5th Annual Sucker Rod Pumping WorkshopWorkshop
Wyndham Hotel, Dallas, TexasSeptember 15 – 18 2009September 15 – 18, 2009
Three Conditions at the P mp Intake That Res lt inPump Intake That Result in Incomplete Pump Fillage
Lynn RowlanLynn Rowlan
Incomplete Pump FillageIncomplete Pump FillageOccurs from C to D on Pump Card Occurs from C to D on Pump Card
Steps C Steps C -- D in D in Pump OperationPump OperationSteps C Steps C -- D in D in Pump OperationPump OperationPump OperationPump Operation
Pump is a Pump is a CompressorCompressor
Pump OperationPump Operation
Pump is a Pump is a CompressorCompressor
BB CCCompressorCompressorCompressorCompressor at [C] Pb = Pintk
at [D] Pb = PdisPDisPDis -- Discharge PressureDischarge PressureAA DD
at [D] Pb PdisggPB PB -- Pressure in BarrelPressure in BarrelPintkPintk -- Intake PressureIntake Pressure
C)C) Standing Valve closes, when plunger reaches Standing Valve closes, when plunger reaches top of stroke, rods start to untop of stroke, rods start to un--stretch to stretch to transfer fluid load, transfer fluid load, FoFo, from rods [C] onto , from rods [C] onto tubing [D].tubing [D].
CC--D) Plunger applies D) Plunger applies pressure to fluids pressure to fluids inside pump barrelinside pump barrelg [ ]g [ ]
D) D) Standing valve Opens when pressure in Standing valve Opens when pressure in pump barrel >= Pump Discharge Pressure, pump barrel >= Pump Discharge Pressure, PDisPDis. .
inside pump barrel, inside pump barrel, to compress fluids to compress fluids in Pump barrel and in Pump barrel and increase pressure.increase pressure.
Incomplete Pump Fillage1.1. Fluid PoundFluid Pound -- Not enough Not enough
liquid to fill the pump barrel: liquid to fill the pump barrel: ll i fl l thll i fl l th
CCwell inflow less than pump well inflow less than pump displacement, pumped off.displacement, pumped off. CompressionCompression
DD
2.2. Gas InterferenceGas Interference -- Both gas Both gas and liquid at pump intake and liquid at pump intake
fill b lfill b lpressure fill pump barrel pressure fill pump barrel during the upstroke.during the upstroke.
DD
CC
CompressionCompression
3.3. Flow into pump intake Flow into pump intake chokedchoked -- flow through SV is flow through SV is
l th ll th l
DD
CCzero or less than plunger zero or less than plunger displacement.displacement. DD Collision?Collision?
Transfer Fluid Load from C to D Transfer Fluid Load from C to D from Rods to Tubingfrom Rods to Tubing
@ [C] Fo = Fluid Load@ [C] Fo = Fluid LoadPb Pi tkPb Pi tk
At [C] SVAt [C] SVBall SeatsBall Seats
BB
Pb = PintkPb = Pintk(Pdis(Pdis--Pintk)*Area PumpPintk)*Area Pump
Ball Seats Ball Seats Pdis > Pb Pdis > Pb Pb = PintkPb = Pintk
BBCC
at [C] Pb = PintkPlunger Plunger
AA DD
Stroke Stroke LengthLength at [D] Pb = Pdis
@ [D] TV Opens@ [D] TV OpensFo = 0Fo = 0
At [D] TVAt [D] TVOpensOpens
Pb = PdisPb = Pdis(Pdis(Pdis--Pdis)*Area PumpPdis)*Area Pump
Opens Opens Pdis = Pb Pdis = Pb Pb > PintkPb > Pintk
Calculated Pump Card Loads:Calculated Pump Card Loads:
Pump Card Rests on Zero Load Line on Down Stroke. Pump Card Rests on Zero Load Line on Down Stroke. Pump Card Near Fo From Fluid Level on Up Stroke. Pump Card Near Fo From Fluid Level on Up Stroke.
