1 - Gas Lift

© Schlumberger, 2001

CE-1: Gas Lift Products and

Gas Lift System Design

INSTRUCTOR :

Greg Stephenson


TYPES OF ARTIFICIAL LIFT


TYPES OF GAS LIFT

• CONTINUOUS FLOW GAS LIFT

• INTERMITTENT GAS LIFT

• CONVENTIONAL & WIRELINE RETRIEVABLE

GAS LIFT EQUIPMENT


APPLICATIONS OF CONTINUOUS FLOW GAS LIFT

• TO ENABLE WELLS THAT WILL NOT FLOW NATURALLY TO PRODUCE

• TO INCREASE PRODUCTION RATES IN FLOWING WELLS

• TO UNLOAD A WELL THAT WILL LATER FLOW NATURALLY

• TO REMOVE OR UNLOAD FLUID IN GAS WELLS

• TO BACK FLOW SALT WATER DISPOSAL WELLS

• TO LIFT AQUIFER WELLS


ADVANTAGES OF GAS LIFT

• Initial downhole equipment costs lower

• low operational and maintenance cost

• Simplified well completions

• Flexibility - can handle rates from 10 to 50,000 bpd

• Can best handle sand / gas / well deviation

• Intervention relatively less expensive


DISADVANTAGES OF GAS LIFT

• Must have a source of gas

•Imported from other fields

•Produced gas - may result in start up problems

• Possible high installation cost

•Top sides modifications to existing platforms

•Compressor installation

• Limited by available reservoir pressure

and bottom hole flowing pressure


CONTINUOUS FLOW UNLOADING SEQUENCE


INJECTION GAS

CHOKE CLOSED

TO SEPARATOR/STOCK TANK

TOP VALVE OPEN

SECOND VALVE

OPEN

THIRD VALVE

OPEN

FOURTH VALVE

OPEN

0

2000

6000

8000

10000

12000

14000

4000

2000 4000

PRESSURE PSI

DE

PT

H F

TT

VD

SIBHPTUBING PRESSURE

CASING PRESSURE

30001000 5000

CASIN

G P

RESSU

RE

TU

BIN

G P

RESSU

RE

6000 7000


INJECTION GAS

CHOKE OPEN


TOP VALVE OPEN

SECOND VALVE

OPEN

THIRD VALVE

OPEN

FOURTH VALVE

OPEN

0

2000

6000

8000

10000

12000

14000

4000

2000 4000

PRESSURE PSI

DE

PT

H F

TT

VD


CASING PRESSURE

30001000 5000 6000 7000


INJECTION GAS

CHOKE OPEN


TOP VALVE OPEN

SECOND VALVE

OPEN

THIRD VALVE

OPEN

FOURTH VALVE

OPEN

0

2000

6000

8000

10000

12000

14000

4000

2000 4000

PRESSURE PSI

DE

PT

H F

TT

VD


CASING PRESSURE

30001000 5000 6000 7000


INJECTION GAS

CHOKE OPEN


TOP VALVE OPEN

SECOND VALVE

OPEN

THIRD VALVE

OPEN

FOURTH VALVE

OPEN

0

2000

6000

8000

10000

12000

14000

4000

2000 4000

PRESSURE PSI

DE

PT

H F

TT

VD

SIBHP

TUBING PRESSURE

CASING PRESSURE

30001000 5000

DRAWDOWN

6000 7000

FBHP


INJECTION GAS

CHOKE OPEN


TOP VALVE OPEN

SECOND VALVE

OPEN

THIRD VALVE

OPEN

FOURTH VALVE

OPEN

0

2000

6000

8000

10000

12000

14000

4000

2000 4000

PRESSURE PSI

DE

PT

H F

TT

VD

TUBING PRESSURE

CASING PRESSURE

30001000 5000

DRAWDOWN

6000 7000

FBHP SIBHP


INJECTION GAS

