presentation of all wells included in the

scan

� Spider Plot: Plan view of all wellpaths included in the scan.

� An Error Ellipse report that describes the geometry of the

uncertainty ellipsoid at all depths down the reference wellpath.

Who Should Use COMPASS

COMPASS is designed for engineers with different responsibilities and

for different types of organizations such as Oil Companies,

Directional/Survey Contractors, and Engineering Consultants. Different

users use COMPASS in different ways and work with different modules

within COMPASS according to their jobs requirements.

COMPASS enables an engineer to track a well through the following

stages:



� The initial data-gathering stage, determining required geological

targets, surface drilling locations, planning constraints.

� The various phases of directional well design, including collision

avoidance, target analysis, operational stages of recording surveys,

checking for anti-collision risks, doing look-aheads, and

performing survey quality assessments.

� The compilation of a final definitive survey.

Within an Oil Company, a Well Planner plans a well to intersect one or

more targets provided by their Geoscience department. Targets are

analyzed and sized in conjunction with the design of the survey

program. The plan can be 2D or 3D and may require the use of rotary or

steerable bottom hole assemblies for it to be drilled. The plan is

communicated to and agreed upon by all concerned parties.

While drilling, the Rigsite Company Representative uses COMPASS to

enter and collate Survey data, report the Wellpath trajectory back to

town, and perform quality control checks on the data to ensure the

survey contractor obtains and records data correctly. In town, the

Operations Engineer in the Drilling Office receives the Survey data,

adds it to their COMPASS database, and shares it with other parts of

their organization or with partners.

Both engineers may perform Anti-Collision scans down the active well

to assess the collision risk. Also, they may compare the actual wellpath

trajectory with the directional well plan to ensure the well is on track. If

the well veers away from the Plan, they can do Back-On track

calculations to steer the wellpath back to its planned trajectory.

When the well is completed, the final Definitive Survey is composed,

locked, and made available for use with Anti-Collision scanning or

Sidetrack planning on future wells.

A Directional Contractor may use COMPASS to plan a well on behalf

of an Oil Company. At the rigsite, contract Surveyors and Directional

Drillers use COMPASS to enter Survey data as it is received at surface

or read on the drill floor, and a comparison is made with the planned

trajectory. The data is checked for errors and then reported to the Oil

Company representative in the form of reports, graphs, or wallplots.

The contractor can also provide the data electronically on floppy disk or

send it across a network. If their client also uses COMPASS, they can

send a transfer file to the Company Representative or Drilling Office.



Directional Well Planners specialize in designing and assessing

wellpaths for a number of conditions.

In addition to planning wells through various targets and assessing the

plan for a collision risk, they use Geologic targets provided by the

Geoscience group to construct Drilling Targets. This is achieved using

survey tool error models applied down the planned wellpath to reduce

the size of the target surface. This enables the planner to design a cost

effective survey program applied to the given geological target sizes.

� A Survey Focal Point is responsible for maintaining an accessible

quality-checked survey database for an oil company. They can also

be involved in analyzing positional uncertainty error models

associated with different types of survey tools. Based on the

accuracy and reliability of different tools, they can recommend the

use of certain tools to the Well Planning group.

Licensing and Installation

There are three types of installations available for EDM applications:

� Local (Standalone) Installation: This type of installation is

appropriate for engineers needing to install EDM locally on a single

computer to be used by one person. This installation will copy the

product software, database, and all required support files to the

designated directory on the computer’s local hard drive. For more

information, please refer to the EDM Common Installation guide.

� Server (Network Server) Installation: This installation should be

used when the EDM applications will be installed centrally on a

server to be shared by a number of users. This installation will copy

the product software, database, and all required support files to the

designated shared directory on the network server. These files must

be accessible tot he network client computers. For more

information, please refer to the EDM Common Installation guide.

� Client (Network Client) Installation: This installation is used

when EDM applications will be run from the network. The client

installation will copy only the required system files to the local

computer’s hard drive and then create shortcuts to the shared

application executable files located in a designated directory on the

network server. For more information, please refer to the EDM

Common Installation guide.



Licensing

FLEXlm is a licensing method common to all Landmark products. It

provides a single licensing system that integrates across PC and network

environments. FLEXlm Licensing files and FLEXlm Bitlocks are

supported for Landmark Drilling and Well Services applications. Please

refer to the EDM Common Installation guide for more information.


Chapter

The Engineer’s Data Model (EDM)Database

Overview

Many of Landmark’s drilling applications use a common database and

data structure—the Engineer’s Data Model (EDM) database—to

support the different levels of data that are required to use Landmark’s

drilling and production software.

This is a significant advantage while using the software because of

improved integration between drilling software products. Currently

OpenWells, WELLPLAN, COMPASS, StressCheck, and CasingSeat use

the common database and data structure. Although the common

database improves integration between products, those products that

don’t use the common database can still share data using DEX.

In this chapter, you will be introduced to:

� Logging in to the database

� Data structure

� Common data

� Data locking

� Importing and exporting data

2

Chapter 2: The Engineer’s Data Model (EDM) Database


Logging In To the Database

Any Landmark drilling software using the Engineer’s Data Model

(EDM) will require you to login. This dialog is used to select the

database and to provide a user id and password.

Starting COMPASS

You can start COMPASS in two ways:

� Use the Start Menu. Select COMPASS using Landmark EDM >

COMPASS.

� Double-click any desktop shortcut you have configured.

The following login screen appears when you launch COMPASS:

Select the database you want

to use from the drop-down

list.User will default to the

last user name entered.



Describing the Data Structure

The EDM database has a hierarchical data structure to support the

different levels of data that are required by different drilling suite

applications. EDM uses the following hierarchical levels.

Hierarchical Level Description

Database The Database is the highest level in the Well

Explorer hierarchy. You can only work in one

database at a time. Refer to “Working at the

Database Level” on page 63 for more

information.

Company Company is the second highest data level in

the hierarchy. You can define several

companies within the database you are using.

Each company must have a unique name. If

you work for an operator, most likely you

may have only one company. If you work for

a service company, you may have several

companies. Refer to “Working at the

Company Level” on page 68 for more

information.

Company

Project

Site

Well

Design

Case

Wellbore

Company

Database

Hierarchical database structure of the

EDM database.



Project Project is the data level directly beneath

company and each project within a company

must have a unique name. A project can be

thought of as a field or as a group of sites. A

project has one system datum (mean sea level,

lowest astronomical tide, etc.) that is used to

define 0 TVD for the project. Within the

project, wellbores can be referenced to the

project level system datum or to additional

datums specified at the well level. Refer

to“Using Datums in EDM” on page 50 or

“Working at the Project Level” on page 89 for

more information.

Site Site is the data level directly beneath the

Project level and each site within a project

must have a unique name. A site is a

collection of one or more wells that are all

referenced from a local coordinated system

centered on the site location. A site can be a

single land well, an offshore sub-sea well, a

group of well drilled from an onshore pad, or

a group of wells drilled from an offshore

platform. Refer to “Working at the Site Level”

on page 96 for more information.

Well Well is the data level directly beneath the Site

level and each well within a site must have a

unique name. A well is simply a surface

location. A well can have more than one

wellbore associated with it. For example,

there may be the original wellbore with one or

more sidetracks tied on to it at different kick-

off depths. Refer to “Working at the Well

Level” on page 108 for more information.

Wellbore Wellbore is the data level directly beneath the

Well level and each wellbore within a well

must have a unique name. A wellbore is a

compilation of one or more sections

originating at the surface and continuing to a

depth. A wellbore can be the original well

drilled from the surface or a sidetrack drilled

from a parent wellbore. If a well has an

original hole and two sidetracks, the well has

three wellbores. Refer to “Working at the

Wellbore Level” on page 115 for more

information.




Associated Components

There are several additional data components that are associated with

Designs or Cases. These are:

Design Design is the data level directly beneath the

Wellbore level and each design within a

wellbore must have a unique name. A design

can be thought of as a design phase.

Associated with each design are a pore

pressure group, a fracture pressure group, a

temperature gradient and a survey. A design

may have several cases associated with it, but

each case will use the same pore pressure

group, fracture pressure group, temperature

gradient and survey. A design can be

categorized as prototype, planned or actual.

You may have several different versions of

prototype designs. For example, assume the

geologist wants to analyze two different

formation fracture gradients. This could

easily be accomplished by having two

prototype designs that are identical except for

the fracture gradient group. Landmark’s

StressCheck and COMPASS applications

routinely use designs. Refer to “Working at

the Design Level” on page 120 for more

information.

Case (WELLPLAN only) Case is the data level directly beneath the

Design level and each case within a design

must have a unique name. A case can be

thought of as a snapshot of the state of the

well. For example, you may use two cases to

analyze the affects of varying the mud weight

or changing the BHA. Associated with each

case are an assembly, a hole section and one

or more fluids. Cases are commonly used in

Landmark’s WELLPLAN application.

StressCheck and COMPASS do not use cases.




Associated with Designs:

Wellpaths

A wellpath is a series of survey tool readings that have been observed in

the same wellbore and increase with measured depth. All Cases within

the same design use the same wellpath.

Pore Pressure Groups

A Pore Pressure group is a set of pore pressures that define the pore

pressure regime over a depth range from surface to some vertical depth.

All Cases within the same design use the same pore pressure.

Fracture Gradient Groups

A Fracture Gradient is a set of fracture pressures that define the fracture

gradient regime over a depth range from surface to some vertical depth.

All Cases within the same design use the same fracture gradient.

Geothermal Gradient Groups

A Geothermal Gradient is a set of undisturbed earth temperatures that

define the temperatures over a depth range from the surface to some

vertical depth. All Cases within the same design use the same

geothermal gradient.

Associated with Cases:

Hole Section Groups

A Hole Section defines the wellbore as the workstring would see it. For

example, a hole section may contain a riser, a casing section, and an

open hole section. A hole section can also have a tubing section or a drill

pipe section depending on the situation. Multiple cases may use the

same hole section.

Assemblies

An Assembly defines the workstring. There are several types of

workstrings, including coiled tubing, casing, drillstrings, liners, and

tubing strings. Multiple cases may use the same assembly.



Fluids

A Fluid defines a drilling, cementing, or spacer fluid. A Fluid is linked

to a Case and a Case can have more than one fluid linked to it. One fluid

can be linked to multiple cases.

Copying and Pasting Associated Items

All of these associated items, with the exception of fluids, are

automatically created and associated ("linked") by Well Explorer to the

design or case. (You cannot manually create or link these items.) Fluids

can be created/linked in WELLPLAN only, using the Fluid Editor.

However, all these items are visible in Well Explorer so that you can

copy and paste them using the right-click menu. For example, when you

copy a wellpath and paste it into a different design, the wellpath that

currently exists for the target design is deleted. Well Explorer replaces

the old wellpath with the copy of the new one.

Again, fluids are the exception. Only the WELLPLAN Fluid Editor can

delete fluids, so after pasting a fluid, the original fluid still exists. The

original fluid is no longer linked to anything. This can’t be seen in Well

Explorer, but WELLPLAN can access this. Note that if the destination

case, or the fluid you are trying to replace, is locked, a message appears

and the paste is not completed.

Rules for Associating Components

The rules for associating components are listed below.

For Definitive Surveys, Pore Pressure Groups, Fracture Gradient

Groups, Geothermal Gradient Groups, Assemblies, and Hole Sections:

� Each component can only be associated with one Design or Case.

� When one component is copied and pasted, an actual copy is made.

� When one component is pasted, the component is replaces will be

deleted (unless it is locked).

� If the destination for the paste is locked (Design or Case) or the

item to be replaced is locked, a message appears and the paste is not

completed.

� If the design is locked, all it’s associated items are also locked.



For Fluids:

� When a fluid is copied and pasted, an actual copy is made.

� When a fluid is pasted, the one is replaces will NOT be deleted.

� Fluids can only be deleted using the Fluid Editor in WELLPLAN.

� If the destination case is locked or the fluid to be replaced is locked,

a message appears and the paste is not completed.



Common Data

Common data stored in the EDM database and available for use by

StressCheck, CasingSeat, WELLPLAN, Openwells, and COMPASS in

database mode include:

• Unit system

• Pipe catalog

• Connections catalog

• Pore pressure

• Fracture Gradient

• Temperature Gradient

• Surveys

• All fields in Well Explorer Properties dialogs

• General data, such as Well Name, Well Depth, Vertical Section

information

Note: Several additional fields are common to two or more applications, but not all.

Drilling applications may share other data not listed.



Data Locking

You can prevent other people from making changes to data by locking

data at various levels and setting passwords. Users can only open the

data item in read-only mode; to keep changes, they will have to use

Save As or Export.

How Locking Works

You can lock Company properties only, or you can lock properties for

all levels below Company (Project, Site, Well, Wellbore, Design, and

Case). Passwords can be set to prevent unlocking.

By default, no passwords are set, and the "locked" check box on all

Properties dialogs can be toggled on and off at will with no security to

prevent users from doing something they shouldn’t.

In the Well Explorer, if a data item is locked a small blue "key" appears

in the corner of its icon. When you open a locked data item, you will see

the message "This Design is locked and therefore Read-Only. Changes

to this Design will not be saved to the database. To keep your changes,

use the Save As or Export options."

Locking Company Properties

In the Properties dialog for the company whose data you want to protect,

there are two buttons, Company Level and Locked Data, and a

checkbox, Company is locked.

When you click the Company Level button, you are prompted to set a

password to protect Company properties (and only the Company

properties). This password will then be required if a user wants to

"unlock" company properties and make changes.

Once the password is set, toggle the Company is locked checkbox on to

lock the company properties and prevent unauthorized changes to the

data.

Locking Levels Below Company

When you click the Locked Data button on the Company Properties

dialog, you are prompted to set a password. This password will then be



required if a user wants to "unlock" any level below the company

(projects, sites, wells, wellbores, designs, and cases).

All levels are locked individually—that is, you can lock a Well, but this

doesn’t mean that anything below it is locked.

Once the Locked Data password is set, you can lock properties for any

data level below Company and prevent unauthorized changes to the

data. Open the Properties dialog for the data level you want to lock and

toggle the "locked" checkbox on. (For example, to lock a Wellbore,

open the Wellbore Properties dialog and toggle Wellbore is locked on.)

Note: Locked Designs...

When a design is locked, all associated items (Pore Pressure, Fracture Gradient,

Geothermal Gradient, and Wellpath) are locked with it.



Concurrent Use of Same Data By Multiple Users

The 2003.5 release of EDM supports concurrency for multiple users on

the same data set. The Simultaneous Activity Monitor (SAM) is the

service used to regulate concurrent access to the EDM database. For in-

depth information on SAM, refer to the EDM Administration Utility

help.

� By default, the SAM server is enabled and connected and you will

see a green "SAM" icon in the status bar of your application.

� If the SAM service is configured but not connected, the "SAM"

icon will appear with a red "X" drawn through it. Consult your

System Administrator.

� If the SAM service is not configured, there will be no SAM icon in

the status bar.

A good practice for any multi-user environment is to frequently use the

F5 refresh key to refresh the Well Explorer contents. Data updates (e.g.,

inserts, updates, deletions) are not always automatically recognized in

other EDM sessions and simultaneously run EDM applications.

How the Well Explorer Handles Concurrent Users

Basically, the Well Explorer and the Simultaneous Activity Monitor

handle concurrency like this: If a user on a different machine has a

Design open (first one to open the Design gets it in Read/Write mode),

then all other users can only open that Design in Read-Only mode. If no

one on any other machine has Read/Write access to the Design, then you

get Read/Write access.

This is the SAM icon:

The red "SAM" icon indicates that one or more users have this item open

and you are restricted to opening it in Read-Only mode. You cannot save

any changes to the database, but you can use Save As and rename the

item.

The blue "SAM" icon indicates that one or more users have this item

open, but you can still open it in Read/Write mode. You can save

changes to the database.



These SAM icons will appear on a Design (COMPASS, WELLPLAN,

StressCheck, CasingSeat) or a Well (OpenWells) in the Well Explorer.

Same User on Same Computer

If the same user has a Design open in one EDM application and then

opens the same Design in another EDM application on the same

machine, the blue "SAM" icon will appear in the Well Explorer of the

second application. This indicates that this user has the Design "locked

for use in Read-Write mode", and has it open in more than one

application. However, because it IS the same user, he/she can Save

changes to the database made from either application.

Multiple Users, Different Computers

The first user to open a Design or Case in that well gets control, and the

Design or Case is then "locked for use in Read/Write mode." A red

"SAM" icon indicates that more than one user is working with the

Design or Case at the same time. However, only the first user can make

changes; all other users open the Design or Case in Read-Only mode.

They can Save As, but not Save.

After the user who had access to the Design or Case in Read/Write mode

closes the Design or Case, the red "SAM" icon goes away, and the

Design or Case is available again. Read-only users will have to close the

Design or Case and re-open to gain control.

(WELLPLAN only) A user can save Cases under a Design that is

currently "locked for Read/Write use" by someone else.

Reload Notification

If you are working with any of the data in the following list, and a user

with read/write privileges saves changes to the database, you will

receive a notification indicating that another user has changed the data

you are working with.

You will have the opportunity to use the changes saved to the database

by the other user. You will also have the opportunity to save the data you

are working with using the Save As option. If you do not save your data

using Save As, your changes will be overwritten by those made by the

other user. (Your changes will only be overwritten if the other user saves

his changes, and you indicate you want to use those changes when you

receive notification.) Keep in mind that if you have read privileges, any



changes you make are only stored in memory and are not written to the

database unless you save your data using Save As.

Items that are refreshed in this manner are: Design, Definitive Survey

(Wellpath), Pore Pressure, Fracture Gradient, Geothermal Gradient,

Assemblies (Casing Scheme)



Simultaneous Activity Monitor (SAM)

The 2003.5 release of EDM (the Engineer's Data Model) supports full

concurrency for multiple applications using the same data set through

the Simultaneous Activity Monitor (SAM).

If the Simultaneous Activity Monitor has not been configured, the

following message will appear: "WELLPLAN could not connect to the

SAM server. Please verify that the settings are configured correctly in

the administration utility, and that the SAM server is running."

The Simultaneous Activity Monitor consists of a Messaging Server that

notifies the user with an open application of all data currently open in

other applications. The SAM icon appears in the application Status Bar

as follows:

If a data item is open, an icon will appear as follows:

� A red SAM icon indicates that one or more users on other PC’s

have this item open and the current user is restricted to read-only

access.

� A blue SAM icon indicates that one or more users on the current PC

have this item open but the current user still has full read-write

access. A user must be careful when making changes to the date

though this method enables data to automatically flow between

applications.

Icon Message Description

A green SAM icon in the status bar indicates that the

Messenger service is active.

A blue SAM icon with a red X on it indicates that the

Messenger Service is not currently active.

No Icon When no icon appears in the application status bar this

indicates that the Simultaneous Activity Monitor has not

been configured for the application.



Importing and Exporting Data

COMPASS provides you with EDM database import and export

functionality, as well as DEX file import and export functionality.

Importing Data into the EDM Database

You can import data from one EDM database into another EDM

database, or you can import a DEX file.

Importing EDM Well Data from Another Database

To import well data from one EDM database to another, follow these

steps:

1. In the Well Explorer, select the EDM database canister.

2. From the Well Explorer right-click menu, select Import. The

following dialog box opens:

3. Select the .XML file containing the well data you want to import,

and click Open. (Well data can be saved in .XML format using the

Export command in the Well Explorer; see page 44 for details.)

4. The well data will be imported into the database.



Importing a DEX File Into the Database

To import a DEX file into the EDM database, follow these steps:

1. Select File > Data Exchange > Import. The following dialog box

opens:

2. Specify the filename for the well information in DEX format you

want to import, and click Open. The following dialog appears.

3. Use the arrow buttons to move the desired data items into the lower

list box. Single arrow buttons move the highlighted file(s). Double

arrow buttons move all files. (Use the upward facing arrows to

remove items from the desired selection.)



4. Click OK to start the import.

5. The data will be imported into memory and displayed in the main

window. The data has not yet been saved to the database. You may

make changes now, if you wish.

6. When you are ready to save the changes to the database, select

File > Save. The Save As dialog opens, allowing you to specify

where in the hierarchy to place the newly imported design, and to

name the design. Click Save. The newly created design will appear

in the Well Explorer tree.

Exporting Data From the EDM Database

You can export well data from the EDM database in .XML format; this

data can then be imported directly into another EDM database. You can

also export data in DEX format.

Exporting Data in XML Format

To export well data for import into another database, follow these steps:

1. In the Well Explorer, select the company, project, site, well,

wellbore, design, or case whose data you want to export and right-

click to open the pop-up menu. Select Export. The following

dialog box opens:

2. Specify a filename for the information you want to export, and click

Save. The parent and child data, and any linked pore pressures,



fracture gradients, etc. will be saved to the .XML file you

specified.

Exporting Well Data in DEX Format

To export well data as a DEX (.DXD) file, follow these steps:

1. Select File > Data Exchange > Export from the main menu. The

following dialog box opens:

2. Specify a filename for the well information you want to export in

DEX format, and click Save. If this is the first time you have saved

DEX data using the specified filename, the export is complete at

Note: Exporting a Large Number of Wells

There may be problems when exporting a company with a large number of wells.



this point. If the specified file already existed, the following dialog

opens to allow you to specify which objects you want to export.

3. Use the arrow buttons to move the desired data items into the lower

list box. Single arrow buttons move the highlighted file(s). Double

arrow buttons move all files. (Use the upward facing arrows to

remove items from the desired selection.)

4. Click OK to start the export. The data will be saved to the .dxd file

you specified.

Wellbore Planner Import / Export

Wellbore Planner is a well planning application integrated into

Landmark’s Geological and Geophysical visualization UNIX

applications. Links with COMPASS enable Wellbore Planner users

(Geologists/Geophysicists) to quickly construct well trajectories with

COMPASS users (drillers), with both using their own data sets. This

reduces planning time by eliminating the paper stage in which

geologist’s targets details are written down, passed to the driller, and



their resultant wellpath trajectory is then copied back and forth until a

final trajectory is agreed upon.

COMPASS can import and export data directly to Wellbore Planner.

This route also enables selective import of Openworks well trajectories.

This type of tool enables Planned Trajectory or Actual Trajectory data

to be easily shared between the Engineering and Geoscience disciplines.

Wellbore Planner Import

This feature allow you to import ‘*.WBP’ files from the Wellbore

Planner application. The file has to be moved to the Windows

COMPASS computer by FTP link.

These are the import rules:

• If you are moving the data to an existing Company, Field, or Site,

open them before the import.

• If you don’t want the import to interfere with existing data, open a

new company. To open the File Open dialog, from the COMPASS

main menu click File, Import, then Wellbore Planner. Select the

file to import (*.WBP).

If you are importing to an existing site, a message box appears

displaying the following:

If you have already chosen a site, the following message appears:

Importing file xxxx.wbp to site yyyy, click OK to

continue.

If the Map coordinates contained in the Wellbore Planner file disagree

with the current site, or disagree within itself, the message ‘Well xxxx

has strange starting coordinates’appears. The data is still imported, but

you must check it.

Click this... To import this...

All Data All data

WP Plans Wellbore Planner plans only

OW Wells OpenWorks wells surveys



Wellbore Planner Export

This feature exports a file in the Wellbore Planner format for import to

a geological application like OpenVision. The file has to be moved from

the COMPASS for Windows PC via FTP. In COMPASS, open the

Customer, Field, and Site of interest. Then, from the COMPASS main

menu, select File, Export, then Wellbore Planner. COMPASS then

asks the name and destined location of the export file.

DIMS for Windows Survey Import

DIMS for Windows (DIMS) is Landmark’s Drilling and Well Services

Daily Drilling and Completions Reporting System. Typically DIMS is

used at the rigsite as part of a client’s daily drilling reporting procedure.

Built-in links between COMPASS and DIMS for Windows enables easy

transfer of survey information from DIMS to COMPASS to reduce

survey data-entry duplication.

To access the DIMS survey import tool, you must open a wellpath in

COMPASS to import surveys into. The DIMS survey import also

requires an ODBC data source that you use to access the DIMS for

Windows database. A database connection is the PC’s mappings of how

software applications should open a database. Both COMPASS and

DIMS for Windows require defined ODBC connections before the

applications run. Consult your systems administrator to build a DIMS

for Windows ODBC data source if one is not available.

Well

Select a DIMS well from the drop-down list. COMPASS populates the

SideTrack list box with the sidetracks for that well defined within

DIMS.

Sidetrack

Select a DIMS sidetrack for COMPASS to import Surveys from. Each

unique survey tool within DIMS for the sidetrack will be displayed in

the Tool Mappings grid.

Tool Mappings

The DIMS survey tools must be mapped to equivalent COMPASS

survey tools. This is necessary because there is no connection between

them, and COMPASS requires a correct tool mapping to calculate



positional uncertainty. You must do this for all DIMS tools before

starting the import. COMPASS remembers survey tool mappings for

future use.

When mappings are complete, press OK, and COMPASS imports the

DIMS for Windows data, creating a separate survey for each one of the

mappings.



Using Datums in EDM

Definition of Terms Associated With Datums

Datum terms are defined below, and are grouped by the Properties

dialog in which they are found.

Project Properties

System Datum:

The System Datum is set in the Project Properties/General dialog, and

represents absolute zero. It is the surface depth datum from which all

well depths are measured, and all well depths are stored in the database

relative to this datum. Usually the System Datum is Mean Sea Level,

Mean Ground Level, or Lowest Astronomical Tide, but it can also be the

wellhead, rigfloor, RKB, etc.

Elevation:

The Elevation is set in the Project Properties/General dialog, and

represents the elevation above Mean Sea Level. (If Mean Sea Level is

selected as the System datum, Elevation is grayed out.)

Well Properties

Depth Reference Datum(s):

The Depth Reference Datum represents zero MD. It is sometimes

known as the local datum, and is measured as an elevation from the

System Datum. You can define one or more Depth Reference Datums

for a well in the Depth Reference Tab (Well Properties Dialog). For each

Depth Reference Datum, you must specify the elevation above or below

the System Datum.

The selected default Depth Reference datum in the list box will be the

viewing datum in all applications (the viewing datum can be changed

‘on the fly’ only in OpenWells and COMPASS.)



You can’t delete or change the elevation of a Depth Reference datum

once it is referenced by a Design.

Offshore check box:

Check to indicate that this is an offshore well; leave unchecked to

indicate a land well.

Subsea check box: (offshore well)

Check to indicate that this offshore well is subsea.

Ground Elevation: (land well)

This is the elevation of the ground above the System Datum; it is set in

the Depth Reference Tab (Well Properties Dialog).

Water Depth: (offshore well)

This is the total depth of the column of water (MSL to mudline); it is

referenced to Mean Sea Level.

Mudline Depth: (only for offshore subsea well)

This is the depth below system datum (MSL/LAT etc.) of the wellhead

flange.

Wellhead Depth: (subsea well)

This is the distance from the wellhead to the system datum, and is used

in some calculations where this is the hanging depth for casing leads

when set. To determine wellhead depth:

Wellhead Depth (to rig floor) = Depth Reference Datum + Wellhead

Depth

Wellhead Depth (set in the Well Properties/General dialog) is positive

for offshore subsea and negative for wellheads above MSL (i.e., onshore

or offshore platform). So, it does not matter in the above calculation

whether it is offshore or subsea. Depth Reference Datum is always

positive. Both wellhead depth and wellhead elevation are distances from

the system datum to the flange.



Wellhead Elevation: (platform and land wells)

This is the height above system datum (MSL/LAT) of the wellhead

flange (surface casing). It may happen that for some land wells using

ground level as the system datum that the user may have to enter a

negative value because the wellhead 'cellar' is often below the ground.

Air Gap (calculated)

This is the distance from the system datum to the rig floor, and is used

in some calculations for hydrostatic head. Air Gap is always positive. To

calculate air gap, the application uses:

� Air Gap (offshore wells) = Depth Reference Datum – Elevation

� Air Gap (land wells) = Depth Reference Datum – Ground Level

Elevation is set in the Project Properties/General dialog. Ground Level

is set in the Well Properties/ Depth Reference dialog.

Design Properties

Depth Reference Information:

From the drop-down list of defined Depth Reference datums, select the

datum you want to reference for this Design. Once you select a datum,

the Datum Elevation, Air Gap, current System Datum, Mudline Depth,

and Mudline TVD are all updated/calculated and displayed adjacent to

the rig elevation drawing on the Design Properties box,

Setting Up Datums for Your Design

1. Project Properties > General dialog - Select the System Datum you

want to use.

2. Project Properties > General dialog - In the Elevation field, enter

the value the System Datum is above Mean Sea Level. If your

System Datum is below Mean Sea Level, this number will be

negative. If your System Datum is Mean Sea Level, Elevation is

grayed out.

3. Well Properties > Depth Reference dialog - If the well is offshore:



a) Check Offshore, and enter the Water Depth below the System

Datum.

b) If the well is subsea, check Subsea and enter the Wellhead Depth

below the System Datum.

4. Well Properties dialog, Depth Reference tab - If the well is a land

well, make sure Offshore is unchecked, and enter the Ground Level

elevation above the System Datum.

5. Well Properties dialog, Depth Reference tab - Define the Depth

Reference Datum (s) you want to use, such as RKB or Rigfloor.

Type the elevation above the System Datum in the Elevation field,

and specify the effective Date for the datum.

6. Import or create a design for this well.

7. In the Design Properties dialog, General tab, select the Depth

Reference Datum you want to use for this design from the drop-

down list of datums you defined in Step 5.

Changing the Datum

(WELLPLAN Only) If a Design was created using one Depth Reference

datum, and the Depth Reference datum is changed, then when the

Design is opened any depths that become negative will be changed to

zero, and all depth-related properties will be adjusted accordingly.

(StressCheck and CasingSeat Only) When you create a design and save

it for the first time, the EDM database keeps track of the Depth

Reference Datum that was set at the time. This "original" Depth

Reference Datum is not displayed; however, if you or someone else

changes the Depth Reference Datum in the Well Properties dialog, and

you then attempt to open that design, a warning message will appear.

You are warned that you are trying to change to a datum that is different

from the datum in which you originally saved the data, and any

calculations will be invalid unless you change your inputs (see details

here). You are given the choice to open the design/case in the original

datum, or to convert to the new datum. If you choose to convert your

data, the data will be adjusted. However, the change is NOT saved to

the database until you save the design, at which time the new datum

becomes the "original" datum.



How this works:

If datum is same as original datum:

If you open a design or case where the Depth Reference Datum (set at

the Design level) is the same as the datum the data was originally saved

in, the design/case will open normally.

If datum is different than the original datum:

If you open a design or case where the Depth Reference Datum (set at

the Design level) is different from the original datum, the following

occurs:

1. The application checks to see if the well is a slant hole. If positive

inclination exists in wellpaths whose depths would become negative

after the datum shift, the program cannot make the adjustments; a

message pops up to inform you of this. Click Open to open the

design in the original datum; if you click Cancel, the design will not

open at all.

2. For wells other than slant holes, the program will issue this

message: "The currently selected design datum is different to the

datum with which the design was created. The application will then

attempt to adjust the data, but some data might be shifted or

removed. If you open the design, we strongly suggest that you

review your input data; any changes will not be saved to the

database until you explicitly save your data. Please select "Open" to

review the design using the datum with which it was created."

If you want to open the Design with the original elevation, select

Open. If you want to convert the data to the new elevation, select

Adjust. Open is the default.

• If you enter "Open": Data is loaded to the original design datum,

but the Depth Reference Datum set in the Design will NOT

change to match the original datum.

• If you enter "Adjust": Well Explorer loads the data to the new

Wellbore datum and attempts to adjust the data; however, some

data may be shifted or removed. The program will resolve the

deltas in the first depths of column data (strings, wellpaths,



columns, etc.) to adjust for the new gap and read zero depth on

the first line.

Note: After Opening a Design...

Once you open the design you should review your input data; remember that the

changes will not be saved to the database until you explicitly save your data.


Chapter

Using the Well Explorer

Overview

In this chapter, you will become familiar with using the Well Explorer.

You will expand your knowledge of the hierarchical levels of the EDM

database discussed in the last chapter.

In this section of the course, you will:

� Become familiar with the components of the Well Explorer

� Become familiar with the data levels accessible using the Well

Explorer

� Become familiar with the items associated with each data level

3

Chapter 3: Using the Well Explorer


Introducing the Well Explorer

In COMPASS, the Well Explorer is located in the right pane area of the

application window (this differs from other drilling applications, such

as WELLPLAN, where it is located by default on the left side of the

application window). Well Explorer functions much like the Microsoft

Windows Explorer. It is organized as a hierarchical data tree. You can

browse the EDM database at five hierarchical levels: Companies,

Projects, Sites, Wells, Wellbores, and Designs.

Well Explorer

Currently selected data

item (a prototype design)

Database

Canister



Use the Well Explorer to:

• Browse, open, copy, delete, create, and otherwise manipulate the

main data items. The currently open item is highlighted. Details of

the data hierarchy are discussed in “Describing the Data Structure”

on page 29.

• "Drag and drop" data between hierarchical levels. For example,

you can select a Project associated with one Company, and copy it

to another Company. When you copy the Project, all the data

(Sites, Wellbores, etc.) associated with the Project are also copied.

Well Explorer Components

The Tree

The hierarchical tree functions much like the Microsoft Windows

Explorer. You can view and manipulate different levels within the

EDM data model hierarchy, in a fashion similar to a directory tree.

Operations are:

• Left mouse button is used to expand or contract branches of the

data tree and to select. Click the + sign to expand the hierarchy and

click the - sign to contract it.

• The right mouse button has a context-sensitive menu. Depending

on the hierarchical level you have highlighted (Company, Project,

Sites, Wells, Wellbores, Wells, Design, Cases, Wellpaths, Pore

Pressure Groups, Fracture Gradient Groups, Geothermal Gradient

Groups, Hole Section Groups, Assemblies, Fluids and Catalogs)

the menu will populate with the relevant options. (New data item,

New Attachment, Copy, Paste, Delete, Properties, etc).

Note: The Well Explorer display will vary slightly from one

application to another.

Applications that do not use Cases (such as StressCheck and COMPASS) will not

display Cases in their Well Explorer.



Associated Data Components

Data components that can be associated with a design or case are

displayed in the Associated Data Viewer at the base of the Well

Explorer.

Data Components Associated with a Design

Data components that can be associated with a design are: Attached

Documents, Fracture Gradient Groups, Pore Pressure Groups,

Geothermal Gradient Groups, and the Wellpath associated with the

design. Refer to “Associated Components” on page 31 for more

information.

The Recent Bar

To save time, you can use the Recent bar to select a recently used

Design instead of browsing for the desired item in the Well Explorer.

Displaying/Sizing the Well Explorer and Recent Bar

In Compass, the components of the Well Explorer are always

displayed. However, you can customize the size of the Well Explorer

two ways. To change the size of the Well Explorer:

� Maximize or minimize the Well Explorer by clicking the

Maximize/Minimize button

� Resize the Well Explorer by using your mouse. To do this, use the

mouse to position the cursor over a Well Explorer border. The

To display the list of recently used designs, wellbores, or

projects, etc., click on the drop-down list. Select the item

you want to use from the list, and it will be displayed in the

main window.



cursor changes from a singe arrow to a horizontal double-arrow.

Left-click and drag to alter the size of the Well Explorer.

Positioning the Well Explorer

If the Well Explorer is in the restored state, you can reposition it with

your mouse. Move the cursor to the top blue border, left-click, then

drag the Well Explorer to the area you prefer.

Tracking Data Modifications

In COMPASS, you can track modification of data using the Audit

Information tab (on the Properties dialog for each data type).

Using the Well Explorer, right click on a data type icon to display the

right-click menu items. Select the Properties to display the Properties

dialog, then click the Audit Information tab to display it. This tab

provides information on the data modifications for this item.

This information indicates who created the

company, project, site, well, wellbore,

design, etc. Also displayed is the date the

item was created as well as the application

that was used to create the item. This information indicates

who modified the company,

project, site, well, wellbore,

design, etc. Also displayed

is the date the item was

modified as well as the

application that was used to

modify the item.

Type comments as

desired to assist with

tracking the use of the

software. New

comments are

appended to existing

comments.



Drag and Drop Rules

"Drag and drop" in the Well Explorer functions somewhat like the

Microsoft Windows Explorer. You can use drag and drop to copy

Companies, Projects, Sites, Wells, Wellbores, Designs, Cases, as well as

associated data items and attached documents.

All drag and drop operations copy the data; data is never cut or moved.

� To copy - Drag and drop the item to copy it from one location and

paste it into another. The item and all associated data will be copied

and pasted.

You can drag and drop associated items (Wellpaths, Pore Pressures,

Fracture Gradients, Geothermal Gradients, Hole Sections, Assemblies,

etc.) into open Designs or Cases from the Associated Data Viewer at the

base of the Well Explorer. The application will automatically update

itself with the copied data.

Some rules:

� You cannot drag and drop an Actual Design. However, if you copy

a Wellbore, any Actual Designs under that Wellbore are copied.

This is also true for copying done at the Well, Site, Project, and

Company level.

� You cannot drag a Wellpath from the Associated Data Viewer into

an Actual Design.

� If you drag a Planned or Prototype Design to a different Project,

targets will not be copied with the Design. As a result, the plan will

no longer have any targets associated with it.

� Depending where a Design sidetrack Wellbore is dropped, Plan and

Survey tie-on information may be lost, and as a result, survey

program may be missing information.

� (COMPASS only) If a Survey is dropped onto a Wellbore or Actual

Design in another Company, the Survey will lose its tool

information.

� You cannot drag and drop Catalogs. Instead, you must use the right-

click menu Copy and Paste functions



Well Explorer Right-Click Menus

When you click on something in the Well Explorer (a Well, Design,

etc.), right-clicking brings up a menu of options pertinent to that

hierarchical level. The options on each hierarchical level are discussed

below.

Working at the Database Level

When a Database is selected on the Well Explorer, the following right-

click menu items are available:

Command Description

Open Opens the selected database.

New Company Choosing this option displays the Company Properties dialog.

(page 64)

Instant Plan Use Instant Plan to quickly create a new plan. Choosing this

command displays the Instant Plan dialog box, which allows you

to quickly select the hierarchy you want -

Company, Project, Site, Well, Wellbore, and Plan - from drop-

down lists of existing database entries. After making your selec-

tions, click OK to create the Plan. (page 64)

Instant Survey Use Instant Survey to quickly create a new survey. Choosing this

command displays the Instant Survey dialog box, which allows

you to quickly select the hierarchy you want - Company, Project,

Site, Well, Wellbore, and Survey - from drop-down lists of exist-

ing database entries. After making your selections, click OK to

create the survey. (page 64)

Well Name Choosing this option displays a sub menu from which you can

select how to name the wells in your project. (page 65)

Wellbore Name Choosing this option displays a sub menu from which you can

select how to name the wellbores in your project. (page 65)

Lithologies Choosing this option displays the Lithologies Editor. Use the

Lithology Editor to configure bitmaps to Lithology names that

may then be used in formation columns for section views.

(page 66)

Import The Import command allows you to import a Well into the data-

base that was exported using the Export command. See “Import

(Database Level)” on page 67 for more information. (page 67)

Search Use this command to display a dialog that enables you to search

for a particular data component in the EDM database. (page 67)

Refresh Use this command to refresh (update) the Well Explorer tree

with any changed information. Pressing the F5 key is another

way to refresh. (page 68)



New Company (Database Level)

To create a new company, select the database canister and right-click;

select New Company. The Company Properties dialog opens. Refer to

“Properties (Company Level)” on page 81 for more information on

using the Company Properties dialog.

Instant Plan (Database Level)

Use this dialog to quickly and easily create the hierarchy required to

start a plan, from the company all the way down to the wellbore. This

allows you to enter minimal information and the effort of going through

the individual property dialogs at each level of the hierarchy.

Instant Survey (Database Level)

Use this dialog to quickly and easily create the hierarchy required to

start a survey, from the company all the way down to the wellbore. This

Expand All To expand all levels below the Database level. (page 68)

Collapse All Use this command to collapse all levels below the Database

level. (page 68)

Select the Company, Project, and Site from

the drop-down list of existing companies,

projects, or sites. You can also enter a new

name for the data level.

Enter the name of the Well,

Wellbore, and Plan.

Use the pull-down menu to select a

Geodetic System. This is the general

mapping system, e.g. "Universal

Transverse Mercator."

If available, use the pull down menu

to select the Geodetic Datum. This

defines the center and radii of the

projection in this location, e.g.

"ED50". Use the pull down menu to

select the zone within the

system, e.g. "UTM Zone

31, North 0 to 6 E".

Enter the map co-

ordinates of the site center

location based on the

Geodetic System selected

above.



allows the user to enter minimal information and saves them from

having to go through the individual property dialogs at each level of the

hierarchy.

Well Name (Database Level)

Choosing this option displays a sub menu from which you can select

how to name the wells in your project. The options are:

� Common Name - Short/abbreviated well name given to well for

day-to-day reference.

� Legal Name - Formal well name assigned for documentation

purposes.

� Universal Identifier - A coded well name that varies from region to

region.

� Slot Name – Post-fixes the chosen well name with the slot name if

available.

Note: You can choose only one of the naming options Common Name,

Legal Name, or Universal Identifier. You can use Slot Name in

conjunction with the other naming conventions.

Wellbore Name (Database Level)

Choosing this option displays a sub menu from which you can select

how to name the wellbores in your project. The options are:

Refer to “Instant Plan (Database Level)” on

page 64 for information on dialog entry.



� Common Name - Short/abbreviated well name given to well for

day-to-day reference.

� Legal Name - Formal well name assigned for documentation

purposes.

� Universal Identifier - A coded well name that varies from region to

region.

Note: You can choose only one of the naming options Common Name,

Legal Name, or Universal Identifier.

Lithologies (Database Level)

The Lithologies command displays the Lithology Editor dialog. Use this

dialog to configure bitmaps to Lithology names that may then be used

in formation columns for section views.

To define a lithology using the Lithology Editor

1. Enter a Lithology Name in the left column grid. This name must be

unique.

2. Select a lithology texture by pressing the browse button (labelled

‘:’) and then choosing a bitmap file using the File > Open dialog.

You may observe the selected texture in the area below the grid.

3. Repeat steps 1-2 until the required set is complete.

4. Click OK and the lithology list will be saved.

The texture sample

for the selected item

is shown here.



Import (Database Level)

The Import command allows you to import a Well into the database that

was exported using the Export command. The import file is in .XML

format, and contains the entire hierarchy of the Well (Company,

Project, and Site, and well as any child data, such as Wellbore, Design,

etc.)

When you select Import, the Import well dialog opens, prompting for

the .XML filename to import. Type the filename, or browse for the file.

Click Open. The Well hierarchical data will be imported into the EDM

database.

Search (Database Level)

Use this command to display a dialog that enables you to search for a

particular data component in the EDM database.

Select the data level you

are searching for from the

drop-down list.

Specify the search criteria using this grid.

Refer to the online help for a description of

the operators.

Check the box

associated with

the field you

want to base the

search criteria

on. Notice that

the checked

items are

displayed in the

grid.

Search results are displayed here.



Refresh (Database Level)

Use this command to update the Well Explorer tree to show any

additions, changes, and deletions. F5 will also refresh the Well

Explorer.

Expand All (Database Level)

This command expands all nodes below the selected level in the Well

Explorer tree.

Collapse All (Database Level)

This command collapses all nodes below the selected level in the Well

Explorer tree.

Working at the Company Level

In the Well Explorer, when you right click on a company, the right click

menu displays the following choices:

Command Description

Open Opens the selected item.

New Project Create a new project for the selected company (page 69).

New Attachment Displays the Attachment Properties dialog. (page 69)

Paste Paste copied company information from the Clipboard

(page 69).

Rename Activates the selected data item in the Tree, enabling you to

edit the name. (page 70)

Delete Delete the selected company and all associated child infor-

mation (page 70).