20.00
22.50
Wrf + Fo Max
Calculated Pump Card Loads:Calculated Pump Card Loads:SV Open Upstroke: SV Open Upstroke:
FoFo Max = (Max = (PdisPdis –– 0)*Ap0)*ApFF ((PdiPdi Pi tkPi tk)*A)*A
Surface Card
15.00
17.50 FoFo = (= (PdisPdis -- PintkPintk)*Ap)*ApTV Open TV Open DownstrokeDownstroke: :
FoFo = 0= 0
10.00
12.50
Fo Max
Wrf
Pump Card Reference Lines:Pump Card Reference Lines:1.1. FoFo MaxMax -- assumes pump intake assumes pump intake
pressure is zero, where well pressure is zero, where well provides no help in lifting the fluidprovides no help in lifting the fluid
5.00
7.50 Fo From Fluid Levelprovides no help in lifting the fluid provides no help in lifting the fluid to the surface.to the surface.
2.2. FoFo From Fluid LevelFrom Fluid Level -- assumes assumes pump intake pressure determined pump intake pressure determined from fluid level shot, where well’s from fluid level shot, where well’s PIP id h l i lifti thPIP id h l i lifti th
Well
Fo ~ Height of Pump Card
0
2.50
156.0
PIP provides help in lifting the PIP provides help in lifting the fluid.fluid.
3.3. Zero Load LineZero Load Line –– assumes assumes pressure above and below the pressure above and below the plunger are equal; no friction dueplunger are equal; no friction due
Fluid Load Lifted by RodsFo ~ Height of Pump Card
0 168.0-2.50plunger are equal; no friction due plunger are equal; no friction due to fluid displacing through SV on to fluid displacing through SV on down strokedown stroke
Pump Card
Fo loads measured Dynamometer or calculated From Fluid Level.Fo loads measured Dynamometer or calculated From Fluid Level.
Incomplete Pump Fillage
1.1. Fluid PoundFluid Pound –– Rod Loading Rod Loading Fo = FoFo = Foggis Fomax, Pintk is low, Pb = is Fomax, Pintk is low, Pb = Pintk.Pintk.
Fo = FoFo = Fomaxmax
Fo Fo flfl = Fo= Fomaxmax
2.2. Gas InterferenceGas Interference -- Rod Rod Loading is Fo fl Pintk isLoading is Fo fl Pintk is
Fo < FoFo < FomaxmaxFo Fo flfl = Fo= Fo
Loading is Fo fl, Pintk is Loading is Fo fl, Pintk is high, Pb = Pintk.high, Pb = Pintk.
Fo Fo flfl < Fo< Fomaxmax
3.3. Flow into pump intake Flow into pump intake chokedchoked -- Rod Loading is Rod Loading is Fo = FoFo = Fomaxmax
Fomax, Pintk is high, Pb = Fomax, Pintk is high, Pb = Zero (0); much << Pintk.Zero (0); much << Pintk. Fo Fo flfl < Fo< Fomaxmax
Synthetic Pump Cards:Synthetic Pump Cards:Fluid Pound ~ PIP is LowFluid Pound ~ PIP is LowSynthetic Pump Cards:Synthetic Pump Cards:Fluid Pound ~ PIP is LowFluid Pound ~ PIP is Low
Tubing anchored, EPT<MPT.Tubing anchored, EPT<MPT. Unanchored tubing, EPT<MPTUnanchored tubing, EPT<MPTTubing anchored, EPT MPT.Tubing anchored, EPT MPT. Unanchored tubing, EPT MPTUnanchored tubing, EPT MPT
Fo Fluid LevelFo MaxFo Up
Fluid pound Fluid pound -- well being pumped off. Pump components are well being pumped off. Pump components are functioning properly. BUT, sudden unloading of rods results in functioning properly. BUT, sudden unloading of rods results in rod buckling and reduced equipment life! Shoot fluid level torod buckling and reduced equipment life! Shoot fluid level torod buckling and reduced equipment life! Shoot fluid level to rod buckling and reduced equipment life! Shoot fluid level to verify pump intake not blocked and fluid level at pump intake.verify pump intake not blocked and fluid level at pump intake.
Control Run Time When Control Run Time When Pump Displacement Exceeds Inflow From WellPump Displacement Exceeds Inflow From Well
Same Well with Full PumpSame Well with Full PumpO TV l h P F llO TV l h P F ll
p pp p
Open TV only when Pump FullOpen TV only when Pump Full
Pump Capacity Exceeds Pump Capacity Exceeds I fl f Fl id f W llI fl f Fl id f W ll
Full
Inflow of Fluids from WellInflow of Fluids from Well..
Full
Controlling Pump Run TimeControlling Pump Run TimeImproves Efficiency, Reduces Improves Efficiency, Reduces
Pound Shock Loads, and Reduces Shock Loads, and Reduces FailuresFailures..
