1 - Gas Lift

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Gas Lift System Design

INSTRUCTOR :

Greg Stephenson

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• CONTINUOUS FLOW GAS LIFT

• INTERMITTENT GAS LIFT

• CONVENTIONAL & WIRELINE RETRIEVABLE

GAS LIFT EQUIPMENT

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• 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

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• 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

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• 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

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INJECTION GAS CHOKE CLOSED

TOP VALVE OPEN

SECOND VALVE OPEN THIRD VALVE OPEN FOURTH VALVE OPEN

0 2000

6000

8000

10000

12000

14000

4000

2000

4000

D

E

P

T

H

F

T

V

D

SIBHP

TUBING PRESSURE

CASING PRESSURE

3000

1000

5000

C A S IN G P_R ES S U R E T U B IN G P_R E S S U R E

6000

7000

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INJECTION GAS CHOKE OPEN

TOP VALVE OPEN

2000

6000

8000

10000

12000

14000

4000

D

E

P

T

H

F

T

V

D

SIBHP

TUBING PRESSURE

CASING PRESSURE

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TOP VALVE OPEN

2000

6000

8000

10000

12000

14000

4000

D

E

P

T

H

F

T

V

D

SIBHP

TUBING PRESSURE

CASING PRESSURE

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TOP VALVE OPEN

2000

6000

8000

10000

12000

14000

4000

D

E

P

T

H

F

T

V

D

SIBHP

TUBING PRESSURE

CASING PRESSURE

DRAWDOWN

FBHP

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TOP VALVE OPEN

2000

6000

8000

10000

12000

14000

4000

D

E

P

T

H

F

T

V

D

TUBING PRESSURE

CASING PRESSURE

DRAWDOWN

FBHP

SIBHP

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TOP VALVE CLOSED

2000

6000

8000

10000

12000

14000

4000

D

E

P

T

H

F

T

V

D

TUBING PRESSURE

CASING PRESSURE

DRAWDOWN

FBHP

SIBHP

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TOP VALVE CLOSED

2000

6000

8000

10000

12000

14000

4000

D

E

P

T

H

F

T

V

D

TUBING PRESSURE

CASING PRESSURE

DRAWDOWN

FBHP

SIBHP

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TOP VALVE CLOSED

SECOND VALVE CLOSED THIRD VALVE OPEN FOURTH VALVE OPEN

2000

6000

8000

10000

12000

14000

4000

D

E

P

T

H

F

T

V

D

TUBING PRESSURE

CASING PRESSURE

DRAWDOWN

FBHP

SIBHP

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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 PM

T ime

P

re

s

u

re

p

s

i

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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

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KEY 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.

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• Methodical

• Equalise pressure

• Valve catcher

• Latches

• Running / pulling tools

• Pressure tests

• Experience

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KEY 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.

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SIDE POCKET

MANDRELS

CONVENTIONAL

MANDREL

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ENGINEERING DATA

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 MAX

Orienting

Sleeve

Tool

Discrim inator

‘G’ Latch

Lug

Polished

Seal Bore

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BASIC DESIGN FEATURESBASIC DESIGN FEATURESBASIC DESIGN FEATURESBASIC DESIGN FEATURES KB KB KB KB 1ST IDENTIFIER 1" POCKET M M M M 1ST IDENTIFIER 1-1/2" POCKET M M M

M 2ND IDENTIFIER OVAL BODY PIPE M

M M

M 3RD IDENTIFIER MACHINED POCKET W/TOOL DISCRIMINATOR G

G G

G TOOL DISCRIMNINATOR AND ORIENTING SLEEVE R

RR

R CAMCO DESIGN - ROUND BODY PIPE T

T T

T TRUGUIDE DESIGN - ROUND BODY PIPE A A A A A POCKET PROFILE U U U

U REDUCED O.D. AND I.D. E

E E

E STANDARD POCKET PORTING - BOTTOM EXHAUST EC

EC EC

EC POCKET PORTED TO TUBING - BOTTOM EXHAUST W

W W

W WATERFLOOD

BASIC DESIGN VARIATIONSBASIC DESIGN VARIATIONSBASIC DESIGN VARIATIONSBASIC DESIGN VARIATIONS

2 22

2 SLIGHTLY REDUCED MAJOR O.D. 3

33

3 SPECIAL THREADING CONSIDERATIONS 4

44

4 THREAD RECUTS 5

55

5 EXTERNAL GUARD DEVICES 7

77

7 SPECIAL INTERNAL MODIFICATIONS 8

88

8 SPECIAL POCKET MODIFICATION 9

99

9 BOTTOM LATCH ONLY 10 10 10 10 PLUGGABLE OR NO PORTS LT LT LT

LT SIDEPIPE POCKET PORTING LTS

LTS LTS

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

Dummy valves

Orifice valves

Unloading valves

•

• Square edged

Square edged

•

• Venturi

Venturi

(nova)

•

• Injection pressure (casing)

Injection pressure (casing)

operated valves

•

• production pressure (fluid)

production pressure (fluid)

operated valves

•

• Throttling/proportional response

Throttling/proportional response

valves

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• 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

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Spring

Stem

Stem Tip

Port

Downstream

Upstream

Upstream/

Casing

Downstream/Tubing

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F = P X A

Pc

1

Pd

Pt

WHEN THE VALVE IS CLOSED

TO OPEN IT…..

Pd x

Ab

=

Pc

1

(Ab - Ap) + Pt Ap

Pd

Pc

2

WHEN THE VALVE IS OPEN

TO CLOSE IT…..

Pd x

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CLOSING FORCE (IPO VALVE)

Fc = PbAb

OPENING FORCES (IPO VALVE)

Fo

₁

= Pc (Ab- Ap)

Fo

₂

= 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 bellows

Pt

= Tubing pressure

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Pb - Pt (Ap/Ab)

Pc =

---1 - (Ap/Ab)

Pb - Pt (R)

Pc =

---1 - R

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

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INJECTION GAS

2000

6000

8000

10000

12000

14000

4000

D

E

P

T

H

F

T

V

D

DRAWDOWN

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0 2000

6000

8000

10000

12000

14000

4000

1000

2000

D

E

P

T

H

F

T

V

D

1500

500 2500

DRAWDOWN

3000

3500

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INJECTION GAS

_{AT SURFACE}

VALVE # 1

VALVE # 2

VALVE # 3

DOME P.

1200 PSI

1260 PSI

1300 PSI

TUBING P.

@ DEPTH

890 PSI

740 PSI

560 PSI

? PSI

1340 PSI

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Pt Pc Bellows Square Edged Seat Check Valve Chevron Packing Stack Chevron Packing Stack

Stem Tip (Ball)

Pt Pc Bellows Check Valve Chevron Packing Stack Chevron Packing Stack

Stem Tip (Ball) Square Edged Seat

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Pt Pc Bellows Tapered T.C. Seat Check Valve Chevron Packing Stack Chevron Packing Stack Large T.C. Ball Pt Pc Square Edged Seat Check Valve Chevron Packing Stack Chevron Packing Stack