Export Export the selected company’s hierarchical information to

an XML file (page 70).

Search Choosing this option displays the Search dialog. (page 70)

Survey Tools Displays the Survey Tools dialog. (page 70)

Properties View or edit the selected company’s properties (page 70).

Expand All To expand all levels below the company level in the Well

Explorer. (page 89)



Open (Company Level)

Opens the selected company.

New Project (Company Level)

To create a new project, select a Company and right-click; select New

Project. The Project Properties dialog opens.

The fields and controls on the Project Properties dialog are explained in

detail on page 92.

New Attachment (Company Level)

Use this dialog to associate a document or picture (Word, Excel, text

file, JPG, etc.). Document can be of any type with a recognized

extension.

Paste (Company Level)

Use this command to paste (insert) the contents of the Clipboard at the

location currently selected in the Well Explorer.

Collapse All Collapses all levels below the company level in the Well

Explorer. (page 89)

Check the Save attachment as a link/shortcut only box if you want to save the attachment

as a link only. If you check this box, only the link to the disk file is stored in the database. Any

edits you make are saved to the original disk file. You can edit the document directly from the

Well Explorer, or you can edit the disk file from its disk location; the changes are reflected in

both places. In the Associated Data Viewer, the icon representing a Linked document is shown

as a paperclip with a small arrow in the lower left corner.

Use the Browse

button to navigate

to the location of

the file. If you

know the path,

you can enter it

without using the

Browse button.

Enter text that

provides detailed

descriptive

information about

this attachment.



In order for this function to be effective you must have Copied (saved)

company data to the Clipboard.

Rename (Company Level)

Use this command to rename the item. You can also rename the data

hierarchy item by highlighting it and the clicking once on it. Type the

new name in the box that appears around the current name.

Delete (Company Level)

Use this command to remove the selected Company from the database.

A confirmation box will open, asking if you are sure you want to delete

the company and all its associated data. Click Yes or No, as

appropriate.

Export (Company Level)

Use this command to export the selected Company’s data in XML

format. Includes any child information associated with the Company. A

dialog will open, allowing you to supply a directory and filename for

the XML file.

Search (Company Level)

Refer to “Search (Database Level)” on page 67 for information on using

the Search dialog.

Survey Tools (Company Level)

Displays the Survey Tools dialog. A survey tool is an instrument that is

used to measure the wellbore’s position using inclination and azimuth

measurements, followed by survey computation or by directly

integrating inertial positions.

Survey tools are used in COMPASS to describe the error characteristics

associated with the tool. The tool’s error characteristics are used to

calculate the magnitude of measurement uncertainty about the wellbore.

COMPASS enables you to define different survey tools with different

error models. Generally, every survey tool operated at one or more

different conditions should have an error model defined. The tools



should have logical names so they can be intuitively selected from the

Survey or Planning modules.

Survey Tool Error Models

A survey tool error model describes how wellpath positional uncertainty

is calculated. When you run Anti-collision, COMPASS uses the error

calculated around each wellpath based on the error model defined and

the survey tools used.

For a particular tool, you only need to enter parameters for the error

model selected. For example, if the model is error cone, you do not need

to enter error values for the Systematic Error, ISCWSA, or Inclination

Cone of Error Grid.

The three supported error models are:

� Cone of Error - For a range of inclinations, you may enter a

different error cone expansion rate.

Hide Survey

Tools that are no

longer used by

Company but

need for

historical

calculations.

Import enables

new survey tool

error models to be

imported from a

transfer file.List of Survey Tool

Names and

Descriptions.

Default Survey

Type defines the

survey

mechanism. This

is a useful feature

for filtering from a

large selection of

tools.

Assign a particular tool

to be the default.

Toggles enable

Tool Error Type to

be selected.

Delete unused Survey Tools

from Company List.

Save new tool or apply changes to

existing tool. This may update error

surfaces of wellpaths with definitive

paths using this tool.



� Systematic Error - Enter six coefficients for the survey instrument

components of error.

� ISCWSA - An extensible survey error modeling system with

configurable error terms and weighting functions.

You must assign a survey tool to the most appropriate error model with

accurate parameters. This information is most commonly provided by

the survey contractor. You should be able to email, phone, or fax any

survey contractor and request precise details of the error model for a

particular tool. Otherwise, you can find descriptions of many survey tool

error models on the Internet on websites for Sperry Sun, SDC, Anadrill,

etc.

In contrast, some operators (e.g. BPA, Shell) decide what the error

model and parameter values are for a tool. This assumes some form of

testing or statistical treatment of available survey data measured by that

tool.

Regardless of where the information is obtained, definition of a survey

tool error model is critical. A COMPASS anti-collision scan is only as

good as the survey tool error model itself.

Cone of Error

For a range of inclinations you can enter different error cone expansion

rates. The example below shows that from 15 to 35 degrees inclination

the cone of error expands at 5.0/1000ft (or 5m/1000m) of measured

depth.



The following depicts the Survey Tool Editor for a tool using the Cone

of Error model:

Systematic Error Ellipse

This is based on SPE paper 9223 by C.J.M. Wolff and J.P. de Wardt,

first published in the Journal of Petroleum Technology in December,

1981. The model is a statistical treatment of the distribution of errors

caused by internal and external influences. The paper demonstrates that

the major causes of error are systematic (that is, they happen

consistently in one vector direction) from one survey reading to the next.

There are error sources that are random, but they are assumed to be small

and tend to cancel out over a number of survey readings. The

mathematical methods applied by the paper have become industry

standard, but some of the example coefficient values and weightings are

not capable of modelling modern directional survey instruments (i.e.

MWD and Rate Gyroscopes).

Enter end of range for

the error term. Note:

grid starts at 0 deg.

Enter the expansion rate

per 1000 units.



The following depicts the Survey Tool Editor for a tool using the

Systematic Ellipse error model.

The Systematic Ellipse error model has six coefficients:

� Relative Depth Error - This is the amount of error in depth

reading per 1000 (ft or m) of measured depth. Depth error is

derived from pipe tally measurement and stretch for pipe run tools

and wireline measurement error for cable run tools.

� Misalignment Error - This is the error due to misalignment of the

survey tool in the borehole. Misalignment affects both inclination

and azimuth and is derived from sensor axis and tool centralizer

misalignment.

� True inclination error - Inclination error may be derived from

weight-induced effects on pipe running gear and is itself, sensitive

to inclination.

� Compass Reference Error - The error in referencing North. For

magnetic surveys this is the error in declination reading for the

locality. For gyro surveys this is the error in surface azimuth

orientation - foresight.

Six Wolff & de Wardt

Error Terms:

Inclination/Azimuth Error Grid. If

populated, overrides inclination and

azimuth errors.



� Drillstring Magnetization - Magnetization Error is the error in

magnetic azimuth readings caused by drillstring magnetization. The

error increases at higher inclinations and east / west azimuth.

� Gyrocompass Azimuth - The error in gimballed gyro azimuth

readings caused by gyro drift. Note that the Wolff & deWardt

weighting for this term is 1/cos(inclination). This means that the

derived error results will ‘explode’ at higher inclinations. The term

is meant to describe film read level rotor gyroscopes, that should

only be used at lower angles. Should you wish to describe a modern

rate/continuous gyro in the systematic error model, you need to use

the Inclination Azimuth error grid, which allows constant weighted

terms.

Because of the variation of error parameters along the X, Y, Z vectors,

the resultant shape of the error surface is an ellipse as projected in 2D,

an ellipsoid as plotted in 3D. The orientation of the ellipsoid with respect

to the wellpath is dependent on the relative change of Wellpath

Inclination and Azimuth.

The systematic error model coefficients and their weighting factors are

recognized as being inadequate for modern solid state magnetic

instruments and for rate gyroscopes. COMPASS provides the

inclination/azimuth error grid to help define error models for more

complex instruments. Again, the inclination and azimuth error

characteristics for each inclination angle range can be provided by the

manufacturers and inserted into the tables.

These error characteristics are substituted for the respective inclination

and azimuth error of the Wolff & de Wardt coefficients, therefore the

True Inclination Error, Drillstring Magnetization, and Gyrocompass

Azimuth coefficients are grayed-out. The inclination weighting factors

would not be applied, because of the relationship defined in the table.

The Interpolate toggle enables error values to be determined for

intermediate inclinations between the ranges entered.

ISCWSA

The Industry Steering Committee for Wellbore Survey Accuracy has

built a survey instrument error model specifically for solid state

magnetic instruments (e.g. MWD & EMS). The model is based on a

paper published by H.Williamson "Accuracy Prediction for Directional

MWD" as SPE56702. The model vastly extends the work started with

the systematic error model and incorporates the experience of the many



participating parties. COMPASS has extended the model by including a

format for defining error terms.

The error terms for this type of survey instrument should be entered in

the grid. The error value and weighting formula is be entered as well as

the vector direction and treatment at survey tie-on.

A row in the grid may be for an individual source of error that can be

from instrument reading, depth measurement, instrument barrel-

hole/collar alignment and external reference and interference terms.

The columns in the grid are as follows:

Name

Give the error source a unique name unless you want it added on to

the same source of error from another or the same tool. See Tie-on

definition to clarify what is in individual error term.Vector

This sets the vector direction for the error source. Select one from

the drop down list:

• A - Azimuth error (WdW).

• B - Azimuth bias

• D - Depth error (WdW)

• E - Depth error (ISCWSA)

• F - Depth bias (e.g. Wireline stretch outrun)

• I - Inclination error (highside)



• J - Inclination bias (uncorrected sag)

• L - Lateral error (error at 90/270 toolface equivalent to azimuth

error/sin(inclination))

• M - Misalignment – forms a disc about the wellpath.

• N - Inertial error – forms a sphere about the wellpath.

Value

The error value for the source of error: i.e. 1.0-degree reference.

Care must be specified to what confidence level and unit type for

the error value. The confidence level for the uncertainty is stated in

the Customer Properties. To get extra precision for this column

data, change the ‘Coefficient of Friction’ unit type in the Units

Editor.Tie-on

This determines how an error source is tied onto sources of the

same name from other tools. Select one from the drop down list:

• R - Random, error is added by RSS (Root Sum Squares) from

station to station.(e.g. Misalignment for rotating MWD)

• S - Systematic, error is added directly from station to station run

but added randomly at tie-on.

• W - Well, error is systematic throughout the well (e.g. Reference

error)

• G - Global, error is systematic across a number of wells. (E.g.

Crustal Declination error)

• N - Not used in error accumulation, (this term is used as an

intermediate calculation)

Units

The following unit selections are available, Select one from the

drop down list:

• N - No unit conversion.

• M – Meters to feet conversion, equivalent to MTF in the

formula.

• IM – Inverse feet to meters conversion, equivalent to 1/MTF in

the formula.

• D – Degrees to radians conversion equivalent to DTR in the

formula.

• T – Error per thousand feet. It is equivalent to a conversion of

0.001.

Other unit types may be given but are not interpreted.Formula

The formula is the weighting for each error term and is given as a

formula that can be parsed like Excel. Typical arithmetic

conventions can be used like: * / - +, power: X^Y,trigonometry:



SIN(), COS(), TAN(), ABS() etc. The capabilities of the parser are

better shown by the examples below.

The following names may be substituted in the formula:

• AZI - Azimuth of current station

• AZM - Azimuth from magnetic north (used for magnetic tools)

• AZT - Azimuth from true north (used for gyro tools)

• AZE - Azimuth error for tie on from previous tools (used to

determine reference error)

• INC - Inclination of current station

• TFO - Toolface angle - The instrument rotation (i.e. alignment of

Y accelerometer with highside)

• TMD - Measured depth from init point.

• TVD - Vertical depth from init point.

The program loads Magnetic Field Data:

• MTOT - Total magnetic field strength given in nanoTeslas (i.e.

50000). Note: Magnetometer bias errors must be same units

• DIP - Magnetic field dip angle from vertical.

• LAT - Current latitude.

• Gyro continuous values:

• AZE - Azimuth error before tie-on

• INX - Inclination error before tie-on

• DMD - Measured depth from start of this survey tool (i.e.

continuous mode drift terms)

• EROT - Earth’s rotation rate = DTR * 15.041 * Cos(Latitude)

• Gyro bias drift values should be entered in degrees/hour.

Constants:

• MTF - Meters to feet - the model evaluates in feet.

• DTR - Degrees to radians - use this when Error is given in

degrees

• GTOT - Gravity total (9.81 m/s^2)

• THO - Thousandths (=0.001)

Range

Check this box to specify an inclination range for this error term.

This term will only be included when the survey station inclination

is between the Min Inc and Max Inc – inclusive.

Example #1

# Model for Wolff &deWardt, Poor Magnetic. This example shows use

# of a bias error term MAGB.

#Name Vector Tie-On Value Formula

DEPTH D S 2 THO



MISAL M S 0.3 DTR

TINC I S 1 DTR*SIN(INC)

REF A S 1.5 DTR

MAGE A S 5 DTR*SIN(INC)*ABS(SIN(AZM))

MAGB B S 5 DTR*SIN(INC)*ABS(SIN(AZM))

Example #2

# Model for Gyro Continuous Tool (GCT)

# This model assumes changeover at 15 degrees

#Name Vector Tie-On Value Formula Min Inc Max Inc

DEPTH D S 2 THO

MISAL M R 0.1 DTR

TINC I S 0.06 DTR

ASFO I S 0.0016 ABS(TAN(INC-20*DTR))

# two reference errors one for each tool mode

REFA S 0.51DTR*COS(60*DTR)/COS(LAT) 0 14.999

REFA S 1.0 AZE 15 99.999

# two gyro bias errors one for each tool mode

GBLL S 0.8 DTR*DMD*TAN(INC)/4800 0 14.999

GBHL S 0.15 DTR*DMD/4800 15 99.999

To create a new tool:

1. Click the New button, to prepare the editor for a new survey tool.

2. Enter a unique name for this survey tool (you may use the same

name to identify the same tool in a different company).

3. If desired, you can enter a description of the tool.

4. Select the button next to the desired model type to enter the errors

you expect from this survey tool.

5. Click the Save button to add this tool to the list.

To edit an existing tool:

1. In the Survey Tools list, click on the tool you want to edit. This will

highlight the tool, and the Tool Properties will be displayed for the

selected tool.

2. Make the required changes.

3. Click the Save button to update the tool.



To delete a survey tool:

1. Click the tool you want to delete.

2. Click Delete. You can only delete tools that are not used by

COMPASS. If a tool you want to delete is used by any Definitive

Path, COMPASS displays a warning message that provides

instructions for removing any links to the tool defined in Surveys or

Plans. It can be difficult to locate all references for a tool.

To export a survey tool:

Export survey tools allows you to transfer tool data between companies

and systems.

1. Select a tool from the Survey Tools list by clicking on it.

2. Click the Export button.

3. Enter the filename to create. The default filename is Toolname.ipm

in the COMPASS/Output directory.

To import a survey tool:

Import Survey Tools allows you to have a common set of tools sites

within a company.

1. Make sure you don't have a tool selected in the Survey Tools list.

2. Click the Import button.

3. Enter the directory and select the filename to import. These file

names should have an extension of .IPM.

Note: Using the Save Button

Once the Save button is clicked you may see a message box with "A number of

Wellbores use this tool…Do you want to rebuild them now?". Choosing Yes will

rebuild the definitive surveys with the new error data. The update process can take

some time.



Properties (Company Level)

Selecting this command allows you to view or edit Company

properties. The Company Properties dialog opens. The Company

Properties dialog is used to create a new company and to provide

information regarding creation and modification of the company. In

COMPASS, the Company controls policy and settings for a number of

operating projects or sites. The Company is either an operating group

within your exploration company or for a contractor it is the operating

company for which the services are provided. The company unit should

have common directional drilling operating practices and policies. The

Company Properties tabs are used to specify the specific survey and

anti-collision policy for the group.

Using the Company Properties > General Tab

A Company Logo can be

selected to appear consistently

in Reports and Wallplots

A Company Level

password enables

settings to be

applied

consistently within

an organization.

Locked Data

passwords enable

Field, Sites, Wells

and Wellpaths to

be locked to

prevent changes.



Using the Company Properties > Anticollision Tab

Survey Error Model

Error System

Use the drop-down list to select the error system. The options are:

ISCWSA and Cone of Error. For more information about the

ISCWA Survey Error Model, see “ISCWSA” on page 75. Output Errors are at_sigma

Enter a numeric value. This value states the confidence level for the

survey errors in number of standard deviations. The errors defined

in the survey instrument error models have to be defined at a known

standard. Error terms are expressed in standard deviations from the

mean (or sigma). One standard deviation implies that roughly 65%

of readings will be within the stated error. Two standard deviations

require that 95% of readings will be within the stated error.

Confidence levels are required to make risk based decisions on

collision and target intercept calculations.

Anticollision Settings

Scan Method

When selecting a scan method you define how wellbore separation

is computed. There are a number of different methods for

computing the distance from the current wellbore to other wells.

Four Scan Methods are available in COMPASS, including:



• Closest Approach 3D: At each MD interval on the reference

wellpath, COMPASS computes the distance to the closest point

on the offset wellpath. At the scan depth on our reference

wellpath, imagine an expanding bubble or spheroid. The

minimum distance occurs when the surface of the spheroid just

touches the offset wellpath. Because the offset wellpath is now

at a tangent to our spherical bubble, the line of closest approach

is perpendicular to our offset wellpath.

The following graphic depicts the 3D Closest Approach Scan

Method (left), and the traveling Cylinder method (right):

• Traveling Cylinder: This scan method uses a plane

perpendicular to the reference wellpath and intercepting offset

wellpaths as they cut through the plane. The surface resembles a

cylinder with the size of the maximum scan radius. The traveling

cylinder method computes distance from the offset wellpath

stations back to the reference wellpath. The benefit of this

method is that intercepts are detected even when the wellpaths

are approaching at a perpendicular. In this case, there may be

more than one point in the TC plane for the same depth on the

reference. Depths are interpolated on the offset wellpaths,

resulting in irregular depths on the reference wellpath.

Therefore, the 3D anticollision view and traveling cylinders



depth slice option are not possible with this method, because

they rely on regular depths on the reference.

• Horizontal Plane: This method is the horizontal distance from

the reference wellpath to the offset wellpath.

The following graphic depicts the Horizontal Scan Method:

• Trav Cylinder North: This scan method uses the same

perpendicular plane as the traveling Cylinder scan method, but

toolface orientation from reference to offset is added to current

Wellbore direction. The traveling cylinder plot is oriented to

Map North when the reference well is at low angles. Toolface

angle to an offset well is then reported as the angle from the

high-side of your current Wellbore + the azimuth of your current

Wellbore. This method avoids the confusion in the traveling

Cylinders plot caused by large changes in toolface angle when

kicking-off from vertical.



Error Surface

When selecting an error surface you define the shape of the

uncertainty envelope about the wellbore. The error surface choice

allows the user to override the standard ellipse to ellipse (default)

ratio calculations in anti-collision, and instead uses the largest

dimension of error at a point to define a cone about the Wellbore. In

most cases, this will be major axis of the ellipsoid. Using the

circular conic method is more conservative and produces lower

ratio values and hence more warnings. The choices are as follows:

• Elliptical Conic: The elliptical method interpolates the error

surface in each wellbore by assuming the surface is an ellipse

with major and minor axis perpendicular to the Wellbore.

Because the center to center plane can intersect the error

ellipsoid at any direction from the Wellbore, the resulting radius

used in the separation factor calculation ranges from the

minimum dimension of the ellipse (minor axis) to a maximum

dimension (major axis). The ellipse also has an intermediate axis

with a magnitude somewhere between the minor and major axis

dimensions.

• Circular Conic: The circular conic method uses the largest

dimension (major axis) of the error ellipsoid at a point to define

a spheroid about the Wellbore. Projected down the Wellbore, this

becomes a cone. Using the circular conic method is always most

conservative because it uses the largest dimension of the ellipse

and therefore produces lower ratio values and hence more

warnings.

• Combined Covariance: This method combines the errors on

the reference and offset by covariance addition before any

distance calculations are performed. The error distance is then

computed by the ‘elliptical conic’ method on the resulting single

ellipsoid. Where Casings are included the radii are subtracted

from the center- to - center distance. The separation factor

derived from the combined covariance technique can be directly

correlated to collision risk as it represents the standard deviation

value for the ‘tail of the probability distribution’.

Casings

Choose one of three options:

• No - Casing diameters are not applied.

• Add - Casing diameters are added to the error ellipse

dimensions. The calculation is:



Separation Factor Ratio = Center to Center Distance /

(Reference Error Radius + Offset Error Radius + Offset

Casing Radius + Reference Hole Radius)

• Subtract - Casing diameters are subtracted from the center-to-

center distance. The calculation is:

Separation Factor Ratio = (Center-to-Center Distance -

Offset Casing Radius - Reference Hole Radius) / (Reference

Error Radius + Offset Error Radius)

Warning Type

There are a number of methods for warning the user of potential

collision problems. The choice made here will decide how the

Anticollision Warning Levels are used. The options are:

• Error Ratio - The warning given will depend on the ratio of the

separation distance divided by the combined error radii of the

reference and offset wells at a given depth.

• Depth Ratio - The warning given will depend on the ratio of the

separation distance divided by the depth times a ratio (i.e.

10/1000 MD) Error values may be added to this cone.

• Rules Based - In this case each offset Wellbore is assigned with

a rule. A warning is given if the rule is failed.

Warning Levels or Rules

This grid is used to define a number of anticollision warning criteria.

The columns and labels that appear on this dialog depend on which

Warning Type is chosen in the Anticollision Settings section of the

Company Properties dialog. The Warning Type determines the

appearance of this grid. Refer to this table for details. Refer to the online

help for specific information on using this grid.

Note: Using the Subtract option...

Be aware that using the Subtract option, it is possible to have a Center-to-Center

distance that is negative in top-hole.



Using the Company Properties > Calc Defaults Tab

Survey Calculation Method

COMPASS offers four survey calculation methods.

• Minimum Curvature

• Radius of Curvature

• Average Angle

• Balanced Tangential

V Section Origin

The default vertical section may start from either slot or from

platform center as shown here. The default vertical section origin

may be overridden in the Wellbore Setup dialog.Walk/ Turn Rate

There are two methods for computing walk and turn rates for curve

sections

• MD - Turn rate = dogleg base length x change in direction /

change in measured depth (default)

Note: Survey Calculation Method

This setting specified on the Company Properties dialog is the company's preferred calculation method and may not be overridden in the survey module.



• HDL - Turn rate = dogleg base length x change in direction x

sine( (I1 + I2) / 2 ) / change measured depth where I1 is the start

inclination I2 is the end inclination.

Validation

• Project – Select a project for the validation process, or select

‘all’ to choose all projects for this customer.

• Create Well Co-ordinates File – Click this button to report all

wells surface and bottomhole co-ordinates to a file in the config

directory called ‘WellCoordinates.log’. This file can be used to

validate the Compass database before and after any significant

data changes.

• Compute all Designs - Click this button to start the re-

calculation of all wellpaths, plans and surveys. When a value is

changed in Company Properties, the wellpath data may not be

built according to the rules in the survey program or the survey

error model. The validation process is provided to re-calculate

all wellpaths using the correct program and survey errors. In the

re-calculate step two files are created in the output directory,

these list the surface and end of well co-ordinates before and

after re-processing and lists any associated errors.

Using the Company Properties > Wellbore Types Tab

A Wellbore type is a set of Wellbore labels or type names. Each

Company can have a range of different Wellbore types and each type

can have a designated color to identify Wellbore groups in plots. Once

the Wellbore type list is created, a Wellbore type may be assigned to a

Wellbore in Wellbore Properties > General tab. Wellbores may then

be selected for plots and anticollision scans based on the type.

Some Examples of Wellbore Types:

� Producing Well - Red

� Injection Well - Blue

� Abandoned Hole - Yellow

� Lateral Wellbore - Green

� Fish (abandoned)



� Pilot Hole

Expand All (Company Level)

Select this command to expand all nodes in the Well Explorer below

the selected Company.

Collapse All (Company Level)

Select this command to collapse all nodes in the Well Explorer below

the selected Company.

Working at the Project Level

Project is the data level directly beneath company and each project

within a company must have a unique name. A project can be thought

of as a field or as a group of sites. A project has one system datum

(mean sea level, lowest astronomical tide, etc.) that is used to define 0

TVD for the project. Within the project, wellbores can be referenced to

the project level system datum or to additional datums specified at the

well level.

In the Well Explorer, when you right click on a project, the right click


Command Description

Open Open selected project.

New Site Create a new site for the selected project (page 90).

Click on the color column

and a palette of colors will be

displayed to choose from.

Type the name.



Open (Project Level)

Opens the selected project.

New Site (Project Level)

To create a new site, select a project and right-click; select New Site.

The Site Properties dialog opens.The fields and controls on the Site

Properties dialog are explained in detail on page 104.

New Attachment (Project Level)


file, JPG, etc.). The document can be of any type with a recognized

extension. Refer to “New Attachment (Company Level)” on page 69

for more information.

New Attachment Displays the Attachment Properties dialog. Refer to “New

Attachment (Company Level)” on page 69 for more information.

Copy Copy the selected project data to the Clipboard (page 91).

Paste Paste copied project information (page 91).

Rename Activates the selected data item in the Tree, enabling you to edit

the name. (page 91)

Delete Delete the selected project and all associated child information

(page 91).

Export Export the selected project’s hierarchical information to an XML

file (page 91).

Search Choosing this option displays the Search dialog. Refer to

“Search (Company Level)” on page 70 for more information.

Targets Accesses the Target Editor. Use the Target Editor to define target

location and shape. (page 91)

Lease Lines A lease line is a United States convention for limiting drilling

territories. Use this dialog to create and maintain lease lines.

(page 92)

Properties View or edit the project properties (page 92).

Expand All To expand all levels below the project level in the Well Explorer

(page 96).

Collapse All To collapse all levels below the project level in the Well

Explorer. (page 96)



Copy (Project Level)

Use this command to copy the selected project from the Well Explorer

and save it to the Clipboard.

This command is disabled if nothing has been selected.

Paste (Project Level)




project data to the Clipboard.

Rename (Project Level)




Delete (Project Level)

Use this command to remove the selected project from the database. A

confirmation box will open, asking if you are sure you want to delete

the project and all its associated data. Click Yes or No, as appropriate.

Export (Project Level)

Use this command to export the selected Project’s data in XML format.

Includes the hierarchical information above and any child information

associated with the Project. A dialog will open, allowing you to supply

a directory and filename for the XML file.

Search (Project Level)


the Search dialog.

Targets (Project Level)

Use this command to access the Target Editor. A target is a point in a

geological space that is used as an aiming point or volume for directing



Wellbores Use the Target Editor to define target location and shape. The

form is also used for managing several targets on a Wellbore or a site.

Refer to “Defining Targets” on page 150 for more information.

Lease Lines (Project Level)

Properties (Project Level)

Selecting this command allows you to view or edit Project properties.

The Project Properties tabs are used to create a new project and to

provide information regarding creation and modification of the project.

Note: If there is no local origin in effect...

If no local origin is in effect, the Coord Type, N/S, E/W, Direction and Distance

columns will not be visible.

This area displays the

existing lease lines in

COMPASS. Select a lease

line to display and edit the

associated data.

Enter the name if you are creating a

new lease line. If you are viewing or

editing an existing lease line, the

name appears in this field when you

select the lease line in the Lease

Line Name area.

Select this checkbox to make the lease

line visible in graphs and plots

Use the pull-down menu to

select how the location of

the point will be defined and

type the required

information.



Using the Project Properties > General Tab

System Datum

Define the common vertical reference for all depth measurements

in this Project. Select a name from the list or type in a new name.

Examples are "Mean Sea Level", "Lowest Astronomic Tide",

"Indian Springs Low".Elevation__ft above Mean Sea Level

Enter the elevation above Mean Sea Level for the System Datum

you selected. Enter a negative value if the elevation is below Mean

Sea Level.Use Well Reference Point

When this box is checked, you can enter a Well Reference Point in

the Well Properties Dialog. A Well Reference Point is a permanent,

recoverable, fixed point in the well and may be used as the tie-in

point for the first survey and plan on this well.Default Magnetic Model

Use the pull-down menu to select a default magnetic model.

Refer to “Using Datums in EDM”

on page 50 for more information

on datums.



Using the Project Properties > Map Info Tab

Geographic Reference System

You must select the correct geodetic system before computing grid

convergence or performing geodetic conversions (latitude & longitude

to easting & northing and vice versa).

Three choices need to be made:

• Geodetic System - The general mapping system, e.g. "Universal

Transverse Mercator". You can use the pull-down menu to

change the project’s geodetic system. Doing so converts all map

and global coordinates from the old system to the new system

using one of two options:

• Convert and preserve map coordinates

• Convert and preserve lat/long.

COMPASS will prompt you for the conversion method, which

will convert data stored in the database in addition to the

onscreen data.

• Geodetic Datum - The datum defines the center and radii of the

projection in this location, e.g. "ED50".

• Map Zone - The zone within the system, e.g. "UTM Zone 31,

North 0 to 6 E"

For more information see “Geodesy” on page 368.



Local Co-ordinate System

The local co-ordinate origin is the zero point for north and east co-

ordinates. The choices are as follows:

• Originates From Well Center – The convention is to use the

rig-floor center position of the current well as the common

reference for all wells relative to it.

• Originates From Site Center – This convention uses a common

point in the template or installation as a common reference.

• Originates From Project Center Based On Site – This

convention is to use a single point within (or without) the Project



as a common reference for all wells. In Compass, you must

create a single site as the center for the Project co-ordinates.

Use Geodetic Scale Factor (local co-ordinates are true distances)

When converting from distances on a map to distances measured on

the ground there is a small difference caused by the curvature in the

earth. A map system is designed to minimize this distortion. In a

UTM system, the difference will be 4m over a 10,000m east/west

traverse at the central meridian. Without this option, land distances

may be converted directly to map distances (provided meters to feet

and true north convergence rotations are calculated). With this

option, a scale factor is applied. The value for a location may be

seen in the Geodetic Calculator.

Expand All (Project Level)


the selected Project.

Collapse All (Project Level)



Working at the Site Level

A Site is a collection of one or more Wells all referenced from a local

coordinate system centered on the site location. A site can be a single

land well, an offshore sub-sea well, a group of wells drilled from an

Note: Project Centered Co-Ordinate Systems

Because each site has a different convergence angle, if you choose a Project

Centred co-ordinate system, local north must be based on the map Grid.



onshore pad, or a group of wells drilled from an offshore platform or

template.

In the Well Explorer, when you right click on a site, the right click

menu displays the following choices

Open (Site Level)

Open the current site.

Command Description

Open Open the current site.

New Well Create a new well for the selected site (page 98).



Copy Copy the selected site data to the Clipboard (page 98).

Paste Paste copied site information (page 98).


the name. (page 98)

Delete Delete the selected site and all associated child information

(page 98).

Export Export the selected site’s hierarchical information to an XML

file (page 99).



Unlock All Unlocks all the data in this site. (page 99)

Templates Use to access the Template Editor. A template is a surface or sea-

bed structure that frames a number of wellheads together with a

regular spacing. The Template Editor is a quick way of calculat-

ing the local co-ordinates of a template array. (page 99)

Properties View or edit the site properties (page 104).

Expand All To expand all levels below the site level in the Well Explorer

(page 107).

Collapse All To collapse all levels below the site level in the Well Explorer.

(page 107)



New Well (Site Level)

To create a new well, select a site and right-click; select New Well. The

Well Properties dialog opens. If you want to “lock” the data and

prevent changes to the well data and all levels below it, set the Locked

Data password in the Company Properties dialog box. Toggle on “Well

is locked:” in the Well Properties dialog after setting the password.

Click OK.

The fields and controls on the Well Properties dialog are explained in

detail on page 111.

New Attachment (Site Level)





Copy (Site Level)

Use this command to copy the selected site from the Well Explorer and

save it to the Clipboard.

Paste (Site Level)




site data to the Clipboard.

Rename (Site Level)




Delete (Site Level)

Use this command to remove the selected site from the database. A


the site and all its associated data. Click Yes or No, as appropriate.



Export (Site Level)

Use this command to export the selected Site’s data in XML format.


associated with the Site. A dialog will open, allowing you to supply a

directory and filename for the XML file.

Search (Site Level)


the Search dialog.

Unlock (Site Level)

Use this option to unlock all data associated with this site.

Templates (Site Level)

Use this command to access the Template Editor. A template is an array

of slot coordinates that define the surface/subsea location of wells. The

Site Template Editor is a coordinate generator that provides an easy way

to define slot template geometries. When you define a template, you can

enter single slot coordinates, or, if the template has a rectangular or

circular slot layout, COMPASS can automatically calculate the local

slot coordinates for you.

A site can have more than one template defined for it—for example, a

collection of sub-sea wells or a platform that has had additional slots

attached to it.

Template Editor

When creating a well, you don’t have to use the Site Template Editor to

define the well location. You can type in the local coordinates directly.

However, if slots are defined, you can select a start slot and assume the

calculated local coordinates of that slot.

The Template Editor uses two resizeable panes located in the same

Window: an Editor and a View. The relative sizes of each may be

adjusted by moving the separator bar. The Editor enables you to define

templates.The View graphically portrays the template currently

selected, and provides the usual COMPASS live graphics tools.The

following graphic depicts the Slot Template Editor and View:



The Template Editor consists of 2 panels.

� The left panel is the Editor Panel and is used to enter name and

numeric data. The Editor Panel has two tabs, including the Slots

tab, and the Geometry tab.

� The right panel is the Template View. It can be used to select

templates and individual slots. The currently selected slot is

highlighted in red. The other slots are in green.

The editor panel may be toggled between viewing the entered template

patterns or a list of each individual slot generated by all the patterns.

COMPASS supports three types of Templates:

Template Type Definition

Rectangular Row by Column slot spacing

Circular Radial slot spacing

Single One slot, such as sub-sea well or onshore

drilling pad

Define template properties here.

View/Select Templates Here



You can convert regular shaped rectangular and circular templates to

single slot templates if required. Note: this is not reversible.

For each type of template, you must enter a short name, a long name, and

the location of slot reference from the site center. If Site is a platform

then coordinates are normally 0 NS, 0 EW. In the example above, the

Echo template has a short name E so that each slot is numbered E1, E2,

E3, and so on. You define the template geometry and then add it using

the Add button in the toolbar, modify it using the Save button, or delete

it using the Delete button. Existing templates may be selected from the

picklist on the Geometry tab or selected using the mouse within the

View. Active templates are highlighted in red within the View.

After generating one or more templates, you use the View Slots tab

available near the bottom left of the editor to display the local

coordinates of all slots in the site. You cannot edit slots or templates

with the View Slots toggle set, you must toggle back to the Geometry

tab. The View Slots tab does enable a group of single slot templates to

be rotated by a given angle about a rotation point. This would be used

where a rectangular or circular template had not been used to define slot

spacings, but the slots needed to be rotated.l

Rectangular Template

Start Number

Start numbering slots from this number. For example, if your site

has two templates, each with 9 slots, you may want to start

numbering the first template from 1 and the second from 10.Numbering

Slot numbers can be ordered by row or column as shown below.

Note: Curved Conductors

If curved conductors are defined in Well Setup, then you will see additional blue slots in the View to indicate different location of Well Reference Point relative to Slot (red).



The following graphic depicts Rectangular Template Slot Numbering:

Slot Geometry

Rectangular templates are defined with a number of spaced rows and

columns with their own regular spacings.

The top left slot is used to determine the location of the Template

Center. The location of the top left slot is entered as X & Y offsets from

the template center without considering rotation.

The following graphic depicts Rectangular Template Geometry:

Template

Center

2m

2m



In the above example there are 3 rows and 5 columns. The template short

name is ‘R’. The row spacing is 2m, and the column spacing 2m. The Y

distance to the top left slot is 2m, and the X distance is -4m. With the

rotation angle set to 45 degrees, our final template appears as above.

Circular Template

Start number

Start numbering slots from this number. For example, if your site

has two templates each of 16 slots, you may want to start

numbering the first template from 1 and the second from 17.With Numbering Clockwise

Slot numbers can be ordered clockwise or counter-clockwise.Radius to first slot

Enter the radius of the circular template.Number of slots

Enter the number of slots on the template. These are evenly

distributed about the circle, starting at the angle to the first slot.Angle to first slot

The direction from local north to the first slot.

The following graphic depicts Circular Template Geometry:

This template example has 8 slots. The template short name is C. The

start number is 1, numbered clockwise. The radius is 4m, and the angle

to the first slot is 22.5 degrees.



Properties (Site Level)

Selecting this command allows you to view or edit Site properties. The

Site Properties dialog opens.

Using the Site Properties > General Tab

The Site Properties dialog is used to create a new site and to provide

information regarding creation and modification of the site.:

This is the security designation for this Site,

based on the current user’s access rights.

UNRESTRICTED is the default. Be careful -

if you restrict this field, certain users will not

be able to view this Site. Tight groups are

created in the EDM Administration Utility

through the EDM Security plug-in. They are

assigned in the Well Explorer at the site or

well level.

Enter the numeric value for

the default site elevation.



Using the Site Properties > Location Tab

Center Location

COMPASS uses the Map Coordinates values to compute the distance

between two sites during field level anti-collision. You can enter Map

Coordinates directly or convert them from latitude and longitude.

Choice Description

None If selected, anti-collision between sites is

disabled

Map Coordinates The map coordinates of your location based

on the Geodetic System selected in the Project

Properties dialog. These are essential if you

compute project level anti-collision. The map

coordinate units are set in the Unit System.

Geographic Coordinates The geodetic co-ordinates of your location

based on the geodetic datum selected in

Project Properties. To enter geographic co-

ordinates, you must first select a geodetic

system in Project Properties.

Lease Lines Enter a distance from one corner of the lease.

Positive numbers are interpreted as from the

south and west lines. Negative numbers are

interpreted as from the north and east lines.



The graphic below depicts Lease Line coordinates. Two site centers are

indicated, one as a distance from a West and North line, another from an

East and South line:

Location Uncertainty

Radius of Uncertainty

This is the accuracy to which the site has been positioned or

uncertainty of the local co-ordinate origin relative to map or

geodetic co-ordinates.

For example, a floating drilling rig may be positioned with accuracy

of 1-2 m and due to wind and wave movement oscillates around the

mean position. When spudding an exploration well, this uncertainty

should be included, as it will be used during anticollision

calculations between wells drilled from different sites.

If drilling over a sub-sea template, you should include the position

uncertainty of the template, not that of the vessel. The unit class is

Note: Anti-Collision Requires Map Co-Ordinates

COMPASS does not use lease line co-ordinates to compute anticollision between

two sites. Anticollision requires map co-ordinates.



Distance and uses the same units as your local co-ordinate system,

not the Map Units.

Slot Radius

This is the radius of the slots in the template view. This field may

also be used as the radius of the drill bit for the first hole section.

For cone of error models, this radius is added to all errors calculated

for the Wellbores included in this site. Example: A drill bit of 26"

diameter has a radius of 1.1'.

Azimuth Reference

North Reference

You may align the site's local co-ordinate system to either True or

Grid north. Depending upon your selection, the north axis of all the

sites in the Project will be aligned to either true or grid north and all

surveys should be corrected accordingly. In a True North system the

azimuths and co-ordinates will be rotated by the convergence angle

from the grid lines on the map. For more information, refer to

“True, Grid, and Magnetic North” on page 377.Convergence Angle

This non-editable field is the difference between grid north and true

north. This angle correction is only applied in the opposite sense to

azimuths when using a Grid North reference. Convergence is used

when computing anticollision between sites when using a True

North co-ordinate system.

Expand All (Site Level)


the selected Site.

Collapse All (Site Level)


the selected Site.

Note: COMPASS uses the ISCWSA survey error framework...

Compass now uses the ISCWSA survey error framework for calculating all survey

errors and requires that all instrument & location error input is to 1 sigma

confidence. This means that the Site and Well location errors are now 0.5 the value

entered in previous versions of Compass where the Company error model was

Systematic or Cone of Error. The only exception is that Compass allows survey

instrument errors to be entered in the Systematic or Cone of Error formats as

before.



Working at the Well Level

A Well is simply a surface location, referenced from the Site local

coordinate system. A well can be located at the site center or offset some

distance N/S - E/W from the site center. If a geodetic system is

configured for the Project, equivalent Map Coordinates are calculated

automatically. If a template has been created for the Site, a Well can be

assigned to a slot in that template. In the latter case, the well location

assumes that of the slot. For Land wells, a Site and a Well are often the

same thing. So, local coordinates from the Site for the Well are set to

0 N/S, 0 E/W, with the names being identical.

A Well can have one or more Wellbores assigned to it. For example, the

original wellbore, with one or more sidetracks tied on to it at different

kick-off depths. In COMPASS, any wellpath trajectory can be traced

directly from its TD back to the Well surface location.



In the Well Explorer, when you right click on a well, the right click


Open (Well Level)

Open the selected well.

New Wellbore (Well Level)

To create a new wellbore, select a well and click New Wellbore. The

Wellbore Properties dialog opens.

The fields and controls on the Wellbore Properties dialog are explained

in detail on page 118.

Command Description

Open Open the selected well.

New Wellbore Create a new wellbore for the selected well (page 109).



Copy Copy the selected well data, and all associated data, to the

Clipboard (page 110).

Paste Paste copied well information, including all associated data

(page 110).


the name. (page 110)

Delete Delete the selected well and all associated child information

(page 110).

Export Export the selected well hierarchical information to an XML file

(page 110).



Properties View or edit the well properties (page 111).

Expand All To expand all levels below the well level in the Well Explorer

(page 115).

Collapse All To collapse all levels below the project level in the Well

Explorer. (page 115)



New Attachment (Well Level)





Copy (Well Level)

Use this command to copy the selected well from the Well Explorer and

save it to the Clipboard.

Paste (Well Level)




well data to the Clipboard.

Rename (Well Level)




Delete (Well Level)

Use this command to remove the selected well from the database. A


the well and all its associated data. Click Yes or No, as appropriate.

Export (Well Level)

Use this command to export the selected Well’s data in XML format.


associated with the Well. A dialog will open, allowing you to supply a

directory and filename for the XML file.

Search (Well Level)

Refer to “Search (Database Level)” on page 67 for information on

using the Search dialog.



Properties (Well Level)

Selecting this command allows you to view or edit Well properties. The

Well Properties dialog opens. The Well Properties dialog is used to

create a new well and to provide information regarding creation and

modification of the well. A well in COMPASS is a surface hole or

wellhead through which a number of Wellbores are drilled. The Well

Properties dialog is used to enter the well's offset location from the site,

plus naming information. Under each well you may define several

Wellbores.

Using the Well Properties > General Tab

Using the Well Properties > Depth Reference Tab

Use the Well Properties > Depth Reference tab to define depth

reference datums relative to the system datum specified on the Project

Note: If the “Well is locked” box is checked.

If the box is checked, you will not be able to edit any of the fields.

This is the default display unit system for the well. When a well

is opened (or one of it's wellbores or designs), the display unit

system will automatically change to the well display unit

system.



Properties > General tab. Refer to “Using Datums in EDM” on

page 50 for more information about datums.

Refer to “Using Datums in EDM” on page 50 for more information

about datums.

Using the Well Properties > Well Ref Pt Tab

The WRP is a permanent, recoverable, fixed point in the well. This point

is usually at the well's position at seabed for offshore installations or at

ground level for land installations. This location will be used as the tie-

in point for the first survey and plan on this well. This tab appears when

Use the grid to view, edit, or add a

new datum. Check the Default box

to indicate which datum is the datum

to be used for all designs created for

this well.

Type, edit, or view the elevation above the System

Datum (this must be a positive number). If you

have a design associated with this datum, you

cannot edit this field.

Refer to the online help for

details on specifying

configuration.

The summary area depicts the selected

configuration.

The label indicates what

the system datum is.



the vertical system in the Project Properties has been set to well

reference point (WRP).

