Compact Separation Design · • Valve Size (Control and Isolation) • Relief Valve Sizing •...

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Compact Separation Design

Clint Kidd, PEBusiness Development Engineer 432-257-1126

Lucas NolanStaff Engineer 307-472-7722


U.S. Process SolutionsProvides customer value in the oil and gas market through the engineering, design, fabrication, distribution and service of oilfield production equipment solutions.


Agenda

- Operator Challenges- Compact/Efficient

Separation & Design through the Production Lifecycle

- Internal Separator Design Techniques

- Optimize Separator Design

- Process Simulation Examples & Economic Impact

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Operator Challenges – Steep Decline Curves

• Typical horizontal well declines 65-85% in the first 12 months

• Initial Production(IP) declines continue to increase year to year

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KEY TAKEAWAY: Accurate upfront

sizing of production

equipment for the

lifetime of the well(s)

will result in proper

vessel design with

economic savings.


Sizing & Design – IP Flow Rates

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TABLE 2 (Ref. API 12J)

Oil GravitiesRetention time,

minutes (Typical)

Above 35 oAPI 3 to 5

Below 35 oAPI

100+ oF 5 to 10

80+ oF 10 to 20

60+ oF 20 to 30

@ 2,000 bpd

48”x10’ Ret Time = 9 min



Sizing & Design – Flow Rate 6-12 Months After IP

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TABLE 2 (Ref. API 12J)

Oil GravitiesRetention time,

minutes (Typical)

Above 35 oAPI 3 to 5

Below 35 oAPI

100+ oF 5 to 10

80+ oF 10 to 20

60+ oF 20 to 30

@ 1,200 bpd



KEY TAKEAWAY:

1. 72”x10’ is extremely

conservative design.

2. Economic savings to

go with 48” over 72” is

~ $30K per vessel for

modular/skidded

design.


Internal Separation Techniques

- Spillover Weir- Uses Interface Level Controllers and

Weir Height to determine Oil and Water Pad

- Bucket & Weir- Uses Bucket Height and Static Head to

determine Oil and Water Pad

- Split-Head- Uses Static Head and Weir Height to

determine Oil and Water Pad (can be adjustable)

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Split-head Design Benefits

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• Provides Fine Tuning of Interface Levels.

• Provides the Ability to Use a Single Float Material.

• External Water Level Adjustments Allow Fine Tuning of Vessel for Changes in Oil/Water Ratio Over the Life of the Well without having to take the vessel out of service.

KEY TAKEAWAY:

Bucket & Weir and

Spillover Weir

designs still have

their place, but the

split-head design is

becoming more

popular.


Internal Separator Design Optimization

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Vane Sections Reduce Foaming, Aid In Emulsion Breaking and Coalesce Aerosols.

Wave Baffles Handle Surge Flows and Ensure Retention Time

Multi Angle Inlet Divert Plate Allows for Smooth Flow Transition


Modular/Skidded Design Optimization

Optimize the Entire Modular Package

• Oil, Water, Gas Meter Size

• Pipe Size

• Valve Size (Control and Isolation)

• Relief Valve Sizing

• Skid Design

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KEY TAKEAWAY:

Keeping the overall

package design at a

competitive cost is

key to these modular

packages being

economic.


Process Simulations for Sizing

Utilizing Process Simulation Tools such

as Promax, Hysis will help optimize

the design. Conditions Needed:

• Flowrate each fluid/gas

• Fluid Analysis

• Gas Analysis

• Required Reid Vapor Pressure (RVP)

• Inlet Temperature

• Gas Gathering Pressure

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Wellhead Separation

Control Valves

KEY TAKEAWAY:

Remember…

Simulation tools

are only as good

as the accuracy of

the data received.


Compact Separation – Additional Data & Analytics

Customer did not believe oil was separating from water.

Actual Production Samples were provided to our lab.

Performing Lab Testing @ Precise Temperature Separation Tests.