Fluid PoundFluid Pound -- Fluid Level @ PumpFluid Level @ PumpTimer or Pump Off Controller CandidateTimer or Pump Off Controller CandidateFluid PoundFluid Pound -- Fluid Level @ PumpFluid Level @ PumpTimer or Pump Off Controller CandidateTimer or Pump Off Controller Candidate
Fl id L lFl id L lFluid Level Fluid Level @ Pump@ PumpFo Pump @ Fo MaxFo Pump @ Fo Max
Fluid Fluid PoundPound
Synthetic Pump Cards:Gas InterferenceSynthetic Pump Cards:Gas Interference
Tubing anchored, EPT<MPT.Tubing anchored, EPT<MPT. Unanchored tubing, EPT<MPTUnanchored tubing, EPT<MPTFF MMg ,g , Unanchored tubing, EPT MPTUnanchored tubing, EPT MPT
Fo Fluid LevelFo Fluid Level
FoFo MaxMax
GasGas InterferenceInterference isis causingcausing decreasedecrease ofof EPTEPT.. PumpPump componentscomponents arearefunctioningfunctioning properlyproperly.. UsuallyUsually unstableunstable pumppump fillagefillage andand EPTEPTchangeschanges fromfrom strokestroke--toto--strokestroke.. WhenWhen gasgas interferenceinterference isis presentpresentexpectexpect increasedincreased rodrod--onon--tubingtubing wearwear duedue toto rodrod bucklingbucklingcompressingcompressing gasgas inin pumppump barrelbarrel..
Gas Interference: Incomplete Pump Fillage and High Fluid LevelGas Interference: Incomplete Pump Fillage and High Fluid Level
Fluid Level Fluid Level Above PumpAbove Pump
Fo Well
pp
Fo Rods
Fo Pump < Fo MaxFo Pump < Fo MaxFo Pump < Fo MaxFo Pump < Fo Max
Synthetic Pump Cards:Synthetic Pump Cards:Severe Fluid Pound Severe Fluid Pound –– Blocked Pump IntakeBlocked Pump IntakeSynthetic Pump Cards:Synthetic Pump Cards:Severe Fluid Pound Severe Fluid Pound –– Blocked Pump IntakeBlocked Pump Intakepppp
Tubing anchored, EPT<MPT.Tubing anchored, EPT<MPT. Unanchored tubing, EPT<MPTUnanchored tubing, EPT<MPTTubing anchored, EPT MPT.Tubing anchored, EPT MPT. Unanchored tubing, EPT MPTUnanchored tubing, EPT MPT
Fo Fluid LevelFo Fluid Level
Fo MaxFo MaxFo UpFo Up
Fo Fluid LevelFo Fluid Level
Severe fluid pound, usually occurs when the intake into the pump is Severe fluid pound, usually occurs when the intake into the pump is completely blocked off. Strainer nipple, pump intake below fill, completely blocked off. Strainer nipple, pump intake below fill, standing valve stuck shut can starve pump. Stuffing box leak and standing valve stuck shut can starve pump. Stuffing box leak and reduced equipment life result! Shoot fluid level to verify pump intake reduced equipment life result! Shoot fluid level to verify pump intake is blocked and fluid level above pump intakeis blocked and fluid level above pump intake
Severe Fluid Pound: Flow into Pump ChokedFluid Pound and High Fluid LevelSevere Fluid Pound: Flow into Pump ChokedFluid Pound and High Fluid Level
Fluid Level Fluid Level Above PumpAbove PumpAbove PumpAbove Pump
Fo WellFo Well
Fo Pump = Fo MaxFo Pump = Fo Max
Fo RodsFo Rods
Gas Compressionp
Traveling valve Traveling valve opens whenopens whenopens when opens when pressure in barrel pressure in barrel exceeds the exceeds the pressure at thepressure at theThe dynamometer card pressure at the pressure at the pump discharge pump discharge at the bottom of at the bottom of the tubing.the tubing.
indicates gas in the pump. Gas compression occurs during the downstroke ggduring the downstroke from C to D and causes the traveling valve to opened at D.