Vertical Distance Above/Below System

Enter the vertical distance of the point above or below the system

datum. For offshore installations the distance is positive below

mean sea level. For land installations the distance is positive above

mean sea level.Non Vertical (curved conductor/slant rig)

If the rig is vertically positioned above the wellhead then all you

need to enter is the vertical distance above /below system. If the rig

is offset from the wellhead for various reasons, you need to enter

the information below to define the offset location of the well

reference point.Additional Measured Depth at WRP

If the wellbore is non-vertical at the WRP then the along hole

distance from rig datum to WRP is longer than the vertical distance.

In this case, enter the additional measured depth, which is usually

less than 1m for curved conductors. This additional distance will

not change if the rig elevation change.Offset from Wellhead North/East

Enter the horizontal distance from the wellhead (on fixed

installation) to the WRP on the seabed/ground. Inclination and Azimuth

Enter the wellbore inclination and direction at WRP, if it is non-

vertical. Azimuth is to the north reference (True or Grid) chosen in

Site Properties.



Using the Well Properties > Location Tab

There is a choice of several methods for defining a wellhead location

relative to the site.

Slot

Select a slot from the list you have defined in the Template Editor.

If this slot is subsequently moved in the Template Editor then the

wellhead and all data will move accordingly.Offset from Site

Enter the offset distance, N/S and E/W from site center to this

wellhead.Map

The wellhead position may be defined in map co-ordinates. Enter

the Easting or Northing of the wellhead and the local co-ordinates

will be calculated from the site center. The well location is stored

relative to the site, so if the site moves, the well will move too.Geographic

You can check this option and enter latitude and longitude

coordinates to indicate the location of the wellhead.Well Position Error

A position error may be associated with the well location. This

error is added to all errors generated on Wellbores in this well. Be

careful not to confuse this error with site position error. The well

error is designed for special cases. For example, when there are a

number of wellheads in close proximity to each other (grouped in

the same site) but not connected by a template. The well error in

this case is the error in measurement of one well relative to the

others, but not the error in the group’s location, which is the site

position error. It is recommended that well error be left as zero for

template wells.



Convergence

This non-editable field is the difference between grid north and true

north. This angle correction is only applied in the opposite sense to

azimuths when using a Grid North reference. Convergence is used

when computing anticollision between sites when using a True

North co-ordinate system.

Expand All (Well Level)


the selected Well.

Collapse All (Well Level)



Working at the Wellbore Level

A Welbore is a borehole, which is one or more contiguous sections of

wellbore traceable up to the surface location. It could be an original well

drilled from surface, or a sidetrack kicked off from a known depth from

a parent wellpath. If a Well has an original hole and two sidetracks

drilled from it, that Well has three Wellbores defined in COMPASS.

When using COMPASS there is only one active wellpath whose name

appears in the Status window. The Wellbore category allows you to file

multiple Surveys and Plans in their respective boreholes. When opening

Surveys or Plans, you are only shown names of items in the current

wellpath.

A Wellbore describes the path of a well that may be planned (or

unplanned) sidetrack or a lateral in a multi-lateral completion. The

original hole must also be represented as a Wellbore. In this dialog the

Wellbore name, and sidetrack information must be defined. In addition

a Wellbore may be drilled from a different rig datum elevation.

In the Well Explorer, when you right click on a wellbore, the right click


Command Description

Open Open the selected wellbore.



Open (Wellbore Level)

Use to open the selected wellbore.

New Plan (Wellbore Level)

Use this command to access the Plan Properties dialog to define the plan

name, contractor, survey tool and tie-on information for this directional

survey. Refer to “Using the Plan Editor” on page 164 for more

information.

New Actual Design (Wellbore Level)

To create a new actual design, select a wellbore and right-click; select

New Actual Design. The Design Properties dialog opens.

The fields and controls on the Actual Design Properties dialog are

explained in detail on page 124.

New Plan Access the Plan Properties dialog. (page 116)

New Actual Design Create a new actual design for the selected wellbore (page 116).

New Survey Access the Survey Properties dialog to define the survey name,

contractor, survey tool and tie-on information for this directional

survey. (page 117)



Copy Copy the selected wellbore data to the Clipboard (page 117).

Paste Paste copied wellbore information (page 117).

Rename Use this command to change the name of the well. (page 117)

Delete Delete the selected wellbore and all associated child information

(page 117).

Export Export the selected wellbore’s hierarchical information to an

XML file (page 117).

Import DIMS Surveys Displays the DIMS Survey Import dialog. (page 118)

Targets Access the Target Editor. (page 118)

Properties View or edit the wellbore properties (page 118).



New Survey (New Wellbore)

Use this command to access the Survey Properties dialog to define the

survey name, contractor, survey tool and tie-on information for this

directional survey. Refer to “Defining New Survey Properties” on

page 264 for more information.

New Attachment (Wellbore Level)





Copy (Wellbore Level)

Use this command to copy the selected wellbore from the Well

Explorer and save it to the Clipboard.

Paste (Wellbore Level)




wellbore data to the Clipboard.

Rename (Wellbore Level)




Delete (Wellbore Level)

Use this command to remove the selected wellbore from the database.

A confirmation box will open, asking if you are sure you want to delete

the wellbore and all its associated data. Click Yes or No, as appropriate.

Export (Wellbore Level)

Use this command to export the selected Wellbore’s data in XML

format. Includes the hierarchical information above and any child



information associated with the Wellbore. A dialog will open, allowing

you to supply a directory and filename for the XML file.

Import DIMS Surveys (Wellbore Level)

To access the DIMS Survey Import dialog, a Wellbore must be open.

COMPASS will connect to the DIMS ODBC data sources listed in

DIMS32.INI. If DIMS32.INI is not available, COMPASS will use the

data sources listed in DFW.INI.

Consult your DIMS administrator for details on these INI files and

ODBC connections.

Targets (Wellbore Level)

Use this command to access the Target Editor. A target is a point in a

geological space that is used as an aiming point or volume for directing

Wellbores. Use the Target Editor to define target location and shape.

The form is also used for managing several targets on a Wellbore or a

site.

Refer to “Defining Targets” on page 150 for more information.

Properties (Wellbore Level)

Selecting this command allows you to view or edit Wellbore properties.

The Wellbore Properties dialog opens. The Wellbore Properties dialog

is used to create a new wellbore and to provide information regarding

creation and modification of the wellbore.



Using the Wellbore Properties > General Tab

Using the Wellbore Properties > Magnetics Tab

Enter the magnetic referencing data for this Wellbore’s operations.

Sample Date

Since the earth's magnetic field changes with time, a date is

required to project the magnetic field. This date may be planned

(extrapolated) or historical (interpolated).Model Name

Select a magnetic model. If 'User Defined' is chosen, you will need

to manually enter declination, dip angle & field strength.

Select a Wellbore type to classify the

Wellbore. This is not essential but may be

useful when filtering Wellbores for

anticollision scans. You can associate a

color with a Wellbore type for plots. Specify

Wellbore Types to appear in the list using

the Company Properties > Wellbore

Types tab.

A Wellbore must start from surface or be

sidetracked from another Wellbore. If it is

sidetracked, select the Wellbore that contains its

starting point.



Otherwise, these values will be computed using the magnetic model

& sample date.Declination

The angle between magnetic and true north at the sample date and

wellhead location.Dip Angle

The angle that the geomagnetic field is tilted with respect to the

surface of the earth.Field Strength

The magnetic field strength at the sample date and wellhead

location.

Using the Wellbore Properties > Anticollision Colour List

In the Travelling Cylinder and Ladder plots, you may color the

proximity results by measured depth on the reference Wellbore. Enter

into the grid the depth on the reference well to start the applying color

and the color to apply.

Working at the Design Level

Design is the data level directly beneath the Wellbore level and each

design within a wellbore must have a unique name.

A design can be thought of as a design phase. Associated with each

design are a pore pressure group, a fracture pressure group, a

temperature gradient, and a wellpath. A design may have several cases

associated with it, but each case will use the same Pore Pressure group,

Fracture Pressure group, Geothermal Gradient, and Wellpath.

Note: If the design is locked, you can open it in read-only mode but

cannot save it back to the database. You can use Save As to save to

Enter the numeric value for the

depth on the reference well that

you want to start applying the color

to and select the color you want to

apply.



another design for editing, or Export to a .XML file. Pore Pressure,

Fracture Gradient, Geothermal Gradient, and Wellpath data associated

with a locked design is also locked. (To let you know that there are

unsaved changes to the open design, an asterisk is placed after the design

name in the application title bar.)

A design can be categorized as prototype, planned or actual. The design

icon indicates the category:

You may have several different versions of prototype designs. For

example, assume the geologist wants to analyze two different

formation fracture gradients. This could easily be accomplished by

having two prototype designs that are identical except for the fracture

gradient group. Landmark’s StressCheck, CasingSeat, and COMPASS

applications routinely use designs.

The datum in which the data is viewed and calculated is set at the Well

level.

With a Design selected, the following right-click menu items are

available:

In the Well Explorer, when you right click on a design, the right click


Icon Type of Design

Prototype (no line down the middle and blue circle is white

inside)

Planned (has yellow line down middle of casing and blue circle

has red inside)

Actual (has red line down the middle of the casing and there is

no blue outline for the circle)

Command Description

Open Open the selected item.

Edit Edit the planned or prototype design using the Plan Editor.

(page 123)

View View the actual design. To edit the actual design, you must use

Properties > Survey Program. (page 123)



Open (Design Level)

Use this command to open the selected design.

New Survey (Actual Designs only.) Accesses the Survey Properties editor.

(page 123)

New

Attachment

Displays the Attachment Properties dialog. Refer to “New


Paste Paste copied design information (page 124).

Rename Rename design. (page 124)

Delete Delete the selected design and all associated information

(page 124).

Export Export the selected design’s hierarchical information to an XML

file (page 124), or DEX file.

Import Import DIMS surveys or a DEX file. (page 124)

Casings Access the Design Casings Editor dialog to enter casing sizes

and depths for each Wellbore to be viewed in graphs and reports.

(page 124)

Formation Access the Design Formation Top Editor. Formation top depths

and lithologies may be included on graphs, wall plots and

reports. (page 125)

Reports Access the Reports dialog to generate a report. (page 126)

Properties View or edit the design properties (page 124).



Edit (Design Level)

Use this command to edit a planned or prototype design using the Plan

Editor dialog.

View (Design Level)

View the actual wellpath for an Actual Design. You will not be able to

edit the data using this dialog. To edit the Actual Design, use Properties

> Survey Program.

New Survey (Design Level)

Use this command to create a new survey. Refer to “Defining New

Survey Properties” on page 264 for more information.

New Attachment (Design Level)







Paste (Design Level)




design data to the Clipboard.

Rename (Design Level)




Delete (Design Level)

Use this command to remove the selected design from the database. A


the design and all its associated data. Click Yes or No, as appropriate.

Export (Design Level)

Use this command to export the selected Design’s data in XML format.


associated with the Design. A dialog will open, allowing you to supply

a directory and filename for the XML file. Also allows for export in

DEX format.

Import (Design Level)

Use this command to import DIMS surveys or DEX data into the

selected Design.

Casings (Design Level)

Enter casing sizes and depths for each Wellbore to be viewed in graphs

and reports. Casing shoes may be added to the definitive survey or

surveys and plans. In the browser you may copy the casing scheme from



another Wellbore. You may configure a standard set of casing sizes for

the pick list in the Tools > Casing List Editor.

Casing dimensions (Casing Size and Hole Size) will be added to error

dimensions for anticollision scans, when configured in the Company

Properties dialog. Hole Size is the hole diameter that the casing was run

into. It is used only as the diameter of the reference well in anticollision.

Casing sizes are used for all offset wells.

Formations (Design Level)

Formation top depths and lithologies may be included on graphs, wall

plots and reports. Formations may be added to the definitive survey.

Select Name, Case Size, and Hole

Size from the drop-down lists.

Configure the lists using Tools >

Casing List Editor.

Target can be created

from Formation Top

information.



Note: Some definitions are required to understand the dipping formation

model.

MD

Is the measured depth of the formation on the Wellbore. This is

normally entered while or after the well has been drilled. The MD

pick comes from cuttings, and logs run while or after drilling.TVD Wh

Is the TVD of the formation directly below the wellhead or vertical

section origin. This is the depth entered during planning. If TVD is

entered then MD will change on the Wellbore.TVD Sys

Is the vertical depth that the formation intercepts the Wellbore. This

field is output only, it will be the same as TVD Wh if the formation

is horizontal (no dip).Lithology

This name is picked from the list of lithologies and is used to build

the texture of the formation column.Dip Angle

This is the maximum angle from horizontal of the formation. (down

dip). The dip angle may change if MD is entered, and is computed

based on the Wellbore interpolation and the TVD below wellhead.Dip Direction

This is the azimuth of the down dip angle.Intercept

This will create a point target where the wellpath penetrates the

formation plane. To enable this button, select a row in the grid by

clicking on the row header with the mouse. The row must contain a

formation that is penetrated by the wellpath.Plane

This will create a rectangular target that mimics the formation

plane. The target will be centered on the vertical section origin. To

enable this button, select a row in the grid by clicking on the row

header with the mouse.

Reports (Design Level)

Use the Reports option to generate many types of reports, including

survey, planning, anticollision, and summary reports. Refer to

“Planning Reports” on page 213 for more information.

Properties (Design Level)

Selecting this command allows you to view or edit Design properties.

The Actual Design Properties tabs are used to create and maintain

properties related to Actual Designs. The Plan Design Properties tabs



are used to create and maintain properties of planned or prototype

designs.

Using the Design Properties > General Tab

The General Tab is used for Actual, Planned, and Prototype Designs.

Do not check the Planned

(Principal) box if the design is a

prototype. The General tab for an

Actual Design will not display this box

at all.

Notice the title bar indicates that this is a Planned

design rather than an Actual design. The General

tab for an Actual design is very similar to this tab

except the title bar would say Actual Design

Properties and the Planned (Principal) box

would not appear.

Refer to “Using Datums in

EDM” on page 50 for

more information about

datums.



Using the Design Properties > Tie-on Tab

The Tie-on tab is not used for Actual Designs.

Using the Design Properties > Survey Tool Program Tab

This tab is not used for actual designs. The Survey Tool Program for a

plan is the sequence of survey tools that will be run as the plan is drilled.

It is used to generate survey errors for the planned wellpath. The planned

wellpath represents the entire wellbore from surface to plan TD and is

used when plotting the plan and running anti-collision scans against it.

User Defined: Enter the MD,

INC, AZI, TVD, N/S, and E/W

of the tie point.

From Wellhead: Enter the initial

Inc and AZI at the wellhead.

These fields are disabled if using

the Well Reference Point system.

From Survey/Plan: Choose the

parent survey or plan and enter

the MD at which to tie onto it.

Compass will give error

messages if you enter a depth

outside the depth range of the

parent survey/plan.



If the plan is tied onto another plan or survey, the tool program from

surface to the tie depth is automatically filled in by Compass. This

portion of the program cannot be edited.

From the tie depth to TD, you may only edit depth ranges and survey

tools. You cannot edit the first Depth From - this is always the plan tie

depth. You cannot edit the last Depth To - this is always the plan TD.

Compass will warn you if you enter depths that are outside the plan

depth range. Compass will also adjust depths so that there are no gaps

between depth ranges.

To add new rows to the program, simply enter a value in the Depth From

cell in the last row of the grid. Compass will automatically update the

To depth in the previous row to match & enter the plan TD in the Depth

To cell.

Depth From

Enter the depth of the first measured station of the survey. It should

not include the tie-in depth if it is measured by another survey

instrument.Depth To

Enter the depth of the last measured depth in this survey section.

When the survey is actually run the actual survey depths will be

used to build the definitive path.Survey/Plan (Wellbore)

Read only. Shows the survey or plan used over the given depth

range. Stations from this survey or plan are used to build the

planned wellpath.Survey Tool

This is the survey instrument used to measure this survey section

from the list of survey tool error models. This defines the error

ellipse over the given depth range.Do Not Use

Indicate that this survey has been planned or run but will not form

any part of a definitive path.Use in Pref.

Use this survey in preference to later surveys. Normally later

survey depths in the program would supersede previous survey

depths, but should a high accuracy survey be planned with

subsequent overlapping lower accuracy surveys, part of the lower

accuracy survey will be overwritten.Program Parts

Examine the state of the program when each of the chosen surveys

is run. This will show both the tie-on sequence for the surveys, but

also the survey instrument sequence when new sections of hole are

drilled.



Edit Tools

Choose this button to display the Survey Tool dialog, which you

can use to add or edit tools.

Using the Design Properties > Vert Section Tab

This tab is used for actual, planned, and prototype designs. Vertical

section defines the vertical plane or planes to measure the well

displacement. The plane requires an origin and a direction. A number of

vertical sections may be defined and each one will start at a specified

vertical depth. Normally with single target Wellbores you need to define

only one. However, with multiple targets and major changes in

direction, multiple vertical sections will better represent the Wellbore

distances on a section plot.

Angle Type

Select one of several options to automatically determine vertical

section plane from local north:

• Bottom Hole Location (of the definitive survey) - The angle is

calculated from the origin to the last survey point in your

definitive survey.

The vertical section dimension has a zero

point that starts from an origin point. You

may define the vertical section zero point to

start from slot, site center, or user.



• Target - Select a target from the list of targets and COMPASS

will compute the angle.

• User - Enter the direction of the vertical section plane from local

north.

Azimuth

Enter the azimuth of the vertical section plane.Origin Type

The vertical section dimension has a zero point that starts from an

origin point. You may define the vertical section zero point to start

from one of the following:

• Slot - The vertical section originates at the current slot or well

co-ordinates.

• Site center - The point you defined as the site center location in

Site Properties.

• User - Enter the co-ordinates of the vertical section origin in the

grid as Start N/S and Start E/W. (i.e. sidetrack point). In this case

there may be several origin points to ensure continuity.

Origin N/S and Origin E/W

The origin point for vertical section zero if user defined.From TVD

The vertical depth from Wellbore datum that this section plane

operates from.

Using the Design Properties > Survey Program Tab

This tab is only used for actual designs. The Survey Program for a

Wellbore is the sequence of surveys used to generate the Definitive

survey. At any stage in drilling a well it can be used to compose the

stations for the actual wellpath based on the depths and order in the

program. This dialog is used to configure the survey sequence. Wellbore

position is determined by processing the results of one or more borehole

surveys. As drilling proceeds, surveys are taken of the new hole section

and sections of Wellbore may be re-surveyed using more accurate

survey tools.

This dialog enables you to select which surveys are used to compute the

definitive survey. Whenever the survey program is updated, COMPASS

records the date and the names of the surveys that were used to compile

the definitive survey.


Chapter

Concepts

Overview

In this chapter, you will be introduced to basic COMPASS features,

including:

� Accessing online documentation and tools

� Using the Status Window and Data Viewer

� Recognizing locked data items

� Using the Menu Bar

� Using the Tool Bar

� Using the Status Bar

� Accessing online help

� Configuring units

4

Chapter 4: Concepts


Accessing Online Documentation

COMPASS is installed with online documentation to assist you with

using the product. This documentation can be found by using the Start

Menu. The default installation will create a program group titled

Landmark EDM. From here, you can select the software you want to

use, the Documentation sub-group, or the Tools sub-group.

Using the Documentation sub-group, you may select:

� Help - This selection provides access to the online help for all the

EDM software applications. The online help is also accessible from

all windows, and dialogs in the software.

� Release Notes - This selection provides access to the release notes

for all the EDM software applications. Release notes provide useful

information about the current release, including: new features, bug

fixes, known problems, and how to get support when you need it.

� User Guides - This selection provides access to the EDM Common

Installation Guide and the Data Migration Tool Kit user guides.


Chapter 4: Concepts

Using the Main Window

COMPASS is a Microsoft Windows MDI (Multiple Document

Interface) application. Data entry and analysis are performed in separate

windows that you view simultaneously within a central application area.

COMPASS itself is composed of the distinct tool areas shown below.

Using the Well Explorer

The Well Explorer is a combined browser and status window for

navigating, managing and launching COMPASS data.

The Status View Browser is divided into three sections, and a drop down

Recent Selections List. The section located on the left of the window is

the Status Window. The top right section of the window is the Browser

Window, and the bottom right section of the window is the Data Viewer.

The Status View Browser is always available. You can minimize it, but

you cannot close it.

These are the essential components of Well Explorer. Note that the Well

Explorer display will vary slightly from one application to another. For

Menu Bar

Tool Bar

Datums

Reference

MDI Document Area. Will

display any number of

Status Bar

Depth, Angle & Map Units

Unit Set

Recent Bar

Well Explorer

Viewing Preferences

Chapter 4: Concepts


example, applications that do not use Cases (such as StressCheck,

CasingSeat, and COMPASS) will not display Cases in their Well

Explorer.

Status Window

The Status Window displays the following information. To change

some of these items, use the Viewing Preferences discussed on

page 137.

� The currently open data set including the Company, Project, Site,

Well, Wellbore, and Design.

� Status box stating which Company, Project, Site, Well, Wellbore, or

Design is open.

� Drawing of vertical datum reference with elevation information for

the open Wellbore.

� Drawing of the slot position with north arrow for co-ordinate

information for the open well.

� Vertical section origin and angle.

Status Window

Recent Bar

Browser

Window

Data

Viewer


Chapter 4: Concepts

� Browser Window (Data Tree)

Viewing Preferences

Use the Viewing Preferences to configure many of the items illustrated

on the Status Window.

Browser Window

The Browser Window is located in the upper right section of the Well

Explorer:

You can use the browser to search for the main Compass data items, like

Companies, Projects, Sites, Wells, Wellbores, Surveys and Plans. The

currently open context is shown in bold typeface.

The browser operates like the Windows 9x/NT Explorer and operates

over the COMPASS data hierarchy in a similar fashion to a directory

tree. For information on the Well Explorer, refer to “Introducing the

Well Explorer” on page 58.

Operations are:

� Left mouse button is used to expand or contract branches of the

data tree and to select.

� Right mouse button has a context sensitive menu. Depending on the

hierarchical level you have highlighted (Company, Project, Site,

Well, or Wellbore) the menu will populate with all of the relevant

Select the unit system you

want to use from the drop-

down list. COMPASS has

two default unit systems,

API and SI, but you can

make your own system.

Refer to “Configuring

Units” on page 146 for

more information.

Select the Datum you want to use

from the drop-down list. Specify

datums using File > Properties >

Well > Properties.

Check the TVDSS box if you want true

vertical depths (TVD) referenced to

the system datum. If the box is not

checked, then TVD is displayed

relative to the datum selected in the

Datum drop-down list. Measured

depths are always relative to the drop-

down list.

Select the coordinate system

you want to use.

Select Grid or True

to specify what you

want to use for the

North reference.

Chapter 4: Concepts


options from the main menu. (New, Open, Edit, Delete, Export,

Import, Report etc.).

� You may use the Browser Window to select additional plans and

surveys for graphs by clicking the left mouse button to check the

boxes associated with the item you want to include on the graph.

� You can use the Browser to "drag and drop" data between

hierarchical levels. For example, you can select a Project associated

with one Company, and copy it to another Company.

Locked Data Items

Both the Status and Browser areas in the Status Window indicate

whether data at a particular level has been locked. This is achieved by

displaying ‘padlock’or ‘key’ icons adjacent to the data. Companies,

Projects, Sites, Wells, Wellbores, and Designs can be locked, as well as

individual Plans and Surveys. This prevents locked data being

mistakenly modified or deleted.

The following graphic depicts Status Window locked data icons or

padlocks:

Concurrency Control

In a multi-user database different users use COMPASS at the same time

to access the same data source. In this environment, it is useful to know

if another user is currently using a data set. The Browser window

indicates when someone is using a design by placing a next to the

A padlock indicates a

locked item.


Chapter 4: Concepts

design name in the list so users know that someone else is accessing it.

This icon is know as SAM.

Interpreting the SAM color:

� If SAM is red, then one or more users have the design open and you

are restricted to accessing the design in read-only mode.

� If SAM is blue, then one or more users have the design open, but

you still have full read/write access to the design.

Data Viewer

The Data Viewer is located in the bottom portion of the right side of the

Status View Browser. It displays information about data belonging to

the current open item (in the Browser Window), like Templates,

Targets, Tool Codes, Casings, Formations Datum and Annotations.

Recent Bar or Recent Selections List

Recent Selections lists recently opened items. Compass will always

open the last selection but you may use this list to open Companies,

Projects, Sites, Wells, Wellbores, and Designs edited previously.

Chapter 4: Concepts


Using the Menu Bar

The menu bar provides access to all tools available within the software.

It is organized as follows:

You can select any item within the menus using the mouse or the

indicated keyboard quick keys.

To use the quick keys to select an item, press ALT and the underlined character. For example, to import a transfer file from another Compass

site, one would use the File Import Transfer File menu item, press ALT F M T.

The Survey, Planning and Anti-collision menus are license-driven

through either a dongle, network licensing, or FlexLm file-based

licensing. If COMPASS is unable to locate a license for these products,

the menus are still active, but a message box appears informing you of

the license restriction. This event may also occur for network-licensed

sites when all available licenses are checked out by other users. You also

find that menus are inactive (grayed out) if a wellpath is not currently

open.

Select... To...

File Open data, Create New Items, Import/Export functions,

Data Exchange between different Landmark

applications

Composer When the Wall Plot Composer is active, use this menu

to access many Wall Plot Composer options.

View Launch certain graphs and Legend, Launch Wallplot

Composer.

Planning Access the Directional Well Planning module.

Survey Access the Survey module.

Anti-collision Access the Anti-collision module.

Tools Launch utility functions, configure default graph and

report settings.

Windows Change full size windows, Standard Windows menu

item.

Help Access the online Help, current version info.


Chapter 4: Concepts

The Survey and Planning modules are mutually exclusive. So, if a

Survey is open, you can’t access the Planning menu and vice-versa.

Chapter 4: Concepts


Using Toolbars

The toolbar is located below the menu bar and enables quick access to

commonly used functions within COMPASS. Intuitive icons indicate

which functionality is accessed by each icon. Descriptive Tool Tips

appear if you pause your mouse cursor over any icon.

Company

Properties

Survey

Tools

Project

Properties

Targets

Site

Properties

Link to

OpenWorks

Magnetic

Calculator

Geodetic

Calculator

Reports

Wallplot

Composer

3D View

Plan

View

Section

View

Select

Offset Wells

Graph Setup

Casing Editor

Formation

Editor

Design

Properties

Wellbore

Properties

Well

Properties

Templates


Chapter 4: Concepts

Using Status Bar

The status bar is the information area at the bottom of the COMPASS

window that displays SAM rights, Help, and Units information.

Chapter 4: Concepts


Accessing the Online Help

The online Help System is remarkably comprehensive and is geared

towards engineering descriptions and solutions instead of the simple

‘What does this button do?’ type Help usually available in other

Windows applications. Much of the Help has been written after

reviewing frequently asked questions from our clients stored in

Landmark’s Call Tracking System. See the Frequently Asked Questions

section in the Help for details.

You access context-sensitive online Help as follows:

• From the COMPASS main menu select Help then Contents.

• Click the Help button located on most dialogs or editors

� Press F1 on your keyboard

The Help functions the same way it does in other Microsoft Windows

applications.

The following graphic depicts the COMPASS Help Contents:


Chapter 4: Concepts

Finding Information in Help

Once in help, you use the Help Toolbar to find desired information as

follows:

In addition, there are hotspots embedded in the text that provide more

information.

Frequently Asked Questions

The Help file contains a FAQ topic area that can be found in the

Frequent Questions section of the Help file. If you have an urgent

question, it could well be that a number of engineers have already asked

the same question and it is included in the FAQ.

Click... To...

Help Topics Go to the main Help Contents (shown above).

Search by subject areas, search by indexed

keywords, or search through Help database

Back Go to the previous Help topic.

Print Print the current help page.

Browse Keys (<< and >>) Browse through related topics.

Glossary Access a glossary of terms commonly used in

COMPASS.

Click here... To...

Jump Hotspot – (solid

underlined green text)

Jump to another related topic.

Popup Hotspot – (dotted

underlined green text)

View descriptive information in a popup

window.

Chapter 4: Concepts


Configuring Units

The COMPASS Units Management System (UMS) is accessible from

the Tools menu. The essential function of the units editor is to configure

display units for each unit class and organize them into unit sets. Display

units are distinct from storage units. At any time, you may change the

display units used by COMPASS and automatically convert any values

with no adverse affects to the data or results. This also means that you

can share data with other users or clients who use a different unit set;

they automatically see your data in their units.

For applications in WELLPLAN and COMPASS, only some units are

meaningful for expressing unit types. For this reason, Unit Classes (sets

of units for a particular unit type) are defined.

Examples of Unit Classes are:

• Diameters:[mm], [inch], [cm]

• Depth: [m], [ft]

• Dogleg Severity:[deg/100ft], [deg/30m], [deg/100m], [deg/10m],

[rad/30m], [rad/10m]

The following graphic depicts the COMPASS Units Editor.

Each tab indicates a

separate unit system.

Two unit systems, API

and SI, are default unit

systems distributed with

COMPASS.

Select the unit system you want to use

from the drop-down list.

Click the New

button to create

a new unit

system. You

can base the

system on an

existing

system.


Chapter 4: Concepts

Each data entry field in COMPASS belongs to a Unit Class, and its

value is displayed in the unit defined for that class. Variables that belong

to different classes do not need to be represented in the same type of

units. For example, while Hole Diameter might be represented in inches

(API), Hole Depth might be represented in meters (SI).

You use the Unit Systems Editor to configure a Display unit for each

Unit Class. These unit specifications can be saved so that each time you

use COMPASS, displayed data appears in the desired units.

COMPASS is shipped with two default unit sets, API & SI, that cannot

be edited. They are provided as a starting point for any customized unit

set that could consist of a combination of API and SI units. Additionally,

there are a default set of units within a given class. You cannot add units

to a particular class.

Oil Companies typically create a unit set for their own employees.

Contractors may create unit sets for each of their clients who receive

WELLPLAN or COMPASS reports or graphs.

Chapter 4: Concepts



Chapter

Planning Module

Overview

The Plan Editor is a mathematical toolbox consisting of a large number

of directional well planning solutions. Solutions are available for a wide

range of planning problems from simple 2-dimensional slant and

S-shaped wells to complex 3-dimensional wells up to and beyond the

horizontal, threaded through any number of targets. Integration with

other Landmark software enables directional well plans to be quickly

evaluated for engineering constraints.

Active plans can be combined with the Anti-collision module and the

Target Editor to provide a powerful decision-making aid. The basic

components of the Plan Editor are:

� Plan Setup

� Planned Survey Tool Program

� Plan Editor Grid

� 2D and 3D Planning Methods

� Project Ahead

� Planned Walk Rates

� Wellpath Optimiser

� Planning Reports

� Plan Export

5

Chapter 5: Planning Module


Defining Targets

Using Targets

To use targets in well planning, the planner must have the location and

geometry of any drilling and geological targets defined within the

Target Editor. These targets must be assigned to the current Wellpath

before they can be used. Most of the planning methods enable you to

select a target to plan to. By default, the planning methods designs to the

aiming point of the target, though there is usually an Adjust button

available that allows you to manually move the aiming point. If a target

is not defined, the well planner can usually enter the location as a point

in space: TVD, Northing and Easting from the local coordinate origin.

Plans that are designed to target locations remain linked to those targets.

If a target location is changed, all linked plans are updated

automatically. Therefore, the plan and target editors can be used

concurrently while directional well planning.

In COMPASS, a target is a subsurface location (TVD, N, E) with an

assigned geometry and orientation which may be used for planning or

wellpath monitoring. COMPASS enables you to define and assign

geologic and/or drilling targets at the Project level, which may then be

selected by any number of Wellpaths within the Project.

Once created, Targets can be used by the Survey and Planning modules,

and can appear on most of the available graphics and be referenced in

planning and survey reports.

Target Geometry

Each target can have a shape defined about its location. A target can be

geometric (either a Point, Rectangle, Circle, or Ellipse) or non-

geometric (defined as a Polygon with any number of points).



The following graphic depicts geometric and polygonal targets:

Each target has an aiming point, the location that the Plan Editor

methods aim toward. For geometric targets the aiming point defaults to

the geometric center. However, this aiming point can be offset laterally

and vertically from the geometric center using X & Y offsets and

thickness up and down. Thickness enables a planar depth to be assigned

to the geometrical target. Polygonal targets can have variable

thicknesses defined, which enables wedge or drillers cones to be

modeled. All targets can be rotated about the aiming point and inclined

from the horizontal along any azimuth; this enables a target to model

geologic dip and strike.

Target geometry is discussed in more detail later in this chapter.

Accessing the Target Editor

There are several ways to access the Target Editor, including:

� File > Properties > Project > Targets

� Select a Project or Wellbore in the Well Explorer and then double-

clicking on the target entry in the Data Viewer.

� Click the button on the Tool Bar.

Point RectangleEllipseCircle

Polygonal Targets



Using the Target Editor

Using the Target List

The Target Editor contains two lists:

Click the Project button to

view all targets for the

project.

Click the Wellbore

button to view only the

wellbore targets.

Check the box associated with

a target to indicate the target is

a Wellbore target.

In the Target Properties section you

can specify the location, shape,

size, and orientation of the target.

Local coordinates are from the local coordinate origin.

Map coordinates are based on the grid system specified using

File > Properties > Project > Properties > Map Info.

Polar coordinates are a distance and azimuth from the local

center.

Lease Line coordinates are specified as distances from the

lease lines. The direction is specified in File > Properties > Site

> Properties > Location.

This is the Target Viewer.

Refer to “Using the Target

Viewer” on page 159 for

more information.



� Project targets list: The project list contains all targets in the current

project. To see all the project targets in the site, click the

button.

� Wellbore targets list: The wellbore list is a subset of the project list

and contains targets associated with the current Wellbore. To see all

the targets associated with a particular path click the button.

To allocate a target to a Wellbore, refer to “Allocating Targets to

Wellbores” on page 153.

The buttons are not available if a Wellbore is not open.

Allocating Targets to Wellbores

A target has been allocated to the current Wellbore when the box

associated with the target in the Target List is checked. You may

allocate or de-allocate targets to Wellbores by clicking the box in the site

list. You may also allocate a target to multiple Wellbores using this

mechanism.

Defining the Target Geometry

Use the Geometry tab to enter information on the target’s shape. A target

can be a simple point location, a radius about an aiming point, a box or

rectangular shape to define lateral tolerance, an ellipse, or a complicated

polygonal target with any kind of irregular geometry.

The Geometry tab in the Target Editor is used to define the shape for the

selected target or for a new target. When you select a shape on this tab,

Note: Adding targets to Projects and Wellbores...

When you add targets with the Project toolbar icon depressed, you must

specifically allocate the target to a wellbore in order for it to be used. When you

add targets with the Wellbore toolbar icon set, targets are automatically allocated

to the current wellbore.

Note: If a Site is Not Open...

If no site is open or if the open site has no center location, you can only locate

targets using map or geographic co-ordinates.



appropriate entry fields will be enabled so that you can define the shape

in detail.

Target shapes can be one of a number of pre-defined shapes, including:

� Circle - A circle or a semicircle or a pie slice. Refer to “Circular

Targets” on page 154 for more information.

� Ellipse - An ellipse or a semi-ellipse. Refer to “Elliptical Targets”

on page 155 for more information.

� Rectangle - Square or rectangle. Refer to “Rectangular Target” on


� Polygon - User defined shape, you can edit the points individually.

Refer to Target Shape

Circular Targets

The following graphic depicts the Circular Target Editor window:

This window enables you to enter a circular target or, by giving the

circle height and a dip angle, you can define a cylinder.

Select the desired

target shape.

Offset from Target Centre

fields enable 3D target

geometry and orientation to be

defined. You can offset the

geometric center of the target

from the plan-to point by

entering X (local East) and Y

(local North) offset.

Start and End Angles enables

‘pie-shapes’ to be defined for

circular and elliptical targets.

For a full circle shape, use zero

for the start and end angles.

Type a value in

the Up and Down

fields to change a

circular target to

a cylindrical

target. The top of

the target is Up,

the distance

above the plan-to

point. The bottom

of the target is

Down, the

distance below

the plan-to point.

Dip angle is the angle you want to be on at the

target. This is 90° minus the inclination of the

target. This is the direction a ball would roll if

placed in the formation bedding plane.



Elliptical Targets

The following graphic depicts the Elliptical Target Editor window.

Rotation angle enables target

to be turned relative to Site

North. Target rotation is about

the aiming point.

Thickness Up and Down

enables the aiming point to be

offset vertically within the

target.

Formation Plane parameters

enables geologic dip and

down dip direction to be

specified, for example, to

model a bedding plane. This

may be different from target

rotation.

For Semi-Minor,

enter the

dimension of the

ellipse along the

local North/South

axis. For Semi-

Major, enter the

dimension of the

ellipse along the

local East/West

axis.



Rectangular Target

The following graphic depicts the Rectangular Target Editor window.

Note: Defining equivalent formation thickness.

Target up and down thicknesses are used to define equivalent formation thickness.

This method is useful because you can define the aiming point at a given depth

below the formation top. For example, if you have a dipping formation that is 30m

thick but want to drill down dip 5m below the formation top, you define the aiming

point as 5m up, 25m down. This method is applicable to all target geometries.

These parameters

define the size of the

target. Length is

parallel to the local

N/S, providing no

orientation is

applied.

Enter the orientation of the

target from local north. The

orientation is zero when

aligned to local north and

increases clockwise.

You can offset the

geometric center of

the target from the

plan-to point by

entering X (local

East) and Y (local

North) offset.

Type a value in the Up and

Down fields to change a

rectangular target to a

cuboid target. The top of

the target is Up, the

distance above the plan-to

point. The bottom of the

target is Down, the

distance below the plan-to

point.

Type the dip angle you want to be on at the target. This is 90° minus the inclination of

the target. Type the azimuth (direction from local north) of the down dip direction. This

is the direction a ball would roll if placed in the formation bedding plane. This is not the

orientation of the target shape.



Polygonal Targets

The following graphic depicts the Polygonal Target Editor:

A polygon can have any number of points defined on it using the points

defined using the grid (above).

There are three methods available to define points on a polygon:

� X and Y: Enter local X and Y coordinates from the target aiming

point to define a polygon shape. By default, the last point is joined

to the first to close the polygon. The Y dimension is parallel to the

local N/S, providing no orientation is applied.

� Map E and Map N: Alternatively enter the map coordinates of the

target as given by the geologists. The Local X and Y are computed

based on the target center. Note that if the target center is moved,

these periphery points move as well.

� Well Viewer – Define Polygonal Targets: With the target created,

press the Define Polygonal Targets icon . The viewer displays

a plan view of the target, on which you can use the mouse to click

each point on the polygon. Depress the icon after all points are

clicked, and the target editor will join up the first and last points.

Each point on a polygon

may be given its own

name or label.

Wedge targets may be

defined by changing

thickness Up and Down

for each polygon point.

Enter the orientation of the

target from local north. The

orientation is zero when

aligned to local north and

increases clockwise. If you

define a dip angle, this is

the down dip direction of

the equivalent formation.



Defining Drilling Targets

If the geologist gives you a target with X dimensions and you drill to it

using MWD, you may hit it near the edge. When the path is later

surveyed using a gyro, quite often the wellbore ends up outside the

target.

To prevent this, the planners should reduce the geologists target by the

expected survey error radius to be found by drilling with MWD (maybe

tied to a gyro at the previous casing). The reduced target is known as a

drilling target. It is a zone within the geological targets that, when drilled

within and monitored using survey instruments with inaccuracies, will

stand a good chance of hitting the geological target boundary.

The drilling target tool creates a new target that has been reduced in size

from the original by the survey errors at the target depth. It requires a

target that is big enough to fit the survey errors and a survey program

that penetrates the target

It is recommended that you create a survey program from a plan with the

survey tools for the situation when drilling the final section of the hole

to the target (i.e. gyro in intermediate casing and MWD in open hole).

The drilling target tool may be used to design a cost effective survey

program applied to the given geological target sizes.

Select Design

Use this tree control to select the wellbore design containing the

survey program, and hence the survey errors, you want to use to

compute the drilling target.Confidence Level

Enter the confidence level (1% - 99%) required to hit the target

using the survey errors from the selected design.Create Drilling Target

Once a design has been selected and a confidence level entered,

press this button to create the drilling target.Delete Drilling Target

If a drilling target exists, press this button to delete it.View Points in NotePad

Press this button to display the computed target points in text

format.

See “Drillers Target Algorithm” on page 380 for an explanation of the

difference between Geologist’s and Driller’s targets.



Using the Target Viewer

The target view displays the currently selected target, which you can

toggle as a Section, Plan, or 3D view with the usual 3D tools available.

You can use the Target viewer to define polygonal targets and to change

the landing point for directional well planning calculations. Refer to

“Polygonal Targets” on page 157 for more information on using the

Target Viewer for designing polygonal targets.

Target Landing Point Adjust

When planning or doing project ahead, the target viewer has another

use. If a target is selected from a drop-down list, click to

adjust the landing point. This invokes the target view in adjust mode.

Click anywhere on the section or plan view to adjust the landing point.

The plan or projection immediately updates the calculations using this

new point. This does not change the target location.

To change the landing point for planning calculations:

The landing point or aiming point is defined in the Target Editor.

1. Create a new plan or open an existing plan.

2. Select a planning method that lets you select a target. For example,

a 2D slant well.

3. In the Plan Editor, select a target.

4. Click Adjust.

5. In the Target View window, move the cursor to the coordinates you

wish to aim for, and click the left mouse button.

6. The plan is automatically re-calculated to hit that point.

• To change the horizontal location click the plan view icon .

• To change the vertical location click the section view icon .

• You can also type in the landing point coordinates and click Set.

• To revert to the original coordinates click Reset.



Creating a Plan

When a New Plan is created, the Plan Properties dialog automatically

appears to allow you to identify the plan. Plan Properties is similar to

Survey Properties. There are several tabs on the dialog to facilitate

creating the plan.

Naming the Plan and Defining the Depth Reference Point

The following graphic depicts the Plan Setup Window.

Specifying the Tie-On Point

Similar to a survey, a Plan must have a defined tie-on point to act as the

starting point of the plan. There are three choices of tie-on point

Lock the plan to

prevent other users

from changing it.

Check the

Planned

(Principal) box to

indicate this is the

final plan, rather

than a prototype

plan. You can only

have one principal

plan for each

Wellbore.

Use the pull-down

menu to select the

depth reference datum.

You define the datums

that appear in this list

using the File >

Properties > Well >

Properties > Depth

Reference tab. Refer to

“Working at the Well

Level” on page 108.



methods. The tie-on point can be defined explicitly, tied to the wellhead

location, or calculated based on a specified measured depth.

Plans must be Tied-On to define a

starting point and orientation. Tie-on

methods are:

• User Defined: Use this method to

explicitly define the tie-on point.

• From Wellhead: Specify the

inclination and azimuth at the

wellhead. These fields are disabled

if you are using the Well Reference

Point system.

• From Survey/Plan - Choose the

parent survey or plan and enter the

MD at which to tie onto it.

COMPASS will give an error

messages if you enter a depth

outside the depth range of the

parent survey/plan.



Defining the Survey Tool Program

Enter the depth of the

first measured station

of the section. It

should not include the

tie-in depth if it is

measured by another

survey instrument.

Survey/Plan (Wellbore) displays the

survey or plan used over the given

depth range. Stations from this survey

are used to build the planned wellpath.

This is the survey instrument used to

measure this survey section from the list of

survey tool error models. This defines the

error ellipse over the given depth range. To

create a new tool, use File > Properties >

Company > Survey Tools.

Check Do Not Use to indicate that this section has

been planned but will not form any part of a

definitive path.

Check the Use in

Pref. box to use this

survey in

preference to later

surveys. Normally

later survey depths

in the program

would supersede

previous survey

depths, but should

a high accuracy

survey be planned

with subsequent

overlapping lower

accuracy surveys,

part of the lower

accuracy survey will

be overwritten.

