Lectures 11-14_Natural Gas Production-II (2)

Natural Gas Engineering Natural Gas Engineering Production II, NGP 604,

By y

Dr. Adel SalemAsst. Prof. of PE, Faculty of Petroleum & Mining Eng.

S C l U i itSuez Canal UniversitySS 2010

Proposed Contents 1.1. IntroductionIntroduction22 Fl R i Ch t i ti i R i Fl R i Ch t i ti i R i

6.6. Inflow Performance Relationship;Inflow Performance Relationship;Factors Affecting inflow PerformanceFactors Affecting inflow Performance

2.2.Flow Regime Characteristics in Reservoir Flow Regime Characteristics in Reservoir 1.1. SteadySteady--State Flow;State Flow;22 UnsteadyUnsteady State Flow;State Flow;

7.7. Tubing Performance;Tubing Performance;Outflow Performance CurvesOutflow Performance Curves

7.7. Choke Performance.Choke Performance.2.2.UnsteadyUnsteady--State Flow;State Flow;3.3.Pseudo steady State Flow.Pseudo steady State Flow.

33 Natural Gas Well PerformanceNatural Gas Well Performance

4.4. Liquid Loading In Gas WellsLiquid Loading In Gas Wells5.5. Methods for Unloading LiquidMethods for Unloading Liquid

I.I. Beam Pumping Units;Beam Pumping Units;IIII Pl l fPl l f3.3.Natural Gas Well PerformanceNatural Gas Well Performance

1.1. Introduction;Introduction;22 Static BottomStatic Bottom--hole Pressure;hole Pressure;

II.II. Plunger lift;Plunger lift;III.III. Small Tubing String;Small Tubing String;IV.IV. Flow Controllers;Flow Controllers;VV S I j tiS I j ti2.2. Static BottomStatic Bottom hole Pressure;hole Pressure;

3.3. Flowing BottomFlowing Bottom--hole Pressure;hole Pressure;1. Average Temperature and Deviation

V.V. Soap Injection.Soap Injection.

6.6. Bean Performance Bean Performance 77 Artificial Lifting MethodsArtificial Lifting Methods1. Average Temperature and Deviation

Factor Method [Rzasa-Katz method];2. The Sukkar and Cornell Method;

7.7. Artificial Lifting MethodsArtificial Lifting MethodsI.I. Gas LiftingGas LiftingII.II. Pumping SystemPumping System

3. The Cullender and Smith Method.4.4. GasGas--Liquid Flow in Wells; Flow Regimes;Liquid Flow in Wells; Flow Regimes;

8.8. Production Forecasting for Gas WellsProduction Forecasting for Gas Wells9.9. Total System AnalysisTotal System Analysis10.10. Gas Well CompletionGas Well Completion

5.5. Prepared Pressure Traverse Curves;Prepared Pressure Traverse Curves;10.10. Gas Well CompletionGas Well Completion11.11. Hydraulic Fracturing of Gas WellsHydraulic Fracturing of Gas Wells

April 30, 2010 NG Eng. Production II_ Dr. Adel Salem Lectures 11- 14: Page: 2

L L 1111 14 14 A f l L f M h dA f l L f M h dLecture Lecture 1111 14: 14: Artificial Lifting MethodsArtificial Lifting Methods

2. Pumping System2. Pumping System

MayMay 20102010


A tifi i l Lift M th dA tifi i l Lift M th dArtificial Lift MethodsArtificial Lift Methods

Dr.Eng.AdelSalemAsst.Prof.ofPetroleumEngineeringAsst.Prof.ofPetroleumEngineeringFacultyofPetroleumandMiningEngineeringFacultyofPetroleumandMiningEngineeringS C lU i iS C lU i iSuezCanalUniversitySuezCanalUniversityEgyptEgypt

Lecture Nr. 11Lecture Nr. 11II S k R d P iII S k R d P iII. Sucker Rod PumpingII. Sucker Rod Pumping

Outlines

Sucker Rod (Beam) Pumps:Sucker Rod (Beam) Pumps:

3.1. Surface Pumping Facilities, 3.1. Surface Pumping Facilities, 3.2. Subsurface Equipments, 3.3. Operating Mechanism, 3.3. Operating Mechanism, 3.4. Sucker and Rod Design, and 3.4. Sucker and Rod Design, and

Power Requirements, andPower Requirements, and3.5. Troubleshooting 3.5. Troubleshooting

Dynamometer.Dynamometer.


Introduction

There are over 949,550Thereareover949,550producingoilwellsallovertheworld,about93%ofthesewellsareoperatedusingdifferentartificiallift

th d d hlmethodsandroughlyover72%areproducingusingbeam pumping systembeampumpingsystem.


IntroductionSuckerrodpumpingisalsoreferredtoasBeamPumping.Itprovidesmechanicalenergy to lift oil from bottom hole to surface. It is efficient, simple, and easy for fieldenergytoliftoilfrombottomholetosurface.Itisefficient,simple,andeasyforfieldpeopletooperate.

Itcanpumpawelldowntoverylowpressuretomaximizeoilproductionrate.Itisapplicabletoslimholes,multiplecompletions,andhightemperatureandviscousoils.Thesystemisalsoeasytochangetootherwellswithminimumcost.y y g

Themajordisadvantagesofbeampumpingincludeexcessivefriction incrooked/d i t d h l lid iti bl l ffi i i ll li it d d thdeviatedholes,solidsensitiveproblems,lowefficiencyingassywells,limiteddepthduetorodcapacity,andbulkyinoffshore operations.

Beampumpingtrendsincludeimprovedpumpoffcontrollers,bettergasseparation,gashandlingpumps,andoptimizationusingsurfaceandbottomholecards.


Main Components Main Components Main Components Main Components of a Sucker Rod of a Sucker Rod

P d W llP d W llof a Sucker Rod of a Sucker Rod

P d W llP d W llPumped WellPumped WellPumped WellPumped Well

CasingSurface i it

Down Hole PumpDown Hole Pump Down Hole PumpDown Hole PumpPrime Mover

Tubingpumping unit

Sucker RodsSucker Rods Surface UnitSurface Unit Sucker RodsSucker Rods Surface UnitSurface Unit

Sucker Rods

Surface UnitSurface Unit Prime MoverPrime Mover Surface UnitSurface Unit Prime MoverPrime Mover

Subsurface Each of the above mentioned Each of the above mentioned

i i ii i iEach of the above mentioned Each of the above mentioned

i i ii i i pumpitems can vary in size, items can vary in size, materials & geometry. materials & geometry. items can vary in size, items can vary in size, materials & geometry. materials & geometry.


Sucker Rod Pump EquipmentsThebeampumpingsystemconsistsessentiallyoffiveparts:1 The subsurface sucker rod driven pump1. Thesubsurfacesuckerroddrivenpump2. Thesuckerrodstringwhichtransmitsthesurfacepumpingmotionand

power to the subsurface pump. Also included is the necessary string ofpowertothesubsurfacepump.Alsoincludedisthenecessarystringoftubingand/orcasingwithinwhichthesuckerrodsoperateandwhichconductsthepumpedfluidfromthepumptothesurface

3. Thesurfacepumpingequipmentwhichchangestherotatingmotionoftheprimemoverintooscillatinglinearpumpingmotion

4 Th i i i d d4. Thepowertransmissionunitorspeedreducer5. Theprimemoverwhichfurnishesthenecessarypowertothesystem


Surface Equipments

The prime mover The prime mover is either an electric motor an electric motor or an internal an internal combustion enginecombustion engine. The modern method is to supply each well

ith it t i El t i t t d i bl with its own motor or engine. Electric motors are most desirable because they can easily be automated. The power from the prime mover is transmitted to the input shaft of a gear reducer by a V-p g ybelt drive. The output shaft of the gear reducer drives the crankarm at a lower speed (440 revolutions per minute [rpm] d di ll h t i ti d fl id ti )depending on well characteristics and fluid properties).


Therotarymotionofthecrankarmisconvertedtoanoscillatorymotionbymeansofthewalkingbeamthroughapitmanarm.Thehorsesheadandthehangercablearrangementisusedtoensurethattheupwardpullontheg g p psuckerrodstringisverticalatalltimes(thus,nobendingmomentisappliedtothestuffingbox).Thepolishedrodandstuffingboxcombinetomaintainagoodliquidsealatthesurfaceand,thus,forcefluidtoflowintotheT

b l h ff bconnectionjustbelowthestuffingbox.April 30, 2010 NG Eng. Production II_ Dr. Adel Salem Lectures 11- 14: Page: 11

SR Specifications Conventionalpumpingunitsareavailableinawiderangeofsizes,withstrokelengthsvarying from 12 to almost 200 in12 to almost 200 in. The strokes for any pumping unit type are available invaryingfrom12toalmost200in12toalmost200in.Thestrokesforanypumpingunittypeareavailableinincrements(unitsize).Withineachunitsize,thestrokelengthcanbevariedwithinlimits(aboutsixdifferentlengthsbeingpossible).

Thesedifferentlengthsareachievedbyvaryingthepositionofthepitmanarmconnectiononthecrankarm.Walkingbeamratingsareexpressedinallowablepolishedg g p prodloads(PRLs)andvaryfromapproximately3,000to35,000lb.Counterbalanceforconventionalpumpingunitsisaccomplishedbyplacingweightsdirectlyonthebeam(insmaller units) or by attaching weights to the rotating crank arm (or a combination ofsmallerunits)orbyattachingweightstotherotatingcrankarm(oracombinationofthetwomethodsforlargerunits).

Inmorerecentdesigns,therotarycounterbalancecanbeadjustedbyshiftingthepositionoftheweightonthecrankbyajackscreworrackandpinionmechanism.


Beam Pumping TypesInadditiontotheconventionalone,therearetwoothermajortypesofpumpingunits.ThesearetheLufkinMarkIILufkinMarkIIandtheAirtheAirBalancedUnits.BalancedUnits.Thepitmanarmandhorsesheadareinthesamesideofthewalkingbeaminthesetwotypesofunits(ClassIIIleversystem).InsteadofusingcounterweightsinLufkinMarkIItypeunits,aircylindersareusedintheairbalanced

i b l h h k h funitstobalancethetorqueonthecrankshaft.