Effect of PIP onGas Interference and Fluid PoundEffect of PIP onGas Interference and Fluid Pound
GasGas
PV PVPV PV((----------) = () = (------------))
Z ZZ Z
IntakeIntake
Z ZZ ZIntake DischargeIntake Discharge
LiquidLiquid
IsoIso--thermalthermalNo Change in RsNo Change in Rs
LiquidLiquidDischargeDischarge
Effect of PIP on Fillage of Pump CardEffect of PIP on Fillage of Pump Card
Gas Free PumpGas Free Pump
GasGas
Gas Free Pump Gas Free Pump Fillage LineFillage Line
GasGasGas Free Pump Fillage = 50%Gas Free Pump Fillage = 50%
@ 10 Psi@ 10 Psi
Total Gas Fillage = 50%Total Gas Fillage = 50%
@ 0 s@ 0 sEff Plunger Stroke = 47”Eff Plunger Stroke = 47”EPS Fillage = 52%EPS Fillage = 52%Gas Fillage [D] = 2%Gas Fillage [D] = 2%
@ 500 P i@ 500 P i
LiquidLiquid
@ 500 Psi@ 500 PsiEff Plunger Stroke = 60”Eff Plunger Stroke = 60”EPS Fillage = 66.7%EPS Fillage = 66.7%Gas Fillage [D] = 16 7%Gas Fillage [D] = 16 7%LiquidLiquid Gas Fillage [D] = 16.7%Gas Fillage [D] = 16.7%
Rods Buckle (Train Wreck Effect)Pump Load & Velocity
Plunger Slows to Open TV
GasGasGas Gas InterferenceInterference
Rods Buckle (Train Wreck Effect )Pump Load & Velocity
Plunger Slows to Open TV
Plunger Slows to Open TV
Fluid PoundFluid Pound
Gas Compression and Train Wreck EffectGas Compression and Train Wreck Effect
1.1. Gas Compression occurs when the pump barrel is Gas Compression occurs when the pump barrel is partially/filled with gas.partially/filled with gas.partially/filled with gas.partially/filled with gas.
2.2. Sudden opening of TV reduce equipment lifeSudden opening of TV reduce equipment lifea.a. Is it uphole compression whacking rods against the tubingIs it uphole compression whacking rods against the tubinga.a. Is it uphole compression whacking rods against the tubingIs it uphole compression whacking rods against the tubingb.b. Pin failures due to rod slap loosening the couplingsPin failures due to rod slap loosening the couplings
3.3. Rod buckling up the hole occurs when the pump slows Rod buckling up the hole occurs when the pump slows ggdown to compress the gas and liquid in the pumpdown to compress the gas and liquid in the pump
4.4. Rods must apply a force to increase the pressure Rods must apply a force to increase the pressure i id th b l t t th th di hi id th b l t t th th di hinside the barrel to greater than the discharge inside the barrel to greater than the discharge pressure. pressure.
55 Rods above the pump go into compression and buckleRods above the pump go into compression and buckle5.5. Rods above the pump go into compression and buckle Rods above the pump go into compression and buckle when the pump velocity decreases in order to increase when the pump velocity decreases in order to increase the pressure inside the pump.the pressure inside the pump.
Fluid Pound and Rod BucklingFluid Pound and Rod Buckling
1.1. Fluid Pound may not be Exactly Correct TermFluid Pound may not be Exactly Correct Terma.a. Occurs with incomplete pump fillage at low pump intakeOccurs with incomplete pump fillage at low pump intakea.a. Occurs with incomplete pump fillage at low pump intake Occurs with incomplete pump fillage at low pump intake
pressure pressure b.b. Forces at pump may not cause trouble Forces at pump may not cause trouble c.c. UpUp--hole rod compression and rod on tubing wear is the likely hole rod compression and rod on tubing wear is the likely
problem problem
2.2. Low Pressure Gas in the pump causes fluid poundLow Pressure Gas in the pump causes fluid poundp p pp p pa.a. Pump stops just as bad if the gas is in the 100Pump stops just as bad if the gas is in the 100--200 psi range, 200 psi range, b.b. Rod on tubing wear can be worse at higher intake pressuresRod on tubing wear can be worse at higher intake pressures
