presentation wells backpressure sr wells

7/29/2019 Presentation Wells Backpressure SR Wells

1/24

8thAnnual Sucker Rod Pumping

WorkshopRenaissance Hotel

Oklahoma City, Oklahoma

September 25 - 28, 2012

Russell Brown,

Lynn Rowlan, James N. McCoy

Positive and Negatives ofTubing Backpressure on GassySucker Rod Lifted Wells


2/24

2

Frequently Observe Gas Pumped Up

Tubing Impacting Sucker Rod Lifted Well1. Gas Pumped up Tubing can be Detrimental to the

Operation of a Sucker Rod Lifted Well

a) Pump Problems because too Much Gas is Being

Pumped up the Tubing

b) Tubing Unloads while Acquiring Dynamometer Data

c) Pump Action Stops.

d) Various Pump Conditions based on Dynamometer

Card Shapes will be Shown.

2. Will Show Field Dynamometer Data Collected on a

Gassy Sucker Rod Lifted Well Using a Calibrated

Horseshoe Load Cell

Sept. 25 - 28, 20122012 Sucker Rod Pumping Workshop


3/24

3

On Sucker Rod Well Producing a Lot of

Gas, Symptoms Frequently Seen Are:Gassy Fluid Level Near Surface

0 93.40

1.6

3.1

4.7

6.3

7.8

9.4

10.9

86.0

Fo Max

Fo From Fluid Level

Wrf

Wrf + Fo Max

No Pump Action ~ Weigh Rods in Air

0 93.2

0.35

1.95

3.55

5.15

6.75

8.35

9.95

86.0

Wra

Subtract Weight

Rods in Air and

Pump Card on

Zero Load Line



4/24

0 168.0-2.50

0

2.50

5.00

7.50

10.00

12.50

15.00

17.50

20.00

22.50

156.0

Fo Max

Fo From Fluid Level

Wrf

Wrf + Fo Max

Calculated Pump Card Loads:Calculated Pump Card Loads:

SV Open Upstroke:SV Open Upstroke:

Fo Max = (Fo Max = (PdisPdis 0)*0)*ApAp

Fo = (Fo = (PdisPdis -- PintkPintk)*)*ApAp

TV OpenTV Open DownstrokeDownstroke::

Fo = 0Fo = 0

Pump Card Reference Lines:Pump Card Reference Lines:

1.1. Fo MaxFo Max -- assumes pump intakeassumes pump intakepressure is zero, where well providespressure is zero, where well providesno help in lift ing the fluid to the surface.no help in lift ing the fluid to the surface.

2.2. Fo From Fluid LevelFo From Fluid Level -- assumesassumespump intake pressure determined frompump intake pressure determined fromfluid level shot, where wellfluid level shot, where well s PIPs PIP

provides help in lifting the fluid.provides help in lifting the fluid.

3.3. Zero Load LineZero Load Line pump card setspump card setson zero load line because rods in tubingon zero load line because rods in tubingfluid with pressure above and below thefluid with pressure above and below theplunger equal; small friction due to fluidplunger equal; small friction due to fluiddisplacing through TV on down st rokedisplacing through TV on down st roke

Fluid Load Lifted by Rods

Well

Fo ~ Height of Pump Card

Pump CardPump Card ShouldShould Rests on Zero Load Line on Down Stroke.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.

Surface Card

Pump Card

4Sept. 25 - 28, 2012

2012 Sucker Rod Pumping Workshop


5/24

Steps C - D inPump Operation

Pump acts asa Compressor

Steps CSteps C -- D inD inPump OperationPump Operation

Pump acts asPump acts asa Compressora Compressor

AA

BBCC

DD

Incomplete Pump FillageIncomplete Pump Fillage

Occurs from C to D on Pump CardOccurs from C to D on Pump Card

C)C) Standing Valve closes, when plunger reachesStanding Valve closes, when plunger reachestop of stroke, rods start to untop of stroke, rods start to un--stretch to transferstretch to transferfluid load, Fo, from rods [C] onto tubing [D].fluid load, Fo, from rods [C] onto tubing [D].

D)D) Traveling Valve Opens when pressure in pumpTraveling Valve Opens when pressure in pumpbarrel >= Pump Discharge Pressure,barrel >= Pump Discharge Pressure, PDisPDis..