Program Parts is

only available when

there is more than

one line in the grid.



Specifying the Vertical Section

Vertical section defines the vertical plane or planes to measure the well

displacement. A number of vertical sections may be defined and each

one will start at a specified vertical depth. Normally with single target

Wellbores you need to define only one. However, with multiple targets

and major changes in direction, multiple vertical sections will better

represent the Wellbore distances on a section plot.

Use Angle Type to select

one of several options to

automatically determine

vertical section plane

from local north.

Select the target type

from the pull-down menu.

From the pull-down list, select the

starting point of the vertical

section.



Using the Plan Editor

The purpose of the Plan Editor is to generate a series of curve types to

form a planned wellpath trajectory to one or more target locations. The

Plan Editor has three areas: an interactive plan grid, a number of plan

method windows for data entry and calculation, and a toolbar. The plan

grid is always present and displays all plan sections and enables key

parameters of each row to be changed. The plan method windows are

used to define individual curves or profiles. The plan method windows

appear when you activate one of the method toggles.

COMPASS has over 20 planning methods. Some methods are divided

into subgroups, accessed from the planning method icons. The planning

methods can be divided into 2-dimensional tools, 3-dimensional tools

and the Wellpath Optimiser.

Each planning solution consists of rows displayed in the Plan Grid. A

row is a line in space with a constant dogleg, build, or turn rate. Different

planning methods construct a different number of rows. For example:

� Hold adds one row

� Slant Well adds three rows

� Thread Targets adds multiple rows

The Plan Editor is similar to the Survey Editor. Rows are added to the

grid using the different planning methods. Multiple planning methods

can be used when constructing a single plan. Like the Survey Editor, the

keyboard can be used to insert new sections at any point in the plan, or

delete sections no longer required.

Rows in the grid are mathematically linked together by the planning

method that was used to construct them. Therefore, deleting a particular

row in the grid results in all rows linked to that method being deleted as

well. To edit a section in the plan, click on the relevant row in the grid,

and the plan method for that section appears.

Accessing the Plan Editor

You can access the Plan Editor in the following ways:

� The Plan Editor is automatically displayed after you finish creating

a plan using the Plan Design Properties tabs.



� You can double-click on an existing plan in the Explorer to open an

existing plan.

� Use Planning > Open Plan and select the desired plan from the list

of existing plans.

The following graphic depicts the Plan Editor.

Don’t like what you last

changed, click Undo or Redo.

Plan Design can be quickly accessed from

the tool bar. Refer to “Creating a Plan” on

page 160 for more information on using the

Plan Design dialog.

Plans can be

generated through

more than one target.

The plan grid is interactive; white cells

are editable—change a value and the

plan re-calculates.

Plan method toggles are

used to choose which plan

method is used. Different

methods can be combined to

form a wellpath through

multiple targets.

When a Plan Method toggle is

activated, the plan method

window displays the inputs

required to calculate sections of

that method.

When values have been entered

for the plan method, hit the

Calculate button to generate a

trajectory.

Some plan methods have

sub-method buttons.Use the Planned

Wellpath tab to view

survey data generated

from the plan.



Plan Grid

The plan grid is always present and displays the geometry data for the

plan trajectory. Each row in the plan grid is equivalent to a survey

station or change point. In the grid, a plan section can contain between

1 and 6 rows, and the full plan trajectory may contain a number of plan

sections joined together. The columns of the grid are as follows.

� MD (Measured depth)

� Inc (Inclination)

� Azi (Azimuth)

� TVD (True Vertical Depth)

� N/S (North/South)

� E/W (East/West)

� Vsec (Vertical Section), Projected vertical section distance along

plotting plane.

� Dogleg (Dogleg Severity), Curve rate from the previous station to

this.

� Tface (Toolface angle), Toolface orientation to get from the

previous station to this.

� Build (Build Rate), Rate of change of inclination with depth. Build

is +ve and Drop is –ve.

� Turn (Turn rate), Rate of change of azimuth with depth. Right is

+ve and Left is –ve.

� CL (Course Length), The measured depth distance from the

previous station to this.

� Type (Plan section), Indicates the plan method associated with the

plan section, marked on the 1st line.

� Target (current target for this row). Name of the target at the end of

this plan section.To Edit directly into the grid

Selecting the Planning Method

In the Planning Methods section of the Plan Editor there are several

methods to select from. Your selection will determine the input data

requirements that will be displayed in the Plan Method Window. See

“Planning Methods” on page 171 for more information on planning

methods.

Using the Plan Method Window

The Plan Method Window portion of the editor displays the input

required depending on the Planning Method selected using the toggles

in the middle of the editor. When the required inputs have been filled,



click Calculate and the data will be input in the Plan Grid portion of the

dialog. See “Planning Methods” on page 171 for more information on

planning methods.

Using the Plan Editor Toolbar

The planning toolbar is located at the top of the Plan Editor. There are a

number of plan options from the toolbar:

• Save As and Save the plan. Save this plan by another name

• Undo and Redo the plan calculations: Restore the last plan

calculation.

• Plan Set-up: Edit the plan detail and tie-on information.

• Import: Import plan data from the clipboard or a file.

• Thread Targets: Construct a trajectory through several targets.

• Apply Walk: Apply azimuth drift where expected in rotary

drilling.

• Interpolate: Use the Interpolate button to interpolate between

two survey data points.

• Wellpath Optimiser: Optimize a plan for torque/drag, construct

drilling limits plots or evaluate redrill options on idle wells.

• Projection Ahead: Quick calculation of vector to hit a target.

• Plan Comments: Click to access the Annotations dialog.

Annotations are comments on the Survey/Plan that do not fit into

the category of Casings or Formation Tops: Examples of

possible use of annotations include: top of fish, sidetrack point,

MWD Check Shot, and Final Depth (TD). Annotations may be

added to wall plots and reports. Predefined auto-annotations can

be added to the plan as well.

• Create Target: Use Create Target to create a target from a row

of plan data. Highlight the row, click the Create Target toolbar

Save and Save As

Undo or Redo

Plan Design

Properties

Import Plan Data

Thread Targets

Apply Walk

Interpolate

Wellpath Optimizer

Project Ahead

Plan Comments

Create Target

Close

Help



button, and the target will be created and added to the File >

Properties > Project > Targets list.

Adding a Plan Section

To add a plan section:

1. Select the last line empty line in the grid, then select a Planning

Method using the radio buttons.

2. Fill in the entry fields that are displayed in the Plan Method

Window section of the Plan Editor dialog.

3. Click the Calculate button to compute the results.

4. Click on the next line in the grid to accept the results and start on

the next plan section. Or click the undo button to reject the

calculations and close the curve data entry fields.

Deleting a Plan Section

To delete a plan section:

1. Click on a row within the plan section you want to delete.

2. Press the Delete key on your keyboard.

Editing the Plan Grid

Once plan section data has been calculated, you may edit the input

values directly into the grid. Alternatively, the last line in the grid may

be used to add plan sections directly. When adding lines to the end of the

plan, only certain combinations of parameters will work. At least three

numbers must be entered (or two if DLS=0).

The data combinations are in listed order below:

Note: Deleting a plan section...

You cannot delete individual rows of a plan section. You must delete the entire

plan section.



1. If Dogleg is defined as zero, then compute a straight line to one of

MD, TVD, or VSec.

2. Inc, Azi and one of MD, TVD or Dogleg. (Inclination, Azimuth

projections)

3. Dogleg, Toolface and one of MD, INC, AZI or TVD.(Dogleg

Toolface projections)

4. N/S, E/W and TVD (constant curve to a point, VSec may be used

instead of N/S and E/W)

5. MD and two of the following Inc, Azi, Dogleg, Toolface.

To Highlight Plan Sections in Views (plots):

Highlight a row in the Plan Grid, and when that plan is displayed in 3D,

section or plan view, the corresponding plan section will be highlighted

in the plot.

Incremental Measured Depths

The planning algorithms remember incremental measured depths, rather

than absolute measured depths. What this means is illustrated in the

following example. A plan to a target has a rathole of 300’; then the

target was moved, and the plan angle changed. The plan would keep the

300’ rathole even though the final TD depth changes.



Viewing the Planned Surveys

Use the Plan Editor > Planned Wellpath tab to view the planned

trajectory that was generated based on the plan.



Planning Methods

Plan methods are selected by clicking a radio button on the Plan Editor.

2D planning methods within a vertical section include Slant and S-Well

design; 3D planning methods and tools include Build/Turn curves for

rotary drilled sections, Dogleg/Toolface curves for steerable drilling

design, Optimum Align, Thread Targets, and Nudge. Additional

planning methods are Hold to add a section with no build or turn, Walk

to apply predicted walk tendencies to hold sections in the plan, and the

Wellpath Optimiser, which is used to optimize the wellpath trajectory

for mechanical constraints, lowest directional drilling costs, or least

anti-collision risk. A Project Ahead tool enables the bottom of the plan

to be projected to a target.

COMPASS has a number of planning methods suitable for different

types of directional drilling assemblies. All these tools construct

mathematical curves. When entering parameters for a planning method,

COMPASS always constructs a path if it is mathematically possible.

Sometimes this results in a peculiar wellbore trajectory (see the

following illustration as an example). A drilling engineer should be

capable of detecting these types of plans, and adjusting the plan

parameters as necessary.

If an engineer enters parameters that result in a plan not being

mathematically possible, warning messages appear with a brief

description of the problem and an indication of what parameter requires

changing. For example, a low build-rate parameter can result in the

wellpath not being able to build in the measured depth needed to get to

a target location.



The following graphic depicts an unexpected Wellpath Trajectory using

Positive Build Rate:

2D Directional Well Planning

The 2-dimensional well planning tools construct wellpath trajectories

that follow the plane of a vertical section. That is, there is no turn from

the slot to the final target. COMPASS provides two methods for

planning 2D wells: Slant well, and S-Well. A slant well is a simple

Hold-Build-Hold profile, whereas an S-Well can be a Build–Hold–

Drop-Hold profile or a Build-Hold-Build-Hold profile.

Slant Well Design

The following graphic depicts 2D Slant Well Design Parameters:



To design a Slant well:

1. Type in the coordinates of the point to aim for or select a target.

2. Check two of the unknowns from the list of four below. Example

unknowns are 2nd hold length and Maximum Angle.

3. Enter the two known parameters:

• 1st Hold Len - Length of initial hold section before the kick-off

point, or more simply the kick-off depth. Enter zero if you wish

no kick-off length.

• 1st Build - The build-up rate.

• Maximum Angle Held - The tangent angle of the profile.

• 2nd Hold Length - The length of the tangent hold section.

4. When ready to calculate press to compute.

Like all Planning methods, the entry parameter values can be changed,

or the parameters checked can be changed, other parameter types

defined, and the plan re-calculated as many times as necessary without

having to exit from the drop-down window.

S-Well Design

An "S" well has three sections—Build - Hold - Build/Drop, and is

defined by seven parameters. You can also add a hold for the kick-off

Slant is the selected

planning method.



The following graphic depicts 2D S-Well Design Parameters:

To enter a 2D -’ S’ well profile:

1. Type in the coordinates of the point to aim for, or select a target.

2. Check two of the unknowns from the list of seven below. Example

unknowns are 2nd hold length and Maximum Angle.

3. Enter the five remaining parameters:

• 1st Hold Length - Length of initial hold section before the

kick-off. Enter zero if you wish no length before the kick-off.

• 1st Build Rate - The build-up rate.

• Maximum Angle Held - The intermediate tangent angle of the

profile.

• 2nd Hold Length - The length of the intermediate tangent

section.

• 2nd Build Rate - The second build or drop rate (+’ve or –‘ve).



• Final Inclination - The inclination you want to achieve at the

target.

• Final hold length - The distance from the end of the last build

to the target. Enter zero if you wish no straight section before

the target.

The following graphic depicts an S-Well Plan Example:

The example above displays a planned S-Well that is planned to target

T9 with the kick-off point at 1500ft, initial build rate of 2º/100ft, second

drop rate of 3 º/100ft, to a final inclination of 10º,with a final hold length

to the target of 1450 ft. With these input parameters, the calculated

inclination of the tangent section is 62.86 º, with an interim hold length

of 3298.7ft. The calculated plan is shown above in 3D (left) and Vertical

Section (right), with each planned section highlighted with boundary

lines.



3D Well Planning

3D planning methods assume that the well is drilled under some form of

directional control, where the well can be turned to a given azimuth from

a particular measured depth.

Build/Turn Curves

The mathematics of Build and Turn curves assumes that the wellpath is

wrapped around the surface of a cylinder. The shape of the wellpath is

resolved into two planes, vertical (inclination) and horizontal

(direction). The build rate is the rate of change of inclination, and turn

rate is the rate of change of direction or doglegs in the vertical and

horizontal planes respectively.

Build and Turn curves are constructed assuming that the sections are

drilled using a rotary drilling assembly. A number of sub-methods are

available to plan different types of Build-Turn curves, utilizing different

types of available information during the design.

The following graphic depicts the Build / Turn Curves Planning Models:

Build-Turn sub-methods are selected by clicking the appropriate icon at

the bottom of the plan method window. Selecting different icons results

in different parameter fields being active and inactive. Active fields

require a value for the sub-method to work. Inactive fields are calculated

using the entered parameters.



The following graphic depicts a Build-Turn Drop Down Layout.

Eight different sub-methods are available:

Click...Click To...o...

Build & Turn to Vertical Depth - Apply a build and turn

rate until the specified measured depth or course length.

COMPASS calculates the final TVD, inclination, azimuth,

northing, and easting.

Build & Turn to True Vertical Depth—Apply a build and

turn rate until the specified true vertical depth. You can

specify a TVD or select a target to define the TVD.

COMPASS calculates the final measured depth, northing,

easting, inclination, and azimuth.

Build & Turn to Inclination—Apply a build and turn rate

until the wellpath reaches a certain inclination. COMPASS

calculates the final location, measured depth, and azimuth.

Build & Turn to Azimuth—Apply a build and turn rate

until the wellpath reaches a certain direction. COMPASS

calculates the final location, measured depth, and

inclination.

Tangent to Point—Enter build and turn rates, and

COMPASS adds three sections. It applies the build and turn

rates until pointed to either the correct direction or

inclination, whichever can be achieved first. The second

section is either a build or a turn to complete the projection.

If pointed to the correct inclination, then a turn is applied to

reach the required direction. If pointed in the correct

direction, then a build or drop is applied to reach the

required inclination. The wellpath is now pointing at the

target, so the third section is a hold to target.

Plan to Point—Enter a point or select a target to aim for.

COMPASS computes the build rate and turn rate required to

hit the target in one curve.

Build-Turn sub-method icons. These

activate the required parameter

entry fields when pressed.

Some B/T Methods enable a target

TVD or location to be selected. If a

target is selected, the Target Adjust

feature is also available.

Required fields

are active.

Calculated fields

are greyed out.



Dogleg/Toolface Curves

The mathematics of Dogleg / Toolface curves assumes that the wellpath

is wrapped around the surface of a sphere - a circular curve with

orientation defined by toolface and radius defined by dogleg. Toolface

is the direction from high-side of the hole. Toolface is 0º at high-side and

180º at low-side. Looking down the wellbore, toolface is positive

clockwise and negative anti-clockwise. If the wellbore has no

inclination, toolface is referenced to local north.

Dogleg-Toolface curves are constructed assuming that the sections are

drilled using a steerable drilling assembly. A number of sub-methods are

available to plan different types of Dogleg-Toolface curves utilizing

different types of available information during the design.

Online by TVD—Enter a point or select a target to aim for.

Specify the depth (True Vertical Depth) by which you want

to be online to hit the target. COMPASS adds two sections, a

build turn section to get the wellpath online by the TVD,

then a hold section to the target.

Align by Inclination—Enter a point or select a target to aim

for. Enter the inclination you require and the build and turn

rates of the curve. At the end of the curve, the wellpath

direction is aligned with the target and at your required

inclination.

Click...Click To...o...



The following graphic depicts the Dogleg-Toolface Curve Sub-

methods:

The same as Build-Turn curves, Dogleg-Toolface curve sub-methods

are selected by pressing the appropriate icon at the bottom of the drop

down layout.

The following graphic depicts the Dogleg-Toolface Drop Down Layout:

Depending on what sub-

method is selected, the

appropriate parameter

fields are activated.

After Calculating, the greyed out

fields display their calculated values.

Plan to tangent to a point

generates 2 sections: either Hold-

Curve or Curve-Hold.

The Dogleg-Toolface sub-methods

are the same as Build-Turn curves,

except the calculated wellpath shape

is different.



Eight different sub-methods are available:

Click... To...

Apply Dogleg / Toolface to Measured Depth—Apply a

Dogleg on an initial toolface angle until the specified

measured depth has been reached. COMPASS calculates the

final TVD, inclination, azimuth, northing, and easting.

Apply Dogleg / Toolface to True Vertical Depth—Apply a

Dogleg on an initial toolface until the specified TVD has

been reached. You can specify a TVD or select a target to

define the TVD. COMPASS calculates the final measured

depth, inclination, azimuth, northing, and easting.

Apply Dogleg / Toolface to Inclination—Apply a Dogleg

on an initial toolface until the wellpath achieves a certain

inclination. COMPASS calculates the final measured depth,

TVD, azimuth, northing, and easting.

Apply Dogleg / Toolface to Azimuth—Apply a Dogleg on

an initial toolface until the wellpath reaches a certain

direction from local north. COMPASS calculates the final

measured depth, TVD, inclination, northing, and easting.

Tangent to Point—You enter a Dogleg and COMPASS

adds two sections. It computes the initial toolface of the

dogleg section and the length of hold required to hit a target

or user-defined point. If you want the dogleg section before

the hold, click Curve-Hold or Hold-Curve for the reverse.

The length of the Hold section is dependent on the dogleg

entered.

Plan to Point—Enter a point or select a target to aim for.

COMPASS computes the radius of the dogleg and initial

toolface to hit the target in one curve. This type of plan

could be expensive in directional drilling costs. However,

the method is very useful, as it calculates the minimum

dogleg required to steer between two points. COMPASS

calculates the final MD, TVD, inclination, and azimuth of

the wellpath.

Online by TVD—Enter a point or select a target to aim for.

Specify the depth (True Vertical Depth) by which you want

to be online to hit the target. COMPASS adds two sections: a

curve to get you online by the TVD, then a hold section to

the target.

Align by Inclination—Enter a point or select a target to aim

for. Enter the inclination you require and the dogleg of the

curve. At the end of the curve, the wellpath direction is

aligned with the target and at your required inclination.



The following graphic depicts a Dogleg-Toolface Plan Example:

The above example displays Dogleg-Toolface planned sections from

target T8 to T9. The entire plan consists of an S-well design to T8

followed by the Dogleg-Toolface curves. Looking at the Dogleg-

Toolface Drop-Down layout, the plan was constructed using the Plan to

Tangent a Point sub-method with a dogleg of 1º/100ft defined to target

T9 selected from the drop-down menu. The two sections are ordered

Curve, then Hold.

Build-Turn vs. Dogleg-Toolface

As discussed in the last two plan method sections, Build-Turn and

Dogleg-Toolface plan profiles have a significantly different geometry.

Build-Turn plans approximate to Radius of Curvature curves that follow

the surface of a cylinder. These curves emulate rotary drilling where

build and walk are predicted. Build-Turn can also design a ‘flat turn’

where the inclination remains constant, for example, when sidetracking

to a different azimuth.

Dogleg-Toolface plans construct a Minimum Curvature geometry that

follows a ‘great circle route’ around the surface of a spheroid. Dogleg-

Toolface curves cannot be used to design a flat turn; the inclination

changes through the turn. For short turns, dogleg and toolface

Slant Well design to target T8

Dogleg-Toolface curve-hold

design from target T8 to T9

Steer from T8 with 1.0° dogleg to

line up on T9

Hold to hit T9



orientation remain constant. For larger turns, Dogleg-Toolface curves

cannot construct a path with constant dogleg and toolface orientation;

over the turn you’ll find that they change. This effect can be

considerable over a long distance.

Optimum Align

The Optimum Align planning method adds three sections: Curve, Hold,

and Curve (also called Steer – Hold - Steer). You can specify a final

inclination and direction for the end of the final curve, or, if you select

two targets, COMPASS computes the inclination and direction between

them for you. If you select a single target, COMPASS lines up on the

target to plan the well down dip.

The following graphic depicts Optimum Align Planning Methods:

To build an Optimum Align profile:

1. Set restrictions on the curve shape in one of three ways:

• Doglegs—Specify the doglegs of both curves.

• TVDs—Enter the start and end TVD of the intermediate hold

section (or TVD at end of first turn, TVD at start of second turn).



• Tangent Length—Enter the length of the intermediate hold

section, COMPASS calculates the TVDs and Inc/Azi. If you

enter 0 for the tangent length, compass will compute a “curve-

curve” trajectory which has no tangent length.

2. Select the first target to land the wellpath. You can adjust the

landing point vertically/laterally using the Target Adjust tool. You

can add a short section before the first target by specifying Hold

length with or without a build rate before hitting the first target.

3. Determine the final inclination and azimuth using one of the

following two methods:

• Selecting a second target to follow on to:

• Pick a target. The target you want to hit.

• Line up on target. The target you want the wellpath to line up on

at the end of the second curve. This target is remembered in the

plan, and a hold is computed between the two targets.

• Defining the End Vector at the target:

• Pick No Target (Freehand). If Target 1 has a dip and strike,

COMPASS assumes you want to plan down dip and calculates

Inclination and Azimuth accordingly. These are defaults that can

be changed. If you want to plot sensitivities in the wellpath

optimizer based on N/S & E/W coordinates, you must enter a

freehand target. When doing so, these parameters will appear in

the profile grid for editing.

• Inc - Enter the final inclination required.

• Azi - Enter the final required direction.



The following graphic depicts an Optimum Align Plan example:

The example above displays an Optimum Align plan to target T8

defined using two doglegs. When the plan hits target T8, the wellpath

trajectory lines up to point directly at T9 so the well can be held to hit

T9. This type of method is very effective to plan a well with the

directional drilling completed top hole to limit costs. Deeper in the well

after hitting T8, the well can be drilled with a stiff assembly and held to

the final TD.

You can enter a short section before the first target by specifying Exit

length and build rate on the tangent length line.

The project back feature can be used to achieve similar results. Project

back is also used to create “soft landings” into a target.

Kick Off Point

T9

First Curve section from Kick Off Point to start

of Tangent section, DLS = 2.5 deg/100ft

Tangent section from end of first turn to start of

second turn

Second Curve section from Tangent section to

target T8, DLS = 3.0deg/100ft

Simple hold section to hit second target T9

Plan to hit target T8 with wellpath orientation

aligned with target T9.



To create a “locked” up section between two targets:

1) Use optimum align as describe above to design to the 2nd target (i.e.

the final target).

2) Project back and select the first target.



3) Create a “soft landing” into Target 1 by highlighting the row in the

planning grid containing Target 1 and then project back again. Enter the

Course Length (CL) required and the build rate into the target. Then

calculate.



Hold Tool

The HOLD tool is a very useful utility for defining planned kick-off

points, or extending the trajectory beyond a target.



You can add a straight line projection to either a MD, TVD, or VSec:

Thread Targets

Click the Thread Targets button on the Plan Editor to access the

Thread Targets dialog.

Thread targets plans curved profiles through a series of targets, with a

number of plan methods available between each pair of targets. The tool

is very useful for quickly generating rough plans through a number of

targets to see what magnitude of doglegs are required to plan through

them. It is also commonly used to plan wells up-dip, using decreasing

TVD targets.

Select... To...

MD Enter the measured depth to project to. If the MD is

less than current MD of the plan, COMPASS

assumes you wish to apply an additional MD. For

example if your plan is at 5410 ft MD and you say

you want to hold to 90ft, COMPASS adds 90ft to

the plan giving a final MD of 5500 ft. If you typed

in 6000ft, COMPASS adds a hold of 590 ft to the

plan.

TVD You can specify the vertical depth of a target by

picking a target or entering a TVD

VSEC You can specify the vertical section distance by

selecting a target or entering a distance



The following graphic depicts the Thread Targets Planning Options:

For each one of the Planning methods, the Thread Targets tool also

enables the user to select how the targets are sorted. The options are by

increased displacement from the slot origin, descending TVD ascending

TVD or by Name. The last option enables targets to be sorted in any

order using the order that the targets were placed in the thread list.

The following graphic displays the Target Threading sort methods:

Desc TVD



The Thread Target window enables you to select which targets you want

to thread. The targets displayed are those selected by the current

wellpath.

To thread targets:

1. Select a number of targets to thread by picking from the Add To List

button, (or double-click on them); you can remove them using the

Remove From list button.

2. Select the order in which the targets are to be threaded by choosing

from Sort Targets:

Choose... To...

Displacement Hit the targets in order of increasing horizontal

displacement.

Descending First hit the shallowest target, then the next deepest, and

so on.

Target Sort Methods

Target Thread Methods:

• Curve Only

• Curve-Hold

• Optimum Align

• Straight

• Least Turn

COMPASS tries to use this dogleg if

possible, otherwise it is incremental

automatically until a solution is

achieved through all targets.



3. Select the threading method from the list:

4. Specify the Dogleg to apply - Enter the Dogleg you require for the

selected curve type (does not apply to curve only). If the dogleg

severity is insufficient, then a better dogleg is suggested and the

path computed. If you’re not sure what dogleg to use, then leave the

value set to a very small value (e.g., 0.1º/100ft) and COMPASS

works out the doglegs. Note: if 0º/100ft is specified, COMPASS

often defaults to 5º/100ft dogleg between each target. If this is the

case, try decreasing the dogleg and re-calculating to see if this is

indeed the minimum dogleg that can be used.

After generating a plan using this method, each set of plan sections

between targets is linked to a particular planning method—not the

Ascending Hit the deepest target first, then the second deepest, etc.

Name Hits the targets in the order specified in the thread target

list.

Choose... To...

Curve Only Add on one curve section per target. COMPASS

computes the dogleg severity required to hit the next

target with one circular curve.

Curve Hold Adds two sections per target. Specify the Dogleg

Severity and COMPASS computes the initial toolface

angle and length of hold section required to hit each

target in turn.

Optimum Align Adds three sections per target a curve, hold, and curve,

and connects the last two targets via a straight line. (See

Optimum Align planning method.) You need to specify

the dogleg severity to make the turns.

Straight Line Finds the best straight line to thread through the targets.

It uses optimum align to get to the first target. Normally

the line starts and ends with the vertical depth of the first

and last target, but if the targets are near horizontal or

'sort by displacement' is chosen, then the line is limited

by displacement. The best-fit line is weighted to hit

targets with smaller dimensions. The best-fit line does

not necessarily pass through each of the target

dimensions; a message is reported if a target has been

missed.

Least Turn Calculates a trajectory with the least amount of turn

through the targets

Choose... To...



Thread Target planning method itself. For example, the Thread Targets

solution can consist of Optimum Align sections and Dogleg-Toolface

curves. After pressing OK in Thread Targets, double-clicking on any of

the constructed sections would not launch the Thread Target drop-down

layout, but the planning method drop-down linked to that section itself.

Nudge

Nudge contains plan methods for horizontal or dipping formation

targets. It is also useful for inserting nudge sections into a plan to assist

with anticollision.

Simple Projection - This computes the trajectory to land at a vector at a

specified TVD, MD or Dogleg.

1. Enter the required Inclination and Azimuth

2. Enter one other parameter from MD, TVD or DLS.The other

parameters in the curve will be computed.

Project Ahead

Click the Project Ahead button to access the Project To dialog.

Project ahead is the process of looking forward from the current bit

depth to see if the path is heading towards the target. If the Wellbore is

not on course, Project Ahead can be used to determine the correction

necessary to get back on the plan or to go directly to the target. The

projection is made from the last observation in the open survey, plus the

initial-hold length. Should stations be added to the survey, the projection

recalculates from the end of these stations. If anticollision is being used,



then the projection will be included in the anti-collision scan.The results

are for information only, and are not added to the plan.

Applied Walk Rates

With non-controllable rotary BHAs and rock bits, there is a tendency for

the hole azimuth to drift to the right (and sometimes the left); this is

known as ‘walk.’ After a few wells have been drilled in the area, you

should know roughly how much correction or lead azimuth to apply to

hit the target. Different amounts of walk are associated with different

formations, which can be defined by vertical depth.

Click Project to Target, Plan or Formation to

specify the required location and COMPASS

computes the trajectory changes using one of

the trajectory types. If the current Wellbore has

a principal plan, the actions required to return

to the plan will be indicated. This will also work

for dipping formations.

Click User Defined Projection,

Curve Only to specify the

projection distance to a MD or

TVD as well as the curve rates

and COMPASS computes the

new location.

Select Target,

Formation, or Plan

to project to.

Click Calculate to calculate

the projection. The

Projection Steps will be

displayed.

Select the method

you want to use.

Refer to the online

help for more

information on the

methods.



If the wellpath is properly led, steering should not be required, as the

natural walk tendency brings the wellpath into the target. If walk is not

included in the design—that is, if the wellpath is planned as tangent

sections between targets—frequent steering could result as the well is

corrected to counteract the natural walk tendency.

To apply walk rates to a plan with straight sections defined:

1. Using one of the 2D planning tools for Slant or S-Well, plan to one

target that has been created in the target editor.

2. Click in the toolbar and enter a number of walk rates in the

grid, and the TVD's where you anticipate the drift begins. Note that

a positive walk is to the right, negative walk is to the left.

3. Click OK or press ENTER to apply the walk rates. COMPASS

modifies the well plan by adding new sections at walk horizons and

uses the first target in the plan as the walk target. It only applies

walk to straight sections. Should you modify a walked plan using

another planning method, you won’t be able to restore the original

un-walked plan.

Enter the TVD of the start

of a known walk section.

This may correspond to a

formation top, change in

lithology, or entry into a

geological structure.



Using the Plan Optimiser

The Plan Optimiser is designed to help you optimize the plan geometry

for mechanical or anticollision conditions. It contains the means to cycle

various plan constraints and then run the trajectory through torque-drag

analysis. Each result is examined for the maximum torque, tension,

buckling, side force, and fatigue condition relative to the pipe limit for

this condition. The optimum solution can be based on your preference

or optimized to be the lowest stress condition meeting all of the criteria.

The mechanical results can be reported, graphed, or the trajectory fed

back into the current plan for anti-collision. The optimizer works on

most common plan types, though it is most useful for plans that have

dogleg/build rates and kick-off or hold sections. You can also choose to

vary drill string or BHA type and length.

Here are the plan methods that are supported:

� Kick-off depths, by tie-on depth or hold section.

� Slant Wells and S-Wells, where dogleg is specified.

� 3D Curve Hold (DT or BT) and Optimum align (by doglegs).

� Straight sections at end of the plan or final projections.

Other plan methods can be in the plan, but their chosen parameters are

not changed.

The first occurrence of the plan type is the one that is manipulated. For

example if a thread target method is chosen to hit multiple targets, then

it is the first Optimum-Align or Curve-Hold that is changed and the

others are not varied but are recalculated.

The grid is used to display one or a number of possible solutions when

you click Calculate. The grid is not available for edit, though there are

a number of actions available through the grid. Selecting a line loads the

parameters from that line into the plan, analyses it and updates the plan

and views. Pressing the top label button of a number column sorts the

list, showing the minimum first of this parameter. Pressing the top label

button of an error column (ER or Error Message) removes those lines

with errors from the list. It helps to do this before sorting.



Torque and Drag Calculations

The Torque Drag calculations used in this simulation are standard 'soft

string,' and have been optimized for speed. They are run at the sample

interval used for the plan survey; this is +/- 100' or shorter for more

severe doglegs. It is an approximation of the model used for

WELLPLAN for Windows, and should not be used as a substitute where

more accurate results are required. There are a number of differences:

� Tortuosity is introduced directly into the side force calculation

rather than changing the survey.

� Sinusoidal Buckling is computed using joint diameter for hole

clearance.

� Friction is split into radial (torque) and along hole (sliding)

components.

� Analysis includes overpull to determine maximum for stuck/jarring

loads.

The numbers for the torque, tension, fatigue, and buckle mean the

following:

Value = Tubular Load Limit / Actual Max Load.

So, if a column is selected, then the maximum value is listed at the top,

which is, in fact, best limit/load ratio. It reports the maximum value for

the load in the whole string for each of the four load cases. Numbers

greater than one mean the limit has not been reached by any actual load.

It is a bit like casing design safety factors. The following values could

be used for the numbers:

� Tension = Pipe tensile yield/Actual max tension

� Torque = Pipe joint make-up torque/Actual max torque

� Buckling = Pipe Critical Buckling Force/Actual Max pipe

compressive axial force

� Fatigue = Fatigue stress limit/Actual max bending stress 25000 psi

for DP, 18000 for HWDP and 13000 for casing or collars. The

bending stress is compensated for tension



Load Cases

This simulation uses five load cases to generate ranges of forces on the

drill string.

� On-bottom drilling/rotating using weight on bit and rotary torque.

The drilling case can include sliding friction when steering with a

motor.

� Off-bottom rotating the drill string with no bit weight and no bit

torque.

� Pick-up (pulling out of hole) uses +ve drag forces only and no

torque.

� Slack-off (running into hole) uses -ve drag forces only and no

torque.

� Overpull uses defined stuck-force plus +ve drag forces; It assumes

you are pulling pipe and encounter a resistance force at the bit (and

are not rotating).

Note: Compound Friction

These do not model compound friction, such as Top Drive rotating while running

pipe. If compound load analysis is required to model actual pipe angular velocity,

you should use WELLPLAN Torque/Drag software instead.



Plan Optimizer Editor

The following graphic depicts the Plan Optimizer Editor.

To start the Plan Optimiser a plan must be open. There is an associated

Plan Optimiser View that shows the torque-drag and side-force charts

for the current plan. Closing the plan gets rid of them all; closing the

optimiser closes itself and the optimiser view only.

Plan Editor Interaction

You may return to the plan editor and manipulate the plan when the Plan

Optimizer is active. To operate the plan optimizer, just calculate a plan

in the Plan Editor, then click the Optimizer button.

Results Grid displays

Torque/Drag and Cost

for different calculated

planned trajectories

within user-entered

planning constraints;

enables user to compare

results.

Torque/Drag ratios compare worst

case string load against string rating.

Can order plans from best to worst.Error Type column

details reason behind

plan row failure.

Error column flags

which plans fail

Torque/Drag or

A Single Plan trajectory can be

optimized within the ranges of

entered constraints in terms of

Costs, Mechanical Limitations or

Anti-Collision constraints.

A Number of Plans can be

calculated for each one of the

ranged parameters. Results for

all plans are then displayed in

the results grid.

Tabs enable user to

define precise or

range of values for

different types of

planning parameters.



Once the plan changes, the Optimizer will re-calculate torque-drag and

update the graphs (and give an error message if a mechanical constraint

is exceeded). When you close the Optimizer, you are given the option

"Do wish to update the plan with the optimized data?", select Yes if you

wish to modify the plan or No if you wish to retain the original plan and

discard the plan chosen by the Optimizer.

Data Context

The Optimiser data is saved in a file with the well so all optimizations

on the well uses the same data. The file is called W*.WOP where * is

the well number, and it is stored in the COMPASS\OUTPUT directory.

Using the Optimizer Tabs

There are eight tabs, containing a number of entry fields. Some tabs

have one or two Use Range check boxes indicating a parameter that can

be cycled or optimized. Depending on the plan methods used, some of

the options may not become available. Parameters that can be varied

have a minimum, maximum, and step field. The minimum field contains



the default value for this parameter if is not to be cycled, and is the

minimum value for the cycling range when the check box is set.

Profile Tab

The profiles tab contains the plan variables from the Plan Editor. In the

Optimizer you can select any number of these user-entered cells to run

a range through or optimize for.

Drill String Tab

The drill string tab is the entry point for the work string for the torque

drag & hydraulics analysis. You can enter up to six sections by name

and length. The catalog items are taken from the 'tubes.csv' file. There

are no entries for minor BHA items like bits, motors, jars, subs or

stabilizers.

Check the Use box to

indicate the associated

variable should be used

in range analysis.

Specify the range to be used

in the analysis.

Select Component from drop-

down list. Enter the components

from the top down.The total length of the

component section.

The top item has its

length computed from

the total depth of the

design, so there is no

need to be exact here.

The bit/shoe is

assumed to be at the

total depth.



Open Hole Tab

The open hole and cased hole tabs allow the setting of some of the hole

section conditions.

Cased Hole Tab

The cased hole tab allow the setting of conditions in cased hole.

Specify the depth of the bit; if this is set

to zero, the bit is assumed to be at the

TD of the plan.

The Hole Diameter is the

bit diameter.

Tortuosity is a measure of the

roughness of the hole when drilled,

in terms of dogleg severity.

Example values for open hole are

0.25 for hole drilled mainly rotating,

and 1.0 for hole drilled while

steering (in degrees/100' or 30m).

Friction Factor is the component of friction

affecting the torque and drag results. Example

values for oil-based mud is 0.21 and for water-

based mud, 0.29.

Use the Max Angle check box to define a

maximum allowable hole angle in this cased

hole (allows for borehole stability or running of

wireline tools.

Specify the depth of the casing

shoe. The location is interpolated

from the plan. If the casing depth is

zero, then the open hole values

are taken to surface.

Specify the inside

diameter of the casing.

Tortuosity is a measure of the

roughness of the casing in terms

of dogleg severity. Example

values for cased hole are 0.25 for

smooth hole, and 0.5 for rough

hole (in deg/100' or 30m).

Use the Max Angle check box to define a

maximum allowable hole angle in this cased hole

(allows for borehole stability or running of wireline

tools.

This is the component of friction affecting the

torque and drag results; the value is unitless.

Example values for oil-based mud is 0.17, for

water-based mud, 0.24, and for brine, 0.30.



Drilling Tab

This tab contains common drilling parameters for the simulations.

Cost Tab

These parameters are used in the time and cost estimates.

This is the assumed torque required to drive the bit

and/or mud motor. The Torque on Bit and Weight

on Bit parameters define the load acting on the

bottom of the string. These loads are used as the

starting conditions for the soft string Torque/Drag

calculations.

Mud Weight is the mud density of the

drilling fluid, assumed constant inside

and outside the pipe.

Overpull Weight is the allowable pulling

tension at the bit used to trip jars or free

stuck pipe. The overpull load condition is

usually the case for maximum tension and

includes the drag forces when pulling out of

hole.

Check Use Sliding Drilling to include

wellbore drag in the drilling load

case. Otherwise the string is set to

rotating and no string drag is

incurred. You will notice that buckling

becomes much less of a problem

when the string is rotating.

Enter the total flow area, PV, and YP of the bit

be used for determining hydraulic limits.

Operating Day Rate is the total cost

per day for this drilling rig, plus

services.

Production Casing Cost is the

cost of production casing for cased

hole section in terms of cost/length.

Liner Casing Cost is the cost of the

liner to complete the open hole

section in terms of cost/length.Enter rates of penetration for rotating or

steering for the vertical depths to be

encountered. This table is used to

determine time costs for drilling the

directional plan.



Limits Tab

Anti-Collision

Check this option to configure the analysis to determine whether

plans collide with offset wells. Define an anti-collision boundary

area around the planned wellbores by entering a minimum range

and depth ratio in terms of x/1000. This computation is only

possible if you have open an anti-collision graph (ladder, traveling

cylinder) with the required offset wells. Note that having a large

number of offset wells slows down the Optimiser.Tension Safety Factor

This is the allowance for torque or tension yield. For example, 1.25

is 80% of yield, or over-torquing. A value less than 1 is not

accepted.Side Force Limit

This is the threshold before it is assumed that tool joints cause

casing wear or keyseating. This constraint is optional; toggle on the

check box to use the constraint.Maximum number of trials

This is the maximum number of option combinations performed

when you click the Calculate button. This feature prevents the

Optimiser from spending a large amount of time computing several

thousand plans when you enter a wide range of combinations. If you

have a fast PC, you can set this value to as much as 2000, although

a value of 100-500 is more common.



Offsets Tab

The offsets tab allows for offset wells to be analyzed as redrill

candidates. Once an initial plan is designed, plans can be generated from

these offset wells using a sidetrack depth range specified in the grid.

When calculated, a list of the computed trajectories for each of the

offsets selected will be displayed in the results grid. These can then be

sorted by cost or any of the other engineering constraints to obtain the

best candidtate for re-entry.

Once the results are displayed in the grid, the desired plan can be

selected. If the optimizer is closed down with a plan selected, it will

create the plan in the new wellbore automatically and open it.

Wellbore

Displays the list of offset designs that were selected prior to

entering the wellpath optimizer.Use AC

Use the offset design for consideration anti-collision. These will

only be used if the anticollision limit was checked in the Limits tab.Use ST

Check this column for any offset design that will be considered as a

candidate for re-entry.ST min

Enter the minimum sidetrack depth for the offset wells selected as

re-entry candidtates.ST max

Enter the maximum sidetrack depth for the offset wells selected as

re-entry candidates.Step

Enter the sidetrack depth increment for which the plans will be

calculated between ST min and ST max.



Buttons and other Features

Calculate or Optimize?

Consider the difference between the Calculate and the Optimize

buttons:

� The Calculate button runs every possible scenario within each

range that has been chosen, and lists them in the Grid. Click on the

columns or lines and look into the Plan Editor or views to decide

which result is best. For instance, if the following are chosen: a

kick-off depth range of 1000 to 2000, at steps of 100 and a build

rate range of 1 to 2 deg/100 at a step of 0.1, then Calculate runs

11x11=121 simulations. There is a default limit on the number of

simulations in the Options tab, but it can be increased.

� The Minimize button, on the other hand, calculates only the best

possible solution. Its optimum criteria is the minimum of the four

limit ratios (i.e., the load case closest to the limit). It then chooses

the solution that, through all the ranges defined, has the maximum

limit (in other words, is the least loaded string). The optimized

solution allows a user to scan more variables at one time than the

Calculate option.’

Which you choose depends on how constrained the problem is. If the

sheet is completely clean, then the Optimiser is more useful. If the

drilling situation is fairly well defined, but can vary two or three options

(like KOP, DLS), then the Calculate option is adequate.

An additional consideration would be that the optimized solution hunts

using any variable within the Min/Max range without the step value,

while the Calculate option uses the step sizes.

Notepad

To access, click the button in the Optimizer toolbar to access

the Optimizer Notepad.

Takes the currently selected analysis and reports the torque/drag

results to Windows Notepad. This file is tab separated and can be

loaded into a spreadsheet for reporting. If no line is selected in the

results grid, then the contents of the grid are reported to the notepad.



The contents of the standard report are explained below.

• DEPTH - Measured depth of this point in the drill string

• PIPE# - Reference number of pipe section, (1=Collar, 2=BHA,

3=Pipe)

• HOLE# - Reference number of hole section, (1 = Cased, 2 =

Open hole)

• WBTRQ - Torque when drilling

• FHTRQ - Torque when rotating off bottom

• MAXTRQ - Make-up torque of pipe, used as limit

• WBWT - String weight/tension when drilling

• PUWT - Weight when picking-up

• SOWT - Weight when slacking-off

• FHWT - Free hanging weight (rotating off bottom)

• OPWT - Weight when pulling with overpull at the bit

• HELB - Helical Buckling limit

• WTMAX - Tension limit of tubular

• BSTR - Bending stress

• BMAX - Maximum bending stress (fatigue endurance limit)

• SFOR - Lateral side force (+is up and - is down/lowside)

• SFMAX - Limit on side force for keyseating/casing wear



Grid Manipulations

The grid is used to display one or a number of possible solutions when

Calculate is pressed. The grid is not available for edit, although there

are a number of actions available through the grid.

� Selecting a line loads the parameters from that line into the plan,

analyses it, and updates the plan and views.

� Pressing the top label button of a number column sorts the list

showing the minimum first of this parameter.