CHOKE OPEN


TOP VALVE CLOSED

SECOND VALVE

OPEN

THIRD VALVE

OPEN

FOURTH VALVE

OPEN

0

2000

6000

8000

10000

12000

14000

4000

2000 4000

PRESSURE PSI

DE

PT

H F

TT

VD

TUBING PRESSURE

CASING PRESSURE

30001000 5000

DRAWDOWN

6000 7000

FBHP SIBHP


INJECTION GAS

CHOKE OPEN


TOP VALVE CLOSED

SECOND VALVE

OPEN

THIRD VALVE

OPEN

FOURTH VALVE

OPEN

0

2000

6000

8000

10000

12000

14000

4000

2000 4000

PRESSURE PSI

DE

PT

H F

TT

VD

TUBING PRESSURE

CASING PRESSURE

30001000 5000

DRAWDOWN

6000 7000

FBHP SIBHP


INJECTION GAS

CHOKE OPEN


TOP VALVE CLOSED

SECOND VALVE

CLOSED

THIRD VALVE

OPEN

FOURTH VALVE

OPEN

0

2000

6000

8000

10000

12000

14000

4000

2000 4000

PRESSURE PSI

DE

PT

H F

TT

VD

TUBING PRESSURE

CASING PRESSURE

30001000 5000

DRAWDOWN

6000 7000

FBHP SIBHP


FIGURE 3-8: Example of the Unloading Sequence

Casing Operated Valves and Choke Control of Injection Gas

0

200

400

600

800

1000

1200

1400

1600

1800

2000

12:00 AM 03:00 AM 06:00 AM 09:00 AM 12:00 PM 03:00 PM 06:00 PMTime

Pre

ssu

re p

si

PRESSURE CASING PRESSURE TUBING


GAS LIFT WELL KICK-OFF

• Unload well carefully– 50 - 100 psi (3.5 bar) per 10 min

– 1 - 2 bbl per min

• Maximize production choke opening

• Gradually increase gas injection rate

• Monitor well clean up and stability

• Get to target position

• Perform step rate production test

• Optimize gas injection rate

• Note - when unloading all valves open!


RUNNING AND PULLING GAS LIFT VALVESKEY LEARNING OBJECTIVES

UPON COMPLETION OF THIS SEGMENT, YOU SHOULD BE ABLE TO:

• Explain the procedure for running and pulling gas lift valves from a side pocket mandrel.

• Describe the precautions that should be taken during running and pulling operations.

• Explain the operation of the OK series kickover tool.• Explain the operation of the BK-1 latch.• List and describe the different latch profiles available and explain the

importance of latch / pocket compatability.


GAS LIFT VALVE CHANGEOUTS!

• Methodical

• Equalise pressure

• Valve catcher

• Latches

• Running / pulling tools

• Pressure tests

• Experience

• Risk




GAS LIFT VALVE LATCHESKEY LEARNING OBJECTIVES

UPON COMPLETION OF THIS SEGMENT, YOU SHOULD BE ABLE TO:

• Understand the purpose of a gas lift valve latch.• Identify key latch components.• Explain the operation of a latch.


GAS LIFT MANDRELS

SIDE POCKET MANDRELS

CONVENTIONAL MANDREL


5 1/2” MMRG-4, 1 1/2” POCKET ROUND MANDREL DESIGN

ENGINEERING DATA

CAMCO

CAMCO 1996

PART NUMBER 05712-000-00001

SIZE 5 1/2”

MAX O.D. 7.982”

MIN I.D. 4.756”

DRIFT I.D. 4.653”