CC--D) Plunger appliesD) Plunger appliespressure to fluidspressure to fluids

inside pump barrel, toinside pump barrel, to

compress fluids incompress fluids in

Pump barrel andPump barrel and

increase pressure.increase pressure.

at [C] Pb = Pintk

at [D] Pb = Pdis

PDisPDis -- Discharge PressureDischarge Pressure

PBPB -- Pressure in BarrelPressure in Barrel

PintkPintk -- Intake PressureIntake Pressure

5Sept. 25 - 28, 2012


GassyGassy

WellWell


6/24

Gas thru the Pump Can Result in FlatGas thru the Pump Can Result in Flat

Pump Cards with NO Pump ActionPump Cards with NO Pump Action1)1) TV Stuck OpenTV Stuck Open -- Pump card on Zero Load, Looks l ikePump card on Zero Load, Looks like

Deep Rod Part but often can tag or jar the rods and knockDeep Rod Part but often can tag or jar the rods and knock

the debris out of the pump and rethe debris out of the pump and re--start pump action.start pump action.2)2) SV Stuck OpenSV Stuck Open Plots on the Fo from the Fluid Level linePlots on the Fo from the Fluid Level l ine

3)3) Tubing Blown DryTubing Blown Dry Missing Buoyancy, plots as a flat lineMissing Buoyancy, plots as a flat line

@ a height of@ a height ofWraWra--WrfWrf lbs above the zero load line..lbs above the zero load line..

6Sept. 25 - 28, 2012



7/24

Gas Filled Pump Card Means that Free

Gas is Being Pumped up the Tubing

0 90.6-1.56

0

1.56

3.13

4.69

6.25

7.81

9.38

10.94

12.50

86.0

Fo Max

Fo From Fluid Level

Wrf

Wrf + Fo Max

Strokes 1-146 gas interference ~

gas pumped into the tubing

0 93.2

-1.56

0

1.56

3.13

4.69

6.25

7.81

9.38

10.94

12.50

86.0

Fo MaxFo From Fluid Level

Wrf

Wrf + Fo Max

Stroke 147-186 No Pump Action

7

Gas Compression TV Stuck Open!



8/24

0 90.4-1.56

0

1.56

3.13

4.69

6.25

7.81

9.38

10.94

12.50

86.0


Wrf

Wrf + Fo Max

0 88.3-1.56

0

1.56

3.13

4.69

6.25

7.81

9.38

10.94

12.50

86.0


Wrf

Wrf + Fo Max

Gas Through the Pump Can Interfere

with the Normal Valve ActionStroke 187 TV Delay Going on Seat Stroke 188 More Gas Up the Tubing

8

TV Goes on Seat

Gas Compression



9/24

0 94.6-1.56

0

1.56

3.13

4.69

6.25

7.81

9.38

10.94

12.50

86.0


Wrf

Wrf + Fo Max

0 94.0-1.56

0

1.56

3.13

4.69

6.25

7.81

9.38

10.94

12.50

86.0


Wrf

Wrf + Fo Max

Flat Pump Card Means No Load

Transfer Between SV and TVStroke 189 Pump Full of Gas Stroke 190-314 SV Open

Some Call This a

Gas Locked Pump

SV Stuck Open and

TV Stays Closed.

9Sept. 25 - 28, 2012



10/24

0 93.4-1.25

0

1.25

2.50

3.75

5.00

6.25

7.50

8.75

10.00

11.25

86.0

Fo Max

Fo From Fluid Level

Wrf

Wrf + Fo Max

0 94.0-1.56

0

1.56

3.13

4.69

6.25

7.81

9.38

10.94

12.50

86.0


Wrf

Wrf + Fo Max

Pumping Gas Into Tubing, Then Light GassyGradient Unloads Tubing, No Pump Action as

Rods Hanging in Tubing Filled With Gas.Next 470 Strokes Fluids in Tubing Flow Off

Could be called aGas Locked Pump

Load Cell Weighing

Rod Weight in Air

0 89.6-1.56

0

1.56

3.13

4.69

6.25

7.81

9.38

10.94

12.50

86.0


Wrf

Wrf + Fo Max

Pump Fillage 50%

Lots of Gas up Tubing

Missing Buoyancy

Tubing Liquids Have

Blown Out and Rod

Buoyancy Missing

10

Gas Compression



11/24

11


12/24

12

Additional Tubing BackpressureAdditional Tubing Backpressure

Needed on this WellNeeded on this Well1. Previous Dynamometer Data Acquired Using a

Calibrated Horseshoe Load Cell While the Tubing

Discharge Pressure Was too Low2. Sufficient Backpressure can Prevent Tubing Fluids

from Unloading

Unloading usually Caused by Poor Downhole GasPoor Downhole GasSeparation with Gas Pumped into the TubingSeparation with Gas Pumped into the Tubing

Tubing Fluids Lighten and Tubing Liquids Flow Off.

3. Best to Keep Gas Out of the Tubing by Setting thePump Intake Below the Perforations

4. Or Use an Effective Downhole Gas Separator to Keep

Gas Out of the PumpSept. 25 - 28, 2012



13/24

Use of Backpressure Regulating Valve

on Tubing of a Sucker Rod Lifted Well


on Tubing of a Sucker Rod Lifted Well1.1. Use of a tubing backpressure regulating valve can maintainUse of a tubing backpressure regulating valve can maintain

pump action and prevent unloading of tubing liquids.pump action and prevent unloading of tubing liquids.