The American Petroleum Institute (API) has established designations for suckerTheAmericanPetroleumInstitute(API)hasestablisheddesignationsforsuckerrodpumpingunitsusingastringofcharacterscontainingfourfields.Forexample,C 228D 200 74:C228D20074:

ThefirstfieldThefirstfieldisthecodefortypeofpumpingunit.Cisforconventionalunits,Aisforairbalancedunits,beamcounterbalanceunits,andMisforMarkIIunits.ThesecondfieldThesecondfieldisthecodeforpeaktorqueratinginthousandspeaktorqueratinginthousandsofinchp q gp q gpoundsandgearreducer. Dstandsfordoublereductiongearreducer.ThethirdfieldThethirdfieldisthecodeforPRLratinginhundredsofpounds.Thelastfieldisthe code for stroke length in inches.thecodeforstrokelengthininches.April 30, 2010 NG Eng. Production II_ Dr. Adel Salem Lectures 11- 14: Page: 13


Types of Beam PumpAllbeamtypepumpingunitgeometriesfallintotwodistinctclasses:

1. TheClassIleversystemwhichhasitsspeed(gear)reducerrearmountedwith the fulcrumat mid beam, represented by the conventional unit and,withthefulcrumat midbeam,representedbytheconventionalunitand,

2. TheClassIIIleversystem,apushupgeometrywithitsspeedreducery , p p g y pfrontmounted,representedbytheairbalanceandLufkinMarkIIunits,wherethefulcrumislocatedattherearofthebeam.

3. Lufkinhasthreetypes;conventional,MarkIIandAirbalancedone.


Conventional Type


Lufkin Mark II Unit


Air Balanced Unit


SR UnitsCONVENTIONALUNITS TheLUFKINConventionalCrankBalancedUnit,widelyknownandaccepted,is, y p ,theoldreliable"WORKHORSE"oftheoilpatch.Thisisthemostuniversallyadaptableunitinthe"LUFKIN LINE" simple to operate and requiresLUFKINLINE ,simpletooperateandrequiresminimummaintenance.Shownhereisthetwopointbasedesigninstalledonfrontandrearconcrete blocksconcreteblocks

MARK II UNITORQUE UNITS The Mark II unit, dueMARKIIUNITORQUEUNITS TheMarkIIunit,duetoitsuniquegeometryandphasedcounterbalancefeature,lowerspeaktorqueandhorsepowerrequirements The unusual geometry of the Mark IIrequirements.TheunusualgeometryoftheMarkIIproducesasomewhatslowerupstrokeandfasterdownstrokewithreducedaccelerationwherethel d i l i i l k l d dloadisgreatest,resultinginlowerpeakloadsandlongerrodlife.


SR UnitsAIRBALANCEDUNITS Theutilizationofcompressed air instead of heavy cast ironcompressedairinsteadofheavycastironcounterweightsallowsmoreaccuratefingertipcontrolofcounterbalance.Asaresult,theweightoftheunitisgreatlyreduced,significantlyloweringtransportationandinstallationcosts.AirBalancedunits have a distinct advantage in the larger sizesunitshaveadistinctadvantageinthelargersizeswithlongstrokes,wherecastironcounterweightsonconventionalcrankcounterbalancedunitsmustbesomassivethattheiruseispracticallyprohibitive.

BEAMBALANCEDUNITS TheLUFKINBeamBalanced unit has the same rugged dependability asBalancedunithasthesameruggeddependabilityastheConventionalunit.Theseunitsfilltheneedofeconomicallyproducingmanyoftheshallowwells


SR UnitsREVERSEMARKUNITS TheLUFKINRMSeriesPumping Unit offers the customer an improvedPumpingUnitoffersthecustomeranimprovedalternativetotheconventionaltypegeometry.

AlthoughsimilarinappearancetotheLufkinConventionalpumpingunit,theRMunitgeometrycanreducethetorqueandpowerrequirementsonmanypumpingapplications.Insome instances a smaller reducer and primesomeinstancesasmallerreducerandprimemovercanbeused.

Lufkinmaintainsanactiveinventoryofusedandrefurbishedpumpingunitsfromvarious

f d i i f imanufacturersandinavarietyofsizestomeetyourreciprocatingrodpumpingunitneeds.



SUBSURFACE PUMPSRoddrawnpumpscanbedividedintothreebasictypes:types:

(1) Tubing pumps(1) Tubing pumps(2) Insert (rod) pumps(2) Insert (rod) pumps(3) C i ( l i f i t )(3) C i ( l i f i t )(3) Casing pumps (a larger version of insert pumps)(3) Casing pumps (a larger version of insert pumps)

Allofthesepumpsareactuatedbyasuckerrodstringandasurfacepumpingunit.g p p g

The functions of he pump are to admit fluid fromp pthe formation into the producing string and to liftthe fluid thus admitted to the surface. Toaccomplish this any pump must contain fouraccomplish this, any pump must contain fouressential elements:

(1) A working barrel(1) A working barrel(2) A plunger(2) A plunger(3) An intake valve (standing valve)(3) An intake valve (standing valve)(4) An exhaust valve (traveling valve)(4) An exhaust valve (traveling valve)( ) ( g )( ) ( g )


subsurface Pumpsp

Tubing pumpTubing pump

Rod or insert pump


SUBSURFACE PUMPS

Roddrawnpumpscanbedividedintothreebasictypes:(1) Tubing pumps(1) Tubing pumps(2) Insert (rod) pumps(2) Insert (rod) pumps(3) Casing pumps (a larger version of insert pumps)(3) Casing pumps (a larger version of insert pumps)(3) Casing pumps (a larger version of insert pumps)(3) Casing pumps (a larger version of insert pumps)

Allofthesepumpsareactuatedbyasuckerrodstringanda surface pumping unit. Any roddrawn pump consists ofasurfacepumpingunit.Anyrod drawnpumpconsistsoffouressentialelements:

(1) A working barrel(1) A working barrel(2) A plunger(2) A plunger(3) An intake valve (standing valve)(3) An intake valve (standing valve)(4) An exhaust valve (traveling valve)(4) An exhaust valve (traveling valve)(4) An exhaust valve (traveling valve)(4) An exhaust valve (traveling valve)

WhatisthedifferenceamongallRodTypesmentionabove?WhatisthedifferenceamongallRodTypesmentionabove?


Subsurface Pumps

Tubing pumpTubing pump

Rod or insert pump


Tubing Pump versus Rod (Insert ) Pump

Tubing Pump

With tubing type pumps, as the name implies, the Tubing Pump

pump barrel is an integral part of the tubing string

Larger bore than a rod pump thus produces a greater Larger bore than a rod pump, thus produces a greater volume of fluid in any give diameter of tubing.

C l t tt h d t d i t d i tRod Pump

Complete pump attached to, and inserted into,well tubing with sucker rod string.

As a complete unit, pump may be pulled out of well without pulling tubing.p g g


Pumping OperationTheadvantageofinsertpumpsisthattheyconnecttothesuckerrodstring,and the entire assembly can be removed from the well merely by pulling theandtheentireassemblycanberemovedfromthewellmerelybypullingtherodstring.

Withthistypeofpump,theworkingbarrelisloweredonrods;consequently,somemeansmustbeprovidedtosecurethebarrelintothebottomofthetubinginordertoprovidefluidpackoff andtofacilitatetherelativemotionoftheworkingbarrelandplunger.

Severalarrangementsareusedforthispurpose.Seatingcupscanbeprovidedontheworkingbarrel,oraspecialseatinghousingmaybeprovidedontheg , p g g y pbottomofthetubing.Holddownanchorscanalsobeusedatthetoporbottomofthebarrel.


Pumping Operational Cycle




Pump Diagnosis: Surface Dynamometer card:

Ideal card (stretch and contraction)Idealcard(stretchandcontraction),

Idealcardacceleration).



Surface Dyna-graphs may not tell the whole story!

Complicated Load (lbs) Surface Card( )

Downhole Card 65%

Pump FillagePump Fillage

Position (in)April 30, 2010 NG Eng. Production II_ Dr. Adel Salem Lectures 11- 14: Page: 38

Surface Versus Downhole Crads


Record Surface Cards Record Surface Cards

SurfaceDynamometercardsistheplotofmeasuredpolishedrodloadatthevariouspositionsthroughouta complete strokeacompletestroke

Itisusedfordesigningand Surface Carddiagnosingsurfaceproblems.

Pump Card


Net pump stroke is important in Net pump stroke is important in determining pump efficiencdetermining pump efficiencdetermining pump efficiencydetermining pump efficiency

Surface Card

lbs)

Pump Card Loa

d (

Pump Card

Unit Stroke Position (in)91 in.Net Stroke

46.9 in.

Gross Stroke84.3 in.April 30, 2010 NG Eng. Production II_ Dr. Adel Salem Lectures 11- 14: Page: 43

Only 30% of the pump stroke is Only 30% of the pump stroke is being used to produce oilbeing used to produce oilbeing used to produce oilbeing used to produce oil

lbs)

Load

(l

55 BFPD 13.6 MCFG/PD

Position (in)

Oil plus waterOil Shrinkage Compressed Gas

Gas CompressionTubing Movement

gPump Leakage

Compressed Gas


Understanding Dynamometer Pump Card Shapes


Fluid Pound ProblemFluidPound asexperiencedinapumping oil well is caused by the

Downhole PumpFluid Poundpumpingoilwell,iscausedbythe

pumpnotcompletelyfillingwithfluidontheupstroke.Asthedownstroke Casing

Upstroke Downstroke

begins,theentirefluidandrodstringloadmovesdownthroughavoiduntilthe plunger hits the fluid level in the

Tubing

R d St itheplungerhitsthefluidlevelinthepumpbarrel.

Rod String

Thetravelingvalveopens,suddenlytransferringtheloadtothetubing,

Fl id L lcausingasharpdecreaseinload,whichtransmitsashockwavethroughthe pumping system It is this shock

Fluid Level

Fluid Poundthepumpingsystem.Itisthisshockwavethatdamagesthepartsofthepumpingsystem.

Pump



Lecture Nr 12Lecture Nr. 12Sucker Rod Pumping DesignSucker Rod Pumping Design

Th s d f f this L t is Ch t 5 fTh s d f f this L t is Ch t 5 fThe used reference for this Lecture is Chapter 5 from:The used reference for this Lecture is Chapter 5 from:Craft, B. C., Holden, W. R., and Graves, Jr. E. D.: Well Design, Drilling and ProductionWell Design, Drilling and Production, Prentice-Hall, Inc. Englewood Cliffs, New Jersey, 1962.


Beam Pump DesignAlthoughthebeamsuckerrodsystemismechanicallysimpleandhasprovento be longlived and economical in operation many factors must betobelonglivedandeconomicalinoperation,manyfactorsmustbeconsideredinthedesignofapropersystem.

Thedesignengineermustbethoroughlyfamiliarwiththefunctionandcomplicatingfeaturesofeachpartoftheoverallsystemifoptimumperformanceistobeexpected.

Al h h i i l i fi ld i h b h i f h b dAlthoughitappearssimple,infieldpracticethebehaviorofthebeamandsuckerrodsystemissurprisinglycomplex.

Therearebasicformulasforcalculatingthevariousfactorsaffectingtheselectionofasuitablesystem,andthispartwillpresentthosecalculations.y , p p


1. Theoretical Analysis of Rod MotionIfthesuckerrodsweresuspendedstaticallyfromapolishedrodoriftheywererisingorfalling at constant velocity, the force on the polished rod would be the weight, Wr, offallingatconstantvelocity,theforceonthepolishedrodwouldbetheweight,Wr,ofthesuckerrod.However,underaccelerationtherewillbeonthepolishedrodanadditionalaccelerationloadWr(a/g).