THREAD 17 LB/FT MANN BDS B x P

TEST PRESSURE INTERNAL 7740 PSI

TEST PRESSURE EXTERNAL 6280 PSI

LATCH TYPE RK, RK-1, RKP, RK-SP

KICKOVER TOOL OM-1, OM-1M, OM-1S

RUNNING TOOL RK-1 15079

PULLING TOOL 1 5/8” JDS 15155

MATERIAL 410 S.S., 13 CR 22 HRC MAXTENSILE STRENGTH (EOEC) 490,000 LBS

OrientingSleeve

ToolDiscriminator

‘G’ LatchLug

PolishedSeal Bore


GAS LIFT MANDREL NOMENCLATURE

BASIC DESIGN FEATURESBASIC DESIGN FEATURESBASIC DESIGN FEATURESBASIC DESIGN FEATURES

KBKBKBKB 1ST IDENTIFIER 1" POCKET

MMMM 1ST IDENTIFIER 1-1/2" POCKET

MMMM 2ND IDENTIFIER OVAL BODY PIPE

MMMM 3RD IDENTIFIER MACHINED POCKET W/TOOL DISCRIMINATOR

GGGG TOOL DISCRIMNINATOR AND ORIENTING SLEEVE

RRRR CAMCO DESIGN - ROUND BODY PIPE

TTTT TRUGUIDE DESIGN - ROUND BODY PIPE

AAAA A POCKET PROFILE

UUUU REDUCED O.D. AND I.D.

EEEE STANDARD POCKET PORTING - BOTTOM EXHAUST

ECECECEC POCKET PORTED TO TUBING - BOTTOM EXHAUST

WWWW WATERFLOOD

BASIC DESIGN VARIATIONSBASIC DESIGN VARIATIONSBASIC DESIGN VARIATIONSBASIC DESIGN VARIATIONS

2222 SLIGHTLY REDUCED MAJOR O.D.

3333 SPECIAL THREADING CONSIDERATIONS

4444 THREAD RECUTS

5555 EXTERNAL GUARD DEVICES

7777 SPECIAL INTERNAL MODIFICATIONS

8888 SPECIAL POCKET MODIFICATION

9999 BOTTOM LATCH ONLY

10101010 PLUGGABLE OR NO PORTS

LTLTLTLT SIDEPIPE POCKET PORTING

LTSLTSLTSLTS SIDELUG TO ACCEPT INJECTION TUBE

VVVV MULTIPLE POCKET


GAS LIFT VALVE MECHANICS


3 basic types of gas lift valve, each available in 1” & 1-1/2” sizes:

Dummy valves Orifice valves Unloading valves

•• Square edgedSquare edged

•• VenturiVenturi (nova)(nova)

•• Injection pressure (casing) Injection pressure (casing)

operated valves operated valves

•• production pressure (fluid) production pressure (fluid)

operated valvesoperated valves

•• Throttling/proportional response Throttling/proportional response

valvesvalves

GAS LIFT VALVE MECHANICS


UNLOADING GAS LIFT VALVE

• Normally required during unloading phase

only

• Open only when annulus and tubing pressures are high enough to overcome valve

set pressure

• Valve closes after transfer to next station

• May be spring or nitrogen charged


Pressure Regulator

Diaphragm/Atmospheric Bellows

Spring

Stem

Stem Tip

Port

DownstreamUpstream

Spring Operated Gas Lift Valve

Upstream/

Casing

Downstream/Tubing


VALVE OPENING & CLOSING PRESSURES

UN BALANCED VALVEUN BALANCED VALVE

F = P X AF = P X A

Pc1

PdPd

PtPt

WHEN THE VALVE IS CLOSEDWHEN THE VALVE IS CLOSED

TO OPEN IT…..TO OPEN IT…..

Pd x Pd x AbAb= = Pc1

(Ab - Ap) + Pt Ap PdPd

Pc2

WHEN THE VALVE IS OPENWHEN THE VALVE IS OPEN

TO CLOSE IT…..TO CLOSE IT…..