2.2. Excessive gas entering (pumped into) the tubing reducesExcessive gas entering (pumped into) the tubing reducesdifferential pressure across plunger and lightens tubingdifferential pressure across plunger and lightens tubing

fluid.fluid.

3.3. Surface tubing discharge pressure is higher whenSurface tubing discharge pressure is higher when

compared to the surface pressure if no backpressurecompared to the surface pressure if no backpressure

regulating valve were present.regulating valve were present.

4.4. Backpressure increases differential pressure across theBackpressure increases differential pressure across the

plunger and increases the tubing fluid gradient, whichplunger and increases the tubing fluid gradient, whichallows pump action to be maintained.allows pump action to be maintained.

5.5. Additional tubing backpressure potentially increasesAdditional tubing backpressure potentially increases

operating cost tooperating cost to Maintain Pump ActionMaintain Pump Action

13Sept. 25 - 28, 2012



14/24

14

Tubing Backpressure Impact on

Pump with 50% Fillage

Tubing Backpressure Impact onTubing Backpressure Impact on

Pump with 50% FillagePump with 50% Fillage

0 86.0-2.50

0

2.50

5.00

7.50

10.00

12.50

15.00

74.1

Fo Max

Fo From Fluid Level

Wrf

Wrf + Fo Max

425 Psi Tubing Backpressure

PR HP = 3.3

200 Psi Tubing Backpressure

PR HP = 2.9

PPRL = 11935 Lbs

MPRL = 6639 LbsMPRL = 5936 Lbs

PPRL = 12149 Lbs

SPM = 5.90SPM = 5.88



15/24

1.1. BackpressureBackpressure

regulating valve usedregulating valve used

to increase the tubingto increase the tubingpressurepressure..

2. Additional tubingbackpressure resultsin increased pressureon the pumpdischarge and

requires additionalhorsepower at thepump to lift the fluidsto the surface

Backpressure

on Tubing

BackpressureBackpressure

on Tubingon Tubing

15Sept. 25 - 28, 2012



16/24

Using a Backpressure Valve can

Prevent Unloading Up The TubingGas Flowing through Pump OR PumpedGas Flowing through Pump OR Pumped into Tubinginto Tubing

Backpressure valve maintains high tubing pressure toBackpressure valve maintains high tubing pressure to

prevent gas from blowing all of the liquid out of tubingprevent gas from blowing all of the liquid out of tubing Without BPR Pump action erratic & discharge may STOPWithout BPR Pump action erratic & discharge may STOP

Flow

Harbison-FischerModel Illustrated

Increase Pressure by Compressing SpringPressure

Gage

Spring Force

BPVBPV

16Sept. 25 - 28, 2012



17/24

17

Some Stuffing Boxes Can Increase

Friction on Polished Rod

Some Stuffing Boxes Can IncreaseSome Stuffing Boxes Can Increase

Friction on Polished RodFriction on Polished Rod1.1. Tubing Backpressure ActingTubing Backpressure Acting

On Some Types Of Stuff ingOn Some Types Of Stuff ing

Boxes Can Result InBoxes Can Result InAdditional Friction Applied ToAdditional Friction Applied To

the Polished Rod.the Polished Rod.

2.2. Pump Card Shows ThePump Card Shows The

Impact From The AdditionalImpact From The AdditionalFriction If Not Removed byFriction If Not Removed by

Calculations at the Surface.Calculations at the Surface.

3.3. Extra Stuffing Box Friction:Extra Stuffing Box Friction:

a)a) Increases Horse PowerIncreases Horse Power

b)b) Increases Upstroke LoadsIncreases Upstroke Loads

c)c) Decreases Down StrokeDecreases Down Stroke

LoadsLoads

FrictionFriction



18/24

1.1. Compare BackCompare Back--

pressure regulatingpressure regulating

valve used tovalve used toincrease the tubingincrease the tubing

pressure from 250pressure from 250

and 1000 Psigand 1000 Psig

2.2. BackpressureBackpressurereduces the polishedreduces the polished

rod load (the polishedrod load (the polished

rod load is reduced byrod load is reduced by

a piston force equal toa piston force equal tothe backpressurethe backpressure

times the area of thetimes the area of the

polished rod).polished rod).18

Back-

Pressure

BackBack--

PressurePressure

Piston Force = BackpressurePiston Force = Backpressurex Area of Polished Rodx Area of Polished Rod