Theaccelerationfactor(Theaccelerationfactor()orthefactorbywhichthedeadweightoftherodmustbe)orthefactorbywhichthedeadweightoftherodmustbemultipliedinordertoobtainthemaximumaccelerationloadisgivenby:multipliedinordertoobtainthemaximumaccelerationloadisgivenby:p g yp g y

ga=

TheaccelerationoftheloadinsimpleharmonicmotioncanbeconventionallyTheaccelerationoftheloadinsimpleharmonicmotioncanbeconventionallyinvestigatedbyconsideringthebodytobeprojection(onthediameterofreferenceinvestigatedbyconsideringthebodytobeprojection(onthediameterofreferencecircle)ofaparticlemovingwithuniformspeedaroundthereferencecircle.circle)ofaparticlemovingwithuniformspeedaroundthereferencecircle.) p g p) p g p

IncaseofSRsystem,thediameterofthereferencecircleisequaltothepolishedrodIncaseofSRsystem,thediameterofthereferencecircleisequaltothepolishedrodk l h d h i f l i f h i l d h i l i lk l h d h i f l i f h i l d h i l i lstrokelength,andthetimeofonerevolutionoftheparticlearoundthecircleisequalstrokelength,andthetimeofonerevolutionoftheparticlearoundthecircleisequal

tothetimeforonecompletepumpingcycle.tothetimeforonecompletepumpingcycle.


1. Theoretical Analysis of Rod MotionThemaximumaccelerationtakesplaceatthebeginningoftheupstrokeandtheThemaximumaccelerationtakesplaceatthebeginningoftheupstrokeandthebeginning of down stroke, i.e. when the projection has its greatest displacement frombeginning of down stroke, i.e. when the projection has its greatest displacement frombeginningofdownstroke,i.e.whentheprojectionhasitsgreatestdisplacementfrombeginningofdownstroke,i.e.whentheprojectionhasitsgreatestdisplacementfromthecenterofthereferencecircle.Therefore,theaccelerationcanbecalculatedfrom:thecenterofthereferencecircle.Therefore,theaccelerationcanbecalculatedfrom:

2

wherec

pr

va2

=where

vp is the velocity of the particle, andrc is the radius of the circle.c

Ifthetimeforonerevolutionoftheparticleist,then:Ifthetimeforonerevolutionoftheparticleist,then:

trv cp

2=andiftheNisthenumberofrevolutionperunittime,andiftheNisthenumberofrevolutionperunittime, Nrv cp 2=


1. Theoretical Analysis of Rod MotionSinceN=1/t,substitutingintopreviousequation:

gNr

grv cc

p222 4 ==

Forapumpingwell,Nisthepumpingspeed,andForapumpingwell,Nisthepumpingspeed,andrrcc isrelatedtothepolishedrodstrokelength,S,isrelatedtothepolishedrodstrokelength,S,by:by:

ggc

S 222gSNandSrc

222 ,2/ ==ThepolishedrodstrokelengthisnormallystatedininchesandthepumpingspeedisgiveninThepolishedrodstrokelengthisnormallystatedininchesandthepumpingspeedisgiveninstrokesperminute,then:strokesperminute,then:

112 222 SNminft/mininSN 2270500sec3600

1. 12

1sec/

.2.32

222

SNmininft

ft/mininSN ==


Example Problem 1:OneOneinchstrokerodsweigh2.88lb/ft.calculatethemaximumpolishedrodloadinchstrokerodsweigh2.88lb/ft.calculatethemaximumpolishedrodloadresulting from 2000 ft of oneresulting from 2000 ft of oneinch sucker rods if the pumping speed is 18inch sucker rods if the pumping speed is 18 spmspm (strokes(strokesresultingfrom2000ftofoneresultingfrom2000ftofone inchsuckerrodsifthepumpingspeedis18inchsuckerrodsifthepumpingspeedis18spmspm (strokes(strokespermin)andthepolishedrodstrokelengthis74in.permin)andthepolishedrodstrokelengthis74in.

Solution:

lbftftlbWr 57602000/ 88.2 ==r

loadnaccleratiorodsofWeightLoadma im mThe340.070500/1874 2

+==

lb7720340.057605760 loadn accleratiorods ofWeight Load maximum The

=+=+=


2. The Effective Plunger StrokeTheproducingvolumefromSRpumpsdependsnotonlyofthepolishedrodlengthbutTheproducingvolumefromSRpumpsdependsnotonlyofthepolishedrodlengthbutalso the movement of the plunger relative to the working barrel. This movement isalso the movement of the plunger relative to the working barrel. This movement isalsothemovementoftheplungerrelativetotheworkingbarrel.Thismovementisalsothemovementoftheplungerrelativetotheworkingbarrel.Thismovementiscalledthenetoreffectiveplungerstroke,anditmaydiffersignificantlyfromthecalledthenetoreffectiveplungerstroke,anditmaydiffersignificantlyfromthepolishedrodstroke.polishedrodstroke.

Fundamentally,plungerandpolishedrodstrokesdifferbecauseofrodandtubingstretchandbecauseofplungerovertravelresultingfromacceleration.p g g

AstheTVandSVopenandcloseduringthepumpingcycle,thefluidloadistransferredlt ti l t th t bi d t th d t ialternativelytothetubingandtotherodstring.

This results in periodic elastic deformations (of rod and tubing) which are out phaseThisresultsinperiodicelasticdeformations(ofrodandtubing)whichareoutphasewitheachotherby180o.

Whiledownstroke,SVisclosedandTVisopen.AtthistimethefluidloadisontheWhiledownstroke,SVisclosedandTVisopen.Atthistimethefluidloadisonthetubing,causingacertainelongationofthatmembertubing,causingacertainelongationofthatmember.Incaseofupstroke,TVcloses,.Incaseofupstroke,TVcloses,causingelongationoftherods.causingelongationoftherods.g gg g


The Effective Plunger StrokeOpeningoftheSVallowsthestretchtocomeoutofthetubing.Restorationofthetubingtoitsoriginallengthcausingtheworkingbarreltomoveupward,andelongationoftherodscausestheplungertomovedownward.Therefore, the effective plunger stroke is decreased by Therefore, the effective plunger stroke is decreased by an amount equal to the sum of rod and tubing an amount equal to the sum of rod and tubing an amount equal to the sum of rod and tubing an amount equal to the sum of rod and tubing elongation resulting from fluid load.elongation resulting from fluid load.Foranelasticdeformation,thereisaconstantratiobetweenthestress

li d b d d h l i iappliedtoabodyandtheresultingstrain:E=Stress/Strain

E h l i i d l i h i i f h i l hi h hE h l i i d l i h i i f h i l hi h hE,theelasticitymodulus,isacharacteristicofthematerialtowhichtheE,theelasticitymodulus,isacharacteristicofthematerialtowhichthestressisapplied.Stressisappliedforceperunitarea:stressisapplied.Stressisappliedforceperunitarea:

Stress=F/A

and strain is fractional change in length:andstrainisfractionalchangeinlength:

Strain=e / l


The Effective Plunger StrokeIfe expressedininchandl infeet,so:

Strain=e / l

Th f E FLAF 12/Therefore,E:

The elongation of the member is:eAFL

LeAFE 12

12// ==

FL12Theelongationofthememberis:

Th f d fl id l d l f h diff i l hTh f d fl id l d l f h diff i l h

EAFL12e =

TheforceduetofluidloadresultsfromthepressuredifferentialacrosstheTheforceduetofluidloadresultsfromthepressuredifferentialacrosstheplungeractingoverthefullplungerarea,plungeractingoverthefullplungerarea,AApp::

F=P ApIfitisassumedthatthepumpissetattheworkingfluidlevelinthewell,thepressure differential is the pressure at depth L in a column of fluid of specificpressuredifferentialisthepressureatdepthLinacolumnoffluidofspecificgravity:

P=0.433GL


The Effective Plunger StrokeForthemoregeneralcasewhereworkingfluidlevelisatdepthD,thepressureForthemoregeneralcasewhereworkingfluidlevelisatdepthD,thepressureduetoacolumnoffluidofheight(Lduetoacolumnoffluidofheight(LD)inthecasingmustbeconsidered:D)inthecasingmustbeconsidered:

P=0.433GL0.433G(LD)=0.433GDTherefore, e:Therefore,e:

e=12 0.433GDAp L/EA=5.20GDAp L/EAItisperfectlygeneralequationforanymember,forthetubingcase:

et = 5.20 G D Ap L / E Atet 5.20GDAp L/EAt

WhereAt,isthecrosssectionalareaofthetubingwall.Fortherodstring:

er =5.20GDAp L/EAr

Where,Ar,isthecrosssectionaloftherods


The Effective Plunger StrokeIncaseoftaperedrodstring,thepreviousequationmustbeappliedtoeach section i e :eachsection,i.e.:

5 20 G D A L / E A d 5 20 G D A L / E A ter1 =5.20GDAp L1 /EAr1ander2 =5.20GDAp L2 /EAr2,etc

WhereWhere eerr11 isis elongationelongation ofof thethe LL11 footfoot sectionsection ofof rodsrods ofof crosscrosssectionalsectional areaarea AArr11,, eerr22 isis elongationelongation ofof thethe LL22 footfoot sectionsection ofof rodsrods ofofcrosscross sectionalsectional areaarea AA etcetc thenthen totaltotal rodrod stretchstretch isis::crosscrosssectionalsectional areaarea AArr22,, .... etcetc.. thenthen totaltotal rodrod stretchstretch isis::

( ) ++= /205 21 LLEGDAe ( ) ++= .../20.5 2211 AAEGDAe pr


Rod Elongation by Rod LoadInadditiontorodstretchcausedbyfluidload,rodelongationsalsoresultfromrodload, which consists of the dead weight of a rods plus acceleration load.load,whichconsistsofthedeadweightofarodsplusaccelerationload.

ForanunForanuntaperedstring,theweightofrodssuspendedbelowanyelementofthetaperedstring,theweightofrodssuspendedbelowanyelementofthestringvariesuniformlyfromzeroatthebottomofthestringtostringvariesuniformlyfromzeroatthebottomofthestringtoWWrr atthetopoftheatthetopofthestringstring.