� Pressing the top label button of an error column (ER or Error

Message) removes those lines with errors from the list. It helps to

do this before sorting.

Grid Columns

The grid columns contain salient parameters for each run of the

analysis.

This

Parameter... Indicates...

ER Whether this analysis was successful. It shows a cross if an

error or failure has happened.

Error Type The type of error (geometry) or limit condition that has

been exceeded.

KOP The Depth of the kick-off from vertical or side-track.

DLS1 The Dogleg Severity of the first build/turn.

DLS2 The Dogleg Severity of the second build/turn.

Time The time needed for directional drilling this well.

Cost The cost incremental in the directional phase of this well.

Torque Maximum ratio value of make-up torque/string torque for

the pipe in this analysis.

Tension Maximum ratio value of yield tension/string tension for the

pipe in this analysis.

Buckle Maximum ratio value of helical buckling limit/string

compression for the pipe in this analysis.

Fatigue Maximum ratio value of fatigue limit/bending stress for the

pipe in this analysis (tension corrected).



Tubular Catalog

The tubular catalog used for the optimiser is called TUBES.CSV and is

located in the COMPASS\CONFIG directory. It can be loaded into a

spreadsheet and edited. The entries are grouped by type and listed within

each group in order of size, then yield strength. This order should be

maintained because the logic of the optimiser depends on it. The units

are API and not changeable. The file contains a number of columns as

follows:

� Name - used for the selection and reporting

� Pipe body outside diameter (in)

� Pipe body inside diameter (in)

� Tool Joint outside diameter (in)

� Pipe weight per length (actual) (lbf/ft)

� Tensile Yield strength (lbf)

� Make-up Torque (lbf.ft)

� Fatigue Strength (psi)

� Pipe Joint Length (ft)

� Tubular Type (1-4) 1= Drill Pipe, 2=Drill Collar, 3=HWDP,

4=Casing

� Material Type (1-4) 1= Steel, 2= Aluminium, 3=BeCu,

4=Titanium)

Drill String The Drill Pipe name from the catalog.

BHA Bottomhole assembly tubular type from the catalog.

Drill String The Drill Pipe name from the catalog.

BHA Bottomhole assembly tubular type from the catalog.

Start NS Surface location North coordinate.

Start EW Surface location East coordinate.

BHA Length Bottomhole assembly length.

Hold Length Length of the final hold section in the plan.

Tangent Angle The intermediate hold angle of the plan (2D plans).

Final Angle The angle of the plan at the target (2D plans).

This

Parameter... Indicates...



Plan Optimizer Viewer

The following graphic depicts the Plan Optimizer Graphics for extended

Build-Hold-Build-Hold Sub-Horizontal Plan:

The plan optimizer graph is a plot of the torque, tension, and side forces

on the currently selected plan. The Viewer appears when the Plan

Optimiser form is called from the Plan Editor. It can be closed without

closing the editor. The viewer is intended to provided a visual

representation of how close the currently selected plan is approaching

any mechanical constraints, such as contact force limit, API tensile

yield, or make up torque limit. This graph is not intended to be a

replacement for a full torque/drag analysis.

The Graphs

A view of torque drag results in graphical form is given when the

optimiser is open. It updates when any single analysis is run, or a line

is selected from the grid. There are three graphs; each single graph

can be altered by clicking in its axis area.

Measured Depth against Torque

This graph has a number of lines:



• On-bottom torque (blue)

• Off-bottom torque (green)

• Make-Up Torque limit (red)

Measured Depth against Tension/Compression

The tension graph has a number of lines:

• On Bottom Drilling (blue)

• Off Bottom Rotating (green)

• Pick -up weight

• Slack-off weight

• Overpull weight (yellow)

• Helical Buckling limit in compression (red)

• Pipe yield limit in tension (red)

Vertical Depth against Vertical Section with Side Force

Commonly known as the hairy wellpath plot, this graph is good for

visualizing the points in the wellbore profile where there is

maximum contact force. The strike marks indicate the side force per

tool joint. Marks on the lowside of the wellpath indicate gravity

forces. Marks on the highside of the wellpath indicate tension in

dogleg forces.

This graph includes:

• The wellpath vertical section line (yellow)

• Side forces adjacent to the wellpath (blue)

• Side force limit lines where requested (red)

• Wellpath labels every 1000' or 500m MD.

• A casing shoe marker to indicate the Last Casing depth.



The red side force limit lines can be turned on/off by choosing the

'use side force limit' in the Options tab of the Wellpath Optimiser.

Bubble View

This plot will display a bubble plot of the first two options checked

in the profile tab. The most useful application of this view is when

N/S and E/W coordinates are sensitized for a given target TVD. In

this case, the user can essentially created a drilling limits plot

showing the reachable area for a given TVD



Planning and Anti-Collision

The Anti-Collision module is designed to use the ‘active’ path as the

reference wellpath when performing an anti-collision scan against offset

wells. If a plan is open, the anti-collision module scans down the plan.

This is a very constructive feature, in that plans can be designed to

adhere to a company’s anti-collision policy as defined within Company

Setup. Changes to a planned trajectory automatically results in all anti-

collision graphs or wallplots being updated automatically. Any reports

that are open would need to be regenerated.

The following graphic depicts the 3D Proximity Graph with a planned

Sidetrack being scanned against an offset slant well:

The example above displays a planned sidetrack well scanning against

another wellpath in the same site. In this example there is a considerable

collision risk, so this sidetrack trajectory has to be changed in order for

the plan to be approved prior to drilling.



Planning Reports

Having designed a wellpath trajectory, an engineer must be able to

communicate that trajectory to other colleagues across disciplines in

order for it to be assessed. COMPASS provides a number of methods to

accomplish this, using Formatted Reports, hard copy output of the live

graphs or multi-sized wallplots, and user configurable export file

formats.

Planning Reports is accessed from the Planning menu if a Plan is open,

or from the main COMPASS toolbar .

The following graphic depicts the Planning Reports Window:

The Select Report area

contains a group of check

boxes that you select to filter

the list of reports that display

in the table.

The Reference Level area displays reference level

information that determines what reports are available

for selection.

Select (by highlighting) the

report you want.

Click:

Preview to preview the report on the screen.

File to generate the report to a file.

Print to print a hard copy of the report.



Planning Report Options

The Report Options dialog is displayed when you select the Preview,

File, or Print buttons on the Report dialog if the report contains survey

data.

If the Interpolate box is checked, the Interval field is

active and you can set the depth interval at which to

interpolate survey stations. Checking this box also

activates the Specify Depths by radio buttons, which

you can use to interpolate by MD or TVD.

Check the Range box to set a

specific depth range to be

included in the report. The From

and To fields become active, and

you enter a numeric value in

each to set the range.

Check Include station at end to

include the end station information.

Select the options you want included on the

report.


Chapter

Anti-Collision Module

Overview

The Anti-Collision module provides the most critical functionality in

COMPASS affecting drilling safety and operator costs.

� Safety in terms of collision avoidance and drilling close rules.

� Cost in terms of the potential risk of a wellpath interfering with one

or more offset wells, requiring decisions to be made on drilling or

production restrictions.

Results from the anti-collision module are used directly to make these

types of decisions.

Companies differ in their approach to anti-collision scanning. However,

COMPASS was designed to accommodate most commonly used

methods. Company anti-collision policy is usually set out in a corporate

drilling procedures manual. This may be your own company or a client.

COMPASS therefore sets anti-collision parameters at the Company

Setup level, which is typically locked and therefore protected from day-

to-day users.

COMPASS enables you to perform an anti-collision scan down any

open design, or survey, including project ahead sections constructed

from within the Survey or Plan Editors. The scan can be conducted

against any number of designs within the same well, site, or project.

Additionally the scan can be applied against nearby designs located in

other projects or companies. If used correctly, COMPASS is capable of

detecting a collision risk from a reference well, including all offset well

trajectories defined in the COMPASS database. Results are available on

a variety of plots and reports.

6

Chapter 6: Anti-Collision Module


Specifying AntiCollision Analysis Parameters

The COMPASS anti-collision module is defined by four concepts:

The Data Structure section of this manual described how the Company

Properties dialog is used within COMPASS to apply company anti-

collision policies so that all anti-collision results are consistent within

the same rules and assumptions defined by the chosen models. It is very

important that companies recognize the importance of ensuring that

COMPASS data is distributed to all sites with exactly the same

Company Properties, and that it is generally kept locked to prevent the

setups being changed.

Use File > Properties > Company > Properties > Anticollision tab to

specify the anticollision analysis properties.

This concept... Determines...

Error System How positional uncertainty is calculated

Scan Method How wellpath separation is calculated

Error Surface How separation factor is calculated

Warning Type What criteria is used to issue warnings

The Error System determines how the

positional uncertainty is calculated.

Refer to “Error Systems” on page 217.

The Error Surface determines how the

separation factor is calculated. Refer to

“Error Surfaces” on page 225.

The Warning Type

determines the

criteria used to

issue warnings.

Refer to “Warning

Types” on

page 224.

The Scan Method

determines how the

wellpath separation is

calculated. Refer to “Scan

Methods” on page 219.

This grid is used to define

a number of anticollision

warning criteria. The

columns and labels that

appear on this dialog

depend on which Warning

Type is chosen.



Error Systems

Prediction of wellpath location uncertainty is fundamental to safe and

cost-effective well design. Wellpath trajectory is only imperfectly

represented by survey measurement and trajectory calculations.

Because survey instruments are not 100% accurate, errors can occur in

calculated borehole trajectory. Uncertainty envelopes for wellpath

trajectory are calculated based on survey tool error models, and provide

the minimum standoff distance to prevent wellbore collisions.

Uncertainty estimates range from field-based rules of thumb to strict

analytical and statistical methods.

COMPASS uses the ISCWSA or Cone of Error survey tool error

models.

ISCWSA

The ISCWSA committee’s remit was to “produce and maintain

standards for the Industry relating to wellbore survey accuracy.” A

number of companies supplied resources (Anadrill, BP, BGS, Gyrodata,

Halliburton IKU, INTEQ, Landmark, Norsk Hydro, Saga, Scientific

Drilling, Shell, Sperry Sun, Sysdrill, Statoil, Tensor) but the main

working group was formed by BP, INTEQ, Statoil and Sysdrill.

The committee recognized that directional drilling requirements have

moved on from the 1970’s when the Systematic Ellipse model was

constructed. Modern needs require smaller geological targets to be hit,

often drilled in mature fields with a large number of nearby wellpaths.

The simplistic WdW model could not handle such strict requirements



and accurately model additional performance parameters measured

from vendor survey tools.

A number of other factors provided the incentive for an alternative

industry model to be developed:

• risk-based approaches to collision avoidance and target hitting

required positional uncertainty to be associated with confidence

levels, a term only implied with the WdW model

• changed relationships between operators, directional drilling,

and survey companies forced all parties to share information on

tool performance

Dynamic Number of Error Sources (Terms), each defined by: •Name e.g. Accelerometer Bias•Vector direction for error source

•Azimuth•Depth•Inclination•Lateral•Misalignment•Inertial•Bias

•Value error value for the source of error •Tie-On determines how an error source is tied onto sources:

•Random•Systematic•Well•Global

Formula weighting for each error term e.g. ASX

Range inclination range for error term

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• drilling and geoscience software enabled more sophisticated tool

error models to be incorporated, with results that could be

viewed in 3D earth model visualizations

• survey program designs to hit smaller drillers targets dictated by

tool error models and smaller geological targets

As described in the Survey Tool Editor section of this manual, the

ISCWSA committee designed a dynamic survey instrument error model

specifically for solid state magnetic instruments (e.g., MWD and EMS).

The resultant model is described in a paper published by H.Williamson

“Accuracy Prediction for Directional MWD” by Hugh Williamson as

SPE56702. Essentially, the model enables an operator or survey

contractor to define a dynamic number of parameters or error terms

appropriate for a survey instrument.

Cone or Error

This model assumes an error sphere around each survey observation.

The model is empirical and is based on field or test observation

comparisons of bottom hole positions computed from various

instruments. The size of the sphere is computed as follows.

Radius of sphere around previous observation + MD interval x survey

tool error coefficient / 1000.

The starting error around the wellbore is the well error plus the top

borehole radius. The survey tool error coefficient depends on the current

tool inclination and the values contained in the Inc/Error grid for that

survey tool.

Scan Methods

The purpose of an anti-collision scan is to calculate the distance from the

scanning point on a reference well to the ‘closest’ point on an offset

well. This distance is known as the center-to-center distance, or wellpath

separation. Different scan methods determine different separation

distances because each technique uses a different algorithm and may not

find the same closest point as another technique.

Four Scan Methods are available in COMPASS:

� Closest Approach 3D

� Traveling Cylinder

� Horizontal Plane



� Trav. Cylinder North

In the following explanations the reference wellpath is the wellpath

being planned, drilled or surveyed. You check the distance from the

reference wellpath to any number of offset wellpaths. COMPASS scans

down the reference wellpath at intervals defined in the Interpolation

Interval, and computes the distance to the offset wellpaths using one of

the following scan methods.

3D Closest Approach

At each MD interval on the reference wellpath, COMPASS computes

the distance to the closest point on the offset wellpath. At some scanning

depth on our reference wellpath, imagine an expanding spheroid. The

minimum separation occurs when the surface of the spheroid initially

touches the offset wellpath; separation is the radius of the spheroid.

Because the offset wellpath is now at a tangent to spheroid, the line of

closest approach is perpendicular to our offset wellpath.

The following graphics display the 3D Closest Approach Scan Method

(left) and the Traveling Cylinder method (right):

Traveling Cylinder

This scan method uses a plane perpendicular to the reference wellpath

and intercepting offset wellpaths as they cut through the plane. The

surface resembles a cylinder with the size of the maximum scan radius.

The traveling cylinders method computes distance from the offset

wellpath stations back to the reference wellpath. The benefit of this

Offset Well Reference Well

3D


Orthogona

l



method is that intercepts are detected even when the wellpaths are

approaching at a perpendicular. In this case, there may be more than one

point in the TC plane for the same depth on the reference.

Depths are interpolated on the offset wellpaths, resulting in irregular

depths on the reference wellpath. Therefore, the 3D anticollision view

and traveling cylinders depth slice option are not possible with this

method, because they rely on regular depths on the reference.

Trav Cylinder North

This scan method uses the same perpendicular plane as the Traveling

Cylinder scan method, but toolface orientation from reference to offset

is added to current Wellbore direction. The traveling cylinder plot is

oriented to Map North when the reference well is at low angles.

Toolface angle to an offset well is then reported as the angle from the

high-side of your current Wellbore + the azimuth of your current

Wellbore. This method avoids the confusion in the Traveling Cylinders

plot caused by large changes in toolface angle when kicking-off from

vertical.

Horizontal Plane

The Horizontal Plane scan method calculates the horizontal distance

from the reference wellpath to the offset wellpath. It is similar to the

traveling Cylinder method, except that the cylinder expands

horizontally irrespective of the wellbore direction. This method is not

recommended for horizontal wells that it might miss and directional

wells where it might provide late warnings, as when the well does

approach, it does so very quickly. It is in COMPASS, but don’t use it.



The following graphic displays the Horizontal Scan Method:

Comparing the Scan Methods

The most important difference in the methods is that they are all capable

of determining a different closest point. It is for this reason alone that

Scan Method should be defined within a company and locked, so that all

anti-collision results can be compared on the same basis.

The following diagram highlights the differences using the example

above. From the same reference well scan point, the different methods

have all found a different closest point, with different values of

calculated wellpath separation.


Horizontal



When comparing scan methods, assess the advantages and

disadvantages of each technique.

Traveling Cylinder Scan and Near-Perpendicular Intersections

The primary deficiency with the traditional traveling cylinder method is

that it can miss near perpendicular intersections if the scan interpolation

interval is large. The following graphic depicts the problem:

On the graph above, E4-S0 (right hand side) is the reference well being

scanned down. A2-S0 is the offset well. The graph displays a depth slice

that represents the orientation of the traveling cylinder at its scanning

point. As the traveling cylinder scans down E4-S0, it misses the nearby

A2-S0 well and finds a ‘closest point’ some distance up A2-S0 away

from the critical area. Even with the interpolation interval set at 25 ft.,

the A2-S0 well is missed entirely.

E4-S0 Reference Wellpath

A2-S0 Reference Wellpath

Scanning Point

Traveling Cylinder Scan calculated closest point from

E4-S0 scan point to A2-S0:

— C-C Separation = 4967.40 ft

— Ratio Factor = 47.57



Warning Types

When we scan a wellpath or plan against other wellpaths, we want the

program to report only those wellpaths that pose a collision risk. To

include wellpath positional uncertainty in the assessment of collision

risk, COMPASS can report separation factors or assess against risk-

based rules or depth ratios.

Error Ratio

Also known as ratio factor, error ratio is a value that includes center-to-

center separation and positional uncertainty, and can be modified to

include casing diameters.

The following graphic depicts the Error Ratio Method and Example

Results:

As described in Company Properties, COMPASS enables multiple ratio

factor warning levels to be defined, and a given warning or action to be

taken if such a level is exceeded. These warning levels appear in the

anti-collision report and in some of the anti-collision graphs in the form

of levels and color-shaded lines.

Error Ratio > 1

Error Ratio = 1

Error Ratio < 1



Depth Ratio

Will form an envelope about the wellbore representing the minimum

separation, with the ratio of depth increasing until Max Radius is

reached.

A ratio of 0.01 with a maximum radius of 10m means that the minimum

allowable separation would consist of a cone expanding at 10m per

1000m, reaching a maximum of 10m at 1000m from the start depth.

After 1000m MD, the minimum separation surface would represent a

cylinder about the wellpath.

Rules Based

Will use a probability of intercept to evaluate risk. A ratio of 0.01 means

there is one chance in 100 wells drilled of intercepting an offset

wellbore. The warning grid in Company Properties will contain all of

the possible rules that may be assigned to a wellpath. The first row in the

grid will be the company default rule. That means when a wellpath is

selected for anti-collision, this rule is automatically applied to that

wellpath. Other rules have to be assigned directly in the Offset Wells

dialog. A warning is given if the rule is determined to fail when

conducting the anti-collision scan.

Error Surfaces

When you select an error system, you define how wellpath position

uncertainty is calculated. When selecting a scan method, you define how

wellpath separation is computed. The error surface enables you to

choose how the radius of the error surface at the reference well scanning

point and the calculated closest point on the offset well are calculated.

The error surface choice allows the user to override the standard ellipse

to ellipse (default) ratio calculations in anti-collision, and instead uses

the largest dimension of error at a point to define a cone about the

wellpath. In most cases, this will be major axis of the ellipsoid. Using

the circular conic method is more conservative and produces lower ratio

values and hence more warnings. The separation factor calculation

includes the dimensions of the error ellipse for both reference and offset

wells. The three error surface choices are as follows:

� Elliptical Conic

� Circular Conic

� Combined Covariance



Elliptical Conic

The standard calculation of separation factor uses ellipse radius

intersections that are determined by projecting the error surface

ellipsoids onto the center-to-center plane calculated between the

reference well scanning station and its closest point on the offset well.

This method most accurately implements the survey tool error models,

because it uses the ellipsoid geometry and orientation as calculated by

the survey tool error coefficients along the course of the wellpath.

Because the center-to-center plane can intersect the error ellipsoid at any

direction from the wellpath, the resulting radius used in the separation

factor calculation ranges from the minimum dimension of the ellipse

(minor axis) to a maximum dimension (major axis). The ellipse also has

an intermediate axis with a magnitude somewhere between the minor

and major axis dimensions. Because the error radius varies in all

directions, the calculated separation factor is generally more optimistic

when compared against the Circular Conic method.

The following graphic depicts an Error Ellipse as Intersected by Center

to Center Plane:

Circular Conic

The circular conic method uses the largest dimension (major axis) of the

error ellipsoid to define a spheroid about the wellpath. Projected down

the wellpath, this becomes a cone. Using the circular conic method is

always most conservative, because it uses the largest dimension of the



ellipse and therefore produces lower ratio values and hence more

warnings.

In mature areas, some companies design wellpaths by applying the

circular conic method, if possible. Should a well trajectory prove

impossible to design safely using separation factors calculated by

circular conic, the operator can then use the elliptical conic method to

evaluate how the revised separation factors meet their close rules policy.

Should elliptical conic prove safe, the operator might then decide to go

ahead and drill that plan.

The following graphic depicts a Circular Conic Error Surface:

Combined Covariance

This method combines the errors on the reference and offset by

covariance addition before any distance calculations are performed. The

error distance is then computed by the elliptical conic method on the

resulting single ellipsoid. Where Casings are included the radii are

subtracted from the center to center distance. The separation factor

derived from the combined covariance technique can be directly

R1R2

C-C Pla

ne

Major

Major

Spheroidal Projection based on Major Dimension of Error Surface Ellipsoid



correlated to collision risk as it represents the standard deviation value

for the ‘tail of the probability distribution’.

Including Casings

Casing dimensions can be modelled within the anti-collision radii. You

define these in the Casing Editor in order for the Anti-Collision

calculations to recognize them. The effect of including casings is to

reduce the center-to-center distance by the sum of the offset and

reference well casing radii. This models edge-to-edge distance (metal to

metal) of the casings in the calculation of separation factor. This method

assumes that casing is centered in the wellbore.

The following graphic depicts the Effect of Casings on Calculated

center-to-center Distance:

With Casing Radii

Centre to Centre Distance

Without Casing Radii

7” Liner9-5/8” Casing

12-1/4” OH 8-1/2” OH



Selecting Offset Designs for Anticollision Analysis

Anti-collision functionality is available under the Anti-Collision menu.

Having defined what calculation methods are used within a Company to

perform anti-collision scans down a design, survey, or project ahead

section, you next select a group of Offset Designs to scan against. Then

configure the scan using the Interpolation Interval dialog. When

performing a scan, the calculated results are available in a number of

graphs and reports.

Anti-Collision Offset Designs

To access the Anti-Collision Offset Well Selector use View > Offset

Designs or click the button on the toolbar.

In this dialog, you use a Tree Control to select offset designs. Each level

in the hierarchy (site, well, wellbore, design) has a checkbox. If a higher

level than Design is checked, all designs belonging to that level are

included.

Designs are included in the choice list to allow multiple offset tracks per

wellbore (i.e. planned and actual).



The following graphic depicts the Offset Design Selection dialog.

Filtering

To perform a rigorous anti-collision scan, you select all wellpaths in the

current field and produce a Ladder plot or Anti-collision Report.

However, on large, multiple-site fields this can take some time to

process. A less precise but quicker and thorough method is to use the

filtering tools to pre-select only those wellpaths within a certain range

of your current wellpath.

You can filter on filtered wellpaths. For example, you can select all

wells of type PRODUCER by clicking Scan All. You can then select all

Use the Filtering options to include designs from

sites within other Projects and/or Companies

within the plot, assuming the same geodetic

system and datum is used.

Filter by

Type or

Range

enables user

to restrict

offset wells to

those of

certain types

and/or within

a given range

of current

wellpath.

Specify type

using File >

Properties >

Company >

Properties >

Wellbore

Types.

Site, Well &

Wellbore Lists

enables user to

manually select

which designs

from current

Project appear in

plot. The user can

select individual

wellbores, all

wellbores within a

well, or all

wellbores within a

site. The

technique is

simple: click on a

wellbore, well or

site to select/de-

select.

The Additional Surveys list display the surveys

contained in the current reference wellbore. You can

add surveys to the offset design list by checking the

boxes associated with each item. The chosen surveys

appear in graphs and reports.

Check Save selection to DB

to save the offset design list

with the Design.



Producers in a range by entering a range and initial distance from

wellpath origin and clicking Scan Selected.

Specifying Anticollision Interpolation Intervals and Other Settings

The Anticollision > Settings dialog is used to set the anti-collision

interpolation interval type and the method for limiting results by

separation or ratio factor. The interpolation settings are used for all anti-

collision calculations, and also for the error ellipse report. Refer to the

online help for more information on this dialog.

Note: Filtering does not perform an anti-collision scan.

Filtering does not perform an Anti-collision Scan, it helps you select wellpaths against which to scan.

Check the Interpolate check box to interpolate

the reference Wellbore for anticollision. If

interpolate is not selected, the survey stations in

the reference Wellbore (plan or survey) are

used.

Use Scan Radius and Separation Factor to limit

the offset Wellbore data that appears in the plots and

the scan report.

Range is used to limit the depth range or the

reference design that is used for anticollision

scanning.



Analyzing Results

Using Live Graphs

Live graphics are available to an engineer to assess anti-collision risk.

These graphs may be used concurrently so that a user can assess risk

from different perspectives. These graphs are termed ‘live’ because they

will update if any survey data or plan trajectories change.

Using the Live Graph Toolbar Buttons

The following is a list of the anticollision live graph toolbar buttons that

provide additional functionality to help assess any collision risk:

Click... To...

Graph Options: Access the Graph Options Tabs to

configure graphs and plots.

Toggle Axis Labels: Turn on or off Axis labels. This

includes the tick mark labels.

Toggle Data Labels: Turn on or off Data labels. These

include labels for depths, targets, casings, formations,

etc.

Toggle Horizontal Boundaries: Label planning

change points and project horizontal dotted line to axis

indicating point of change.

Toggle Vertical Boundaries: Label planning change

points and project vertical dotted line to axis indicating

point of change.

Toggle Targets: Show or hide targets.

Toggle Project Targets: Show the project targets. Must

have the toggled.



Toggle Cross: Show the local point of the view. This is

also the point of rotation.

Toggle Wellbore Center: As you move along the

Wellbore, re-center the view.

Well Labels: Toggle well labels on or off.

Depth Labels: Toggle depth labels on or off.

Grid Lines: Toggle background grid lines on or off.

Casing Shoes: Turn casing points on and off. Casing

points are displayed as casing shoes on section and plan

views, and as casing tunnels on template and spider

views.

Ellipses: Plot ellipses of uncertainty on wellbores. The

ellipsoid of uncertainty is projected into the viewing

plane.

Symbols: Turn symbols on and off.

Templates: Turn on Template slots.

Rescale Axis: Rescale axis provides an expanding box

to use to select a portion of the graph. Refer to the

online help for more detail.

Zoom: Zoom in or out on the plot.

Print: Print to printer or plotter.

Click... To...



Show Offset Designs: Include additional wells on the

plot.

Close: Close the graphic view.

Pedal: (Travelling Cylinder Plots) Show no-go areas.

The no go area is the combined ellipse size plus

additional criteria like casings. The shape may resemble

a dumbbell and is known as the pedal curve about the

combined ellipse shapes.

Shadows: (Travelling Cylinder Plots) Show error

shadows. The shadow is a line surrounding several no-

go areas for the color depth band defined in

Interpolation Setup.

Error Bars: (Ladder Plots) Click this button, and the

error bars show the edge to edge separation. The length

of the error bars is the sum of the error around current

and offset Wellbores. The distance from the bottom of

the error bars to the X-axis represents the edge to edge

distance.

Magnetic Equivalent Distance: (Ladder Plots) Show

the Magnetic Equivalent Distance. This distance is the

inverse square sum of the distances to all of the ‘drilled’

(not planned) wellbores. The line represents total

magnetic effect of several adjacent casings, as a single

distance to one cased wellbore.

Ratio Warning Levels: (Travelling Cylinder Plots,

Separation Factor Plots and Ladder Plots.)Turn off or

on the lines indicating ratio warning levels.

Depth Slice: The depth slice button will activate the

interactive travelling cylinder view.

Depth Plane: (3D Proximity View) Displays a

proximity plane at the current scan depth. The depth

plane is shown as a disc perpendicular to the reference

with the scan radius. The closest positions on the offset

Wellbores are shown as cross hairs in the well’s color.

Curtain Axis: (3D Views) Replace the north and east

walls with a vertical grid that follows the trajectory of

the Wellbore. The curtain will illustrate wells with large

changes in azimuth.

Click... To...



When performing an anti-collision scan, COMPASS uses the current

design’s wellpath as the reference wellpath. If a plan, survey, or project-

ahead section is open, the anti-collision module uses that instead of the

current design wellpath.

Example Anti-Collision Analysis

To describe the Anti-Collision graphics in this section of the manual, a

planned sidetrack wellpath A1-S2 designed to launch from the parent

wellpath A1-S0 at 4300 ft MD is used as an example. Note that for

actual use, COMPASS can scan any design, survey, or project ahead

section.

The plan is shown in the next diagram highlighted in green with plan

section boundaries projected vertically and horizontally. Shadows are

turned on to display where the plan launches from the parent wellpath.

If you observe the shadows, you can see where the sidetrack departs

from the parent on the horizontal and vertical projections.

All offset wells included in the scan are also portrayed. The offset wells

are located in two sites: Alpha and Echo.

Set Center: (3D Views) Use the mouse to place the

zoom center at the point on the Wellbore.

Click... To...



The following 3D View displays a planned sidetrack (A1-S2) and offset

wells from two sites, Alpha and Echo:

Spider View

One of the traditional anti-collision graph types, a Spider Plot is a plan

view of a number of wells. Traditionally, a spider plot was easily hand

drawn by the directional driller or operations engineer as survey data

came in with measured and true vertical depths drawn adjacent to the

plotted wellpath trajectory. The spider plot displays wellpaths with East

(X-axis) against North (Y-axis).

There are two types of Spider Plot:

� Spider View—Local, which shows the data using local coordinates.

� Spider View—Map, which shows the data using map (grid)

coordinates.

Because it only portrays the horizontal projection of the wellpaths, it is

difficult to visually assess anti-collision risk, except perhaps if the TVD

labels are turned on where you might be able to see two wellpaths cross

or approach at a similar TVD.

AlphaEcho



Viewing Casing Tunnels

If you turn on casings in the Spider and Template views, a

tunnel is drawn down the wellpath. The diameter of the tunnel is

dependent on the diameter column being filled in on the Casing

editor.

Note: Helpful Hints

• Always turn on errors to assess lateral uncertainty.

• You can use the Line Data Reader to assess TVD proximity for nearby or

overlapping wells.



The following diagram depicts a Spider View of the planned sidetrack

well within the Alpha site in the Sample Field:

The above example shows that the planned sidetrack (A1-S2P1 in

middle) crosses the A2-S0 wellpath and approaches E4-S0. From this

simple view you can assess that A2-S0 and E4-S0 are the only wellpaths

that pose a collision risk.

The insert graphic displays just the area about the sidetrack wellpath.

TVD labels are turned on, which show that the offset wellpaths are

nearby in terms of TVD with both offset wells crossing between 5500ft

and 6000ft TVD.

Ladder View

The Ladder View plots Measured Depth of the reference well against

calculated center-to-center separation of one or more offset wells. You

use this graph to assess the true anti-collision risk of an offset well and

display center-to-center distance, magnetic interference equivalent

distance, error surface magnitudes, and ratio factor warning levels.

Sample - AlphaAll depths referenced to Sample Alpha DFE 150.0ft

West(-)/East(+) [ft]

South(-)/North(+) [ft]

-8000

-8000

-6000

-6000

-4000

-4000

-2000

-2000

0

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12000

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16000

-6000 -6000

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-2000 -2000

0 0

2000 2000

4000 4000

6000 6000

8000 8000

E4 (E4-S0) A2 (A2-S0)

C3 (C3-S0)

C5 (C5-S0)

B2 (B2-S2)B2 (B2-S1)B2 (B2-S0)

A1 (A1-S0)

E7 (E7S2)

E7 (E7S0)

E5 (E5S0)

E6 (E6S0)

E9 (E9S0)

E1 (E1S0)

A1-S2

A1-S2P1

EchoAlpha

Planned Sidetrack Well

Sample - AlphaAll depths referenced to Sample Alpha DFE 150.0ft

West(-)/East(+) [ft]

South(-)/North(+) [ft]

0

0

200

200

400

400

600

600

800

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1000

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-1000 -1000

-800 -800

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-200 -200

0 0

200 200

400 400

600 600

800 800

1000 1000

1200 1200

1400 1400

1600 1600

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4000

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60006500 7000

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40004500500055006000

6500

7000

40004500500055006000

6500

7000

45005000550060004000

4500

5000

5500

Planned Sidetrack Well



To set up a Ladder Plot:

1. Set the Anti-collision scan limit and the Depth range, both of which

are defined in the AntiCollision Setup dialog. The scan limit sets the

maximum value on the Y separation axis.

2. Select the designs for inclusion in Offset Designs.

3. Start the Ladder Plot.

Optionally

• To change the scaling area of the graph click Graphics Options.

• Select the scan method defined in Company Properties (usually

defined by Company Policy).

The following is a list of the graph toolbar icons for the ladder view

that are commonly used to help assess any collision risk:

Click... To...

Display uncertainty ellipse magnitudes (R1 + R2) relative

to each wellpath.

Color wellpaths with appropriate ratio factor warnings.

Display Equivalent Magnetic Distance of casing in offset

wells.

Use mouse to read wellpath name,

center-to-center separation, etc.

Access Graphics Options dialog to change Y-axis scale.

Note: Helpful Hints

• Always plot error bars to assess collision risk. Horizontal wells can have a

very large lateral uncertainty.

• Use the Line Data Reader to determine the exact closest point.

• Try limiting your Scan Limits in the Interpolation Interval dialog to more

accurately assess critical areas.



The following Ladder Plot displays calculated separation of all offset

wells located in the Alpha and Echo Sites. The Echo wells are those that

come in from the top-left of the plot:

The above plot displays the center-to-center separation relative to the

planned sidetrack wellpath (A1-S2P1). The plan itself is not visible; it is

plotted along the X-axis. From this graph we can see that three offset

wells require investigation:

� the wellpath that departs from the X-axis at 4600 ft

� the wellpath that approached at 6300 ft

� the wellpath that approaches at 7600 ft

All other wellpaths scanned against can be discounted as anti-collision

risks using this graph, as they don’t approach the sidetrack, and if you

include error surface magnitudes, there is no overlap of the error

surfaces against the X-axis. The wellpaths that interfere are A1-S0, the

parent wellpath, A2-S0, and E4-S0 as seen in the Spider View on the

A1-S2 plan. A1-S0 at 4600 ft displays where the sidetrack launches

from the parent, so it poses no anti-collision risk.

The graph above has error bars turned on for each wellpath. These error

bars plot the sum of the uncertainty ellipses of both the plan and each

offset well (R1 + R2), assuming the error surface selected in Company

Properties (Elliptical Conic/Circular Conic). The reason why the

planned sidetrack wellpath has no error bars plotted along the X-axis is

because its own error surface magnitude (R1) changes for each offset

Plan: A1-S2P1 (A1/A1-S2)

Measured Depth [ft]

Centre to Centre Separation [ft]

4400 4600 4800 5000 5200 5400 5600 5800 6000 6200 6400 6600 6800 7000 7200 7400 7600 7800 8000

0

1000

2000

3000

4000

5000

6000

7000

8000

A2-S0E4-S0



well. So, R1 error magnitudes are included in the error bars plotted

against each offset wellpath.

In this example, the Ladder and Spider Views enable an engineer to

determine that the only wellpaths that pose any form of anti-collision

risk are A2-S0 and E4-S0. You can use the Anti-Collision Offset Wells

tool to turn off all other wellpaths in the anti-collision scan.

The following graphic depicts a Ladder View displaying A2-S0 and E-

S0 collision risk:

The above ladder graph displays the collision risk determined for A2-S0

and E4-S0 wellpaths. The other wellpaths in the Alpha and Echo sites

are turned off using the Offset Designs tool.

Highlights are added that display the line data reader results for the

closest points. The wellpaths themselves are shaded blue, green, and red

to display warning factors. Both wellpaths have reasonable separation

(152.68 and 155.81 ft) at the calculated closest point; however, with the

error bars turned on, you can see that the planned sidetrack well error

surface overlaps on both wellpaths. This occurs where the error bars

intersect the X-axis.

Over this area, the calculated separation factor is less than 1.00, which

means that within the accuracy of the survey tools, you cannot tell if the


Measured Depth [ft]

Centre to Centre Separation [ft]

5400 5600 5800 6000 6200 6400 6600 6800 7000 7200 7400 7600 7800

0

100

200

300

400

500

600

700

800

900

A2-S0: X: 6200.00 MD: 5964.02 INC: 49.23 AZ: 79.02

Y: 152.68 TVD: 5290.24 N/S: 510.63 E/W: 1942.96

E4-S0: X: 7625.00 MD: 7717.06 INC: 49.76 AZ: 268.10

Y: 155.81 TVD: 5766.78 N/S: 533.97 E/W: 3270.81



wellpaths are going to collide or not. This is an unsafe situation. The

only solution here would be to redesign the planned sidetrack trajectory.

Equivalent Magnetic Distance

The Equivalent Magnetic Distance is a broad red line drawn on the

ladder view to show the combined magnetic effect of multiple casing

strings on the current plan. This line may be selected from the options

tab in the Graph Options, or from the Tool Bar icon.

The Equivalent Magnetic Distance line shows where the well plan

passes close to existing wells, and hence where magnetic interference

from casing can be expected. It is useful in survey program design, when

determining where to plan the switch from gyroscopic to magnetic

single shots. A simple rule of thumb is if the magnetic equivalent

distance is less than 50ft, then gyro survey tools should be used.

The scan differentiates drilled wells from planned wells by the status of

the survey program; only those wells with real surveys are assumed

drilled. Note that a program which consists of a planned section tied to

real surveys will have status planned, and will not be included in the

scan, even over the depth interval covered by the real surveys.

Additionally only the part of the wellpath deeper than the sidetrack

depth is included in the scan.

The perpendicular distance to all neighboring drilled wells is calculated

at intervals down the planned well. The combined magnetic effect of all

casing strings is then expressed as an Equivalent Distance to a single

casing string (using the inverse-square law for magnetic fields). For

example, if there are four casing strings at 18, 22, 25 and 27 meters

distance, their combined magnetic interference would be equivalent to a

single string at a little over 11 meters distance. The algorithm does not

consider casing diameters.

Separation Factor View

The Separation Factor View plots measured depth of the referenced

wellpath against the Separation Factor with the offset wellpaths. The

plot automatically plots the warning levels as defined within Company

Setup. This enables a quick review of the separation factor against

warning levels defined as company policy.

It can also be a very effective first place to look to determine the anti-

collision risk associated with an offset well. The only drawback, when



compared to the Ladder View, is that you cannot determine the center-

to-center separation.

The example below shows the same conclusions that were determined

using the Ladder View. Both wellpaths are unsafe, with ratio factors

dipping below the lowest safe level ‘STOP DRILLING NOW’.

Reduced Error Bars with Depth

With the elliptical conic method, it is possible to observe declining

combined error surface magnitudes with depth seen most prominently

on the ladder and ratio factor views. This can be observed in the above

ladder graph for A2-S0 from 6400 ft to 6850 ft, where R1 + R2 can be

seen to reduce, and on the ratio factor view where it increased over the

same depth range before reducing again from 6900ft.

Note: Helpful Hints

• Use Graphics Options to change the vertical axis scale using Fixed Range to

something reasonable if using Scan Radius to limit results.

Separation


Measured Depth [ft]

Ratio Factor

5400 5600 5800 6000 6200 6400 6600 6800 7000 7200 7400 7600 7800

0.0

1.0

2.0

3.0

4.0

5.0

STOP DRILLING NOW

Shut-in producers

Advise and Monitor



This phenomena is not an error, and is due to the relative orientation of

the reference wellpath (our plan in this example) and/or offset wellpath

ellipsoids with increased depth. The reduced error bars occur when the

center-to-center plane changes orientation, about one or both of the

ellipsoids from intersecting from a large axis to a relatively smaller axis.

The following diagram depicts this situation:

Traveling Cylinder View

One of the traditional anti-collision plot types, the Traveling Cylinder

plot shows the polar positions of offset wells relative to the reference

wellpath center. This is the distance to the offset well at an angle that is

either measured from wellbore high side (toolface) of the reference

wellpath, or North (azimuth only when using Horizontal plane scan

method). The largest radius of the plot is the scan limit, and the distance

scale is displayed to the left of the graph. The interpolated labels on the

Reference

Wellpath

Measured Depth

R1 + R

2

Offset

Wellpath

A

B

C

D

E

F

G

H

I

KJ

Centre-C

entre Pl

ane

AB

CD E

F

G

HI

J K

Error Surface Intersection

TD

TD

Centre-Centre Plane intersects

(R2) through major axis then

around to minor axis of ellipse.

R2

R1



traces are the measured depth of the points on the reference wellpath, not

the offset wellpath.

To set up a Traveling Cylinder Plot

1. Define the interpolation frequency and range limit in AntiCollision

Settings.

2. Select the wellpaths for inclusion in Offset Designs.

Optionally

3. Select the scan method defined in Company Setup (usually

company policy).

To determine the distance between the reference wellpath and an offset

wellpath at a given depth, follow the trace of the offset well until you

find the MD you require. Measure the distance from the center of the

plot to this point. That is the distance between the reference wellpath and

the offset wellpath at that MD on the reference well. The line data reader

is useful for determining separation.

If the offset well point is along the 180 degree line the offset wellpath is

below your reference wellpath and if along the 0 degree line the offset

wellpath is above your reference wellpath. Any other direction and the

offset well is off to the left or right as you look down the well. The 90-

270 degree line separates offset well positions that are above the

reference wellpath or below, assuming a wellbore reference.

Note: Helpful Hints

• The reference wellpath is never shown on the traveling cylinder view; it is

assumed to plot in the center of the graph.

• The center-to-center separation shown on the traveling cylinder graph is

applicable for the configured scan method. Therefore, the traveling cylinder

graph is available for all scanning methods, not just the traveling cylinder

scan method. Do not confuse the traveling cylinder graph with the traveling

cylinder scan.



Here’s a list of the toolbar icons that are commonly used to assess

collision risk for the traveling cylinder view:

Click... To...

Toggle error ‘pedal’ surface on/off

Toggle error shadows on/off

Color wellpaths with appropriate ratio factor warnings.

Display MD labels along Wellpath. Depths are for the

reference wellpath.

Display offset Well labels at end of Wellpath.

Interactively traveling cylinder view or depth slice, used

to manually scan down the reference wellpath.

Use the mouse to read wellpath name, center-center

separation, etc.

Access Graphics Options dialog to customize plot.

Note: Helpful Hints

• Turning on Well and depth labels while in interactive mode enables you to

maintain a reference.

• Color shading provides a quick way to see where the critical intervals are

along each offset wellpath.

• If you don't see depth labels on the plot, you can set a labelling exclusion zone

(see Graphics Options).



The following graphic depicts a Traveling Cylinder View with

Offset wellpath and error surface plotted:

The above graph refers to the A2-S0 wellpath of our example only,

E4-S0 has been turned off for clarity. The graph shows that the A2-S0

wellpath initially appears within our scan limit (10000 ft scan radius)

above and to the right of our reference well as it would appear as

looking down the reference well.

With increased depth, A2-S0 approaches to its closest point, whereby

the error surfaces are overlapping (ratio factor = 0.67). A2-S0 then

moves below our wellpath and moves from right to left.

The graph clearly displays the overlap of the combined (offset +

reference) pedal error surface with the origin of the plot. This indicates

an unsafe drilling condition; again, the sidetrack planned trajectory will

need to be re-designed and/or different survey programs planned or

conducted on the wellpaths to reduce the size of the error surface.

Pedal Curve Error Surface

The traveling cylinder plot provides a tool bar icon that enables a

statistically correct form of the combined error surface to be plotted

against the offset wellpaths. This error surface is known as a pedal

curve, also referred to as ‘footprint’, dumb-bell, or a peanut shape. This

Reference Toolface Angle [deg] vs Centre to Centre Separation [ft]

0

200

200

200

200

400

400

400

400

600

600

600

600

748

748

748

7480

30

60

90

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330

Colour To Depth5000550060006500700075008000

43004400

4500460047004800490050005100520053005400

550056005700

5800

5900

600061006200

6300

6400

6500

6600

67006800690070007100

72007300

74007500

76007700

78007900

Wellpath A2-S0 is above and to

the right.