19/24

19

Compare

250 to 1000 Psig Backpressure

Compare

250 to 1000 Psig Backpressure

Load-

Klbs

Stroke Length - Inches

Tubing Head Pressure 250 Psig Tubing Head Pressure 1000 Psig

PPRL= 12057 PPRL=13046

MPRL= 6568MPRL= 5795

Pump HP = 7.0

Pump HP = 3.1


20/24

20


on Tubing Results in Lower Efficiency1.1. Increased the tubing fluid gradientIncreased the tubing fluid gradient

2.2. Increased the fluid load applied by the pump to the rodsIncreased the fluid load applied by the pump to the rods

3.3. Increased polished rod horsepowerIncreased polished rod horsepower

4.4. Increased Rod loading with Higher Stress Range.Increased Rod loading with Higher Stress Range.

5.5. Increased the load on the prime moverIncreased the load on the prime mover

6.6. Reduced the plunger effective stroke length due toReduced the plunger effective stroke length due to

increased static stretchincreased static stretch

7.7.

Reduced in the pumping speed, due to motor sl ipReduced in the pumping speed, due to motor sl ip

8.8. Reduced the effective pump displacementReduced the effective pump displacement

9.9. IncreasedIncreased frictional forces the stuffing box applies to thefrictional forces the stuff ing box applies to the

polished rod.polished rod.Sept. 25 - 28, 2012 2012 Sucker Rod Pumping Workshop


21/24

21

Observations/Recommendations

1.1. Gassy Wells Difficult to Sucker Rod PumpGassy Wells Difficult to Sucker Rod Pump

2.2. Horizontal LateralsHorizontal Laterals can Unload a LOT OF GAScan Unload a LOT OF GAS3.3. Sufficient Backpressure on Tubing can ImproveSufficient Backpressure on Tubing can Improve

the performance of Gassy Rod Pumped Wellsthe performance of Gassy Rod Pumped Wells

4.4. Use Backpressure ONLY IF a well is Flowing OffUse Backpressure ONLY IF a well is Flowing Off

due to TOO Much Gas Produced Up the Tubingdue to TOO Much Gas Produced Up the Tubing

5.5. If the tubing unloads and pump action stops,If the tubing unloads and pump action stops,then try 200then try 200--300 Psi of backpressure on the300 Psi of backpressure on the

tubing BUT use more if required by welltubing BUT use more if required by well



22/24

22

Benefits of Backpressure1.1. Maintain Pump ActionMaintain Pump Action

2.2. Reduced Well Intervention by theReduced Well Intervention by theOperatorOperator

3.3. Significantly Reduced Stuffing Box LeaksSignificantly Reduced Stuffing Box Leaks

4.4. More Consistent Production From DayMore Consistent Production From Day--toto--

Day.Day.

5.5. Backpressure May Increases OperatingBackpressure May Increases Operating

Cost, But Allows You to Pump the WellCost, But Allows You to Pump the Well



23/24

23

CopyrightRights to this presentation are owned by the company(ies) and/orauthor(s) listed on the tit le page. By submitting this presentation tothe Gas Well Deliquification Workshop, they grant to the Workshop,

the Artificial Lift Research and Development Council (ALRDC), andthe Southwestern Petroleum Short Course (SWPSC), rights to:

Display the presentation at the Workshop.

Place it on the www.alrdc.com web site, with access to the site to be

as directed by the Workshop Steering Committee. Place it on a CD for distribution and/or sale as directed by the

Workshop Steering Committee.

Other use of this presentation is prohibited without the expressedwritten permission of the author(s). The owner company(ies) and/orauthor(s) may publish this material in other journals or magazines ifthey refer to the Sucker Rod Pumping Workshop where it was firstpresented.



24/24

24

DisclaimerThe following disclaimer shall be included as the last page of a Technical Presentation orContinuing Education Course. A similar disclaimer is included on the front page of the SuckerRod Pumping Web Site.

The Artificial Lift Research and Development Counci l and its officers and trustees, and the Sucker

Rod Pumping Workshop Steering Committee members, and their supporting organizations andcompanies (here-in-after referred to as the Sponsoring Organizations), and the author(s) of thisTechnical Presentation or Continuing Education Training Course and their company(ies), prov idethis presentation and/or training material at the Sucker Rod Pumping Workshop " as is" withoutany warranty of any kind, express or implied, as to the accuracy of the information or the productsor services referred to by any presenter (in so far as such warranties may be excluded under anyrelevant law) and these members and their companies will not be liable for unlawful actions andany losses or damage that may result f rom use of any presentation as a consequence of any

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The Sponsoring Organizations cannot and do not warrant the accuracy of these documentsbeyond the source documents, although we do make every attempt to work from authoritativesources. The Sponsoring Organizations provide these presentations and/or training materials asa service. The Sponsoring Organizations make no representations or warranties, express orimplied, with respect to the presentations and/or training materials, or any part thereof, includingany warrantees of title, non-infr ingement of copyright or patent rights of others, merchantability, orfitness or suitability for any purpose.


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