Ontheaverage,theweightofrodstendingtocauseelongationofanelementisOntheaverage,theweightofrodstendingtocauseelongationofanelementisWWrr //2.thisisequivalenttoL/2.inanyeventheelongationoftherodsattheendofthe2.thisisequivalenttoL/2.inanyeventheelongationoftherodsattheendofthed t k ill bd t k ill bdownstrokewillbe:downstrokewillbe: ( )rr

d EALWWe 2/12 +=

Theelongationoftherodsattheendoftheupstrokewillbe:Theelongationoftherodsattheendoftheupstrokewillbe:

rEA

( )rru EA

LWWe 2/12 =rEA


Rod Elongation by Rod LoadSincetheaccelerationloadswillbeinoppositedirections.Theplungerovertravel,i.e.thenetelongationresultingfromacceleration,is:, g g ,

d EALWeee /12 ==Theweightoftherodstringis:

rrudp EALWeee /12

144/rrr LAW =WhereWhererr isthedensityoftherodstringinpoundspercubicfoot.Thedensityisthedensityoftherodstringinpoundspercubicfoot.Thedensityofsteelisapproximately490lb/ftofsteelisapproximately490lb/ft33,then:,then:

UnidiameterrodELLA

EALe rr

p 28.40

14449012 ==

Empirical for tapered rod:

r

Le 28.32=Empiricalfortaperedrod: Eep


Rod Elongation by Rod LoadTheeffectiveplungerstrokeisnowseentobethepolishedrodstrokeTheeffectiveplungerstrokeisnowseentobethepolishedrodstrokedecreased by the effects of rod and tubing stretch resulting from fluiddecreased by the effects of rod and tubing stretch resulting from fluiddecreasedbytheeffectsofrodandtubingstretchresultingfromfluiddecreasedbytheeffectsofrodandtubingstretchresultingfromfluidloadandincreasedbytheeffectofplungerovertravel.Thentheloadandincreasedbytheeffectofplungerovertravel.Thentheeffective plunger stroke is:effective plunger stroke is:effectiveplungerstrokeis:effectiveplungerstrokeis:

)( rtpp eeeSS ++=

Combiningthepreviousequations,weget:

++++= ...20.58.402

2

1

12

AL

AL

AL

EGDA

ELSS

t

pp

Incaseofanuntaperedrdstring,

++=rt

pp AAE

LGDAELSS 11

20.58.40 2 rt


3. Calculation of Polished Rod LoadsTheselectionofsurfaceequipmentforapumpinginstallationisinfluenced to a great extent by the anticipated maximum or peakinfluencedtoagreatextentbytheanticipatedmaximumorpeakpolishedrodload.

TheprimaryestimationofcounterbalancerequiredisbasedontheTheprimaryestimationofcounterbalancerequiredisbasedontheanticipatedmaximumandminimpolishedrodloads.Therefore,theseanticipatedmaximumandminimpolishedrodloads.Therefore,these

titi t b d t i d i ttiti t b d t i d i tquantitiesmustbedeterminedinaccuratemanner.quantitiesmustbedeterminedinaccuratemanner.

Th 5 f t t ib t t th t li h d d l dThereare5factorscontributetothenetpolishedrodload:1. Fluid Load, 2. Dead weight of sucker rods,3. Acceleration load of sucker rods,4. Buoyancy force on sucker rods submerged in fluid, and5. Frictional forces.

Anyothervibrational loadwillbeneglected.


Calculation of Polished Rod LoadsTheweightofataperedrodstringisgivenby:

+++ LMLMLMWWhereMWhereM11 istheweight,inlb/ft,andListheweight,inlb/ft,andL11 isthelength,infeet,ofsection1ofaisthelength,infeet,ofsection1ofatapered string Mtapered string M is the weight and Lis the weight and L is the length ofis the length of ofof section 2 etcsection 2 etc

...332211 +++= LMLMLMWrtaperedstring,Mtaperedstring,M22 istheweightandListheweightandL22 isthelengthofisthelengthofofof section2..etc.section2..etc.

Maximum acceleration load = Wr Mi i l ti l d WMinimum acceleration load = -Wr

Rodvolume,orhevolumedisplacedbytherodiscalculatedas:Rodvolume,orhevolumedisplacedbytherodiscalculatedas:

Volume=wt/ =Wr/490ft3

Byassumingthedisplacedfluiddensity(ofspecificgravityG)is62.4Glb/ftByassumingthedisplacedfluiddensity(ofspecificgravityG)is62.4Glb/ft33,,thebuoyancyforceontherods:thebuoyancyforceontherods:

The ve sign because buoyancy is upward action

( ) GWGWforceBuoyancy rr 127.04.62490/ ==The ve signbecausebuoyancyisupwardaction.April 30, 2010 NG Eng. Production II_ Dr. Adel Salem Lectures 11- 14: Page: 63

Calculation of Polished Rod LoadsThefluidloadtobeusedincalculatingpolishedrodloadsistheweightsofThefluidloadtobeusedincalculatingpolishedrodloadsistheweightsofthe fluid column supported by the plunger The volume of a column having asthe fluid column supported by the plunger The volume of a column having asthefluidcolumnsupportedbytheplunger.Thevolumeofacolumnhavingasthefluidcolumnsupportedbytheplunger.ThevolumeofacolumnhavingasitsbasetheplungerandasitsheighttheSRstringwouldbe:itsbasetheplungerandasitsheighttheSRstringwouldbe:

3144/ ftLAVolume

Thevolumeoffluidisobtainedfrom:Thevolumeoffluidisobtainedfrom:

144/ ftLAVolume p=

( )490/W 144/ r= pLAFluidofVolumeThenthefluidloadis:Thenthefluidloadis:

( )[ ]LAGW 490/W144/462= ( )[ ]( )rp

pf

WLAGLAGW

294.0433.0490/W 144/4.62 r

==

Itisnotedthatthefluidloadisonthepolishedrodonlyduringtheupstroke.Itisnotedthatthefluidloadisonthepolishedrodonlyduringtheupstroke.


Calculation of Polished Rod LoadsThefrictionloadcannotbepredictedmathematically.Foraninstalledpump,Thefrictionloadcannotbepredictedmathematically.Foraninstalledpump,it can be estimated from dynamometer tests For new pump design since theit can be estimated from dynamometer tests For new pump design since theitcanbeestimatedfromdynamometertests.Fornewpumpdesign,sincetheitcanbeestimatedfromdynamometertests.Fornewpumpdesign,sincethefrictionforcesactinadirectionoppositethedirectionofmotionofthebody,frictionforcesactinadirectionoppositethedirectionofmotionofthebody,frictionloadinupstrokeis+Fandfrictionloadinupstrokeis+FandFonthedownstroke.Fonthedownstroke.

Insummary,themaximumorpeakpolishedrodload,whichoccursontheInsummary,themaximumorpeakpolishedrodload,whichoccursontheupstrokeis:upstrokeis:

FWWWW rrf +++= max

The minimum polished rod load which occurs on the downstroke isThe minimum polished rod load which occurs on the downstroke isTheminimumpolishedrodload,whichoccursonthedownstrokeis:Theminimumpolishedrodload,whichoccursonthedownstrokeis:

FGWWWW = 1270F can be neglected without much loss in the accuracyF can be neglected without much loss in the accuracy

FGWWWW rrr = 127.0min Fcanbeneglectedwithoutmuchlossintheaccuracy.Fcanbeneglectedwithoutmuchlossintheaccuracy.April 30, 2010 NG Eng. Production II_ Dr. Adel Salem Lectures 11- 14: Page: 65

4. Design of the Sucker Rod StringTherearetwopossibleapproachestothedesignofataperedSRstring.1 Lengths of individual sections may be selected in such a manner as to make1. Lengthsofindividualsectionsmaybeselectedinsuchamannerastomake

theunitstressatthetopofeachsectionthemaximumpermissibleworkingstress,or

2. Lengthsmaybeselectedsoastomaketheunitstressesatthetopsofthesectionsequal.(moregeneral)

Indeterminingthestressatanypointinarodstring,theforcecausingtheIndeterminingthestressatanypointinarodstring,theforcecausingthestressisconsideredtoresultfromfluidloadontheplungerandweightofstressisconsideredtoresultfromfluidloadontheplungerandweightofd b l h i d id id b l h i d id irodsbelowthepointunderconsideration.rodsbelowthepointunderconsideration.

Assumptions:Assumptions:1. Static conditions, i.e. no acceleration loads,2. The specific gravity is 1,3 The fluid load acts over the full plunger area and3. The fluid load acts over the full plunger area, and4. The pump is set at the working fluid level.

Undertheseconditionthefluidloadis0.433Undertheseconditionthefluidloadis0.433LALApp pounds.pounds.


Design of Two-way Taper RodAtaperedrodsconsistsofL1ofcrosssectionalareaA1inin2,andAtaperedrodsconsistsofL1ofcrosssectionalareaA1inin2,andthe weight M1 pounds per foot and L2 A2 and M2 for the secondthe weight M1 pounds per foot and L2 A2 and M2 for the secondtheweightM1poundsperfoot,andL2,A2,andM2forthesecondtheweightM1poundsperfoot,andL2,A2,andM2forthesecondpart.LetR1andR2asfollows:part.LetR1andR2asfollows:

R1 =L1/LandR2 =L2/LWhere L +L L and stress at the top of the lower section is thenWhereL1+L2 =L,andstressatthetopofthelowersectionisthen:

1111 433.0433.0A

MLRLAA

MLLA pp +=+

LIKEISE,THESTRESSATTHETOPOFTHEUPPERSECTIONIS:11 AA

43304330 MLRMLRLAMLMLLA ++++

If the stresses at the tops of the sections are equals:If the stresses at the tops of the sections are equals:2

2211

2

2211 433.0433.0A

MLRMLRLAA

MLMLLA pp ++=++

Ifthestressesatthetopsofthesectionsareequals:Ifthestressesatthetopsofthesectionsareequals:

2

2211

1

11 433.0433.0A

MRMRAA

MRA pp ++=+21


Forselectedrodandplungersizes,thelengthofeachsectioncanbedetermined by use the previous equation plus the fact that:determinedbyusethepreviousequationplusthefactthat:

R R 1R1+R2 =1

Fortaperedstringconsistingofmorethantwosections,theequationFortaperedstringconsistingofmorethantwosections,theequationwillbemorecomplex,forexamplefor4taperedsections:willbemorecomplex,forexamplefor4taperedsections:

4

44332211

1

11 433.0433.0A

MRMRMRMRAA

MRA pp ++++=+

And: R1+R2+R3+R4 =1IncaseoftwoIncaseoftwowaytaperconsistingof5/8waytaperconsistingof5/8in(M1=1.16lb/ft)andin(M1=1.16lb/ft)and

( / )( / )in(M2=1.63lb/ft)rodsyoucouldget:in(M2=1.63lb/ft)rodsyoucouldget:p

ARAR

089602410

0896.0759.01 =pAR 0896.0241.02 =


5. Pump Displacement and Production RateThetheoreticalpumpdisplacementcanbecalculatedas:

/bbl9702inmin/day1440

minstrokesN

strokeinSinAV 3pp

2 =daybblNS0.1484A

/bbl9702inminstrokepp / =

Foragivenplungerdiameter,theterm0.1484Foragivenplungerdiameter,theterm0.1484AApp isindependentofisindependentofsurfaceoperatingconditionsandiscalledthepumpconstant,K,then:surfaceoperatingconditionsandiscalledthepumpconstant,K,then:

For API pumps there is Table for K of each pump size

NKSV p=ForAPIpumps,thereisTableforKofeachpumpsize.