3.3. Traveling valve opens when pressure in barrel exceeds Traveling valve opens when pressure in barrel exceeds discharge pressure at the bottom of the tubing.discharge pressure at the bottom of the tubing.a.a. TV always opens before hitting fluid (except blocked intake)TV always opens before hitting fluid (except blocked intake)b.b. Plunger maybe a 1/16th inch away when "fluid pound“ occursPlunger maybe a 1/16th inch away when "fluid pound“ occurs
Rods Buckle (Collision with Liquid )
20.00
22.50
Wrf + Fo Max
15.00
17.50
Wrf
Wrf Fo Max
Pump Load 0 &
10.00
12.50
Pump Load 0 & Velocity -11 ft/sec
5 00
7.50
10.00
Plunger Stops After TV Opens
Gas Compression Does Not Slows Plunger to Open TV
2.50
5.00 Fo Max
Fo From Fluid Level
Blocked IntakeBlocked Intake
Plunger to Open TV
0 120.0-2.50
0 106.7Blocked IntakeBlocked IntakeNegative Effective Load
0 BBLS in Tank ~ Pump Disp 26.9 BPD
Slippage Between Plunge/Barrel Fills PumpSlippage Between Plunge/Barrel Fills Pump0 BBLS in Tank Pump Disp 26.9 BPD
CC
EmptyEmpty
D
Plunger Velocity -11 to -5 in/sec
Blocked IntakeBlocked Intake
Pump Fillage Due to Only SlippagePump Fillage Due to Only Slippage
25 BPD 25 BPD Pump Pump FillageFillageFillageFillage
23” 23”
Blocked IntakeBlocked Intake
Incomplete Pump FillageIncomplete Pump Fillage1) Fo, Pump Load location w/ respect to Zero, Fo
From Fluid Level and Fo Max Load Lines areFrom Fluid Level, and Fo Max Load Lines are Used to Identify Incomplete Pump Fillage.
2) Fluid Pound and Blocked Intake Pump cards look ) psimilar except that:• Fluid Pound – Fluid level at Pump
Bl k d I k Fl id L l Hi h b P• Blocked Intake – Fluid Level High above Pump3) Fluid Pound and Gas Interference both have gas
in the pump that must be compressed from [C D]in the pump that must be compressed from [C-D]4) When the Intake is Blocked, then no gas is in the
pump barrel and Plunger “Pounds” the Fluid insidepump barrel and Plunger Pounds the Fluid inside the Pump Barrel.
5) Negative Load seen when Plunger HitsHits Liquid
Data Requirements Data Requirements -- PFLPFLqq•• Requires stabilized conditionsRequires stabilized conditions
•• Determination of Liquid Level DepthDetermination of Liquid Level Depth–– Avg. Joint Length, Acoustic Velocity, SG Gas ….Avg. Joint Length, Acoustic Velocity, SG Gas ….g g yg g y
•• Measurement of casing pressureMeasurement of casing pressure
•• Tubing Casing Size & TVD Pump DepthTubing Casing Size & TVD Pump Depth•• Tubing, Casing Size, & TVD Pump DepthTubing, Casing Size, & TVD Pump Depth
•• Oil, water and annular gas densitiesOil, water and annular gas densities
•• Measurement of casing pressure buildup rate Measurement of casing pressure buildup rate (at Producing Conditions)(at Producing Conditions)
Sept. 15 - 18, 2009 2009 Sucker Rod Pumping Workshop 25
Data Requirements Data Requirements -- DynoDyno•• Requires stabilized conditionsRequires stabilized conditions
M t f t biM t f t bi
•• Requires stabilized conditionsRequires stabilized conditions
M t f t biM t f t bi
qq yy
•• Measurement of tubing pressureMeasurement of tubing pressure
•• True Vertical Pump DepthTrue Vertical Pump Depth
•• Measurement of tubing pressureMeasurement of tubing pressure
•• True Vertical Pump DepthTrue Vertical Pump Depth
•• Oil, water and gas densitiesOil, water and gas densities
•• Oil water and gas Production RateOil water and gas Production Rate
•• Oil, water and gas densitiesOil, water and gas densities
•• Oil water and gas Production RateOil water and gas Production RateOil, water, and gas Production RateOil, water, and gas Production Rate
•• Tubing Fluid GradientTubing Fluid Gradient
Oil, water, and gas Production RateOil, water, and gas Production Rate
•• Tubing Fluid GradientTubing Fluid Gradient
•• Plunger Diameter, Rod String Plunger Diameter, Rod String
•• Damping CoefficientsDamping Coefficients
•• Plunger Diameter, Rod String Plunger Diameter, Rod String
•• Damping CoefficientsDamping Coefficients
Copyrightpy g
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Sept. 15 - 18, 2009 2009 Sucker Rod Pumping Workshop 27
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Sept. 15 - 18, 2009 2009 Sucker Rod Pumping Workshop 28