Pd x Pd x AbAb = = Pc2

(Ab)


CLOSING FORCE (IPO VALVE) Fc = PbAb

OPENING FORCES (IPO VALVE) Fo1 = Pc (Ab- Ap)

Fo2 = Pt Ap

TOTAL OPENING FORCE Fo = Pc (Ab - Ap) + Pt Ap

JUST BEFORE THE VALVE OPENS THE FORCES ARE EQUAL

Pc (Ab - Ap) + Pt Ap = Pb Ab

Pb - Pt (Ap/Ab)

SOLVING FOR Pc Pc = --------------------------1 - (Ap/Ab)

WHERE: Pb = Pressure in bellowsPt = Tubing pressurePc = Casing pressure

Ab = Area of bellowsAp = Area of port




Pb - Pt (Ap/Ab)Pc = ----------------------

1 - (Ap/Ab)

Where R = Ratio Ap/Ab

Pb - Pt (R)Pc = ----------------------

1 - R

Pb = Pc (1 - R) + Pt (R)


INJECTION GAS

PRODUCED FLUID

0

2000

6000

8000

10000

12000

14000

4000

1000 2000

DE

PT

H F

TT

VD

TUBING PRESSURE

CASING PRESSURE

1500500 2500

DRAWDOWN

3000 3500

FBHP SIBHP


GAS LIFT VALVES CLOSE IN SEQUENCE

0

2000

6000

8000

10000

12000

14000

4000

1000 2000

DE

PT

H F

TT

VD

TUBING PRESSURE

CASING PRESSURE

1500500 2500

DRAWDOWN

3000 3500

FBHP SIBHP


INJECTION GAS

PRODUCED FLUID

CASING P.CASING P.

TO OPENTO OPENCASING PCASING P

TO CLOSETO CLOSE

AT SURFACEAT SURFACE

VALVE # 1VALVE # 1

VALVE # 2VALVE # 2

VALVE # 3VALVE # 3

DOME P.DOME P.

1200 PSI1200 PSI

1260 PSI1260 PSI

1300 PSI1300 PSI

NOTE : ALL VALVES 3/16” RNOTE : ALL VALVES 3/16” R--2020

R = 0.038 1R = 0.038 1--R = 0.962R = 0.962

Pd = Pc (1Pd = Pc (1--R) + Pt (R)R) + Pt (R)

TUBING P.TUBING P.

@ DEPTH@ DEPTH

890 PSI890 PSI

740 PSI740 PSI

560 PSI560 PSI

? PSI? PSI

? PSI? PSI

? PSI? PSI

1340 PSI1340 PSI ? PSI? PSI


Pt

Pc

PbDome

Bellows

Square EdgedSeat

Check Valve

Chevron PackingStack

Nitrogen Charged Bellows Type Injection Pressure (Casing) Operated Gas Lift Valve


Stem Tip (Ball)

Pt

Pc

PbDome

Bellows

Check Valve


Nitrogen Charged Bellows Type Production Pressure (Fluid) Operated Gas Lift Valve


Stem Tip (Ball)

Square EdgedSeat


Pt

Pc

PbDome

Bellows

TaperedT.C. Seat

Check Valve


Nitrogen Charged Bellows Type Proportional Response Gas Lift Valve


Spring

Large T.C. Ball

Pt

Pc

AtmosphericBellows

Square EdgedSeat

Check Valve


Spring Operated Injection Pressure (Casing) Operated Gas Lift Valve


Stem Tip (Ball)

Spring AdjustmentNut & Lock Nuts




GAS LIFT VALVE FEATURES

• Bellows protection

• Max dome charge

• Check valve

• Stem travel

• Metallurgy

• Elastomers

• Max fluid rate


OPERATING GAS LIFT VALVE

• Typically an ‘orifice’ type Gas lift valve

• always open - allows gas across Passage whenever correct differential exists

• Gas injection controlled by size and differential across replaceable choke

• Back-check prevents reverse flow of well fluids from the production conduit


ORIFICE VALVES

THERE ARE 2 TYPES OF ORIFICE VALVE:

• SQUARED EDGED ORIFICE

• VENTURI (NOVA)

• Valve designed for accurate gas passage prediction.

• One-way check valve for tubing integrity.


NOVA VALVENOVA VALVENOVA VALVE

Documents

1 - Gas Lift