TheratiobetweenthefluidactuallyhandledandthepumpTheratiobetweenthefluidactuallyhandledandthepumpdisplacementisthevolumetricefficiencyofthepump:displacementisthevolumetricefficiencyofthepump:

EqVorVEqorV

qE ===v

vv EVorVEqorVE


6. Counterbalance DesignTheprimaryfunctionofthecounterbalancesystemistostoreenergyontheTheprimaryfunctionofthecounterbalancesystemistostoreenergyonthedownstroke,whenpolishedrodloadislow,andtoreleaseenergyonthedownstroke,whenpolishedrodloadislow,andtoreleaseenergyontheupstroke,whenpolishedrodloadishigh,thusdistributingmoreuniformlyupstroke,whenpolishedrodloadishigh,thusdistributingmoreuniformlythroughoutthepumpingcycle,theloadsandtorqueswhichmustbethroughoutthepumpingcycle,theloadsandtorqueswhichmustbesustainedbytheprimemover.sustainedbytheprimemover.

Theoretically,theidealcounterbalanceeffect,Theoretically,theidealcounterbalanceeffect,CiCi,wouldbesuchthatthe,wouldbesuchthattheprime mover would carry the same average loads on the upstroke and on theprime mover would carry the same average loads on the upstroke and on theprimemoverwouldcarrythesameaverageloadsontheupstrokeandontheprimemoverwouldcarrythesameaverageloadsontheupstrokeandonthedownstroke,thisis:downstroke,thisis:

The ideal counterbalance effect is then:minmax WCCW ii =

Theidealcounterbalanceeffectisthen:( )minmax5.0 WWCi +=

Substitutingandusingoneofthepreviousequations:( )GWWC rri 127.015.0 +=

Fromthepreviousequation,itisseenthattheidealcounterbalanceeffectFromthepreviousequation,itisseenthattheidealcounterbalanceeffectbalancesonebalancesonehalfthefluidloadplustheweightoftherodsinfluid.halfthefluidloadplustheweightoftherodsinfluid.

( )rri


Counterbalance Effect of the Counterweight


Counterbalance DesignThefigureshowsthatthecounterbalanceeffectThefigureshowsthatthecounterbalanceeffectCCww duetoacounterweightofduetoacounterweightofWWcc pounds,pounds,dependsonthegeometryofthepumpingunitandonthestrokelength,aswellasontheweightdependsonthegeometryofthepumpingunitandonthestrokelength,aswellasontheweightandpositionofthecounterweight.andpositionofthecounterweight.

At a given time,At a given time, ,, ,, are the angles as shown in the figure.are the angles as shown in the figure.Atagiventime,Atagiventime,,,,, aretheanglesasshowninthefigure.aretheanglesasshowninthefigure.d:distancefromcrankshafttothecenterofgravityofthecounterweight.d:distancefromcrankshafttothecenterofgravityofthecounterweight.r:distancefromcrankshafttopitmanbearing.r:distancefromcrankshafttopitmanbearing.

i f i h ii f i h iFFpp:tensionforceinthepitman.:tensionforceinthepitman. ( ) ( )( ) ( )( )

cos

sinsincoscoscos

2

112 +=lC

lFlFlC ppw

Taking moments about Point O:

( )( ) ( )( )

sinsincoscoscos

1

2

+= llCF wp

TakingmomentsaboutPointO:

( ) ( )( ) ( )( ) cossinsincossin 1+= lFrFdW ppc( )( ) ( )( )[ ]

cossinsincos

sin+= rdWF cp


Counterbalance DesignThelasttwoFpequationsgivesarelationshipbetweenthecounterweight and its resulting counterbalance effectcounterweightanditsresultingcounterbalanceeffect.

F i lif i id 0 d C 1Forsimplifying,consider 0,andCos =1,so;

idWlC ( )( )211

2 // sin

sincos

cos llrdWCorrdW

llC

cwcw ==

Inadditiontotheeffectofcounterweights,somecounterbalanceInadditiontotheeffectofcounterweights,somecounterbalanceeffectmaybeprovidedbystructuralunbalanceofthesurfaceeffectmaybeprovidedbystructuralunbalanceofthesurfaceinstallationitself.IfwecallthiseffectCs,thetotalcounterbalanceinstallationitself.IfwecallthiseffectCs,thetotalcounterbalanceeffect at the polished rod is:effect at the polished rod is:effectatthepolishedrodis:effectatthepolishedrodis:

( )( )21s //CC llrdWc+=April 30, 2010 NG Eng. Production II_ Dr. Adel Salem Lectures 11- 14: Page: 73

7. Calculation of TorqueAsshownintheFigure,ifthegeometryofthesurfaceinstallationisnotconsidered(i.e.AsshownintheFigure,ifthegeometryofthesurfaceinstallationisnotconsidered(i.e.l1 = l2) the previous reduces to:l1 = l2) the previous reduces to:l1 l2)thepreviousreducesto:l1 l2)thepreviousreducesto:

R=S/2. SdWc /2C =ThetorqueTiscalculatedas:

c

Therefore:2/ : .

sinsinTCSdWeqnpreviousfromand

dWWr

c

c

==

Instantaneous torque

( ) ( )( )( )

sin2/ T

sin2/sin2/TSCW

SCSW=

= on the gear box

Thisequationisanapproximateexpressionforinstantaneoustorqueonthegearbox.Thisequationisanapproximateexpressionforinstantaneoustorqueonthegearbox.ThehighestpossiblevalueforvariableWandsinThehighestpossiblevalueforvariableWandsin are,respectively,peakpolishedrodare,respectively,peakpolishedrodloadload WW and sin 90 (=1) Peak torque is then:and sin 90 (=1) Peak torque is then:

( )( )

load,load,WWmaxmax,andsin90(=1).Peaktorqueis,then:,andsin90(=1).Peaktorqueis,then:

( )( )2/T maxp SCW =April 30, 2010 NG Eng. Production II_ Dr. Adel Salem Lectures 11- 14: Page: 74

8. Speed Reduction from Prime Mover to Crankshaft

Poweristransmittedfromtheenginesheave,ofdiameterdPoweristransmittedfromtheenginesheave,ofdiameterdee,tounitsheave,of,tounitsheave,ofdiameter ddiameter duu, by means of V, by means of Vbelts. If the speed of the prime mover engine is Nbelts. If the speed of the prime mover engine is Neediameterddiameterduu,bymeansofV,bymeansofV belts.IfthespeedoftheprimemoverengineisNbelts.IfthespeedoftheprimemoverengineisNeerevolutionsperminute,thebeltvelocityis:revolutionsperminute,thebeltvelocityis:

min/inNdvb =Andthespeedoftheunitsheaveis:Andthespeedoftheunitsheaveis:

min/ inNdv eeb

If the gear ratio at the gear reducer is Z pumping speed is:If the gear ratio at the gear reducer is Z pumping speed is:

( ) rpmddNdvN ueeubu // ==IfthegearratioatthegearreducerisZ,pumpingspeedis:IfthegearratioatthegearreducerisZ,pumpingspeedis:

ueeu ZddNNN /Z/ == ueeu


9. Power Requirements of the Prime MoverTherearetwopowerloadsmustbeconsideredinmovingfluidfrompumptosurface:1. HydraulicHorsepower,Hh,and2. FrictionHorsepower,Hf.

HydraulicHorsepowerHydraulicHorsepowerHHhh::ftLlb/bbl350Gbbl/dayq

Friction Horsepower HFriction Horsepower H

hpqGLlb/min/hpft33000min/day1440

ftLlb/bbl350Gbbl/dayqHh 1036.7 6=

=FrictionHorsepower,HFrictionHorsepower,Hff..Itisthefractionalenergylossbetweenpumpandpolishedrod.TheEmpiricalItisthefractionalenergylossbetweenpumpandpolishedrod.TheEmpiricalformulausedis:formulausedis:

lb/ hpSNWlb/min/hpft33000in/ft12lb/mininSN0.25WH rrf 1031.6

7==

Thetotalhorsepoweristhesumofthepreviousequations.ConsideringasafetyThetotalhorsepoweristhesumofthepreviousequations.Consideringasafetyfactor,then:factor,then: ( )fhb HHH += 5.1 ( )fhb HHH +5.1April 30, 2010 NG Eng. Production II_ Dr. Adel Salem Lectures 11- 14: Page: 76




Lecture Nr. 13Lecture Nr. 13III Jet PumpsIII Jet PumpsIII. Jet PumpsIII. Jet PumpsIV PCP PumpsIV PCP PumpsIV. PCP PumpsIV. PCP Pumps

Agenda:4.JetandPCPpumps4.JetandPCPpumps4 1 Jet Pump4.1.JetPump:

Main Components and Operating Mechanisms, Pump Types Pump Types, Performance Curves and Pump Selection,Required Power Fluid Rate Required Power Fluid Rate, Surface Pressure and Horse Power, Design of a Jet Pump SystemDesign of a Jet Pump System.

4.2.PCP:Surface and Sub-surface Equipment of PCP, Surface and Sub surface Equipment of PCP, Top drive PCP, Bottom Drive PCP, Performance curve and power requirement.p q


Outlines

1.1. Jetpump:Jetpump:Maincomponentsandoperatingmechanisms,pumpMaincomponentsandoperatingmechanisms,pumptypes,performancecurvesandpumpselectionrequiredtypes,performancecurvesandpumpselectionrequiredpowerfluidrate,surfacepressureandhorsepowerpowerfluidrate,surfacepressureandhorsepower

2. PCP:Surface and subsurface equipment top drive PCPSurfaceandsubsurfaceequipment,topdrivePCP,bottomdrivePCPandpowerrequirement


Pump Pump ClassificationsClassificationsClassificationsClassifications



Jet Pump: Introduction

TheThe jetjet pumppump convertsconverts thethe powerpower fluidfluid receivedreceived toto aa highhigh velocityvelocity jetjetthenthen mixesmixes itit withwith wellwell fluidsfluids wherewhere enoughenough energyenergy isis exchangedexchanged toto

llll thth tt ff b thb th fl idfl id tt ffallowallow thethe returnreturn ofof bothboth fluidsfluids toto surfacesurface..