Examined Fluid @ Various Time Intervals to Determine Exact Retention Times.

Example shows that @ 72oF, it takes 60 seconds for complete separation.

@ 38oF, it takes 90 seconds for complete separation.

Example

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KEY TAKEAWAY:

Designs can be

optimized through

lab testing of

actual production

samples of your

specific fluid.


Preliminary Separator Sizing Example

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Design Parameters

Specific

Gravity

Gas 2 MMSCFD 0.7 Design Pressure 200 PSIG

Oil 1000 BPD 0.708 MAWP 250 PSIG

Water 3000 BPD 1.01 Temperature 100 F

Vessel Size 48" x 12' Vessel Id 46" Effective Length 138"

EXAMPLE 13 Speed of Gas 0.27 fps

-2.5 Retention Oil 5.39 minutes

*inches above or below vessel centerline Retention Water 5.1 minutes

5.5

20.5


-5 Retention Oil 4.87 minutes


5

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-8.5 Retention Oil 8.16 minutes


8.5

14.5

*Oil/Water Interface

Oil Pad Thickness

Water Pad Thickness

Water Pad Thickness

*Gas/Oil Interface


Oil Pad Thickness

Water Pad Thickness

*Gas/Oil Interface

Flow Pressures & Temperatures

*Gas/Oil Interface


Oil Pad Thickness

0

0.05

0.1

0.15

0.2

0.25

0.3

Centerline + 3 Centerline Centerline

Speed of Gas vs. Oil Pad Height

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5

6

7

8

9

1 2 3

Oil

Oil Pad Thickness(in) Oil Retention Time(min)

3

7

11

15

19

23

1 2 3

Water

Water Pad Thickness(in) Water Retention Time(min)

KEY TAKEAWAY:

1.Excel sizing sheet

can get in the

separator size

ballpark in minutes.

2.Slight modifications

in Oil/Water pad

heights & thicknesses

can have significant

affects on retention

time.


Final Separator Sizing Example

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KEY TAKEAWAY:

Final sizing based

on GPSA. Attempt

to get as much

data upfront to

make accurate

decisions.


60”x10’ vs 60”x15’ Separator Sizing Example

Weir Height Calculation

- (Vessel ID x 70%) – Inner Radius = Weir Height

(58.5”*70%) – 29.25” = 11.7”

- Round down so there is some crest height over the weir. Weir height of 11.5” above centerline = 70%

- Note: 70% weir height is the maximum weir height due to gas velocities becoming to high.

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Design Parameters

Specific

Gravity

Gas 1 MMSCFD 0.75 Design Pressure 500 PSIG

Oil 1500 BPD 0.835 Operating Press 350 PSIG

Water 2000 BPD 1.02 Temperature 120 F

50% 70%

60" x 10' 7 10.5 $50K $100K

60" x 15' 10.5 16 $60K $120K

Note: Prices are very much estimations. Depends on a detailed scope of supply.

ASME Code

Vessel Price

Estimate

Skidded

Modular Vessel

Price Estimate

Retention Time

(min)@ Weir HeightsVessel

Flow Pressures & TemperaturesKEY TAKEAWAY:

Internal weir

heights can be

adjusted to

achieve longer

retention times in

smaller, more

economical

vessels.


Compact Separator Package Leads to Battery Optimization

• Smaller Square Footage Batteries

• Battery Standardization

• Lower Construction & Installation Costs

• Increased Flexibility

NOTE: Consider battery plot plans, long term production plans, overall company strategy, IP separator sizes when deciding on final separator design and sizing.

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KEY TAKEAWAY:

1.Compact Separator

Design = Battery

Optimization.

2. Consider a

Company Standard

Separator Design

(i.e. Satellites,

Batteries, IP, Etc.)


Scalable Modular Compact Separator Package

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Compact Separation Design · • Valve Size (Control and Isolation) • Relief Valve Sizing •...

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