This depth range here displays

overlap of the offset and

reference well ‘pedal’ curves.

Wellpath A2-S0 is now below

moving from right to left.



shape is different than all other graphics within COMPASS where an

ellipse(oid) or sphere(oid) is depicted.

The elliptical error surface is usually used to represent the positional

uncertainty of a point on a wellpath. This uncertainty can be described

mathematically using a 3D covariance matrix which describes the

mathematical derivation of the dimensions and orientation of the

ellipsoid:

where sigma n, e, and v refer to the uncertainty in an ‘earth centered’

frame of reference (north, east & vertical)

The radius of the error ellipse in any direction does not represent the

positional uncertainty in that direction. Restricting the formulae to

horizontal uncertainty, the expression to calculate positional uncertainty

for any azimuth A is:

The resultant shape of this surface is a pedal curve. This shape can be

drawn from the standard error ellipsoid by drawing tangent lines in all

directions from the ellipsoid origin, and then drawing a set of

perpendicular opposing lines connecting the first point of contact of the

line onto the ellipse.

The following graphic displays how a pedal curve can be constructed

from the systematic error ellipse:

3DCovarianceMatrix Cnev

( )=

σn2σne

σnv

σne

σe2σev

σnv

σev

σv2

=

σA Acos Asin

σn2σne

σne

σe2

Acos

Asinσn2

A2

cos σne

2Asin⋅ σe2

Asin⋅+ +⋅= =



The pedal curve is essentially the combined ellipse distance (extremity

to extremity) + in all directions. The traveling cylinder plot assumes that

you are not on the plan, and that you can approach the offset wells in any

direction. So the combined ellipse distance computed in old COMPASS

is only in one direction; with Pedal curves the no-go zones are

determined for all directions (i.e., 0-360) about the reference and drawn

on the offset. It’s a better representation of where you can go. Note that

other limits are combined in the no-go zones, such as casing diameters

and arbitrary limits like 10m, where configured. If you use risk-based

rules, then you are no longer comparing ellipses, and the pedal curve

routine can draw weird shapes like butterflies.

Interactive Traveling Cylinder View

The Depth Slice tool bar icon activates the interactive traveling

cylinder view. The view switches to show offset data for a single depth

on the reference wellpath. The same functionality is available within the

3D Proximity view.

Using the scroll bar at the right hand side of the plot, you can change the

measured depth to any point along the reference wellpath. Like the 3D

view, you can also use the keyboard control and Up, Down, Page Down,

Page Up, Home, and End buttons to move along the reference wellpath.

For each measured depth, COMPASS plots the range and orientation

from high-side to the offset wells. In the bottom window, the wellpath

center-to-center distance and separation factor are displayed for each

offset wellpath. At any depth, if the ratio factor falls below one of the

company warning levels, that warning also appears.

Standard Error Ellipse

Pedal Error Surface



The circle/ellipse around the offset well and reference wells represent

the error ellipse’s geometry at the current scan depth.

The following graphic depicts a Traveling Cylinder Depth Slice with

Projected Ellipse Extents:

The above example displays the interactive view with the depth set to

6850 ft on the reference well. The position of the calculated closest point

on A2-S0 is shown with its uncertainty ellipse at the depth.

The uncertainty ellipse of the reference well at 6850 ft is also shown

projected about the origin. Note that even though the ratio factor is less

than 1 (0.67), the ellipses do not appear to overlap. This is because the

ellipses are displayed using the wellpath frame of reference. If you plot

the center-to-center plane and then project those ellipses onto the center-

to-center plane, you can see (above) that the ellipses do overlap.

Offset Well Ellipse

A2-S0 @ 6850 ft

S.F. = 0.67

Centre-Centre Plane

Centre-Centre Plane

Reference Well Ellipse

Centre-Centre Plane

Reference Well Offset Well

Ellipse Projected Extent



3D Proximity View

The 3D Proximity View provides both a 3-dimensional graphic

representation of selected well paths and a tabulated list of anti-collision

results. The graph is essentially a 3D live graph with additional tools

useful for anti-collision assessment. For visual assessment, this graph is

very useful to quickly obtain a picture of what is happening relative to

the reference wellpath. For absolute anti-collision assessment, the

Ladder View and the Anti-Collision Report provide a quicker method

for determining risk.

To set up a 3D Proximity graph:

1. Set the interpolation depths and scan limit in the AntiCollision

Settings dialog box.

2. Select Offset Designs to be shown in the view.

3. Start the Graph by selecting it from the menu.

Here’s a list of the toolbar icons that are commonly used to assess

collision risk for the 3D Proximity view:

Interactive Scroll Bar

3D Proximity computes the distance between the reference wellpath

and selected offset wells for a given depth on the reference wellpath.

Use the vertical scroll bar at the side of the graphic to change the

reference wellpath depth. As you do so, the closest point on nearby

wells, marked with a cross, changes. The positions of these markers

can change for different scan methods.

Click... To...

Project a shadow of the wellpaths on to the horizontal and both

vertical planes.

Replace the north and east walls with a vertical grid.

Display the depth plane at the current depth.

Display an ellipse down each wellpath indicating the positional

error at each point.



The wellbore center-to-center distance and separation factor are

tabulated for each offset well. The maximum separation reported is set

in the AntiCollision Settings dialog box under anti-collision scan limit.

If no values are reported for a particular wellpath, this means that the

calculated results fall outside your scan limits.

Note: Helpful Hints

• Click and drag the left mouse button to rotate and tilt the 3D frame.

• Click and drag (up/down) the right mouse button to zoom in and out.

• Use the keyboard buttons to rotate, zoom, or step the wellpath point.

• To differentiate between wells, click on each wellpath name in the legend

box. The wellpath is highlighted on the graphic.

• To adjust the radius of the depth plane, use Anticollision Settings dialog and

change scan radius.

• Try not to rotate, zoom in and out too often, or too quickly. It is very easy to

become disoriented.



The following graphic depicts a 3-D Proximity View:

The above example portrays a planned sidetrack well (A1-S2) together

with the parent wellpath (A1-S0) and the offset wells A2-S0 and E4-S0.

Note that E4-S0 has been drilled from another site and so comes in from

the right. From this graph you can see that the planned sidetrack well

appears to have a close approach to both offset wellpaths. It also shows

that the E4-S0 error ellipsoid is much larger than the A2-S0 error

ellipsoid. Perhaps this anti-collision problem could be solved by

surveying E4-So with a more accurate survey tool? This confirms the

other diagnosis made using the other anti-collision graphics.

A1-S0 Parent

Wellpath

E4-S0 Offset Well

A1-S2 Planned

Sidetrack

E4-S0 Ellipsoid

A1-S2 Ellipsoid

A2-S0 Offset Well



Reports

Access the Report dialog by:

� Click the toolbar button.

� Use Anticollision > Reports

Ellipse Separation Report

The anti-collision report is a very quick and quantitative way to evaluate

collision risk for a number of offset wells. To generate this report,

COMPASS runs down the current well at intervals and calculates the

distance to each offset wellbore. The report consists of Page Header,

Report Header, Summary, and a Results section for each offset

wellbore.

Check the Anti-collision box to list the

anticollision reports. Uncheck all other boxes

to remove other types of reports from the list.

Reference Level displays

information that indicates what

reports are available.



To set up a data scan report:

1. Select Offset Designs for the scan.

2. Define the interpolation interval, range and scan limit in the

Anticollision Settings Dialog.

3. Start the Report; from the anti-collision menu select Anti-Collision

Reports, then from the list select Anti-Collision Report.

Definition of sections:

Page Header

Printed at the top of each page the page header contains the name of

the reference wellpath, date and time, and page number. Using

Report Setup under the Utilities menu, it can also be set up to display

Company and User logos.

Report Header

The report header shows the parameters setup in interpolation

interval and the error model and warning method that are defined in

Company Setup.

Summary

The summary section shows the point of minimum separation factor

between the reference and offset wellpaths. Because separation

factor considers the size of the wellpath error ellipsoid, the point of

minimum separation factor cannot coincide with the closest center-

to-center distance.

Results

The results section contains 11 columns:

Column... Description...

Reference MD and TVD Columns 1 and 2 show the measured depth and

true vertical depth of the point on the reference

wellpath. These depths are referenced to the

drilling datum on the reference wellpath.



Offset MD and TVD Columns 3 and 4 show the depth of the nearest

point on the offset wellpath from the point on

the reference. Note: The measured depth and

vertical depth on the offset wellpath are

referenced to the drilling datum of the offset

wellpath. The result depends on the Scan

Method selected.

Major Semi-Axis Error Ref.

and Offset

Columns 5 and 6 are the ellipse of uncertainty

major semi-axis dimensions of the reference

and offset wellpaths. When you scan with 3D

Closest Approach or Traveling Cylinder

separation, the error quoted is the maximum

"radius" of the error ellipsoid in a plane

perpendicular to the wellpath at that point.

When scanned by Horizontal Plane, the error is

the radius of the ellipsoid in a horizontal plane.

The size of the error depends upon surface

errors and survey tools assigned the current

and any parent wellpaths.

Orientation: AZI, TFO (HS)

or TFO+AZI

Orientation to set the reference wellpath to

move towards the nearest point on the offset

wellpath. The angle displayed will depend on

the anti-collision method chosen for this

Company.

Closest Approach – TFO (HS) High-side

toolface angle.

Horizontal Plane – AZI – Azimuth angle from

reference point to offset well at the same

vertical depth.

Traveling Cylinder – TFO (HS) Highside

toolface in traveling cylinders plane.

Highside + Azimuth – TFO+AZI Toolface +

the current well azimuth.

*North and East North and East are the co-ordinates of the

offset well at the depth of interest as they

would appear in a Spider Plot. The co-

ordinates have been adjusted to the origin for

the reference well (Site or Slot).

Ctr to Ctr Distance Distance from the center of the reference

wellpath to the offset wellpath in the plane

defined by the anti-collision method.

*Edge To Edge Distance This is the distance from the edge of the error

ellipsoid around the reference wellpath to the

edge of the error ellipsoid around the offset

wellpath.




*The columns marked with an asterisk do not appear on ‘rules based’

reports and are substituted with the following:

Error Ellipse Report

The error ellipse report describes the geometry and orientation of the

uncertainty ellipse with depth along the reference design. The report is

a very useful way to assess how the ellipse geometry develops along the

design. The error ellipse is computed from parameters contained in the

survey tools assigned to the active design in the survey program editor.

*Separation Factor The separation factor at that point. See

warning method for a description of separation

factor. This column does not appear in ‘rules

based’ anti-collision.

Warning In company set-up you may enter text to be

printed on anticollision reports when a

separation factor threshold is passed. In ‘rules

based’ anti-collision, the warning ‘Passed’ or

‘Failed’ appears for the appropriate rule for

this wellpath.


No Go Area The No-Go Area appears on ‘rules based’ anti-

collision reports. It is the combined distance

from the offset wellpath that must not be

exceeded. It is the sum of the combined errors

(in the vector between the two wells), the

casing and hole radii and the tolerance radius

defined in the rule.

Casing Is the casing diameter on the offset well.

Allowable Deviation (from

plan)

This is the maximum distance that can be

drilled from the plan in the direction of the

offset wellpath. It is essentially the Ctr-Ctr

distance minus the No Go Area. In designing

the well plan, the allowable deviation value

should not be less than or equal to zero, or

there will be no room to drill the well.




To set up an ellipse survey report:

1. To generate an error ellipsoid around a wellpath, you must assign

tool codes to the design. To assign tool codes to an actual design, use

the Actual Design Properties dialog; to assign tool codes to a plan,

use the Plan Design Properties dialog.

2. State the interpolation interval, and range for the ellipse data in the

Anticollision Settings Dialog.

3. Start the Report, launch reports from the anti-collision menu and

then select Ellipse Survey Report from the available list.

Definition of Columns:

NOTE: Ellipse dimensions

All ellipse dimensions reported are half-axes or radii, and not diameters.

This column... Means this...

MD Measured depth

Incl Inclination

Azim Azimuth

TVD True vertical depth

Uncertainty The radius of the error envelope and its

confidence level is stated in standard

deviations from the mean, as noted in the

header of the report.

Bias The amount the ellipse center is displaced from

the center of the wellpath. Bias is caused by

error sources that have an unbalanced

distribution. For instance, magnetic surveys

often plot to the north of gyro surveys, due to

the earth’s magnetic field polarizing the

drillstring in a consistent direction.

High Side Uncertainty (cross

borehole plane)

Semi-axis error in position on the high side of

the hole (toolface 0/180).

High Side Bias Error in position lateral to wellbore.

Lateral Uncertainty Semi-axis value of error lateral to wellpath in

horizontal plane (toolface 90/270)



Lateral Bias Lateral Bias component for the ellipse relative

to the direction of the wellpath

Vertical Uncertainty Semi-axis value in the vertical direction from

the wellbore depth.

Vertical Bias Vertical Bias Component

Magnitude of Bias This is the total displacement of the ellipse

from the center of the borehole.

Semi Major Uncertainty This is the largest dimension of the ellipse.

Semi Minor Uncertainty Minor axis dimension

Semi Minor Azimuth The direction of the horizontal minor axis from

local north.

Tool Survey tool used to measure this survey

station.

This column... Means this...



The following graphic portrays parameters described within the Error

Ellipse Report:

Survey Bias

Survey Bias is the tendency for the most likely position of a wellpath, as

determined by the error model, to be different than its position as

calculated from survey data. This is demonstrated when the error model

calculates an error surface which is not centered about the wellpath

trajectory. For example, magnetic surveys tools can have azimuthal bias

due to a systematic effect of drillstring magnetization. Gyrocompass

error can occur due to gimballing effects.

The following graphic demonstrates this concept. The wellpath to the

left displays Wolff & de Wardt error ellipses which are centered on the

trajectory calculated from the displayed survey stations. The wellpath to

the right displays ISCWSA error ellipses, which are offset to the

calculated trajectory. A dotted line displays the ‘most likely trajectory’

which passes through the center of the ellipses, the solid line displays the

calculated trajectory. ‘Most likely’ is used as a description because the

Vertical Section View

in Borehole Azimuth

Plan View

TVD

East

V.SectionTVD

North

Vertical Unc.

Lateral Unc.

High

Side Bias

Semi-Minor Unc

Semi-Min.Azi

High Side Unc.

Lateral Unc.

High

Side Unc.X Borehole Plane =

Perpendicular to wellpath

vector at depth of interest

3 Dimensional View

Compass Error Ellipse Report

X Borehole

X BoreholeBias

Vertical Bias

Lateral Bias

Semi-Major

Unc.



error model is indicating that statistically the wellpath position would be

at the center of the error surface.

In COMPASS, Survey Bias is shown on all ellipse drawings; it’s just

that the ISCWSA model is the only error model in COMPASS that

generates bias errors, so it is not observed on Systematic Ellipse error

surfaces.

Systematic Ellipse Error Surface

ISCWSA Error Surface Displaying ‘Bias’

Calculated Trajectory

‘Most Likely’ Trajectory

Survey Bias

Survey Station


Chapter

Survey Module

Overview

The Survey module calculates drilled wellbore trajectories from entered

survey data using the company-specified survey calculation method,

such as Minimum Curvature. The module can be used to enter

traditional survey data (MD, Inc. & Azi), Inertial Survey data (TVD, N,

E), and Inclination Only survey data (MD, Inc.). Using an assigned

survey tool error model for each survey, the wellpath positional

uncertainty over the depth range of the survey can be calculated and

included in the actual wellpath, to be used in anti-collision calculations.

The main components of the Survey module are:

� Survey Properties

� Survey Import

� Survey Editor

� Project Ahead and Interpolate

� Quality Assessment tools

� Survey Analysis

� Survey Reports

� Survey Export

Properties is used to enter the survey tie-on point, and assign a survey

tool. The Editor lets you type in survey measurements, compute the

wellpath trajectory, project ahead from any point to a target location,

depth on a plan, or calculate a trend using existing survey data to a MD

or TVD. You can also interpolate points on the survey by either MD,

TVD, Inc., or Azi. Quality control tools enable a user to check for the

presence of errors in the data that can be immediately corrected.

Analysis tools enable you to create comparative T-Plot charts as well as

assess survey data quality using graphs or reports. Survey Reports let

you preview canned reports supplied with COMPASS. Export tools

enable survey data and almost all other data available within COMPASS

to be exported in a variety of user defined formats to a text file or the

Windows clipboard.

7

Chapter 7: Survey Module


Defining New Survey Properties

Before creating a new survey check the Status Box to ensure you are

entering the survey into the correct Company, Project, Site, Well, and

Wellbores.

To create a new survey, use one of the following two methods:

� From the menu bar select Survey > New Survey

� Right-click in the browser on the Wellbore or Design name and

select Insert Survey.

Naming and Specifying General Information About the Survey

The most important items in Survey Properties are the name, survey tool

and the tie-on point designation. An intuitive survey naming convention

should always be adopted and supported within a company so that

unfamiliar survey data can be easily recognized. Two good

recommendations are to include the hole size the survey tool was run in,

as well as the tool name itself. Examples of easily recognizable survey

names are:

� 12-1/4” Sperry-Sun MWD

� 9-5/8” Finder Gyro (0hr)

� 13-3/8” Keeper Gyro in Csg

� 26” Totco

You can also enter Description, Company, and Engineer details to

provide additional information about the survey, although this is not a

system requirement. Company and Engineer fields are populated

automatically with your name and Company name when a new survey

is created.



The following graphic depicts the Survey > Survey Properties >

General tab.

Note: Survey tool determines error radius during anticollision.

The survey tool you assign determines the error radius around the wellbore during

anticollision. If you do not specifically assign a toolcode, COMPASS will assign

the default survey toolcode to this survey.

Ensure that the survey is

given an intuitive name to

help other engineers

reference it.

To prevent

unauthorized

changes to the

Survey, lock it!

Inertial - Imported

surveys that do not get

re-calculated.

Inclination only

surveys (e.g.

TOTCO)- Surveys with

no azimuth column.

Specify the dates that the

survey began and ended.

Select the Survey

Tool from the drop-

down list. If the desired

tool is not listed, use

File > Properties >

Company > Survey

Tools to define the

tool you want to use.



Specifying the Tie-On Point

You can choose between three tie-on point methods. The tie-on point

can be defined explicitly, tied to the wellhead location, or calculated

based on a specified measured depth.

You may select a different survey to tie-on to from the drop-down list.

The start point (tie-line) items are as follows:

The three tie-on point methods are discussed below.

Note: Sidetracks...

If starting a sidetrack, you should create a new wellpath first.

This start point... Does this...

MD Starting measured depth for the survey.

Inc. Starting inclination from vertical. Vertical is

zero degrees.

Azi Starting direction from Local North.

TVD True vertical depth measured from the active

Datum.

N/S North distance from the local coordinate

center.

E/W East distance from the local coordinate center.

Tie the survey to the

wellhead, a user

defined point in space,

or to any depth along

another survey.



Specifying User Defined Tie-On Points

Type in the coordinates and depth of the start point. This is attaching the

survey to a free point in space. No checks are made to ensure the validity

of this tie-on point. It is assumed that you know why you are using this

method.

Specifying Tie-On Points From Wellhead

COMPASS will start the survey at the N/S E/W co-ordinates of the well

or the well reference point. You may still specify inclination and

azimuth should the start point be non-vertical.

Specifying Tie-On Points From Survey

Ties on to the last point on the selected survey by default. You can

specify another measured depth to interpolate from within the survey.

User Defined - you may define all the

values of the tie-on point. Nothing is

calculated for this point.

From Survey - enter a MD from

within the Survey and

COMPASS will interpolate the

other values.



Validating Survey Data

Use the Validation tab to specify survey validation parameters. Refer to

“Input Validation” on page 281 for more information.

This is the average dogleg severity

over entire survey. This value may be

equated to tortuosity and is a

measure of the average roughness or

noise in the survey measurements.

When Input Validation is

checked, COMPASS examines

each survey to determine if that

survey observation results in a

dogleg greater than the Dogleg

Tolerance. The excessive

doglegs are displayed in red on

the Survey Editor.

Specify the maximum dogleg tolerance to

be used during input validation.



Managing Survey Data

The Survey Editor is essentially an enhanced spreadsheet with built-in

survey calculation functionality. The spreadsheet enables surveys to be

easily edited and viewed, and forms an area where additional tools can

be launched. If a survey editor is open, any live views highlight the

depth range of any survey data entered.

Some general rules apply to the Survey Editor:

� The first row, row 1, is the tie-in point that is defined in Survey

Properties and may not be changed in the survey editor.

� The current MD (Measured Depth) must be greater than the

preceding MD.

� Inc (Inclination) must be in the range 0-180 degrees.

� Azi (Azimuth) must be in the range 0-360 degrees.

Using the Survey Editor

The Survey Editor is the data entry grid for manually adding or editing

survey stations. Once you have entered or imported the survey, it is a

good practice to save it right away and then complete a Varying

Curvature scan to check for poor-quality surveys.

To access the Survey Editor, double-click on the survey name in the

Data Viewer portion of the Status Window. The Survey Editor is

automatically displayed when you create a new survey.



Interpolate the current

survey by MD, TVD,

Inc or Azi.

Use Project Ahead to project ahead to:

• see existing directional trend

• determine directional parameters to hit target

• perform back-on track calculations to plan

• perform look-ahead anti-collision

If you press Enter

without typing in a new

MD, COMPASS will

automatically increment

the MD. If you are

incrementing from the

first line the amount will

be 100 feet unless depth

units are meters in which

case it is 30m. If you are

incrementing from

subsequent lines, the

additional MD is

computed from the

previous two lines.

To delete a row, click on the

row number in the grid and

press the keyboard Delete

button. To insert a row,

highlight row above which you

want to insert and press the

keyboard Insert button.

When entering or editing inclination

only surveys the azimuth column is

not available. It is assumed zero and

the North and East co-ordinates are

computed to be vertical below the

start point.



Using the Survey Editor Tool Bar

The Survey Editor has a tool bar with the following functions:

� Save - Save the survey.

� Save As - Save the survey using a different name.

� Undo - Undo the last change.

� Redo - Reapply the last change.

� Survey Properties - Access the Survey Properties dialog. See

“New Survey (New Wellbore)” on page 117 for more information.

� Import - Import survey data. See “Importing Survey Data” on


� Interpolate - Use to interpolate surveys along the survey. See

“Interpolating Surveys” on page 271 for more information.

� Project Ahead - Determine if a path is on course to hit a target or

specific MD/TVD. See “Project Ahead” on page 273 for more

information.

� Survey Comments - Add comments or annotations to the survey.

Interpolating Surveys

Use the Point Interpolation dialog to determine the survey position and

vector for depths that do not coincide with survey station depths. You

can enter as many points as you require into the interpolation grid at a

time. If the entered depth is above the tie-on depth of the survey or plan

then the definitive survey will be interpolated. If the entered depth is

Save

As

Save

Survey Properties

Interpolate

Project

Ahead

Survey Comments

Close editor

Help

Undo and Redo

Import



below the end of the survey then a straight line is projected to that depth

beyond the end of the survey.

Results are available by clicking on the Notepad button at the bottom of

the window. This enables the interpolated results to be printed,

incorporated into another document via the Windows clipboard, faxed,

or emailed.

The following graphic depicts the Survey Point Interpolation Window.

The Interpolation algorithm used is determined from the Calculation

method specified in Company Properties > Calc Defaults tab. This is

also true for the Definitive Wellpath Spreadsheet Interpolation tool and

the Casing, Formation, and Annotation editors.

Depending on the calculation method you might get some unexpected

results. For example, Minimum Curvature uses the 'great circle route'

between two survey stations. If the first station was at 1 deg inclination

with heading due north and the second survey station had 1 inclination

deg due south. Minimum Curvature would track the path going under

itself (around the sphere), hence the point halfway would have zero

inclination! Radius of curvature tracks the path going around the

cylinder (like a spiral), so all intermediate points would have the same

inclination, and azimuth would go 0 to 180. But Minimum Curvature

has the least overall angle change. You can prove the same thing in

planning by using Dogleg/ Toolface to the same inclination—the

Results are available in text format using the

Windows Notepad feature. This may be

printed, copied to clipboard, or sent/emailed

to a colleague.

Within the current survey can interpolate by MD, Inc, Azi or TVD.

For each method, the other entry parameters plus N/S, E/W, VSec

and DLS are calculated.

Highlight the desired row,

and click Create Target to

add interpolated survey

point as a target. The

target will be added to the

File > Properties >

Project > Targets editor.



interpolated inclinations will dip in the middle, whereas the Build/Turn

equivalent will maintain a constant inclination.

Project Ahead

Project Ahead is a very useful tool to determine whether a wellpath

currently being drilled is on course to hit a target or project to an MD or

TVD using a set of directional drilling parameters. If it is determined

that the wellpath is not on course, Project Ahead can be used to

determine what is required to get the wellpath back on track to a plan or

directly to a target. Directional drilling parameters for both rotary and

steerable drilling assemblies can be determined.

The projection is made from the open survey, plus the initial hold length.

Should stations be added to the survey, the projection recalculates from

the end of these. If anti-collision is currently being used, then the

projection is included in the current anti-collision scan to enable ‘look

ahead anti-collision.’



The following graphic depicts the Project Ahead Window:

Results are available in text format using

the Windows Notepad feature. This may

be printed, copied to clipboard or

sent/emailed to a colleague.

Enter values here for

the projection,

depending on what

method is selected.

Project Ahead to An

Object:

• Target

• Formation

• Plan

Specify Initial Hold Length to apply a hold or calculate a trend for this

length before computing doglegs to hit the targets or define trend.

Whether projecting to target or a free projection, you can apply an initial

hold section to represent the already drilled wellbore behind the bit.

This is especially useful when you consider that the survey instrument

can be 50ft or so behind the bit. COMPASS enables a user to include

a hold section with 0.0 deg dogleg through this interval, or a trend can

be calculated from adjacent survey data. This section is included in the

Projection Steps grid.

... or calculate a User

Defined Projection

using:

• Dogleg/Toolface

• Build/Turn

• Trend calculated from

survey

The target aiming point

can be adjusted laterally

and vertically.

The Projection Steps

grid displays the results

(below) and the trajectory

determined for the hold

section.

Click Calculate to

calculate and observe the

Projection Steps.



Project Ahead can operate in one of two ways:

Two other areas in the window complete the dialog. The parameter entry

area enables you to enter MD, TVD, Dogleg/Toolface, and Build/Turn

values as required by the projection method. Below lies the results grid

that displays the directional drilling parameters of one or more projected

sections.

The following graphic depicts the Projection Parameters Area:

Use the... If you want to...

Project To Target / Plan or

Formation

Specify the required location and let

COMPASS compute the trajectory changes

using one of the trajectory types. If a plan has

been selected, it shows the actions required to

take the wellpath back to the plan. This also

works for dipping formations.

User Defined Projection - Curve

Only

Specify the projection distance to an MD or

TVD and the curve rates, and then let

COMPASS compute the new location.



Projecting To Target / Plan or Formation

The following graphic depicts the Project to Target or Plan Area within

Project Ahead:

Procedure: Using the Project To Target/Plan or Formation Option

1. Select the Object to Project to:

• Target: Select a target from the target list, or enter a point to aim

for. If you don't see the required target on the list you have not

allocated it to the wellpath list. When a target is selected, the

tabular display is updated and shows the requirements to hit five

extremity points on the target for Curve Only, or displays the

projection sections for Curve-Hold and Optimum Align.

Projecting to a target enables the use of the Landing Point adjust

feature in the Target Viewer. Click on Landing and the Target

Viewer appears, which enables you to select any point to Project

to.

Choose a Wellpath Projection Type:

• Curve Only - Single section: continuous steering to the

Target/Plan

• Curve+Hold - Two sections: steer to line up on Target

then hold to hit the target

• Optimum Align - Three sections: steer, hold, then steer

again to line up on target or align wellpath back with

the plan

• Ouija Board - Modify the current project ahead view to

allow calculation of two of the following when the

remaining two are specified: final inclination, final

azimuth, dogleg, or tool face angle.

Select a Target, Formation,

or Plan defined within the

current wellpath.

Select a Target from the list

currently associated with the

current wellpath.

If projecting to a target,

override the target’s

aiming point by selecting

a new location vertically

or laterally using the

Target Landing Adjust

feature.



• Plan / Formation: Select the plan or the formation to steer into.

This method not only returns the wellpath back to the plan, but

also directs the well so that it aligns with the correct inclination

and azimuth.

2. Choose the Wellpath Projection Type to get to the point:

• Curve Only: Projects a single curve to the target or plan point

through continuous steering. COMPASS calculates the dogleg

required for the projection.

• Curve and Hold: Can be used for slant wells and sidetracks

where the intercept point is close to the target. Curve+Hold adds

two sections. The curve gets you aimed at the plan/formation and

then holds until it’s been hit. While this method returns you to a

point on the planned wellpath, it does not align you with the

direction and inclination of the plan.

Curve + Hold requires the dogleg severity for the curve to be

entered in the parameter fields below. If not entered, a Projection

Warning window displays, explaining that it is not

mathematically possible to project to the required point.

• Optimum Align: Method is best applied to horizontal wells,

where full steering control is possible. Optimum align adds three

sections—curve / hold / curve. This not only returns you to the

planned wellpath, but when you select the plan you are on, the

planned inclination and correct azimuth displays at that point.

This projection also requires the dogleg severity for the two

steered sections to be entered.

• Ouija Board: COMPASS modifies the current project ahead

view to allow calculation of two of the following parameters

when the user enters the other two:

•Final Inclination

•Final Azimuth

•Dogleg

•Tool face angle

3. You need to set the measured depth you want to reach in the plan,

and the dogleg severity to use in steering. If you specify a measured

depth that is too short to reach the plan, the program cycles depths

in 10' (5m) increments until the plan can be reached.

4. When all parameters are defined, click Calculate to generate the

Projection. Depending on what has been requested, one or more

rows appear in the results grid. Projections to targets can display

parameters to hit different points on the target, projection, or

projections to user selected aiming points. Curve+Hold and

Optimum Align projections display section details. All rows in the

results grid display the Build & Turn rate required for rotary

drilling assemblies, Dogleg/Toolface required for steerable



assemblies and the projected point, including MD, TVD, Inc, Azi,

N, E, and Vsec.

The following graphic depicts the Project Ahead - Optimum Align to

Target results:

The Projection Steps results grid also displays the directional

parameters calculated for the hold section, whether hold or calculated

for trend. This information is very useful to a directional driller who

includes the information when setting up their tools for a slide.

Click Notepad button in the tool bar to make Projection details available

as a text file that can be shared with other engineers.

If the object projected to is a target and the Projection is Curve Only,

COMPASS displays a number of Projections to hit different locations

on the target:

The following graphic depicts the Project Ahead results to Target for

Curve Only:

You can interact using the Live views and the different projected

sections. Clicking on a row in the results grid results in that projection

being displayed in all live views.

Using the User Defined Projection - Curve Only

User-defined projections enable ‘what if’ type projections to be

completed to a MD or TVD through continuous steering only. For rotary

drilling assemblies, you can define Build and Turn rates; for steerable

drilling assemblies you can define a Dogleg and Toolface Orientation.

To determine if a wellpath is on course to a target or other location, a



trend can be established from a number of existing surveys to a MD or

TVD.

The following graphic depicts the User Defined Projection in Project

Ahead:

1. Select the Depth to Project to:

• MD—Measured Depth

• TVD—Vertical Depth

Depths must be entered into the parameter entry fields below.

2. Select the Projection Type:

• Build & Turn Rate (for rotary drilling).

• Dogleg Rate and Tool Face Orientation (for steering drilling).

• Apply the Trend over a number of previous survey points (to

continue the current trend) or Hold for a given Bit-Survey tool

distance. You can enter the number of survey points to construct

the trend directly, or use the up/down arrows to change the

number of points.

3. Enter the necessary projection parameters highlighted in the line

below, then press Calculate.

The results grid populates, and any live views are updated to display

the Projected section.



The following graphic depicts the COMPASS 3D view displaying

Project Ahead Curve+Hold from a survey ending at circular target T1

projecting ahead to rectangular target T10:

Survey Data Quality

One of the more useful tools in COMPASS enables you to check for

errors in the survey data. The large amount of survey data typical of

modern surveys means that it is very difficult to visually assess whether

any errors are present and if they are, where they are located.

Unfortunately, survey errors are very common due to a number of

reasons that include:

� Typing/communication (language) problems

� Inconsistent interpretation of survey measurements

� Bad individual survey

� Survey tool operating incorrectly

� Survey tool run badly

� Incorrect tie-on points

Because of the large source of errors and potentially serious

consequences, every survey should be checked and ideally, each

company should have some form of survey quality control procedure in



place to ensure that these errors are detected. Remember, the surveyor

should be checking for errors too!

You can assess the quality of the survey data using Input Validation to

check for high doglegs, or use the more rigorous Varying Curvature

method, which checks for the individual effect that each survey

observation has on the calculated bottomhole location.

Both tools allow you to determine the depth of any suspect points that

can be fed back to the surveyor for them to check.

Input Validation

The Input Validation is configured using the Survey Properties >

Validation tab. When turned on, survey observation calculated dogleg

severities higher than the validation dogleg severity are highlighted in

red. Remember, there are valid reasons for high local doglegs, such as

controlled directional drilling. Refer to “Validating Survey Data” on

page 268 for more information on specify validation criteria.

The following graphic depicts Input Validation in the Survey Editor:

With Input Validation on, the entire survey should be parsed to check

for suspect doglegs. If there is any question about a survey point, get the

surveyor to check it or delete the survey.

6.11 deg/100ft dogleg

highlighted in red.



Importing Survey Data

COMPASS enables survey data to be imported from other sources; for

example, from the survey contractor at the rigsite or directional drilling

office. The Survey Import feature is one of the best tools to reduce errors

in the survey data entered into COMPASS by eliminating the potential

for typing mistakes when survey readings are re-entered. It is designed

to be flexible and easy to use.

To import survey data, click the toolbar button.

To import survey data, you must know exactly how the survey data is

formatted in the source data location. Normally, the COMPASS user

would agree to a format with the surveyor/contractor, or the operator can

simply dictate exactly what the format should be. The following graphic

depicts the Import Survey window:

Whatever the data location or format, COMPASS survey data import

reads only the data from rows in the source location that have the correct

format. Any rows in the source location that do not have the exact

specified format are ignored. This is quite useful, as it means that other

parties can include survey header information, such as column titles and

Inclination Only

data will be

imported.

COMPASS will

calculate TVD but

not Azimuth N or E.

To complete the

import format, select

Blank/Tab as the

column separator, or

simply type it in.

Import survey data from a

Text File or the Windows

Clipboard.

Select the appropriate

units of the source data

set. COMPASS will convert

the data as it is imported to

the current unit set

configuration if necessary.

Choose the type of

survey data to import.

Define the column

order of the data table

you are going to import.

Define the numeric

delimeters used for

countries where

commas are used

as decimal

separator.

Specify corrections to the input

survey data. These values will

be added or subtracted from the

survey as it is imported. Normally, the survey

contractor would complete all corrections,

utilizing their own software prior to making the

survey data available. Note: negative values

can be entered into these fields



units, or other notes about the survey data that is passed over during the

import process.

Survey Types

COMPASS is capable of importing different types of corrected and

partially corrected survey data. COMPASS can read in the survey

observations and is capable of applying minor corrections to the data as

it is imported.

Different types of surveys that can be imported are:

Normal Survey

A survey consisting of MD, Inclination and Azimuth. From this,

COMPASS computes the TVD, N/S and E/W of each survey station.

Use this method when importing three values, such as:

Inertial Survey

A survey consisting of 6 columns: MD, Inclination, Azimuth, TVD, N/S

and E/W. COMPASS reads the co-ordinates (TVD, N/S and E/W) of

each survey station. MD, Inclination and Azimuth are not back

calculated. Use this method when importing all six values.

Inertial Survey - Calculate MD/Inc/Azi

A survey consisting of 3 columns TVD, N/S and E/W. COMPASS reads

the co-ordinates (TVD, N/S and E/W) of each survey station and back

calculates the MD, Inclination and Azimuth, using a method consistent

with Minimum Curvature. Should the standard import result in erratic

Inclination and Azimuth, then use the Spline switch & this will compute

MD Inc Azi

100 0.1 345.1

200 0.5 300.2

MD Inc Azi TVD N/S E/W

100 0.1 345.1 100 -2.5 5.5

200 0.5 300.2 200 -2.7 5.8



smoother angles using a 3 point spline method. Use this method when

importing three values, such as:

Inclination Only

A survey consisting of 2 columns MD and Inclination. Other columns

are ignored. Compass will import the survey calculating the data as for

an inclination reading instrument (TOTCO). The azimuth will be

assumed to be zero and N/S and E/W will be computed vertical below

the start point. Use this method when importing two values, such as:

MD N/S E/W

100 -2.5 5.5

200 -2.7 5.8

MD Inc

100 1.50

200 1.75



Analyzing Survey Data

Using Varying Curvature

Use Survey > Data Analysis > Varying Curvature to access the

Varying Curvature Setup dialog.

Varying Curvature is used to check survey data quality. Varying

curvature considers the effect on the calculated bottom hole location of

each survey point by removing each point from the survey and

recalculating the trajectory. For each station the calculated result is

called inconsistency—this is the distance the calculated bottomhole

location would move if a survey observation were removed, and this

value is expressed as a percentage of the adjoining survey’s depth

interval. For example, if the measured depth interval of your survey

stations is 100ft, and the removal of an observation moves the bottom

hole location by 5ft, then the inconsistency value of that observation is

5%.

The following graphic depicts the Varying Curvature algorithm:

To help filter out suspect observations, a Tolerance limit can be defined,

essentially a Quality Control level. Any observation above this tolerance

is plotted in red and summarized on the varying curvature report.



As a general rule, any observations with an inconsistency greater than

2% are suspect. However good-quality survey data with a very low

mean inconsistency can show suspect inconsistencies much lower than

2%.

Varying Curvature tools are accessed from the Data Analysis submenu

in the Survey menu of the COMPASS menubar. When accessed, a

choice window appears. You can choose to review a varying curvature

report, launch a 2D varying curvature graph, or a 3D varying curvature

graph.

The following graphic depicts the Varying Curvature Selection

Window.

Using the 2D Varying Curvature Graph

The 2D varying curvature graph plots total inconsistency against

measured depth of the survey. It is an easy graph to interpret; all one has

to do is look for irregular spikes in the data, read off the depth of the

spike using the line data reader, then check the survey observation data

at that point. These graphs are live, so you can move the survey editor

to see both editor and graph, update the observation in question, and

immediately assess whether the correction has removed the spike.

Varying Curvature Analysis Options:

• Produce a graph of combined

inconsistency for each survey station

• Produce a graph of Inconsistency split into

its vertical and horizontal components

Define Quality Level to be

highlighted in graphs or

appear in reports.



The following graphic depicts an example of 2D Varying Curvature

Graph:

The example above displays two suspect points. Even though their

inconsistency is well below the tolerance, both of these points should be

checked with the survey contractor. It could well be that these survey

stations were reported incorrectly, or were incorrectly recorded by the

survey hand.

3D Varying Curvature graph

The 3D varying graph separates inconsistency into it’s vertical

(high/low) and horizontal (left/right) components and plots it against

measured depth of the survey. Spikes in the high/low side graph are

mainly due to errors in inclination. Spikes in the left/right are mainly due

to errors in azimuth.

Use the Line Data Reader to see

survey station details of any suspect

points within the survey

Despite being below the 2% threshold, it would be

advisable to check the survey measurements on both

these stations.



The following graphic depicts 3D Varying Curvature Graphs:

The example above displays the two suspect points as an error in

inclination at 1496 ft. and an error in azimuth at 2923 ft. With this

information, one could phone up the survey hand to check the

inclination and azimuth at these depths and get them to report back if the

survey requires a correction.

Using Graphs to Analyze Survey Data

Analysis Graphs enable the production of comparison plots of survey

and plan data. You can for example plot MD against inclination or

azimuth or Dogleg Severity against Wellbore Inclination to see how

well the directional driller is controlling direction as he builds angle.

Multiple surveys can be overlain to compare different surveys within the

same hole section, plot planned trajectories against actual, or assess

survey variation against that defined by the survey tool error model.

A comparison of dogleg against MD can indicate areas of possible

casing wear, or indicate locations where keyseating can occur.

Similarly, dogleg against TVD can indicate which formations were

difficult to drill.

Likely Inclination

ErrorLikely Azimuth Error



There are two options available, Min/Max graph or Analysis Graphs.

Max / Min View

You must have a survey open to gain access to Max / Min View. The

Min/Max view displays two graphs:

� Inclination against measured depth

� Azimuth against measured depth for the entire measured depth

range of the current survey

Additionally, the title area details the range of inclinations and azimuths

present in the survey data. This graph can be useful as a first quality

control check on survey data. However, varying curvature scan offers a

more rigorous method of identifying poor survey data.

Analysis Graphs

To create analysis graphs, first open the survey you wish to plot, then

choose Analysis Graphs from the Data Analysis submenu in the main

Survey menu.

The next step depends on the type of analysis you require. You have a

choice of two types of graph selection. COMPASS is supplied with a

number of commonly used Predefined formats, mainly against

Measured Depth. In addition, User Defined plot formats can be

generated.



The following graphic depicts Pre-defined Survey Analysis Graphs:

You can choose to cross plot as many graphs as you like at a time, but

this is realistically limited to the amount of vertical resolution required.

Too many graphs, and it is difficult to interpret or even see any change

in the data in the graph.

Like all COMPASS graphs, Analysis Graphs come supplied with the

usual toolbar icons; they can be printed or sent to Print Preview to see

what would be sent to the printer.

Plotting Multiple Surveys

Additional surveys can be included in an existing graph for comparison

purposes. For example, you may want to compare survey tool results

over the same section of wellbore to see if the extra time running a Gyro

survey was well spent.

Additional Surveys may be selected using the toolbar button.

Choose

between

canned

comparisons or

user defined or

define your

own formats

Select parameters to

cross-plot from dropdown

selection lists.



The following graphic depicts an Analysis Graph cross plot displaying

comparative survey data:

The above example is taken from the COMPASS training course. The

plot displays two surveys—an Electronic Multi-shot (EMS) survey, and

a series of conventional SRG single shots, run over the same depth

interval. The top inclination graph shows that the well profile is build,

hold and drop—an S-well. It also shows no real difference between the

two sets of survey data. On inclination at least, the two surveys agree.

The second azimuth graph shows that the well is being turned slightly to

the right through the build section, then roughly holds direction until the

end of the survey. Looking at the survey data, one can see that as the

well builds angle, the surveys start to disagree, and that it is the

Magnetic data which is displaying a higher azimuth. When the

inclination starts to drop, one can see that the magnetic data drops back

into line with the single shot gyro data. This type of behavior would

suggest that the magnetic data is subject to some form of inclination-

driven interference that is not affecting the Gyro readings—possibly the

survey tool has been poorly located and is being affected by drill string

magnetization. Alternatively one can see the sudden shift in the trend of

the gyro data at 1500ft and say that it is suspect from that depth.

Whatever the reason, the graph clearly shows that there is a difference

in the survey readings and that further investigation is required.



Relative Instrument Performance

Expected measurement errors for Inclination and Azimuth axes may be

displayed on the analysis graphs by clicking the error bars button

on the toolbar or in graphic options. The quality of overlapping

surveys may be determined by evaluating the actual inclination and

azimuth differences against their expected performance shown by the

error bars.

The error bars on survey analysis graphs are a combination of the errors

on both the reference survey and the survey chosen for comparison

(using RSS addition of independent sources of error). Note that the size

of the error bars is determined from the confidence level chosen for

Output Errors in customer set-up.

The following graphic displays a relative instrument performance:

The above graph compares the SRG and EMS surveys. Looking at the

Delta Inclination data, there is considerable variation between the two

surveys; however, no trend can be observed between them. When

comparing against the expected variation due to error, the variation is

greater than expected for the tool error models and the confidence level

defined within the company.