ThTh j tj t hh ii tt iiTheThe jetjet pumppump hashas nono movingmoving componentscomponents soso maximummaximumproductionproduction capacitiescapacities areare defineddefined forfor aa givengiven combinationcombination ofofthroatthroat andand nozzlenozzle.. CavitationCavitation phenomenaphenomena causedcaused byby extremelyextremelypp yy yyhighhigh flowflow ratesrates throughthrough thethe annularannular areaarea ofof thethe throatthroat limitslimitsproductionproduction raterate.. DesignDesign relationshipsrelationships inin thethe jetjet pumppump sectionsection ofofthithi ll ii tt hi hhi h b ttb tt id tifid tif itiitithisthis manualmanual reviewreview parametersparameters whichwhich betterbetter identifyidentify capacitiescapacitiesandand limitationslimitations


Overview of Jet Pump Operation

Casing Casing free installations offer the simplest design for review of jet free installations offer the simplest design for review of jet gg p g jp g jpump operation. The pumping action is achieved through the pump operation. The pumping action is achieved through the energy transfer from the power fluid to the well fluidsenergy transfer from the power fluid to the well fluids..

HighHigh--pressure pressure power fluid passes through a nozzle where its power fluid passes through a nozzle where its potential energy (pressure) is converted to kinetic energy in potential energy (pressure) is converted to kinetic energy in p gy (p ) gyp gy (p ) gythe form of a high velocity jet stream. Well fluids surround the the form of a high velocity jet stream. Well fluids surround the exit of the nozzle to intermix with the jet stream in the mixing tube exit of the nozzle to intermix with the jet stream in the mixing tube

ll d th th t Th t f th fl id i t f d ll d th th t Th t f th fl id i t f d called the throat. The momentum of the power fluid is transferred called the throat. The momentum of the power fluid is transferred to the well fluids. to the well fluids.

The The mixture then passes through an expanding area called a mixture then passes through an expanding area called a diffuser to convert the mixture kinetic energy to static pressure diffuser to convert the mixture kinetic energy to static pressure b l i d th fl id th h th i i fl Th b l i d th fl id th h th i i fl Th by slowing down the fluid through the increase in flow area. The by slowing down the fluid through the increase in flow area. The pressure of the mixture must be sufficient to reach the surface.pressure of the mixture must be sufficient to reach the surface.


Jet Pump Principle

Performance Characteristics :Performance Characteristics :Performance Characteristics :Performance Characteristics :Lift capacity of the jet pump is dependant on throat and nozzle Lift capacity of the jet pump is dependant on throat and nozzle dimensions and the ratio of areas between them. Larger throat dimensions and the ratio of areas between them. Larger throat and nozzles have higher flow capacities The ratio of nozzle area and nozzles have higher flow capacities The ratio of nozzle area and nozzles have higher flow capacities. The ratio of nozzle area and nozzles have higher flow capacities. The ratio of nozzle area to throat area determines relationship between pressure and to throat area determines relationship between pressure and flow rate.flow rate.


Jet Pump Application Range


Advantage of Jet Pump




Th N 165 T S rf UnitTh N 165 T S rf UnitThe New 165 T Surface UnitThe New 165 T Surface Unit


Th N 165 T S rf UnitTh N 165 T S rf UnitThe New 165 T Surface UnitThe New 165 T Surface Unit


200 T200 T 5 S rf Unit S r i In5 S rf Unit S r i In200 T 200 T -- 5 Surface Unit Service In5 Surface Unit Service InSouth DABAA Pet. Co. South DABAA Pet. Co.


200 T200 T 5 J mb V l M n f t r d B5 J mb V l M n f t r d B200 T 200 T -- 5 Jumbo Vessel Manufactured By 5 Jumbo Vessel Manufactured By EGY OTS Service In South DABAA Pet. Co. EGY OTS Service In South DABAA Pet. Co.


300 Q 5 H Surface Unit Service InEast Zeit Pet. Co. East Zeit Pet. Co.


h h l fh h l fEGY OTS Team Prepare The Pump To operate In The PlatformEGY OTS Team Prepare The Pump To operate In The Platform


300 Q300 Q 5 M S f U i P h d B5 M S f U i P h d B300 Q 300 Q 5 M Surface Unit Purchased By5 M Surface Unit Purchased BySouth DABAA Pet. Co. South DABAA Pet. Co.


Free Style Jet Pump y p


C l Fl SSD Conventional Flow SSD Jet PumpJet Pump


Reverse Flow SSD Jet JPump


P iti f t N ti f t

Hydraulic Jet PumpsPositive features Negative features

Simple to vary rate Relatively inefficient lift method

Retrievable without pulling tubing Design of system is more complex.

No problems in deviated or crooked holes Pump may cavitate under certain conditions.

Has no moving parts Power oil systems are fire hazard

Unobtrusive in urban locations. Very sensitive to any change in back y y gpressure

Applicable offshore. The producing of free gas through h d i i bilithe pump causes reduction in ability to

handle liquidsCan use water as a power sourceCan use water as a power source

Corrosion scale emulsion treatmenteasy to performeasy to perform.


Jet Pump Design

TheparameterrepresentedonFigurebelowarethefollowing:

PP11 PowerfluidpressurePowerfluidpressurePP22 DischargepressureDischargepressurePP33 =P=Pwfwf intakepressureintakepressureAA Nozzle areaNozzle areaAAjj NozzleareaNozzleareaAAss NetthroatareaNetthroatareaAAtt TotalthroatareaTotalthroatareattqq11 PowerfluidratePowerfluidrateqq22 TotalliquidrateinreturncolumnTotalliquidrateinreturncolumnVV Intakevolume.Intakevolume.


Jet Pump DesignDimensionlessarea:Dimensionlessarea:The ratio R of the nozzle area to the total area of the throat is called the area

p g

TheratioRofthenozzleareatothetotalareaofthethroatiscalledthearearatio,

Di i l fl tDi i l fl tDimensionlessflowrate:Dimensionlessflowrate:

Where:V: Volume of the produced fluid rate (Liquid + gas).q1: : Power fluid rate.

Whenpumpingslightlycompressiblefluidssuchasliquids,Vcanbeconsideredconstant and equal to the surface rateconstantandequaltothesurfacerate.April 30, 2010 NG Eng. Production II_ Dr. Adel Salem Lectures 11- 14: Page: 104

Dimensionlesshead:Dimensionlesshead:The dimensionless head (H) is defined as the ratio of the pressure increaseThedimensionlesshead(H)isdefinedastheratioofthepressureincreaseexperiencedbytheproductionfluidtothepressurelosssufferedbythepowerfluid:

Where:P1 PowerfluidpressureP2 Dischargepressure'P3 Intakepressure


The parameters represented on areThe parameters represented on areThe parameters represented on are:The parameters represented on are:

PP Power fluid pressurePower fluid pressurePP11 Power fluid pressurePower fluid pressurePP22 Discharge pressure'Discharge pressure'PP =P=P intake pressureintake pressurePP33 =P=Pwf wf intake pressure intake pressure PPss Surface operating pressureSurface operating pressurePP hh wellhead pressurewellhead pressurePPwhwh wellhead pressurewellhead pressureqq11 Power fluid ratePower fluid rateqq22 Total liquid rate in productionTotal liquid rate in productionqq22 ota qu d ate p oduct oota qu d ate p oduct o

tubingtubingV V Intake volume.Intake volume.


Pump EfficiencyEfficiency:Efficiency:

In pumping liquid the efficiency isInpumpingliquid,theefficiencyis:

Therefore,itdependsofvariousparameters:Therefore,itdependsofvariousparameters: Geometry (shapes defined by the manufacturers),Geometry (shapes defined by the manufacturers), Geometry(shapesdefinedbythemanufacturers),Geometry(shapesdefinedbythemanufacturers), Typeoffluid:powerandpumped,andTypeoffluid:powerandpumped,and Flowrate,pressures.Flowrate,pressures.o a e, p essu eso a e, p essu esEachmanufacturerproposesformulascorrespondingto,theirequipments.Eachmanufacturerproposesformulascorrespondingto,theirequipments.


Dimensionless Performance CurveAnexampleoftheseequationresultsshowingHandp versusMforseveral values of R is represented in the following Figure (next slide)severalvaluesofRisrepresentedinthefollowingFigure(nextslide).

It i d fi ld ti t tt t t t th t it kItisgoodfieldpracticetoattempttooperatethepumpatitspeakefficiency.Inthatcase,theMandHratioswillbefixed;hence:

WhereMp andHparethepeakefficiencyflowratioandthepeakffi i h d ti ti lefficiencyheadratiorespectively.


Dimensionless Performance Curve


Power Fluid and PressureSimilar to hydraulic pumps, Jet pumps utilize either water or oil as a powerfluid The actual power fluid rate is a function of the pressures P and P offluid. The actual power fluid rate is a function of the pressures P1 and P2 ofthe flow area of the nozzle Aj, and of the specific gravity of the power fluid 1.When everything is measured in common oilfield units, the power fluid ratecan be estimated from the following equation:

hwhere

q1 fluid fate, bpdP and P pressures psiP1 and P3 pressures, psiAj nozzle area, in2.

Innormaloperations,thesurfaceoperatingpressureshouldnotexceed4000psior28MPa.ps o 8 a


Input PowerInputpowerInputpower

The input power requirement is estimated from the following equations:


i C it Progressing Cavity PPump


Global PC Pump Market by Region

U. S. A.Asia

PacificEurope Africa

U. S. A.

ME/CIS

Pacific

CanadaME/CIS

SouthSouth America


Surface DriveTypical PC Pump System

Casing Surface drive Casing

Production Tubing

Surface drive

Sucker rod or continuous rod Production TubingSucker Rod

Sucker Rod Progressing Cavity Pump

St t t d t t bi

Stator

Coupling

Tubing Collar Stator connected to tubing

Rotor connected to rod string

Rotor Accessory equipment

Tubing Collar

Tag Bar Sub


Typical PC Pump

Stator Double helix geometry Elastomer Stationary, attached to tubing

Rotor Single helix geometryS g e e geo e y Hardened Rotates, attached to rod otates, attac ed to odstring


PC Pump Surface Drives

Supplies rotation and torque to downholeb di d i d iPC pump by suspending and rotating a drive

string.

The drive string is typically made up of conventional or Corod continuous sucker rods.Configurations available:

Direct electric motor drivesDirect gearbox drives that may be coupled to an electric motor or gas engineHydraulic drive systems for both gas andelectric applications


PC Pump Applications

HeavyOilandBitumen(lessthan12API)withSurface Drive

sandcutsupto50%.MediumOil(from12to23API)withlimitedH2Scontent.SweetLightOil(over24API)withlimited

Casing

aromaticscontent.DewateringCoalbed Methane.

Production Tubing

Sucker Rod

WaterSourceWells.Evaluationandtestingofnewareas.

Sucker Rod Coupling

Tubing CollarStator

Tubing Collar

Rotor

Tubing Collarg

Tag Bar SubApril 30, 2010 NG Eng. Production II_ Dr. Adel Salem Lectures 11- 14: Page: 117

PC Pump System AdvantagesHigh System Efficiency (to 85% w/o gas)

l f lid ( 0% d l )Tolerant of solids (50% sand slugs)Multiphase pumping: oil, water, solids, gasLow Power ConsumptionLow Capital CostLow Maintenance CostsLow Surface Profile for Visual and Height Sensitive AreasgSimple Installation, Quiet OperationPortable Surface EquipmentPortable Surface EquipmentHorizontal/Directional Wells


PC Pump System LimitationsDepths to 11,000 feet (3,400 M)1

l 000 (63 3/d )1Volumes to 4,000 BPD (635 M3/day)1

TemperaturesT 300 F (150 C) i ilTo 300F (150C) in oilTo 185F (85C) in water

Aromatics and some produced fluidsAromatics and some produced fluidsLow volumetric efficiencies in high-gas environmentsPotential tubing and rod coupling wear in deviated wells (guides or Corod required)R i C t t Fl id L l b PRequires Constant Fluid Level above Pump_________________1Depth and volume limited by drive system torque1Depth and volume limited by drive system torque.


System Application Considerations

TYPICAL MAXIMUM2

Operating Depth 2,000 - 4,500 TVD600 1,400 m TVD11,000 TVD3,440 m TVD

Operating Volume 5 2,200 BPD1 350 m3/dayOver 4,000 BPDOver 635 m3/day

Operating Temp 75 185 F24 85 C300 F150 COperating Temp 24 85 C 150 C

System Efficiency 60% to 80% 85%

Prime Mover Type Electric Motor or Internal Combustion EnginePrime Mover Type Electric Motor or Internal Combustion Engine

Solids Handling ExcellentGas Handling GoodFluid Gravity Below 45 API

Wellbore Deviation N/A Build Angle < 15/100 ft (15/30m)

Offshore Good footprint, SSSV issues, surface sand handling

Servicing & Repair Requires Workover or Pulling Rig2 Special Analysis Required


PC Pump Systems

Wellhead Surface Drives

Continuous & ThreadedS k R dSucker Rods

Subsurface PC Pumps& Accessories


Application Guide for Typical Elastomers

NBRM NBRA HNBR FKM

Hardness (Shore A) 65 72 72 72

ACN Content (%) 33 44 42 N/A

Maximum Temp (F) 195 210 300 340

Service Temp (F) 175 190 265 300

Mechanical Resistance ++ ++ ++ -

Abrasion Resistance ++ + ++ -Abrasion Resistance

Carbon Dioxide - + ++ -

Hydrogen Sulfide - - ++ +

Aromatics Resistance + ++ + +++

Hot Water - + + ++

Steam - - - +

APPLICATION Heavy crudes with low contents of aromatics on presence of abrasives.

Light and medium crudes (26

PC Pump Technology

Elastomer Benchmarking

Tensile Strength

2000

2500

3000

3500Elongation

400

500

600

700Tear Strength

80

100

120

140

0

500

1000

1500

2000

WFD 59O Artemis Geremia Kachele 366 Mono A Moyno 102 Netzsch0

100

200

300

400

WFD 59O Artemis Geremia Kachele 366 Mono A Moyno 102 Netzsch0

20

40

60

80

WFD 59O Artemis Geremia Kachele 366 Mono A Moyno 102 NetzschW A B C D E F W A B C D E F W A B C D E FNO80 NBR-M NBR01 NO80 NBR-M NBR01 NO80 NBR-M NBR01

Water Swell35

903 Oil Swell14

16Abrasion Resistance

180

200 Abrasive Wear

W A B C D E F W A B C D E F W A B C D E F

10

15

20

25

30

4

6

8

10

12

14

60

80

100

120

140

160

0

5

WFD 59O Artemis NO80 GeremiaNBR-M

Kachele 366 Mono A Moyno 102 NetzschNBR01

0

2

WFD 59O Artemis NO80 GeremiaNBR-M

Kachele 366 Mono A Moyno 102 NetzschNBR01

0

20

40

WFD 59O ArtemisNO80

GeremiaNBR-M

Kachele 366 Mono A Moyno 102 NetzschNBR01W A B C D E F W A B C D E F W A B C D E F


PC Pump Technologyp gy

Elastomer Analysis

12 endurance test benches, 1 slurry test bench Numerous performance test benches, 3 for oils Chemical analysis 3-D nonlinear finite element elastomer modeling for

temperature, stress, and deflection.


Subsurface PC Pumps

Sizefrom6BPD/100rpmto1100BPD/100rpm/ p / pLiftcapacityto12000feetofequivalentcolumnofwaterwater

PumpsengineeredforspecificapplicationsFluid compatibility Geometry and fitFluidcompatibilityGeometryandfit


Uniform Thickness Pumps

Improved heat dissipationImprovedheatdissipationUniformelastomer swellUniformthermalexpansionWiderapplicabilityHigherpressureratingModel available with displacementModelavailablewithdisplacementcapacitiesfrom60to660BFPD@100RPMLiftcapacityupto9200feetofequivalentcolumnofwaterq


Insert PC Pumps

Twosettingdesigns:CloverleafandArrowheadd d i d l d lli b l CReducedowntimeandcostrelatedtopullingatubularPCP.

OnlypieceoftheequipmentinthetubingstringisthePumpSeatingNipple(PSN)(PSN).

PSNislocatedatthetoptoavoidsandbuildupbetweenpumpandtubing.Allow change of capacity/lift of pump without a work over rig No Turn toolAllowchangeofcapacity/liftofpumpwithoutaworkoverrig.NoTurntoolincludedintheconfiguration


Surface DrivesSizesfrom5Hpto250Hp

i f d i fi iVarietyofdriveconfigurationsDirect/beltGearGearHydraulic remoteIntegral hydraulic motor

Compactandefficient,lowprofileHingedBeltGuardsPatentedHollowShaftDesignStandardWellheadConnectionsRecoilspeedadjustmentandtestfeaturesHydraulicandcentrifugalbrakesystemsRemovablestuffingboxes


Horizontal Downhole Gas SeparatorTheVSlotautomaticallyorientsthetooltothelowsideofthewellbore.Heavierliquidsentertheseparatorwhilelightergaspassesabovetheseparator.


PROGRESSING CAVITY PUMPING (PCP)Theuseofprogressingcavitypumpsisbecomingthepreferredmethodof artificial lift in areas having highhigh solidssolids heavyheavy APIAPI oiloil and highhighofartificialliftinareashavinghighhigh solidssolids,heavyheavy APIAPI oiloil,andhighhighvolumesvolumes.

Over50,000wellsworldwidearenowusingPCPforthesedemandingapplicationsapplications.

During operation several factors can inhibit the PCP pump fromDuringoperation,severalfactorscaninhibitthePCPpumpfromperformingoptimally.Varyinginletproductionrates,PCPpumpwear,and clogged inlet screens can each mask themselves as other problems.andcloggedinletscreenscaneachmaskthemselvesasotherproblems.Withoutthecorrectoptimizationsolution,itisverydifficulttodiagnosecurrentproblemsandnearlyimpossibletoperformpredictiveanalysis.


PCP Pumps of NETZSCHPCPartificialliftpumpsareidealforshallowtomediumdepthwellswith fluid volumes between 1 bpd and 2200 bpdwithfluidvolumesbetween1bpdand2200bpd.

Th ffi i tl h dl h i il d fl id ith hi hThesepumpsefficientlyhandleheavyviscous oilandfluidswithahighcontentofsand,gas andwater.Awiderangeofelastomers areavailable for various applicationsavailableforvariousapplications.

1 Higher pump efficiencies results in power savings1. Higherpumpefficienciesresultsinpowersavings2. Efficienthandlingofawiderangeoffluids3 N l t l k3. Novalvestogaslock4. Loweroperatingcosts5. Resistanttodamage6. Flowratesto:4000b/d7. Pressuresto:3400PSI8. Installationdepthto:6700ftApril 30, 2010 NG Eng. Production II_ Dr. Adel Salem Lectures 11- 14: Page: 131

WELLSITE INTELLIGENCE WITH THE PCP SOLUTION

ThePCPsolutionusestheWeatherfordVFD,avectorfluxdrive(VFD)thatprovides infinite speed control with constant torque control throughoutprovidesinfinitespeedcontrolwithconstanttorquecontrolthroughoutthespeedrange.TheVFDcanbeusedbyitselforcoupledwithdownholegaugesformoredefinedcontrol.Anintelligentremoteterminalunit(RTU)canadddataloggingcapabilityforfinerresolutionindatacapture.( ) gg g p y p

VectorFluxDrive(VFD)W th f d' PCP l ti th W th f d t fl d i (VFD)Weatherford'sPCPsolutionusestheWeatherfordvectorfluxdrive(VFD)thatprovidesinfinitespeedcontrolwithconstanttorquecontrolthroughoutthespeedrange.

TheVFDprovidesasystemthatoffersequipmentprotectionwhileoperatingindynamicconditionssuchaswaterfloodsorhighsandcut.TheVFDconstantlymonitorstherodstringtorqueandautomaticallyadjuststhepoweroutputtoensurethesystemdoesnotexceedusersetlimits.Internalprogrammingmakesonlinedecisionstosafelyhandle

l ti f lid i th d d fl id dd t l daccumulationsofsolidsintheproducedfluids,suddenwaterslugs,andothershorttermconditionswheretheoperatordoesnotwantthewelltoshutdown.


VFDTheVFDprovidesthefollowingbenefits:

1. Totalspeedcontrol2. Totaltorquecontrol3. IntegralRTU4. Specificprogrammingforliftapplication

DownholeSensorsWeatherford's downhole sensors provide reliable pressure and temperature readingsWeatherford sdownholesensorsprovidereliablepressureandtemperaturereadings.AllofWeatherford'ssensorsaremanufacturedwiththehighestqualitystandardstoassurestabilityandlongevityintheharshdownholeenvironment.Theuseofhigh

l l l d l b k l li bili Thpressuremetaltometalsealsandelastomer backupassureslongtermreliability.Thesensorsarebuiltwithcompactdesignstofitmostapplicationsincludingslimholes.Thesensorsofferhighlevelaccuracyinacostefficientdesign.


SAM PCP Progressive Cavity Pump Controller

TheLufkinSAMProgressiveCavityPump(PCP)Controller works in conjunction with a variable speedControllerworksinconjunctionwitha variablespeeddrive(VSD) tooptimizefluidproductionwhileprotectingthepump. Thepatentedcontrolalgorithmvariesthespeedofthepumpwhilemeasuringtheamountoffluidproductionfromthepump.