Turn on error bars to see how the

survey tool performed against its

defined error model.

These graphs compare surveys, so

at least one additional survey

needs to be selected to see any

results



The Delta Azimuth graph displays a clear trend between the two

surveys, again highlighting that one of the surveys is being affected by

some physical effect which is not affecting the other survey. Survey

errors are almost within their expected margins.



Survey Reports

The Reports functionality within COMPASS provides a flexible, easy to

use, survey/directional well planning reporting mechanism suitable for

all users of directional drilling software. COMPASS offers several

survey reports.

Survey Reports are accessed from the main Survey menu or from the

icon in the COMPASS toolbar. Note that the reporting

functionality is available whether a survey is open or not. If the latter,

then the report details the design wellpath; otherwise, the data is for the

open survey.

The following graphic depicts the Reports dialog.

All reports can be

previewed and printed in a

professional format or they

can be output to a text file.

Click the Survey button to

view a list of survey

reports.



Survey Export

COMPASS can export a survey, a plan, or a definitive path in any ASCII

format.

The following graphic depicts the Survey Export Window. (The same

dialog is used to export Plans.)

Export File Format

You can export using a pre-defined format or you can define your own

format. If you use a pre-defined format, you can specify some

information not to be included in the export.

Note: Exporting a Survey...

The survey editor must be open for that survey to be exported. If a survey is not

open, the open Design is exported.

The output can be directed to a file or to the

Windows Clipboard for pasting into a word

processor, spreadsheet, or the Windows

Notepad. When exporting to paste into Excel, you

should set the delimiter to tab.

Data can be exported to a file format available

from a picklist. Format files may be constructed

by clients. Refer to “Exporting to a Pre-Defined

Format” on page 296 for more information.

Check to include the final driller’s

depth (TD) at the end of the

interpolations.

Click User Defined to specify export format

details. Refer to “Exporting to a User

Defined Format” on page 296 for more

information.



Exporting to a User Defined Format

If you want to use a User Defined format, click the User Defined radio

button. You must then specify:

1. Units: Select the units for depth, inclination, and azimuth from the

associated drop-down lists.

2. Column Delimiter: Select the button associated with the delimiter

you want to use. When exporting to paste into Excel, you should set

the delimiter to tab.

3. Interpolate: Specify interpolation details. In user defined exports

an interpolation type may be defined. When interpolations are

requested the original survey intervals are discarded in favor of

interpolated stations at regular intervals.

�Interval - The depth frequency to interpolate the survey.

�Specify depths by - Measured Depth or Vertical Depth

�Range - The start depth end depth to clip the interpolations.

�Include station at end - Attach the last recorded station at the end

of the interpolations.

�Whole Path- If a survey is open, check the Whole Path box if

you wish to include the definitive path above the tie-on point

when you export the open survey.

Exporting to a Pre-Defined Format

COMPASS allows you to configure export file formats. The format files

(*.cef) are placed in the COMPASS\CONFIG directory, and when the

export dialog is called, a drop-down list containing the different formats

available is listed.

Custom export formats can be used for a number of reasons:

� Quick export to spreadsheet of various data.

� Formats for geological or geophysical applications.

� Exports to other engineering applications.

� Preview of data in Notepad, to cut and paste.



If requested Landmark can supply formats for a number of third-party

applications, or can assist with the development of new format

configuration files.

If you want to use a Pre-Defined format, click the Pre-Defined radio

button. You must then select the format you want to use from the drop-

down list. Items that are included in this format will become active and

be checked by default. If the item is checked, it will be included in the

export. If you don’t want to include the item, uncheck the associated

box.


Chapter

Plots

Overview

There are two types of graphics in COMPASS.

� Live Graphs

� Wall Plots

Comparing Live Graphs and Wall Plots

Live Graphs

Live graphs or views are primarily designed for on screen viewing. This

type of graph can be output to a printer or exported to a file, however the

flexibility of Live Graphs is inferior to Wall Plots. You can use live

graphs at any time to view your work. These graphs are termed live

because they are online and are updated automatically as data is changed

in the editors or data entry windows.

You can print a Live Graph using the toolbar icon. However, a better

method is to use the Print Preview feature by clicking File > Print

Preview. The Print Preview window displays the formatted changes and

uses the actual printer driver to present the graph on the window. This

enables you to see exactly what will be printed before you send it to

hardcopy.

The Live Graphs can display different types of Wellpath data. In

addition to the Definitive Path (default color = Blue), Live Graphs

display:

• currently open Survey (default color = Red)

• currently open Plan (default colours = Red and Green)

• Survey Project Ahead sections (default color = Green)

• Other wellpaths in the Field using Offset Wells

Examples of Live Graphs are:

8

Chapter 8: Plots


• 3D view

• Vertical Section view

• Plan view

• Target Viewer

• Template Viewer

• Wellpath Optimizer view

• Anti-Collision Plots

Wall Plots

Wall Plots are designed for printer or plotter output. You can configure

a Wall Plot in many ways as you will see later in this chapter. For

presentation output, use Wall Plots in COMPASS because Live Graphs

are not WYSIWYG (What You See is What You Get). All Live Graphs

are formatted as they are sent to the printer.


Chapter 8: Plots

Using Live Graphs

Accessing Live Graphs

Live Graphs Common to All Modules

Access Live Graphs common to all COMPASS modules using toolbar

buttons.

� 3D View,

� Section View,

� Plan View,

� Template Viewer,

� Target Viewer,

� Optimizer Viewer,

Live Graphs in the Survey Module

Access Live Graphs in the Survey module by:

� Survey > Data Analysis > Min/Max Graph

� Survey > Data Analysis > Varying Curvature

� Survey > Data Analysis > Analysis Graphs

Live Graphs in the Anticollision Module

Access Live Graphs in the Anticollision module by:

� Anticollision > Travelling Cylinder View

� Anticollision > Ladder View

� Anticollision > Separation Factor View

Chapter 8: Plots


� Anticollision > 3D Proximity View

� Anticollision > Spider View - Local

� Anticollision > Spider View - Map

Customizing Live Graphs

Use the General Graph Setup dialog to configure the appearance of Live

Graphs. Access the General Graph Setup dialog by:

� Tools > Graph Setup

� Clicking the Graph Setup toolbar button.

Current Track Identification

To help distinguish different trajectories on a graph, you may assign

different colors and symbols to Definitive Survey, Current Survey, and

the Current Plan. You can’t assign a symbol to Targets.

Offset Track Identification

???How does this work now???You may assign colors only for offset

information including Offset Wellbores, Offset Surveys, and Offset

Plans.


Chapter 8: Plots

Multi-Color

In the options for the Offset Wellbores, Surveys and Plans you may

choose "Multi-color" which will assign a different color to each

new track. Color by Type

In the options for Offset Wellbores you may choose a pen color

based on the type defined in the Wellbore Properties. The colors are

assigned to Wellbore types in the Wellbore Type editor.

Sizes (% of the window)

Text in this category does not change size as you enlarge the view. Font

sizes are shown as a proportion of the window size, so when you change

the window size, the font sizes also change.

Sizes (% of the graph)

Text in this category changes size as you enlarge the view. Font sizes are

shown as a proportion of the graph size. When you change the window

size, the font size does not change. Also when there are multiple graphs

on a plot, such as an analysis, plot symbols and data labels are scaled to

the area occupied by each individual graph not the overall windows size.

Why is size based on % of window or % of graph?

When you enlarge graph details using zoom some text is enlarged while

other text is unchanged. The reason for this is that enlarging the titles

and axis labels gives a clear indication that the view has been magnified.

On the other hand when you zoom in to magnify detail, you don't want

to make symbols, depth labels and casing shoes, too large to read.

Symbol Spacing

The frequency (number of stations) symbols are to be plotted along a

Wellbore.

Chapter 8: Plots


Background

This causes the graphs to display on a black background. Black lines

will now appear as white lines.

Note: Black background color...

Setting the background color to black will not affect the printed versions of the

graphs.


Chapter 8: Plots

Using the Live Graph Toolbar Icons

Each Live Graph has its own set of properties and tools, but there is a

common subset of tools. The following graphic depicts the COMPASS

Live Graphs Toolbar icons:

You activate these additional tools and settings by clicking the icon. The

appearance of the graph can change, or an additional window can

appear. The most useful feature is the online help available for each type

of graph. Each graph type has its own subset of tools to manipulate the

plot, and graphic options to customize the plot.

COMPASS for Windows Live View Icon Map

Symbols

• Turn on Line Symbols for B & W Printing

• Helps differentiate lines on plot

Axis at (0,0) On/Off

• Major grid axis displayed in center or to left of plot

Formations

• Display Formation Tops

Display Error Surface

• Display ellipse of uncertainty along wellpath

• Ellipse interval may be adjusted in graphic options

• Ellipse is projected onto viewing

surface

Display Casing Shoes

• Display casing shoe symbols and labels along wellpath

Grid On/Off

• Turn grid lines on or off

• Useful to turn off grid lines on b & w plots

Display Targets

• Include Wellpath targets in plot

Vertical Section Lines

• Display Vertical Section Lines in Plan

Horizontal Section Lines

• Display Horizontal Section Lines in PlanData Labels On/Off

• Turn display of data labels on or offAxis Labels On/Off

• Turn display of axis labels on or offGraphics Options

• Access to all Live View/Wallplot Customizations

or simply double-click on graph

Point Data Reader

• Read X & Y axis values from selected point on graph

• Read Delta X & Y between 2 points on graph

Line Data Reader

• Read X & Y axis values on selected point along line

• Move Mouse to select point

Rescale Axis

• Drag mouse pointer to reduce graph area

Zoom In

• Click area to zoom in on

Zoom Out

• Click to pan out to original scale

Display Definitive Wellpath

• Turn Definitive Wellpath On/Off

Graphics Offset Wells

• Select Offset Wellpaths to include

in current plot

Print Live View

• Format, then send graphic to printer

Close

• Turn off the graph

Online Help

• Launch the Help to see the tips available for the current graph

Chapter 8: Plots


There are additional icons that appear on certain graphs.

Legend Box

When you launch a live graph, COMPASS also opens a Legend Box that

contains a list of all wellpaths displayed on the current view.

The Legend Box has the following features to help you distinguish

different wellpaths.

• The first wellpath is always the current Definitive Wellpath.

• If you open a survey or a plan it is next in the list.

• The next line is a blank line.

• The rest of the Legend contains additional offset wellpaths.

• Clicking on a wellpath name in the Legend Box highlights its trace

in the graphic view.

• Clicking on the blank line unhighlights all wellpaths.

• Double-clicking the name of each offset wellpath in the Legend

Box changes its color or symbol.

• To change the color of the current wellpath or survey, see Graph

Setup.

Using the 3D View

This is one of the most commonly used Live graphs, as it quickly

enables you to obtain a good overall perspective of wellpath trajectory

entered in COMPASS.

The selected wellpath line will be

highlighted in bold on all live views.

To change wellpath color or symbol,

double-click on it within the Legend

and choose from list.


Chapter 8: Plots

There are two types of tools available:

• Keyboard quick keys

� Toolbar icons

The following graphic depicts the keyboard quick keys and toolbar

icons:

The 3D view is actually a 2D line drawing representation of 3D. When

zoomed out, perspective is easy; however, when you zoom in and start

rotating objects, it becomes difficult to keep your frame of reference. If

this occurs, zoom out, regain your perspective, then rotate the object

back to where you think it should be, and zoom in again.

In addition to the keyboard, you can use the left mouse button to drag

the 3D view around, and the right mouse button to zoom in and out.

Using the Vertical Section View

The Vertical Section view displays the current wellpath as projected

onto a vertical plane defined in Wellpath Setup. You can add additional

Chapter 8: Plots


wellpaths to this plot, show target and casing details, and use the line

data reader to select points on the wellpath.

Using the Plan View

The plan view displays a horizontal projection of the wellpath. You can

display the current line of the vertical section from the origin to the end

of the wellpath.


Chapter 8: Plots

Using the Wall Plot Composer

What is the Wall Plot Composer?

The Wall Plot Composer is used to create and customize plot layouts for

windows, file, or professional hardcopy output by creating a template of

the page layout that can be saved and reused. A wallplot consists of any

combination of graphical and data elements generated from COMPASS,

in addition to bitmaps or windows metafiles constructed elsewhere. The

only limitation is the amount of real estate available on hardcopy.

Accessing the Wall Plot Composer

The Wall Plot Composer is accessed by clicking the toolbar button.

Chapter 8: Plots


Examining the Wall Plot Composer Components

What is an Object?

An object is a graph, legend, text box, or other item that is added to a

Wall Plot Composer plot. Add objects by:

• Using the Object Toolbar

• Composer > Add

• Right-click menu

Indicates the name of the plot. This plot has not

been saved, so the name is still the default

name of New Plot. The * indicates the plot has

been changed since the last save.

General toolbar

Object toolbar

Layout toolbar

Rulers indicate the

location of the printable

page area, margins, and

objects.

This section view and legend

are both objects. Objects have

sub-objects such as labels,

grids, lines, and text.

This numeric

display indicates

the position of the

cursor.

The dotted blue line

indicates the

margin. You can

change the margins

by using the ruler.

Click on the ruler

where the margin is

and move the

double-arrow cursor

to the new margin

location.

The white area is

the page. The solid

gray line indicates

the printable area

of the page.

The gray dots on the page indicate

the snap-to-grid settings that can

aid with lining up objects of the

page. Refer to “Using the Layout

Toolbar” on page 316 for

information on snap-to-grid.


Chapter 8: Plots

Objects can be configured, resized, and customized in many ways. The

following objects can be added:

• XY Graph

• Traveling Cylinder graph

• 3D graph

• Data Box

• Geological Column

• North Arrow

• Legend

• Text

• Pictures

• Rectangles, Polygons, Ellipses, Circles, Lines, Segmented Lines,

Curved Lines, and Arrows

What is a Sub-Object?

Objects contain sub-objects. Sub-objects can’t be moved outside of the

object they are in. Examples of sub-objects are:

• Lines

• Text

• Labels

• Grids

Setting Up the Wall Plot Composer Page

Use the Page Setup dialog to specify the paper size, margins, scaling,

and layout for printing Wall Plot Composer plots. Refer to the online

help for more specific information about dialog options.

Click the to access the Page Setup dialog.

Chapter 8: Plots


Using the Toolbars

The Wall Plot Composer has three toobars, including:

� General toolbar: The General toolbar is used for many functions,

including saving plots, zooming, configuring wall plot layout, and

printing.

� Object toolbar: The Object toolbar is used to select objects (plots,

data, arrow, legends, etc.) to place on the wall plot.

� Layout toolbar: The Layout toolbar is used to align the position of

objects on the wall plot and customize the grid.

Use the scaling options to

convert a plot to a larger or

smaller sized paper.


Chapter 8: Plots

Using the General Toolbar

Refer to the online help for more information concerning a toolbar

button than what is presented below.

Icon Description

New: Open a new template.

Open: Open an existing template file. Use the drop down

arrow to open template from recent selection list.

Save: Save the open template to file.

Save As: Save the open template with the different file name

(save as). Plots can be saved as WPC files only. Refer to

“Wall Plot Composer Files” on page 329.

Undo: Click this button to undo the most recent actions.

Redo: Click this button to redo actions that you have undone

using the Undo button.

Zoom: Use this button to zoom in and out.

Page Units: Use this button to select inches or centimeters

as the units for the Wall Plot Composer ruler.

Properties: Click this button to access the Properties dialog

to configure the selected object. If an object is not selected,

this button is not accessible.

Chapter 8: Plots


Using the Object Toolbar



Bring to Front / Drop to Back: Click this button to place

the selected object behind or in front of another object on the

Wall Plot. When two graphs are marked as opaque the top

component will overwrite the bottom component.

Import: Click this button to import an object from a file into

the Wall Plot.

Export: Click this button to export selected objects.

Exported objects can be imported using the Import toolbar

button.

Page Setup: Click this button to access the Page Setup

dialog. Use the Page Setup dialog to select the paper the plot

is to be designed for.

Printer: Click to send this Wall Plot to the printer.

Close: Click to close this template plot file. If the plot has

changed, you are obliged to save the layout.

Help: Click to access online help.

Icon Description

XY Graphs: Click this button and select the desired graph

from the list.

Icon Description


Chapter 8: Plots

Traveling Cylinder: Click this button to add the Traveling

Cylinder graph to the Wall Plot.

3D Graph: Click this button to add the 3D graph to the Wall

Plot.

Data Boxes: Click this button to select information to

include on the plot from pre-defined data groups.

Geological Column: Click this button to add the Geologic

Column to the Wall Plot.

North Arrow: click this button to add a North Arrow to the

Wall Plot.

Legend: Click this button to add a legend to the Wall Plot.

Text: Click this button to add a text box to the Wall Plot.

Picture: Click this button to add a picture to the Wall Plot.

Rectangle: Click this button to add a rectangle to the Wall

Plot.

Polygon: Click this button to add a polygon to the Wall

Plot. See Placing an Object on the Wall Plot Composer for

more info

Ellipse: Click this button to add an ellipse to the Wall Plot.

Icon Description

Chapter 8: Plots


Using the Layout Toolbar



Circle: Click this button to add a circle to the Wall Plot.

Line: Click this button to add a line to the Wall Plot.

Poly Line: Click this button to add a poly (segmented) line

to the Wall Plot.

Curved Line: Click this button to add a curved line to the

Wall Plot.

Arrow: Click this button to add an arrow to the Wall Plot.

Icon Description

Align Left: Click this button to align two or more objects

along a vertical line defined by the left-edge of the last

object selected.

Align Right: Click this button to align two or more objects

along a vertical line defined by the right-edge of the last

object selected.

Align Top: Click this button to align two or more objects

along a vertical line defined by the top-edge of the last

object selected.

Icon Description


Chapter 8: Plots

Align Bottom: Click this button to align two or more

objects along a vertical line defined by the -bottom edge of

the last object selected.

Center Vertically: Click this button to align one or more

object(s) along a vertical line defined by the middle of the

page.

Center Horizontally: Click this button to align one or more

object(s) along a horizontal line defined by the middle of the

page.

Space Across: Click this button to evenly space three or

more objects across the page.

Space Down: Click this button to evenly space three or

more objects down the page.

Make Same Width: Click this button to make all selected

objects the same width as the object selected last.

Make Same Height: Click this button to make all selected

objects the same height as the object selected last.

Make Same Size: Click this button to make all selected

objects the same size as the object selected last.

Grid: Click this button to toggle the grid on or off.

Snap-To-Grid: Click this button to create a background

grid on the plot to help position graphs on a plot. When snap

to grid is selected graphs will resize and move to the next

closest grid point.

Grid Settings: Click this button to access the Grid Setting

dialog.

Icon Description

Chapter 8: Plots


Working With Wall Plot Composer Objects and Sub-Objects

Wall Plot Composer objects and sub-objects can be configured,

customized, moved, and resized. You must select the object(s) or sub-

object(s) that you want to change the appearance of before you can

change it. For a more complete explanation of what objects and sub-

objects are, refer to “What is an Object?” on page 310 and “What is a

Sub-Object?” on page 311.

Adding an Object to the Wall Plot

1. Select the object you want to add to the Wall Plot. Use any of the

following three methods.

• Object toolbar buttons. Refer to “Using the Object Toolbar” on

page 314 for more information on the Object toolbar. (If the

toolbar buttons are not active, click anywhere on the Wall Plot

page to activate them.)

• Composer > Add

• Selecting an object from the right-click menu. To use the right-

click menu, click anywhere on the Wall Plot page where there is

not already an object.

2. Using the mouse, place the crosshair cursor where you want one

corner of the object to be located. If you are adding an art object

(other than a circle or ellipse), refer to “Adding an Art Object to the

Wall Plot” on page 318. Use this procedure for circle and ellipses.

3. Click and hold the left mouse button as you define the size of the

object.

4. Release the mouse button when the object is the desired size.

Adding an Art Object to the Wall Plot

1. Select the art object you want to add to the Wall Plot. Use one of the

following three methods to add an art object.

• Object Toolbar buttons. Refer to “Using the Object Toolbar” on

page 314 for more information on the Object toolbar. (If the

toolbar buttons are not active, click anywhere on the Wall Plot

page to activate them.)

• Composer > Add

• Select an art object from the right-click menu. If you are adding

a circle or ellipse, refer to “Adding an Object to the Wall Plot”


Chapter 8: Plots

on page 318. To access the right-click menu, click anywhere on

the Wall Plot page where there is not already an object.

2. Using the mouse, place the crosshair cursor where you want the

starting point to be. Then, refer to the following:

• Lines: Click where you want to begin the line. Continue to hold

the mouse button as you move the cursor to the end point.

Release the mouse button.

• Polygons: Begin as if you were drawing a line. To add another

segment to the line, click anywhere on the line, and continue to

press the mouse button as you move the cursor where you want

the segment to be. Release the mouse button. The last point will

automatically be joined to the first point.

• Polyline: Same procedure as for polygons except the first and

last points are not joined.

• Curved Lines: Same procedure as for polylines except that the

line segments are curved.

• Arrow: Same procedure for lines except there is an arrow head

at one end of the line.

Selecting an Object(s) on the Wall Plot

Click on the black line outlining the object. The outline will change to

to indicate the object has been selected. To select more

than one object, press the Shift key as you select objects.

Selecting a Sub-Object(s) Within an Object on the Wall Plot

A sub-object within an object is selected by clicking on the sub-object.

The outline will change to to indicate the sub-object has

been selected. To select more than one sub-object, press the Shift key as

you select sub-objects. To select all sub-objects in a group, select the

first sub-object, then press the Alt key when you select the second sub-

object.

Moving an Object(s) or Sub-Object(s) on the Wall Plot

1. Select an object(s) or sub-object(s) that you want to move. Refer to

“Selecting an Object(s) on the Wall Plot” on page 319 or “Selecting

Note: Selecting an object prior to resizing, moving, or customizing...

You must select an object before you can resize, move, or customize it.

Chapter 8: Plots


a Sub-Object(s) Within an Object on the Wall Plot” on page 319 for

instructions on selecting objects or sub-objects.

2. Slightly move the cursor until it changes to .

3. Press and hold the left mouse button until the object or sub-objects

is in the desired location. Sub-objects within an object can’t be

moved outside of the object.

Deleting Object(s) or Sub-Object(s)

1. Select an object(s) or sub-object(s) that you want to delete. Refer to



instructions on selecting objects or sub-objects within objects.

2. Press the Delete key. Labels are not really deleted, but are hidden.

Refer to “Using Wall Plot Composer Right-Click Menus” on

page 328 for more information on hiding/showing labels.

Resizing an Object(s) or Sub-Objects(s)

1. Select an object(s) or sub-object(s) that you want to resize. Refer to



instructions on selecting objects or sub-objects within objects.

2. Slightly move the cursor over a box located in the boundary of the

object or sub-objects until it changes to . If you want to

resize the text within an object while you resize the object, press the

Shift key as you resize the object.

3. Press and hold the left mouse button until the object or sub-objects

is the desired size. Sub-objects within an object can’t be resized

outside of the object. To rescale the fonts and line thickness and

maintain size relative to the object box, hold the Shift key down

when resizing an object.

Note: Resizing objects with a specific scale...

You can not resize an object that you have specified a specific scale.


Chapter 8: Plots

Placing Object(s) and Sub-Object(s) Relative to Each Other

1. Select an object(s) or sub-object(s) that you want to move relative to

other overlapping object(s) or sub-object(s). Refer to “Selecting an

Object(s) on the Wall Plot” on page 319 or “Selecting a Sub-

Object(s) Within an Object on the Wall Plot” on page 319 for

instructions on selecting objects or sub-object(s) within objects.

2. Click the right mouse button and select Order. Bring to Front

moves the object to the front of all objects that overlap it. Bring

Forward moves the object forward one place when overlapped by

other object(s). Send to Back moves the object to the back of all

objects that overlap it. Send Back moves the object back on place

when overlapped by other object(s).

Aligning Object(s) and Sub-Object(s) on the Page

1. Select an object(s) or sub-object(s) that you want to align on the

page. Refer to “Selecting an Object(s) on the Wall Plot” on page 319

or “Selecting a Sub-Object(s) Within an Object on the Wall Plot” on

page 319 for instructions on selecting objects or items within

objects.

2. Use the Layout toolbar options to align the object on the page.

Refer to “Using the Layout Toolbar” on page 316 for more

information on using the Layout toolbar.

Editing Style, Thickness, and Color

Double-click on any line, and the Properties dialog for the Wall Plot

Composer displays. Use this dialog to edit the style, thickness, and

color.

Exporting Selected Objects

Export the currently selected object(s) to create a library of customized

objects. You can import this library into any plot. The exported objects

appear on the import drop-down menu.

Chapter 8: Plots


Designating an Object’s Properties as the Default Setting

1. Customize an object with your preferred line styles, color schemes,

and fonts.

2. Right click and choose the Defaults > Save option.

3. Use the Defaults > Apply option to apply the default properties to

existing objects.

Setting an Exact Graph Size

Make a graph exactly the size you want by specifying both a scale and

a range on the Scale tab of the graphs properties. The graph will be

resized to adhere to the scale and range and will always spring back to

that size even if you try and resize it using the mouse.

Embedding Images on a Plot

Any images used on a plot will get embedded in the.WPC file when the

plot is saved. This means the.WPC file can be used on different

machines without having to copy the images around. The exceptions to

this are logos, which are refreshed based upon the current context. Refer

to “Wall Plot Composer Files” on page 329 for more information.

Changing Object Properties

There are many dialogs that are used to change the properties of Wall

Plot Composer objects and sub-objects. In this section, the tabs

associated with each type of object are listed along with a short

description. For more information about a specific tab, refer to the

online help.

To change the properties of an object or sub-object:

1. Select an object(s) or sub-object(s) that you want to change the

properties of. “Selecting an Object(s) on the Wall Plot” on page 319

or “Selecting a Sub-Object(s) Within an Object on the Wall Plot” on

Note: Defaults for different paper sizes...

Different defaults are maintained for different ranges of paper sizes


Chapter 8: Plots

page 319 for instructions on selecting objects or sub-objects within

objects.

2. To access the Properties tabs, right-click and select Properties or

click the toolbar button.

Changing XY Graph Properties

XY graphs can be changed using the following Properties tabs. Not all

tabs apply to all types of XY graphs. Refer to the online help for more

specific information about a tab.

Tab Name Functionality

Analysis Use this tab to specify what is to be displayed on the X and

Y axis of an XY Analysis graph.

Annotations Use this tab to include and to configure the display of

annotations on the 3D and XY Graph Wall Plot Composer

objects. To specify annotations, open a Plan and click the

Plan Comments icon.

Axis & Grid Use this tab to configure the axis (top, bottom, left, and

right) and to control the display of the grid on an XY Graph

Wall Plot Composer object.

Azimuth and

Inclination Labels

Use this tab to include and configure the display of azimuth

and inclination labels on XY Graph Wall Plot Composer

objects. The title of this tab will be either Azimuth Labels or

Inclination Labels depending on the XY Graph selected.

Background Use this tab select a background color and border style,

thickness, and color for many Wall Plot Composer objects.

Casings Use this tab to include and to configure the display of casing

sizes and placement on the 3D and XY Graph Wall Plot

Composer objects.

Errors Use this tab to configure the display of error ellipses on an

XY Graph object.

Formations Use this tab to include and configure the display of the

formation tops on the 3D or XY Graph Wall Plot Composer

objects.

Options Use this tab to configure a variety of items associated with

XY Graph Wall Plot Composer objects.

Chapter 8: Plots


Changing Traveling Cylinder Graph Options

Traveling Cylinder graphs can be changed using the following

Properties tabs. Refer to the online help for more specific information

about a tab.

Picture Use this tab to select a picture for display within a Wall Plot

Composer object. You can resize the picture to fit the screen

or by maintaining the aspect ratio. For XY Graphs, you can

apply the picture to the grid area only.

Scale Use this tab to specify the axis scale and range, and to

configure axis location and grid configuration.

Targets Use this tab to include and to configure the display of

targets.

Template Use this tab to display templates on some of the XY Graphs.

TVD or MD Labels Use this tab to include and configure the display of MD and

TVD labels. The title of this tab will be either MD Labels or

TVD Labels depending on the XY Graph selected.

Well Labels Use this tab to specify the location, frequency, orientation,

and other options associated with well labels.




Depth Labels Use this tab to specify the location, frequency, orientation,

and other options associated with depth labels


Traveling Cylinder Graph Wall Plot Composer objects.



or by maintaining the aspect ratio.

Scale & Grid Use this tab to configure the scale, graph labels, and grid

options.

Well Labels Use this tab to specify the location, frequency, orientation,

and other options associated with well labels.



Chapter 8: Plots

Changing 3D Graph Options

3D graphs can be changed using the following Properties tabs. Refer to

the online help for more specific information about a tab.

Wellpath Selection Use this tab to select the offset wells you want displayed on

the Traveling Cylinder object. The list of selections

available on the tab is based on the offset wells selected

using the View > Offset Designs dialog.


Annotations Use this tab to include and to configure the display of

annotations. To specify annotations, open a Plan and click

the Plan Comments icon.



Casings Use this tab to include and to configure the display of casing

sizes and placement on the 3D Graph Wall Plot Composer

objects.

Errors Use this tab to configure the display of error ellipses on a 3D

Graph object.

Formations Use this tab to include and configure the display of the

formation tops on the 3D or XY Graph Wall Plot Composer

objects.


3D Graph Wall Plot Composer objects.




Targets Use this tab to include and to configure the display of targets

on the 3D and XY Graph Wall Plot Composer objects.

Wellpath Selection Use this tab to select the offset wells you want displayed on

the 3D object. The list of selections available on the tab is

based on the offset wells selected using the View > Offset

Designs dialog.


Chapter 8: Plots


Changing Data Boxes Graph Options

Data Box objects can be changed using the following Properties tabs.

Refer to the online help for more specific information about a tab.

Changing Geological Columns Graph Options

Geological Column objects can be changed using the following

Properties tabs. Refer to the online help for more specific information

about a tab.

Changing North Arrow Options

North Arrow objects can be changed using the following Properties tabs.





Data Box Use this tab to configure what is displayed in a Data Box

object. If you have selected a pre-defined Data Box, you can

change what is displayed using this tab. If you have selected

a User Defined Data Box, you must use this tab to specify

what you want displayed in the Data Box.







Geological

Columns Options

Use this tab to configure the Geological Columns objects.








Chapter 8: Plots

Changing Legend Options

Legend objects can be changed using the following Properties tabs.


Changing Text Box Options

Text Box objects can be changed using the following Properties tabs.


Changing Picture Options

Picture objects can be changed using the following Properties tabs.








Legend Options Use this tab to configure many Legend object options.





Colors and Lines Use this tab to configure the appearance of lines, polylines,

curved lines, arrow, or text boxes.

Text Box Use this dialog to specify and configure the text you want to

add to the Wall Plot.





Chapter 8: Plots


Changing Rectangle, Polygon, or Ellipse Options

Rectangle, polygon, or ellipse objects can be changed using the

following Properties tab. Refer to the online help for more specific

information about a tab.

Changing Line, Segmented Line, Curved Line, or Arrow Options

Line, segmented line, curved line, or arrow objects can be changed using

the following Properties tab. Refer to the online help for more specific

information about a tab.

Using Wall Plot Composer Right-Click Menus

Right-click menus are a convenient way of accessing commonly used

functionality. The content of the right-click menus vary depending on

what the cursor is on when you right-click. Right-click menus are

available for:

� Wall Plot Composer: Use this right-click menu to select an object

for placement on the Wall Plot. You can also use Composer > Add

or the Objects Toolbar to select objects for placement. Also

available on the Wall Plot Composer right-click menu is the Import

option that can be used to import a Wall Plot Export (.wpe) file.

You can also use the toolbar button to import the WPE

file.








Colors and Lines Use this tab to configure the appearance of lines, polylines,

curved lines, arrow, or text boxes.



Chapter 8: Plots

� Wall Plot Composer Objects: Use this right-click menu to access

many useful configuration features for Wall Plot Composer objects

or sub-objects within an object. You can also right-click on the Wall

Plot Composer to select an object for inclusion on the Wall Plot.

� Wall Plot Composer Art Tools: Use this right-click menu to access

many useful configuration features for lines, polylines, polygons,

curved lines, or arrows.

Wall Plot Composer Files

Wall Plots can be saved. If you create a Wall Plot file using one set of

wells and then reopen the file using the same set of wells, all changes

you made to the plot will be included. If you open the file with a

different set of wells, the layout and settings will be remembered, but

changes you made to labels will not be included.

Plots can be saved WPC (.wpc) files only. Stored in the plot file is:

� File version: To allow tracking changes over time and to maintain

backward compatibility with previous versions of the software.

� Printer and page settings: The Wall Plot Composer will attempt to

select this printer by default when printing or preview printing.

� Colors and symbols: Any colors and symbols used by any offset

wells that are currently selected. When the WPC file is opened,

these settings will be restored in the same offset wells are already

selected. After the WPC file is opened, selecting the offset wells

will not apply the color and symbols settings. The offset wells must

be selected prior to opening the WPC file.

� Plot objects and sub-objects: Including any property changes and

the positions of all labels.

Chapter 8: Plots



Chapter

Tools

Overview

In addition to the setup windows for each level of the data structure, you

commonly use a number of additional utilities and resources when

working with COMPASS.

9

Chapter 9: Tools


Geodetic Calculator

The geodetic calculator is a simple tool used to calculate Grid

Convergence and Scale Factor for a given location, assuming a chosen

geodetic system. You can also use it to do quick geographic conversions

and calculate a UTM zone from geographic coordinates. Calculated

results are displayed in the window and can be shared using Windows

Notepad.

The Calculator

The following graphic depicts the Geodetic Calculator.

Geodetic System, Datum and Map Zone

You must select the correct geodetic system before doing geodetic

conversions (latitude and longitude <> easting and northing). The

default system is taken from the current Field.

Some Geodetic Systems have a fixed Datum (e.g. Nigerian Projection

System uses Clarke 1880) while others (e.g., UTM) enable any datum to

be selected. Additionally, some Geodetic Systems have a fixed Map

Zone (e.g., Brunei/Borneo grid = NW Borneo Grid), or enable a

Full selection of Geodetic

Systems and Datums available.

A Geodetic Coordinate ‘System’

comprises the Geodetic

System itself, a Geodetic

Datum or Ellipsoid, and a Map

Zone.

Location may be entered as local

offsets from Site Center, Map

Coordinates, or Geographic

Coordinates.

You can determine appropriate

UTM zone from entered Latitude

& Longitude.


Chapter 9: Tools

selection of one or more Map Zones (e.g. Lambert Algerie North &

South).

Select one of the input coordinate types using the radio button, then

enter the position of interest in the coordinate system based on the

following criteria:

Results

Grid Convergence

The angle difference from True North to Grid North for the location.

Scale Factor

The scale factor is the ratio between measured distance on the map and

measured distance on the ground at the location. Even though it is

calculated, Scale Factor is not used to conduct map to local coordinate

conversions unless the COMPASS geodetic system configuration file is

set up to apply it. Scale Factor conversion is normally turned off by

default.

UTM Zone

The geodetic calculator has a UTM Zone button to compute the correct

UTM Zone for the latitude and longitude you enter. This button is only

available when you choose the Universal Transverse Mercator system.

Position Criteria Description

Local to Site Enter the location of interest as local Northings

and Eastings from Site Center.

Map Position Enter Map coordinates based on the Geodetic

System.

Geographic Geodetic coordinates of your location based on

the Spheroid.

Chapter 9: Tools


Geomagnetic Calculator

Where the local magnetic field cannot be measured or obtained, the

Geomagnetic calculator enables the local geomagnetic field to be

calculated using a set of Geographic coordinates, a Date, and a

predictive global Geomagnetic model. The calculator is most commonly

used to calculate magnetic declination, which is a required correction for

magnetic survey readings.

The calculated values are not used in any COMPASS calculations.

However, the results appear in most surveying reports and the Site data

block in Wallplot Composer output. A Norths arrow is displayed in the

Status Box reference area which can also be included in a Wallplot.

The Calculator

The following graphic depicts the Geomagnetic Calculator.

The Geomagnetic Calculator can be launched from the Site Setup

window or from the COMPASS toolbar. The geographic coordinates

Location defaults from

current Site. Change it by

retyping, using up/Down

arrows or selecting Field,

Site, Well or User defined

location.

A short Geomagnetism Report is available using the

Windows Notepad feature. This text can be easily

printed or copied to other documents via the Windows

Clipboard.

You can compare the results from

different Geomag models;

however beware of date restrictions

on certain models.

Vertical Depth value can be

entered to calculate geomag field

lower down the wellpath.

Date defaults to current

date, but it can be changed

to compute historical values.


Chapter 9: Tools

default to those of the current site, assuming that a site is open with a

geodetic system defined. The date defaults to today, but can be changed

to any date. The geomagnetic model defaults to that selected in Site

Setup.

The Geomagnetic Field can be calculated at surface, or calculated at

different TVDs below the current site. This is a useful feature to gauge

the effect of TVD on declination of surveys taken down the wellpath.

Results

The Geomagnetic field varies slowly in time and can be described as

that of a bar magnet with north and south poles deep inside the Earth,

and magnetic field lines that extend well out in space. Because the field

varies, models are used predict what the geomagnetic field is at a

particular time and place.

The results are in nanoteslas (nT) and degrees (°).

The geomagnetic field can be quantified as total field, dip angle,

horizontal intensity, vertical intensity, and declination. Total field or

total intensity is the magnetic strength, which ranges from about 23

microteslas (equivalent to 23000 nanoteslas or gammas, or 0.23 oersteds

or gauss) around Sao Paulo, Brazil to 67 microteslas near the south

magnetic pole near Antarctica. The angle of the field relative to the level

ground is the dip angle or inclination, which is 90° at the north magnetic

pole. Note dip angle is positive downwards.

Vertical and horizontal intensity are components of the total intensity.

X-North is the component of the magnetic field that is aligned north /

south. Y-East is the component of the magnetic field that is aligned east

/ west. Z-Vertical is the component of the magnetic field that is aligned

with gravity.

Finally, the angle of the horizontal intensity, with respect to the north

geographic pole, is declination. Declination is the angle between where

a compass needle points and the true north pole.

Chapter 9: Tools


The following graphic depicts the seven parameters of the Earth’s

Magnetic Field:

Results can be shared with other colleagues or contractors using the

Notepad feature.


Chapter 9: Tools

Using the Site Optimizer

When drilling to a number of targets, you can use the Site Optimiser to

determine the optimum site location to minimize the drilling required to

hit all targets defined for the Site. The Optimiser plans a series of 2D

Slant or S wells to each target aiming point. Results are displayed with

the total well drilled, maximum inclination held, maximum measured

depth, and total displacement. You can manually adjust the site center,

or use an optimize function that automatically determines the site

location.

Similar to other tools in COMPASS, the Site Optimiser consists of two

windows:

� Optimiser, which is used to control and view results,

� Viewer, which is used to display the relative positions of the site

center and target locations.

Note: Site Optimizer plans are not saved when tool is closed.

The simple plans Site Optimiser creates to determine the best location are not

saved when you close the tool. When you determine the best drilling location,

click OK to update the Site center or click Cancel to exit without updating the

location.

Chapter 9: Tools


Both dialogs come with specific tools.

ViewerOptimizer


Chapter 9: Tools

Site Optimizer

The following graphic depicts the Site Optimiser.

Targets

When design constraints are entered, the targets list contains a short

description of the plan to each target. The description includes the target

location, displacement from site center, maximum inclination of the

well, and its MD and TVD.

Design Constraints

This area is used to define which type of well design is used to drill to

each target.

You have two choices:

� Slant well

� Optimum Align using dogleg severity.

The Kick Off field enables you to define a typical KOP. If you are using

optimum align, the optimiser uses the Dogleg entered in the DLS1 field

for Slant wells. Also note that you can increase DLS1 and DLS2 using

The Target List displays the MD, TVD,

and maximum inclination to drill a well

to the target location.

The Summary Statistics display the

worst case directional parameters for all

wells to hit all targets.

The Design Constraints enables the

user to define directional drilling

parameters for Slant and Optimum

Aligned wells to hit targets.

Chapter 9: Tools


the Optimiser if a plan to a particular target is not possible using the

parameters entered.

The optimiser assumes a well is used for each target in the site list; no

wells are planned that intersect multiple targets. Also note that all wells

are drilled in a vertical section—they are 2D.

Site Centre

This area enables you to manipulate the site center location. There are

three ways to change the site location:

� Type in the new Centre Location map coordinates.

� Click one of the buttons to move the site north, south,

east or west by 100 map units.

� Click the Optimiser Viewer , then move the cursor and click

the left mouse button on the required location.

When you decide on a location click Set Site Centre to assign the

current coordinates to the current Site.

Click Optimize to sums the target Eastings and Northings, and divide

both by the number of targets to provide a first-guess start location.


Chapter 9: Tools

Optimiser Viewer

This graph is a plan view of the site targets and the site center connected

by lines that represent each plan. The optimiser view appears

automatically when site optimiser is shown.

The site optimiser viewer enables you to toggle between UTM (Map)

and Local coordinates display.

You can change the site center by entering the coordinates in the edit

controls, or by clicking the graph when it is displays Map coordinates.

Results

As you move the site location, COMPASS reports the following:

This... Means...

Maximum Angle The maximum inclination of any wellpath.

Average Angle The sum of the final inclinations divided by the

number of targets.

Maximum MD The maximum measured depth to any of the

targets.

Total Measured Depth The sum of the measured depth to all the

targets.

Chapter 9: Tools


The maximum results also reports which target required this worst case

value.

Maximum Displacement Horizontal displacement to the furthest target.

Total Displacement The sum of all the horizontal displacements to

all targets.

Centre Location The origin for the well plans.

Kick-off The depth at which each wellpath launches.

Build Rate The build rate for kick-off.

This... Means...


Chapter

Theory

Overview

This section of the training manual discusses in detail some of the theory

referenced in other sections of the manual. In addition, there is an

introduction to directional drilling.

10

Chapter 10: Theory


Introducing Directional Drilling

This section briefly introduces directional drilling and survey

measurement techniques, and describes the hardware technology related

to use of COMPASS. This section is not intended as a complete

reference and there are numerous, more thorough publications that deal

with this subject.

Directional drilling is the science of drilling a well so that its trajectory

follows the planned path to one or more drilling and/or geological

targets. The well must be drilled precisely using the planned directional

parameters designed for the well. If the well steers off course, the

trajectory must be redesigned and drilled to get the well back on track.

Different planning techniques enable wells of varying complexities to

be planned. Different tools enable the well to be drilled and surveyed so

the trajectory drilled is physically as close as possible to that of the plan.

Origins

Directional drilling has always been a part of drilling. In the early days

of drilling at Spindletop, Texas, resourceful drillers put wooden wedges

(Whipstocks) down wells to deviate them towards nearby gushers. This

practice was known as poaching. To prevent this, laws were enacted that

required wells to be positioned within a lease boundary, and wells had

to be inspected for deviation by the Texas Railroad Commission and

other bodies.

The same methods of deviation and measurement enabled wells to be

deviated under obstacles, such as cities, lakes, seas, mountains, shallow

gas, and pipelines. Sidetracks are wellpaths intentionally deviated from

the original hole, which are used to get past fish (lost drill string), correct

unwanted deviation, or reuse an old hole to reduce costs.

Blowout relief wells started in the 1920’s and required precision control

to drill the relief well to within a few feet of a blowout well. Early survey

instruments were developed to meet the requirement to know the exact

trajectory of both blowout and relief wells. When the relief well was

determined to be close to the blowout well, cement was pumped to plug

the formation and control the pressure. In modern relief wells, magnetic

ranging methods are used to accurately position the well close to the

blowout.


Chapter 10: Theory

Platform Drilling negates the requirement for additional platforms. A

single template underneath the platform is used to access a number of

locations within a reservoir. Deviated wellpaths permit tapping an

extended area of the reservoir from a compact drill site.