Thecontrollerrampsupthepumpspeedinuserdefined steps, measuring production rate at each stepdefinedsteps,measuringproductionrateateachstepandestablishingaspeed/raterelationship.Atthepointthatastepincreaseinspeeddoesnotproducetheproportionalstepincreaseinfluidproductionrate,thecontrollerstartstoslowthespeedbystepsuntilareduction in fluid production rate is measured Thereductioninfluidproductionrateismeasured. Thecontrolalgorithmcontinuestotesttheoptimumproductionratebyrepeatingthespeed

/increase/decreasesequence.April 30, 2010 NG Eng. Production II_ Dr. Adel Salem Lectures 11- 14: Page: 134

New TechnologyTheThe resultingresulting highhigh torquetorque andand frictionfriction losses,losses, asas wellwell asas thethe tubingtubing andand rodrodfailurefailure cancan bebe reducedreduced byby placingplacing thethe motormotor downholedownhole thisthis isis knownknown asas aafailurefailure cancan bebe reducedreduced byby placingplacing thethe motormotor downholedownhole thisthis isis knownknown asas aaProgressingProgressing CavityCavity ElectricElectric SubmersibleSubmersible PumpPump..

Secondly,lowcostreplacementofthePCPunitcanbeachievedbySecondly,lowcostreplacementofthePCPunitcanbeachievedbymakingitwirelineretrievable.makingitwirelineretrievable.gg


The Progressing Cavity Electric Submersible Pump (PCESP)

ThePCESPsharethesameelectricmotor,seal,cableandcontrolThePCESPsharethesameelectricmotor,seal,cableandcontroltechnology as thetechnology as thetechnologyasthetechnologyasthe

conventional Electric Submersible Pumps (ESP) The major difference isconventional Electric Submersible Pumps (ESP) The major difference isconventionalElectricSubmersiblePumps(ESP).ThemajordifferenceisconventionalElectricSubmersiblePumps(ESP).ThemajordifferenceisthatagearboxisrequiredtoreducethespeedofrotationsincethethatagearboxisrequiredtoreducethespeedofrotationsincethecentrifugalpumpemployedwithaconventionalESPisahighcentrifugalpumpemployedwithaconventionalESPisahighspeedspeedg p p p y gg p p p y g ppdevice;whileaPCPisalowspeeddevice.Thelayoutofthetwopumpdevice;whileaPCPisalowspeeddevice.Thelayoutofthetwopumptypesiscomparedinthefigurebelow.typesiscomparedinthefigurebelow.


Comparison between ESP and PCESP

April 30, 2010 NG Eng. Production II_ Dr. Adel Salem

137




Lecture Nr. 14Lecture Nr. 14V. ESP PumpsV. ESP Pumps

Electrical Submersible Pumps5.1. ESP

Basic Components, Basic Components, Pump Design and Construction, andPump Performance, Pump Intakes

5 2 ESP5.2. ESPPump Sizing, Application, Seal Section & Cable Selection, andVoltage Drop Calculations.

5.3. ESP Fixed Speed Drive Transformers Variable Speed Drive Fixed Speed Drive Transformers, Variable Speed Drive, Motor Pump Performance at Different Speed Frequencies, and

AMP Charts, and Failure Analysis and Troubleshooting.

II. Comparison and Selectivity of Artificial Lifting II. Comparison and Selectivity of Artificial Lifting TTTypesTypes


Outlines

1.1. Introduction, General Hydraulics,Introduction, General Hydraulics,2.2. Hydraulic Pumps,Hydraulic Pumps,3.3. Centrifugal Pumps Fundamental,Centrifugal Pumps Fundamental,4.4. Electrical Submersible Pump Equipment Electrical Submersible Pump Equipment

Description and Function,Description and Function,p ,p ,5.5. ESP Running & Pulling Procedures, and ESP ESP Running & Pulling Procedures, and ESP

ApplicationApplicationApplicationApplication6.6. ESP Design and Selection,ESP Design and Selection,77 ESP Troubleshooting andESP Troubleshooting and7.7. ESP Troubleshooting, andESP Troubleshooting, and

II.II.ComparisonandSelectivityofArtificialLiftingTypesComparisonandSelectivityofArtificialLiftingTypes


ESP Systems: IntroductionAbout15to20percentofalmostonemillionwellsworldwidearepumpedwithsomeformAbout15to20percentofalmostonemillionwellsworldwidearepumpedwithsomeformofartificialliftemployingelectricsubmersiblepumps.Inaddition,ESPsystemsaretheofartificialliftemployingelectricsubmersiblepumps.Inaddition,ESPsystemsarethep y g p p , yp y g p p , yfastestgrowingformofartificialliftpumpingtechnology.Theyareoftenconsideredhighfastestgrowingformofartificialliftpumpingtechnology.Theyareoftenconsideredhighvolumeanddepthchampionsamongoilfieldliftsystems.volumeanddepthchampionsamongoilfieldliftsystems.

Foundinoperatingenvironmentsallovertheworld,ESPsareveryversatile.TheycanFoundinoperatingenvironmentsallovertheworld,ESPsareveryversatile.Theycanhandleawiderangeofflowratesfrom70handleawiderangeofflowratesfrom70bpdto64,000bpdto64,000bpdormoreandliftrequirementsbpdormoreandliftrequirementsf i t ll t h 15 000f i t ll t h 15 000 ft f lift A l ESP h l ffi i ift f lift A l ESP h l ffi i ifromvirtuallyzerotoasmuchas15,000fromvirtuallyzerotoasmuchas15,000ftoflift.Asarule,ESPshavelowerefficienciesftoflift.Asarule,ESPshavelowerefficiencieswithsignificantfractionsofgas,typicallygreaterthanabout10percentvolumeatthewithsignificantfractionsofgas,typicallygreaterthanabout10percentvolumeatthepumpintake.Giventheirhighrotationalspeedofupto4000pumpintake.Giventheirhighrotationalspeedofupto4000rpmandtightclearances,rpmandtightclearances,th l l d t l t l t f lid lik dth l l d t l t l t f lid lik dtheyarealsoonlymoderatelytolerantofsolidslikesand.theyarealsoonlymoderatelytolerantofsolidslikesand.

IfsolidIfsolidladenproductionflowsareexpected,specialrunningproceduresandpumpladenproductionflowsareexpected,specialrunningproceduresandpumpp p , p g p p pp p , p g p p pplacementtechniquesareusuallyemployed.Whenverylargeamountsoffreegasareplacementtechniquesareusuallyemployed.Whenverylargeamountsoffreegasarepresent,downholegasseparatorsand/orgascompressorsmayberequiredinlieuofapresent,downholegasseparatorsand/orgascompressorsmayberequiredinlieuofastandard pump intake.standard pump intake.standardpumpintake.standardpumpintake.


IntroductionESPsystemscanbeusedincasingassmallas4.5ESPsystemscanbeusedincasingassmallas4.5inoutsidediameterandcaninoutsidediameterandcanbe engineered to handle contaminants commonly found in oilbe engineered to handle contaminants commonly found in oilaggressiveaggressivebeengineeredtohandlecontaminantscommonlyfoundinoilbeengineeredtohandlecontaminantscommonlyfoundinoilaggressiveaggressivecorrosivefluidssuchasH2SandCO2,abrasivecontaminantssuchassand,corrosivefluidssuchasH2SandCO2,abrasivecontaminantssuchassand,exceptionallyhighdownholetemperaturesandhighlevelsofgasproduction.exceptionallyhighdownholetemperaturesandhighlevelsofgasproduction.IncreasingwatercuthasbeenshowntohavenosignificantdetrimentalIncreasingwatercuthasbeenshowntohavenosignificantdetrimentaleffectonESPperformance.effectonESPperformance.

ESPshavebeendeployedinvertical,deviatedandhorizontalwells,buttheyESPshavebeendeployedinvertical,deviatedandhorizontalwells,buttheyshould be located in a straight section of casing for optimum run lifeshould be located in a straight section of casing for optimum run lifeshouldbelocatedinastraightsectionofcasingforoptimumrunlifeshouldbelocatedinastraightsectionofcasingforoptimumrunlifeperformance.performance.

OnacostOnacostperperbarrelbasis,ESPsareconsideredeconomicalandefficient.barrelbasis,ESPsareconsideredeconomicalandefficient.WithonlythewellheadandfixedorvariableWithonlythewellheadandfixedorvariablespeedcontrollervisibleatthespeedcontrollervisibleatthe

f ESP ff ll f i d lf ESP ff ll f i d l fil i ffil i fsurface,ESPsystemsofferasmallfootprintandlowsurface,ESPsystemsofferasmallfootprintandlowprofileoptionforprofileoptionforvirtuallyallapplications,includingoffshoreinstallations.Table1providesavirtuallyallapplications,includingoffshoreinstallations.Table1providesasummaryofESPartificialliftapplications.summaryofESPartificialliftapplications.su a y o S a t c a t app cat o ssu a y o S a t c a t app cat o s


ESP Application Range

Rate: Rate: 100100--100,000 BPD100,000 BPDPower: 10Power: 10--1500 HP1500 HPPressure: Up to 10,000 psiPressure: Up to 10,000 psiSize: 4Size: 4--1/2 and Larger Casing1/2 and Larger Casing4000 lt4000 lt4000 volts4000 volts140 amps140 amps


ESP Artificial Lift Application


ESP SystemInESPsystems,anelectricmotorandaInESPsystems,anelectricmotorandamultistagecentrifugalpumprunonamultistagecentrifugalpumprunonaproductionstring,connectedbacktoaproductionstring,connectedbacktoasurfacecontrolmechanismandtransformersurfacecontrolmechanismandtransformerviaanelectricpowercable.viaanelectricpowercable.

Carefulconsiderationmustbegiventoeachdownholeandsurfacecomponentofthepsysteminthedesignstage.

An ESP can pump intermittently orAnESPcanpumpintermittentlyorcontinuously.BecauseanESPcanbeeasilyadaptedtoautomationandcontrolsystems,numerous surface control andnumeroussurfacecontrolandcommunicationdevicesareavailable.

Additionally the downhole components canAdditionally,thedownholecomponentscanvarydependingonthespecificapplicationorconditions.


ESP Basic Components

ESPsareroutinelyusedonshoreandf l tf llforplatformwells.

They are a versatile form ofTheyareaversatileformofpumping,especiallywherehighratesarerequired.

ThebasicarrangementforatubingdeployedESPisshowninbesideFigurewithapumpstage(impellerand diffuser) shown in Figure asanddiffuser)showninFigureaswell.


Downhole and Surface Components

SubsurfaceequipmentsofESPare:SubsurfaceequipmentsofESPare:1. Multistage Centrifugal Pump,2. Motor,3 G S t3. Gas Separator,4. Seal Section, and5 P C bl5. Power Cable.6. etc

SurfaceComponents:SurfaceComponents:1 Tubing Head1. Tubing Head,2. Fixed or Variable Speed Controllers and Drives,3 Transformers and3. Transformers, and4. Electrical Supply System.5. etc5. etc

April 30, 2010 NG Eng. Productio

Lectures 11-14_Natural Gas Production-II (2)

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Transcript of Lectures 11-14_Natural Gas Production-II (2)