Salt Dome drilling is performed to access traps that form on the

upthrown side of the plug. Drilling can be problematic due to plastic salt

deforming casing and high pressure gas at shallow depths. Sidetracks

are made to re-use wells from depleted zones and to drill new ones.

Planned and unplanned deflections are called doglegs. Bit Walk is a

natural tendency for BHAs to steer off course due to formation and BHA

effects. Planned well trajectories can be corrected for this effect to keep

the well on target.

The following graphic depicts the origins of Directional Drilling:

Chapter 10: Theory


Early Means of Directional Control

Oriented Drilling

Directional drilling began with the use of devices such as whipstocks or

techniques such as jetting, rotary assemblies to maintain course, and

wireline steering tools to orient and survey.

Whipstock is the name of a wooden wedge that was the first widely-used

deflection tool for changing the wellbore trajectory. It was run and

oriented on drill pipe and the drill bit was deflected off it, provided the

whipstock was harder than the formation. Use of a whipstock was

problematic because a fill in the hole could seriously impede its

performance. Also, much experience was required to use this method

effectively.

The fulcrum and pendulum bottom hole assemblies are mechanical

methods of increasing or decreasing hole angle once an angle is built.

All BHAs cause a side force at the bit that makes the bit build, drop, or

hold angle and turn to the right or left. BHAs can be designed to provide

a desired performance. This technique relies on precise stabilizer

placement and blade diameters that are used to stand-off and pivot the

collars and bit. This functionality, used with the natural turning

characteristic of different bit types, provides drillers with three-

dimensional, rotary, and directional control.

Keeping the well vertical is very difficult in areas of dipping or hard

formations. The weight applied to crush rock at the bit buckles the pipe

and causes deflection into the dip. Heavy collars and pendulums are

used to counteract these trends.

An example is ‘Oklahoma measured depths’ which was an early study

to determine the pipe depth required to reach top reservoir. Some wells

required 10-50% more pipe to reach the reservoir in so-called vertical

wells. This was because hard Okie formations required much weight to

be drilled. The large compressive forces caused buckling in the drillpipe

which caused the drillstring to be deflected.

Jetting is used in soft formations (gumbo) where one nozzle in a tri-cone

bit is enlarged and oriented to create a rathole, into which the string is

dropped. The technique has been very successful in the Gulf of Mexico,

but has not had much success in the North Sea. Jetting uses the hydraulic

energy of the drilling fluid to erode a hole along a given azimuth. The

string is dropped into the rathole.


Chapter 10: Theory

This jet and drop procedure is performed for 3 to 6 ft. without rotating

to establish the new direction. Rotary drilling then proceeds until a

survey is taken to verify the new wellbore trajectory.

This technique is dependent on the formation being drilled. Weakly

cemented sandstones and oolitic limestones prove good candidates,

while very soft or hard formations fail due to the jet blowing away too

much hole in soft formations and not having sufficient power to make

new hole in hard formations. The primary advantage of jetting is that it

can be performed with the same BHA used to drill.

Survey Measurement

The wellpath trajectory is determined by measuring the inclination and

direction at various depths. Early measurement tools included the acid

bottle and punch card, which were used to record inclination in order to

indicate whether the trajectory had deviated. These tools were run on

slick-line (steel wireline). Hydrofluoric acid was poured into a glass

bottle and etched the bottle at the angle at which it came to rest. The

punch card technique was the basis for the TOTCO tool used for

inclination measurement.

Magnetic and gyroscopic tools are used to record inclination and

direction. They use either a single or multi-shot timed camera or

sensitized paper to record stations for deviated wells. Gyros are usually

run on a conductor cable, which supplies power and can be used to

transmit readings to the surface. Other gyros are battery-powered and

are run on a wireline inside casing. Magnetic multi-shot tools are run on

a slick-line, sand line (braided cable), or dropped inside non-magnetic

collars and brought back to surface as the string is tripped.

The muleshoe ensures that the single shot survey tool is consistently

located inside the bottom of the BHA relative to the bent sub, jetting bit,

whipstock wedge, undergauge stabilizer blade, or other tool used to

orient the BHA. As the survey tool lands in the BHA, a stub in the

muleshoe landing ring (in pipe) draws the recess in the survey tool spear

point round so that the tool seats in the direction of the tool face. For

quality control, a lead slug is seated in the recess to indicate a good

survey orientation. Marks in the slug indicate that the landing ring had

seated right into the muleshoe recess.

Chapter 10: Theory


The following graphic depicts the early means of directional control:

Modern Directional Drilling

During the 1970’s, directional drilling requirements escalated on

platforms designed to access large parts of the reservoir. Drilling at

these sites became more complex as the fields matured and wells were

safely directed around existing producing and injecting wells. During

the 1980’s and 90’s, directional drilling techniques and equipment

improved dramatically due to requirements to drill a large number of

horizontal wells though fractured limestone reservoirs to increase

production, instead of vertical wells. The Austin Chalk in Texas and the

Cretaceous chalks in the North Sea were driving areas of this

cost-effective technique.

Extended Reach Drilling (ERD) wells are defined as those wells with

departures that exceed twice the well TVD. Different classes of ERD

well have evolved based on increasing Reach/TVD ratios. These include

conventional directional drilling (<2.0), ERD wells (>2.0), and severe

ERD wells (>3.0).

Modern equipment and techniques can drill wells with 10km stepouts at

only 1.5km depth. The best example is Wytch Farm in southern England

where the Sherwood Sandstone reservoir underlies Poole Bay, which is

environmentally protected. Parts of the target are problematic in that the


Chapter 10: Theory

reservoir dips onshore, requiring the wells to hit the target downdip,

build, and drill up through the reservoir. These extended wells have been

used as a test site for some of the emerging technologies described in

this section. Even greater ERD wells are being drilled all the time.

Horizontal Wells were pioneered in fractured chalk reservoirs where

vertical wells are uneconomic, because they fail to hit vertical fractures.

Examples include Farmington (short radius), Austin Chalk (medium

radius) and offshore Denmark (long radius). Horizontal wells are now

used in reservoirs where greater life and productivity can be expected

from fewer wells by limiting Water and Gas coning. The economic

success of these wells has resulted in horizontal wells becoming the

norm. The question now is ‘why drill a vertical well?’

Heavy Oil projects (Alberta, Canada) require steam injection from

horizontal wells to warm up the viscous oil and make it mobile so that it

flows into an adjacent parallel wellbore—this is an example of an

Enhanced Oil Recovery (EOR) method. One well is drilled for

production and a second steam injection well is drilled 10/20’

underneath using magnetic ranging from the MWD to the magnetized

casing of the top wellpath. The hot steam from the injection well reduces

oil viscosity, enhancing oil flow into the overlying producer.

Multi-lateral wellpaths are drilled from the same well. Laterals are

planned side-tracks where each path is selectively available to

completion equipment.

River crossing is where a hole is drilled under a river to carry a pipeline

or cable. The hole is drilled and widened using a mining rig on a truck

and deviated up to a target location. Then the pipeline is attached to the

bit and pulled back through.

Chapter 10: Theory


The following graphic depicts modern directional drilling techniques:

Mud Motor

The mud motor is the workhorse of modern directional drilling,

representing a major advancement in directional control. First employed

in the oil field by Dynadrill (Smith, Halliburton, now Pathfinder) in

1968 as a directional tool, Positive Displacement Motors (PDM) offer

greater torque and better pressure feedback than turbines. Drilling with

motors is easier because the surface standpipe pressure reflects motor

torque, which in turn can reflect weight on bit (WOB). As motor torque

increases, standpipe pressure increases and vice-versa. Therefore, the

directional driller uses standpipe pressure to advance the bit by

controlling torque. If the bit stalls you get an increase in pressure.

The motor is composed of four standard sections:

� The Dump Sub is used to divert mud so that the roughnecks don’t

get wet feet. It is used to bypass the fluid from the motor while the

tool is tripped into and out of the hole. Essentially it enables the

drillstring to fill with mud from the annulus while tripping in, and

enables the drillstring to drain while tripping out—this prevents it

from flowing out onto the drillfloor when a connection is made.


Chapter 10: Theory

When the pumps are started, the fluid forces a piston down, closing

the bypass ports, directing fluid through the motor.

� The Power Section converts hydraulic horsepower into mechanical

horsepower, resulting in drill bit rotation. It consists of two parts,

the rotor and the stator, that when assembled form a continuous seal

along their contact points. The rotor is an alloy steel bar shaped into

a helix and is specially coated in chrome to reduce friction, wear

and corrosion. The stator is a length of tubular steel lined with an

elastomer compound shaped into a helix to mate with the rotor.

PDMs use a reverse application of the Moyno pump principle to

generate power from the mud stream. Slugs of mud are driven

through slots in the rotor/stator, generating torque, which causes the

rotor to cycle backwards through the grooves in the stator

(epicyclical motion). Different rotor/stator lobe ratios (1/2 5/6 9/10)

are used for more power and lower speed. The most common PDM

is a half-lob motor where the rotor has one lobe and the stator two.

PDMs always have 1 more lobe in the stator than the rotor; this

results in a progressive series of cavities for the fluid to flow

through. The pressure of this fluid causes the rotor to rotate. Torque

is then transmitted to the Universal Joint.

� A Universal Joint forms the coupling assembly, which converts the

epicyclical motion of the rotor into rotation at the drive shaft, which

is connected to the bit. It is either a U Joint (Car FWD) or a solid

piece of Beryllium Copper.

The Bent Housing was originated in 1982. Previously a bent sub was

used above the motor. The bent housing allows the whole motor to

be rotated to drill straight, or oriented from surface to drill at an

angle. Bent housing angles are now adjustable.

� The Bearing Assembly supports the motor drive shaft that transmits

drilling thrust which turns the bit. It consists of on- and off-bottom

thrust bearings and radial bearings. Of all the components in a mud

motor, the Bearing Assembly is most exposed to harsh conditions.

Controlled curved wellpaths are drilled using a sequence of

curved/oriented and straight/rotating sections. The bend is always

over- designed by 25-50%. The Stabilizer on the bearing housing is

used to balance the bit and the bend for optimum direction control.

MWD data will tell the Directional Driller which way the bend is

pointing, and the inclination and azimuth of the well heading.

Chapter 10: Theory


The following graphic depicts the Mud Motor:

Measurement Systems

Accurate knowledge of wellbore position is important to:

� Optimize the recovery from a reservoir by strategic positioning.

� Build an accurate 3-dimensional map of reservoir surfaces.

� Enable the well to be relocated in the event of an underground

blowout.

� Prevent loss of wells and damage caused by inter-well collisions.

Modern wellbore surveying tools to achieve these objectives include

MWD and Gyros.

Magnetometers are the primary measurement method used while

drilling. The MWD and Multi-shot tools have triaxial magnetometers

and accelerometers. Magnetic surveys are affected by variations in the

earth's magnetic field and by steel from the drill string; they require

special non-magnetic drill collars to be spaced about the survey tool.

Gyroscope surveying is used to obtain more accurate logs. Gyros are

normally run inside casing, although some gyros have been adapted for

pump down and MWD.


Chapter 10: Theory

The rate gyroscope has become the standard in the business; it was

developed for cruise missiles. It uses one fixed axis gyro, with gimbal

axes that are held steady by electro-magnetic resolvers. The current

required to prevent swing indicates the rate of turn of the assembly.

These gyros are sufficiently sensitive to pick up the earth’s motion. This

is called gyrocompassing. The initial angle of the tool is detected, and

the sensors then detect movement as the tool moves down the wellbore

on wireline. The movements are integrated into angles and then into

positions.

Because gyros are generally more accurate than magnetic surveys, they

are typically used to correct the wellbore trajectory as calculated from

the magnetic survey data. Magnetic surveys when compared against the

plan can indicate that the well was not drilled to the plan, resulting in

some serious discussion between drillers and geologists. The solution is

to run a gyro and recalculate the wellbore trajectory to see how it

compares against the plan.

The following graphic depicts Magnetic and Gyroscopic Systems:

Measurement While Drilling

MWD tools are instruments that signal the surface with information

about the wellbore and formation at the drill bit. The first application

was directional information (Inc/Azi), which replaced the existing

single-shot instruments.

Chapter 10: Theory


In the early 1980’s, formation information was available that included

short normal resistivity and natural gamma ray tools. Recent

developments include sensors that measure formation acoustic velocity

(sonic) and provide electrical images of dipping formations. These types

of tools are called Logging While Drilling (LWD), because the quality

data they provide results in equivalent wireline runs no longer being

required. Tools include sensors that measure Temperature, Neutron

Porosity, Density, Pressure, Vibration, etc.

Additional information provided by MWD systems include downhole

WOB, downhole pressure at bit (PWD), drillstring dynamics data

(vibration), neutron porosity, bulk density, and ultrasonic caliper

measurements. This type of information is used to aid geo-steering.

MWD tools typically consist of a power system, telemetry system,

directional sensor, and formation measurement tools.

� Power is supplied to the tool by turbine or batteries. Batteries can

supply tool power without drilling fluid circulation. Turbine energy

is abundant as it is supplied by fluid flow.

� The Telemetry equipment transmits data back to surface. The

signals are sent via mud pulses, which are interpreted by a pressure

transducer in the stand pipe at the surface.

An example is negative pulse, made by diverting mud from the pipe

to the annulus; it reduces the pressure in the stand pipe. Pressure

pulses are slow. A single pulse takes less than 1 second to transmit.

A digitized angle (Toolface) can take 10-20s to transmit in digital

form.

Positive pulse is also widely used, where the pulse is caused by a

valve restricting flow in the pipe. Both the negative and positive

mud pulse systems use a solenoid driven by a bank of capacitors to

drive the valve. Other methods for signalling the surface have been

tried, such as cable in the pipe (wears out quickly) and radio

transmission (VLF is used but limited by depth).

� Directional survey information is detected by triaxial

magnetometers (electronic compass) and triaxial accelerometers

(electronic plumb bob).

� Geophysical traces are transmitted for geosteering, These are the

Gamma Ray detector (a Geiger counter) and Resistivity (via

electromagnetic wave coils).

� At surface the pulses are converted into log data, which is made

available at the rig floor in terms of dial readings and to the

operator in the form of logs. Log plotting requires a depth tracking

system and computer software.


Chapter 10: Theory

The following graphic depicts the MWD at Rigsite:

Inability to steer mechanically while rotary drilling resulted in the

design and implementation of Variable Blade Stabilizers (VBS) also

known as Adjustable Gauge stabilizers (AGS). These tools are designed

to enable blade diameters to be changed while drilling.

These tools, along with other fixed-gauge BHA stabilizers, are used to

change the build and drop tendency of rotary and steerable BHAs with

a simple pumps-on/pumps-off procedure. This enables BHA steering

tendency to be changed to downhole without having to trip the

assembly.

Chapter 10: Theory


Other benefits include improved hole cleaning, due to continuous

rotation of the drill string, and torque/drag tortuosity reduction by

limiting dogleg severity.

Emerging Technologies

A number of new technologies are being employed in directional

drilling to enable extended reach or designer well trajectories to be

achieved.

Coiled Tubing/Underbalanced Drilling

Coiled Tubing (CT) rigs were originally developed for workover

operations inside existing wells, but have now been adapted for

sidetracking and drilling. CT rigs can drill short length wells (1500’

horizontal) at lower cost and time than a conventional drilling rig (with

a smaller footprint). The coiled tubing (2” steel) is coiled onto a drum

and fed into the wellbore through an injector with spools that can push

or pull the tubing into the hole. The standard steering combination of

bent mud-motor and MWD has been modified for CT with the addition

of a ratchet indexing device for orienting the motor bend. This is used

because CT cannot be rotated for orientation.

In the Underbalanced Drilling (UB) method, the drilling fluid is made

less dense than the formation fluid inside the reservoir. As a result, the

formation fluid flows into the wellbore. This is desirable because if the

drilling mud overbalances pore pressure, it will invade the reservoir pore

space and reduce permeability. Reduced permeability results in reduced

formation productivity, particularly in horizontal wells where the

reservoir is subject to longer contact times with the drilling fluid, and

open hole completions are more prevalent.

In addition to reducing formation invasion, underbalanced drilling

results in reduction of drilling time due to increased ROP, increased bit

life, and less chance of differential sticking. In normal drilling, lower

mud densities are avoided because pressure problems (blowouts) will

occur which can be difficult to control.

In UB drilling the pressure can be regulated with a special blow-out

preventer and choke at surface. Fluid densities can be reduced by foam

drilling or injecting nitrogen into the drilling fluid. Special equipment is

used at the surface for solids separation and cuttings sampling.

A major drawback with the technique has been the inability to use

MWD—and therefore geosteer—due to the presence of compressible


Chapter 10: Theory

gas in the annulus which prevents mud pulse systems from transmitting

back to surface. Electro-magnetic tools (EMT) have solved this problem

for shallow wells enabling direct transmission back to surface. Depth

and temperature restrictions in addition to formation restrictions have

limited the use of EMT, though repeaters/transmitter technology seems

to enable EMT tools to be used at deeper depths.

The following graphic depicts the Coiled Tubing Rig and

Underbalanced Drilling:

Multi-Laterals

Planned multi-lateral (ML) wellbores are now a part of modern

completion practices. Lateral wellbores allow simultaneous production

from two or more zones without the cost of the extra upper wellbore and

surface equipment. Second and subsequent wellbores can be drilled at

30% of the cost of the original well. This method only suits reservoirs

that have good mechanical stability.

ML wells comprise a parent wellbore with one or more secondary

wellbores (laterals), all of which produce or inject fluids or provide

information. They are classified based on the junction mechanism

between the parent and sibling wellbores.

Chapter 10: Theory


Whether the junction is open or closed, or whether the tubing or casing

is installed across the junction determines a ML well’s classification. A

common classification scheme contains six variants with increasing

complexity:

The lateral wellbore shown below (Level 3) is constructed by installing

casing in the primary wellbore with a window joint positioned and

rotated in the desired direction. A protective sleeve is removed and a

drilling whipstock is oriented and installed. The window is opened with

a milled tooth bit run on a steerable motor.

Once the lateral is drilled, the junction is cased off with a short liner, the

section of the primary wellbore is washed over and recovered. Drilling

of the lower lateral is then performed through the primary wellbore.

Re-entry into the upper lateral can be performed at any time by installing

a retrievable workover whipstock.

This classification... Has these features...

Level 1 No zonal isolation, such as openhole sidetracks.

Specific branch access is difficult, sometimes

impossible.

Level 2 Cased and cemented parent wellbore with a milled and

slotted liner in the sibling, but provides no zonal

isolation or pressure integrity across the junction.

Level 3 Contained cased and cemented parent and sibling

wellbores with cement or epoxy at the junction. The

junction provides no zonal isolation, and cannot sustain

a differential pressure greater than the formation

fracture pressure.

Level 4 Same as Level 3 but contains cement at the junction

designed to provide pressure support greater than the

fracture pressure. Packers in the parent wellbore

provide zonal isolation by being placed on both sides of

the sibling.

Level 5 Achieves full zonal isolation using a downhole

deflector at the junction and a system of packers in both

parent and sibling wellbores. This enables production

tubing to be mechanically sealed.

Level 6 Uses mechanical splitters to achieve full zonal isolation

along both branches.


Chapter 10: Theory

The following graphic depicts the Multi-Lateral Level-3 Completion:

ML wells can also be classed based on their relative geometry. Different

types include:

� opposed dual laterals

� stacked dual laterals

� multi-laterals

� branched multi-laterals

� splayed multi-laterals

� forked dual laterals

Rotary Steerable Systems

Rotary steerable devices (also known as Steerable Rotary Drilling -

SRD) enable inclination and azimuth correction during rotary drilling.

The concept was first introduced in 1991 by Camco. There are currently

several rotary steerable systems in an expanding market. A number of

different types of systems are being tried.

Rotary steerable systems offer considerable advantages over the

steerable mud motor system:

� Drillstring torque and drag should decrease, resulting in less

tortuous wellbores. This should reduce stuck pipe, and make

workovers and completions easier.

Chapter 10: Theory


� Drilling in rotary mode should reduce bit walk.

� ROP should increase 50-100% by enabling bits to be selected for

performance reasons rather than steerability.

� The number of trips required to directionally drill a well should

decrease.

� LWD data quality should improve due to drilling in rotary mode as

well as because the data is obtained closer to the bit. Drilling course

corrections can be made earlier.

� Cuttings transport is better in rotary mode resulting in easier hole

cleaning, less chance of forming cuttings beds, and getting stuck.

� Fewer wiper runs are required (smoother wellbore, less cuttings

beds, and so on).

� Dogleg severity and wellbore spiralling should decrease, resulting

in easier completions.

� Steering should enhance production by keeping the well within the

reservoir.

In comparison, mud motor systems are slow when steering because the

drill string is not rotating and the string will pick up friction and cuttings.

The resultant extra drag becomes so great that the motor becomes

unsteerable, especially if the pipe buckles. A rotary steerable system

will drill faster and farther. They do not offer the range of radii of

motors; therefore they are best suited to extended reach wells.

A rotary steerable device consists of two sections:

� The bias unit is located immediately above the bit. It has three

actuator pads which can be operated in synchronization with bit

rotation in order to provide a lateral displacement in a constant

direction and hence steer the well. The pads are operated

hydraulically using the drilling fluid, and are controlled by a rotary

valve that is mechanically connected to the control unit.

� The control unit is mounted inside a non-magnetic drill collar and

contains a directional sensor package, roll sensors, and control

electronics.

The example below (a hybrid of three designs) has a non-rotating

stabilizer body with three buttons on hydraulic pistons in each blade.

Pressurized oil is driven through a rotating valve to one blade’s pistons.

This imparts thrust to the wall, which by reaction will drive the bit in the

opposing direction, causing it to drill laterally by side cutting.

The rotating valve determines which direction the thrust moves. The

valve itself is driven by an electric stepper motor at to a position which

is synchronized with the rotation detected by a Hall effect transistor.

An oil pump is driven by the rotation movement.


Chapter 10: Theory

The following graphic depicts the Hybrid Rotary Steerable Device:

Geo-Steering

Geo-steering is directional steering within the close confines of a

payzone. Wellpath adjustments are made based on real time geological

and reservoir data, in addition to drilling observations. The goal is to

maintain a bit position at an optimum depth near the top of a producing

formation.

Geo-steering enables the planned wellpath trajectory to be evaluated

against the geological model as the well is drilled. The planned build

trajectory may be compromised by inaccurate depths from seismic data,

resulting in the formation tops coming in higher or lower than expected.

Formation markers are detected by Gamma/Resistivity sensors while

drilling the well. The planned trajectory is adjusted to any changed

formation tops to ensure that the well meets it geological requirements.

Steering in the payzone is achieved by watching the petrophysical

sensors for signs of the producing formation, and steering away from

poor formations. Shales and non-productive formations have high

gamma counts (radioactivity) and low resistivity. Productive formations

are ideally clean of radioactive clay minerals, and therefore show low

gamma counts and high resistivity (especially in oil/gas zones).

Chapter 10: Theory


Geo-steering equipment consists of detectors near the bit which provide

faster reaction times than sensors located 40’ to 80’ behind the bit. This

enables thinner zones to be drilled with confidence. In a thick productive

zone, other indicators may be used, such as examining cuttings from the

shale shakers, looking for microfossils in limestone, or evaluating

hydrocarbon returns at surface. These measurements can be more

immediate if ROP is low through the reservoir.

The following graphic depicts Geo-Steering Equipment at the Bit:

To maintain quick reaction times, geo-steering is a team effort requiring

close coordination between the driller, the directional driller, MWD

operator, and the geologist interpreting the formations.

With a typical ROP of 30ft/hr, the engineers have two data points per

foot on which to interpret the well against the predicted

geological/petrophysical model. Log curves must be compared and

interpreted against predicted responses to ensure that the well is drilled

to its planned target. These interpretations are fed back to the directional

driller and adjustments are made to the well trajectory where necessary.


Chapter 10: Theory

The following graphic depicts the geosteering as a team effort at the

rigsite:

Chapter 10: Theory


Survey Calculation Methods

You use survey calculation methods to calculate the final wellbore

position of a second measurement station that is deeper than a first

station, using the position and vector (inclination and azimuth) of the

first station, the vector of the second station, and the measured distance

between the two. Working down the wellpath, a survey calculation

method enables you to determine the total wellpath trajectory.

COMPASS offers four survey calculation methods.

• Minimum Curvature

• Radius of Curvature

• Average Angle

• Balanced Tangential

This setting is the company's preferred calculation method and cannot

be overridden in the Survey module except for Inclination-only surveys.

The following graphic depicts Wellpath Trajectory Calculation

Parameters:

Vertical Section View

TVD

East

V.SectionTVD

North

DVD

3 Dimensional View

Compass Survey Calculation

DMD

Plan View (horizontal)

RI (radcur)

I2

I1

A1

A2

DNS

DEW

R (mincur)

Tangents to Sphere

Great Circle

DVS

East

RA (radcur)DL


Chapter 10: Theory

General Parameters

• TVD2 = TVD1 + ∆TVD

• NS2 = NS1 + ∆NS

• EW2 = EW1 + ∆EW

Input Parameters

• MD1 = measured depth of top point (ft./m)

• MD2 = measured depth of bottom point (ft./m)

• I1 = inclination of top point (rad)

• I2 = inclination of bottom point (rad)

• A1 = azimuth of top point (rad)

• A2 = azimuth of bottom point (rad)

Output Values

• ∆NS = change in North/South position between points 1-2 (ft./m)

• ∆EW = change in East/West position between points 1-2 (ft./m)

• ∆TVD = change in true vertical depth between points 1-2 (ft./m)

• DL = Dogleg Angle (rad)

• DLS = Rate of Change of angle with depth in 3D space

• Build = Rate of change of inclination with depth (may be Drop)

• Walk = Rate of change of azimuth with depth (also called Turn)

• ∆MD = MD2 - MD1

• DL = ArcCos (Cos(I2 - I1) - Sin(I1) * Sin(I2) * (1.0 - Cos(A2 - A1)))

• DLS = DL/∆MD

• Build = (I2-I1) / ∆MD

• Walk = (A2-A1) / ∆MD (Note: azimuth is normalized for > 180

degree turns)

Chapter 10: Theory


Calculation Methods

Minimum Curvature (also called Circular Arc)

This survey calculation method is most widely adopted in the oil

industry. The path taken conforms to the tangential arc in the 3D sphere

shown in the diagram on the previous page.

Calculate RF (Minimum curvature ratio factor) Smoothing Factor

• if (DL < 0.0043633 rad) RF = 1.0

• if (DL >= 0.0043633 rad) RF = (2.0 / DL) * Tan(DL/2.0)

Note: (0.0043633 rad = 0.25 deg)

• ∆NS = ∆MD/2.0 * (Sin(I2)*Cos(A2) + Sin(I1)*Cos(A1)) * RF

• ∆EW = ∆MD/2.0 * (Sin(I2)*Sin(A2) + Sin(I1)*Sin(A1)) * RF

• ∆TVD = ∆MD/2.0 * (Cos(I2) + Cos(I1)) * RF

Radius of Curvature

The Radius of Curvature survey calculation produces slightly different

results from the Minimum Curvature method. The path taken conforms

to the two separate radii in the plan and section views shown in the

COMPASS Survey Calculation diagram. It does not have a single 3D

radius, and hence dogleg severity (DLS) changes over the course length.

• ∆NS = ∆MD * [Cos(I1) - Cos(I2)] / (I2 - I1) * [Sin(A2) -

Sin(A1)] / (A2 - A1)

• ∆EW = ∆MD * [Cos(I1) - Cos(I2)] / (I2 - I1) * [Cos(A1) -

Cos(A2)] / (A2 - A1)

• ∆TVD = ∆MD * [Sin(I2) - Sin(I1)] / (I2 - I1)

Average Angle

Average angle is a survey calculation easily adopted to hand calculation.

The differences between it and the above two methods are very small.

• ∆NS = ∆MD * Sin((I1+ I2)/2)*Cos((A1+ A2)/2)

• ∆EW = ∆MD * Sin((I1+ I2)/2)*Sin((A1+ A2)/2)

• ∆TVD = ∆MD * Cos((I1+ I2)/2)*Cos((A1+ A2)/2)


Chapter 10: Theory

Balanced Tangential

The balanced tangential survey calculation method is essentially the

Minimum Curvature method with RF=1. It is considered to be the least

accurate of these four methods.

• ∆NS = ∆MD/2.0 * (Sin(I2)*Cos(A2) + Sin(I1)*Cos(A1))

• ∆EW = ∆MD/2.0 * (Sin(I2)*Sin(A2) + Sin(I1)*Sin(A1))

• ∆TVD = ∆MD/2.0 * (Cos(I2) + Cos(I1))

Inclination Only

The inclination only method is included in COMPASS to handle

inclination-only measurement tools like TOTCO. It calculates vertical

depth in the same way as Radius of Curvature or Minimum Curvature,

but does not calculate the North and East dimensions.

Chapter 10: Theory


Geodesy

Geodesy is the science of measuring the earth's surface. The Earth is

round (sort of) and maps are flat. A geodetic system enables you to

convert geodetic coordinates (angles on a round earth—latitude/

longitude) to map coordinates (distances on a flat map—easting/

northings). To do this you must know the system, the datum (ellipsoid),

and the zone.

System

A geodetic system is one or more map projections covering adjacent

parts of the globe. A system can comprise one or more zones. If you do

not know the geodetic system for your area, or if you have no need to

convert between geodetic and map coordinates, select Flat Earth. By

selecting Flat Earth you disable conversion between geodetic and map

coordinates throughout the Field. Otherwise, select the geodetic system

agreed on for use in an area.

COMPASS ships with a pre-defined set of geodetic systems that cover

the majority of systems used in the oilfield. Certain locations require

additional or customized geodetic systems. These are easily added in

COMPASS as geodetic configuration files, which are commonly

constructed by your regional Landmark Support Office.

Datum

A datum or ellipsoid is essentially a mathematical model that best

represents the actual shape of the Earth’s surface in a given area. The

Earth’s surface is generally geometric like an American football or

rugby ball. However, it is an irregular, slightly flattened sphere—a

geoid. We cannot compute geodetic conversion on a geoid, so we

assume the earth to be an ellipsoid. Because the earth's surface is

irregular, different shaped ellipsoids better represent different parts of

the globe. The size and shape of the ellipsoid varies depending on part

of the globe mapped.

Regional geographic organizations, and even oil operator survey

departments recommend which geodetic system and ellipsoid to use for

a given operating area.


Chapter 10: Theory

Map Zone

A geodetic system can contain one or more map zones. Each zone maps

a different area. Following are three examples of geodetic systems

shipped with COMPASS:

US Stateplane Coordinate System 1983

This system maps the United States. It is a combination of

Transverse Mercator and Lambert Projections and comprises 124

zones. Most States have more than one zone—Alaska has ten zones,

Texas has five, Maryland has only one. Unlike the UTM projection,

just one ellipsoid is used for the entire system—GRS 1980.

Universal Transverse Mercator

The UTM system maps the entire world by dividing it into 60 zones,

each 6° of longitude wide, extending up to 84° N and S. When the

UTM system is selected COMPASS makes all datums available and

lets you select any one of the 60 zones north or south.

The diagram below depicts a UTM zone covering both southern and

northern hemispheres. Two reference points are plotted, one in the

West side of the Northern Hemisphere, the other in the East side of

the Southern Hemisphere. Note that convergence (angle from True

North to Grid North) for both points is negative. In the other two

quadrants (NE & SW), convergence is positive.

Chapter 10: Theory



Chapter 10: Theory

UK National Grid

This system maps the United Kingdom, has one zone, and is based

on the Airy 1949 ellipsoid.

Chapter 10: Theory


Geomagnetism

What is the Magnetic North Pole? The Earth's core has remained molten

due to heat from ongoing radioactive decay. Convection currents

flowing in the outer core generate a magnetic field, but the poles of this

field do not coincide with north and south poles (the axis of rotation of

the Earth). In early 1998, the average position of the modeled north

magnetic dipole (according to the IGRF-95 geomagnetic model) was

79.5° N, and 106.3° W, 40 kilometers north-west of Ellef Ringnes Island

in the Canadian Arctic. This position is 1170 kilometres from the true

(geographic) North Pole.

It is generally believed that a compass needle points to the magnetic

north pole. Because the geomagnetic field is the effect of complex

convection currents in magma composing the Earth’s core, the local

field must be described as several dipoles, each with a different intensity

and orientation. Because of this, the compass needle actually points to

the sum of the effects of these dipoles at a given location. In other words,

the needle aligns itself with the magnetic lines of force. Other factors, of

local and solar origin, further complicate the resulting field. It may be

all right to say that a compass needle points to magnetic north, but it only

roughly points to the north magnetic dipole.

The following graphic depicts the Magnetic Declination variation as

calculated by IGRF95. Mercator projection. IAGA Division V,


Chapter 10: Theory

Working Group 8, International Geomagnetic Field, 1995 Revision, J.

Geomag, Geoelectr.,47,1257-1261, 1995:

Geomagnetic Main Field Models

A geomagnetic main field model is a set of a few hundred numbers

determined by 3D curve fitting a large number of geomagnetic field

observations from sites around the world. Predictive geomagnetic

models can be used worldwide, and only predict the values of that

portion of the field originating in the deep outer core.

Different geomagnetic models are available, some of which are used

within COMPASS:

� World Magnetic Model (WMM): updated every five years. Public

model available from the US Department of Defense, who provide

it on behalf of the US National Geophysical Data Center. Available

from the Internet at

http://ftp.ngdc.noaa.gov/seg/potfld/DoDWMM.shtml.

� International Geomagnetic Reference Field (IGRF): public model

updated every five years. Available from the International

Association of Geomagnetism and Aeronomy on their Internet site

at http://ftp.ngdc.noaa.gov/IAGA/wg8/igrf2000.html.

Chapter 10: Theory


� Definitive Geomagnetic Reference Field (DGRF): model describes

how the field actually behaved. This is also provided for five-year

intervals, and is also available from the International Association of

Geomagnetism and Aeronomy.

� British Geological Survey Geomagnetic Model (BGGM): The BGS

annually computes a model of the geomagnetic field, meeting the

demands of accuracy and Quality Assurance required for

directional drilling and well placement. The BGGM is supported by

major oil companies, service companies in the oil sector, and by the

Health and Safety Executive.The model is updated every year, and

is therefore considered more accurate. It is a commercial model,

and is therefore not shipped automatically with COMPASS. Clients

must provide proof of a license from the BGS before Landmark

will ship geomagnetic model files for use with BGGM. Information

is available from the BGS on the Internet at

http://192.171.143.111/bggm.html.

Factors that Influence Declination

The following factors influence declination and therefore magnetic

survey instruments. Their effects are noted in parentheses:

� Location (one to thousands of kilometers/degree)

� Local magnetic anomalies (0-90 degrees; 3-4 degrees frequently)

� Altitude (negligible to 2 degrees)

� Secular change (2-25 years/degree)

� Diurnal change (negligible to 9 degrees)

� Solar magnetic activity (negligible to extreme)

Location has an obvious effect, as magnetic declination varies over the

entire globe. Each position on the Earth has a particular declination. The

change in its value as you travel is a complex function. If you travel

along a straight line of equal declination, called an isogonic line, it

varies little over thousands of kilometers. However, if you cross

isogonic lines at high latitudes, or near magnetic anomalies, the

declination can change more than one degree per kilometer.

Local anomalies originating in the upper mantle, crust, or surface,

distort the WMM or IGRF predictions. Geologic features include the

following:

� ferromagnetic ore deposits

� volcanic structures, such as dikes and lava beds

� topographical features such as ridges, trenches, seamounts, and

mountains


Chapter 10: Theory

� ground that was hit by lightning and possibly harboring fulgurites

Cultural features include the following:

� power lines, pipes, rails, and buildings

� personal items, such as a steel watch or belt buckle, which can

cause an error of three to four degrees

In some places the field is completely vertical and a compass will

attempt to point straight up or down (for example, at the magnetic

dipoles), but there are other locations where extreme anomalies create

the same effect. Around such a place, the needle on a standard compass

drags so badly on the top or the bottom of the capsule that it cannot be

steadied.

The effect of altitude is normally negligible. According to the IGRF, a

20,000 meter climb even at a magnetically precarious location as

Resolute, NWT, Canada (500 kilometers from the north magnetic pole),

results in a two-degree reduction in declination.

Secular change is the movement of the magnetic north pole itself. As

convection currents churn in apparent chaos in the Earth's core, all

magnetic values change erratically over the years. The north magnetic

pole has wandered over 1000 kilometers since Sir John Ross first

reached it in 1831. Its rate of displacement has been accelerating in

recent years and is currently moving about 24 kilometers per year. That

is several times faster than the average of six kilometers per year since

1831.

The stream of ionized particles and electrons emanating from the Sun,

known as solar wind, distorts the Earths’ magnetic field. As the Earth

rotates, any location is subject alternately to the lee side, then the

windward side of this stream of charged particles. This has the effect of

moving the magnetic poles around an ellipse several tens of kilometers

in diameter, even during periods of steady solar wind without gusts.

The resulting diurnal change in declination is negligible at tropical and

temperate latitudes. For example, Ottawa is subject to plus or minus 0.1

degree of distortion. However; in Resolute, NWT, Canada, the diurnal

change cycles through at least plus or minus nine degrees of declination

error. This error can conceivably be corrected, but both the time of day

and the date have to be considered, as this effect also varies with

seasons.

The solar wind varies throughout an 11-year sunspot cycle, which itself

varies from one cycle to the next. In periods of high solar magnetic

Chapter 10: Theory


activity, bursts of X-rays and charged particles are projected chaotically

into space, which creates gusts of solar wind. These magnetic storms

interfere with radio and electric services, and produce dazzling auroras.

The varied colors are caused by oxygen and nitrogen being ionised, and

then recapturing electrons at altitudes ranging from 100 to 1000

kilometers. The term geomagnetic storm refers to the effect of a solar

magnetic storm on the Earth.

For wellbore magnetic survey instruments other conditions that can

affect the measurement of wellbore azimuth are:

� Nearby casing, for example at KOPs

� Drillstring magnetization

� Nearby offset, P&A’d or junked wells


Chapter 10: Theory

True, Grid, and Magnetic North

True north

Imagine a line from you to the North Pole. This is a line of constant

longitude and points to true north. In many cases, True North is chosen

because directional survey instruments read azimuth to true (or

magnetic) north. In both cases the convergence correction does not need

to be applied. True North is an accepted reference for local co-ordinates.

Grid north

On a map, a line joining two points with equal Easting co-ordinates

points to grid north. By representing the spherical earth on a flat map,

the distortion introduced means that (over most of the map) grid north

does not point to true north. The difference between grid north and true

north is called the grid convergence. Grid north is an accepted reference

for local co-ordinates.

Magnetic North

Additionally, Magnetic north is a North reference, but is not used in

COMPASS. A magnetic compass points to the horizontal component of

the earth's magnetic field and is measured from true north. Magnetic

north varies with location and time. Magnetic North is not an accepted

convention for local co-ordinates. When loading azimuths and local co-

ordinates into Compass they should already be corrected to True or Grid

North depending on the convention chosen in the Project Properties.

Chapter 10: Theory


The following graphic depicts Norths’ Reference custom in Northern

and Southern Hemispheres:

In COMPASS, the convention for displaying convergence in the

northern hemisphere is that positive values are to the East (right) of True

North, negative values are to the West (left) of True North. South of the

equator, this convention is reversed.

NOTE: Diagrams are schematic.

These diagrams are schematic. The direction and magnitude of magnetic

declination and grid convergence depends upon the location.


Chapter 10: Theory

The following diagram depicts conventions for the sign of grid

convergence in northern and southern hemispheres, and west/east of the

geodetic zone’s central meridian.

Central

Meridian

Equator

500,000 m

G T GT

GT G T

Grid = True - Conv

Grid = True - Conv

Grid = True - Conv

Grid = True - Conv

+

+

-

-

Compass - Sign of Grid Convergence

Chapter 10: Theory


Drillers Target Algorithm

The following explanation describes the statistical algorithms employed

to construct a driller’s target from a geological target using the

positional uncertainty surface calculated for the wellpath down to the

TVD of the target.

Surveys show that a wellpath has penetrated a target at position.

Uncertainty at this position is represented by an error ellipse (this one

drawn at 2 standard deviations).

Points are 100 possible repeat survey locations of the actual point of

penetration in the target. The eight points lying outside the target

represent the 8% probability that the target has been missed. From this,

the inclusion probability of hitting the geological target at the calculated

point is 92%.

Geological

Target


Chapter 10: Theory

We can calculate the inclusion probability at every point within the

geological target and color-code it as follows:

The following graphic depicts the Plan View and 3D view (inset),

displaying a reduced size Driller’s target constructed from a circular

Geologic Target using the displayed Error Ellipse dimensions down an

example wellpath. The drillers target was constructed using a 75%

confidence level:

Well

Direction

< 90%

90-95%

> 95%

Drillers Target

defined from 90%

confidence contour

Drillers Target

Geological Target

Chapter 10: Theory


Select the confidence for hitting the target. The confidence is the

percentage probability that if the wellpath, when surveyed, intercepts

the target at this point, that it really is within the boundaries of the target.

A useful range is from 80% to 95%. Neither 0% nor 100% is possible.

The drilling target boundary represents a contour of confidence—points

within the boundary represent better than the required confidence.

Because the Driller’s Target tool uses the errors on the current definitive

path at the depth of the target, if the path does not go to this depth or no

errors exist, an error message appears. Additionally, to construct a

driller’s target, the tool needs a geological target that is big enough to fit

the errors, otherwise an error message appears saying the target isn’t big

enough. In this situation, you have two options: use a bigger geological

target, or assume a more accurate (and possibly more expensive!) survey

program to make the errors smaller. The driller’s target is given the

name of the original target, with the confidence label displayed.

Note: Drillers targets in live views...

In the live views, it is possible to only display drillers targets and hide geological

targets. Look in the Options tab in Graph Setup.


Chapter

References

Brooks, A.G. and Wilson, H., An Improved Method for Computing

Wellbore Position Uncertainty and its Application to Collision and

EUROPEC, Milan, 22-24 Oct. 1996.

DuBrule, O. and Nelson, P.H., Evaluation of Directional Survey

Errors at Prudhoe Bay. SPE 15462, 1986 ACTE, New Orleans, Oct

5-8.

Harvey, R.P., Walstrom, J.E. and Eddy, H.D., A Mathematical

Analysis of Errors in Directional Survey Calculations, SPE 3718,

JPT, pp. 1368-1374, Nov. 1971.

McClendon, R.T. and Anders, E.O., Directional Drilling Using the

Catenary Method, SPE/IADC 13478, 1985 SPE/IADC Drilling

Conference, New Orleans, Mar 6-8.

Thorogood, J.L., Instrument Performance Models and their

Application to Directional Survey Operations, SPE 18051, 1988

ATCE, Houston, Oct 2-5.

Thorogood, J.L. and Sawaryn, S.J. The Travelling Cylinder

Diagram: A Practical Tool for Collision Avoidance, SPE 19989,

SPEDE pp. 31-36, Mar 1991.

Walstrom, J.E., Brown, A.A. and Harvey, R.P., An Analysis of

Uncertainty in Directional Surveying, JPT, pp. 515-523, April

1969.

Walstrom, J.E., Harvey R.P. and Eddy, H.D., A Comparison of

Various Directional Survey Models and an Approach to Model

Error Analysis, SPE 3379, SPE 46th Annual Meeting, New

Orleans, Oct 3-6, 1971.

Williamson, H.S., Accuracy Prediction for Directional MWD, SPE

56702, 1999 ACTE, Houston, Oct. 3-6.

Wolff, C.J.M. and deWardt, J.P., Borehole Positional Uncertainty -

Analysis of Measuring Methods and Derivation of Systematic

Error Model, JPT pp.2339-2350, Dec. 1981.

11

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