CE-1: Gas Lift Products and
Gas Lift System Design
INSTRUCTOR :
Greg Stephenson
© Schlumberger, 2001
TYPES OF ARTIFICIAL LIFT
© Schlumberger, 2001
TYPES OF GAS LIFT
• CONTINUOUS FLOW GAS LIFT
• INTERMITTENT GAS LIFT
• CONVENTIONAL & WIRELINE RETRIEVABLE
GAS LIFT EQUIPMENT
© Schlumberger, 2001
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
© Schlumberger, 2001
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
© Schlumberger, 2001
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
© Schlumberger, 2001
CONTINUOUS FLOW
UNLOADING SEQUENCE
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TO SEPARATOR/STOCK TANK
PRESSURE PSI
0 1000 2000 3000 4000 5000 6000 7000
INJECTION GAS
CHOKE CLOSED
2000
TOP VALVE OPEN
4000
CA
SI
N
G
TU
PR
BI
E
DEPTH FTTVD
6000
SS
NG
U
SECOND VALVE
PR
RE
OPEN
E SS
UR
E
8000
THIRD VALVE
OPEN
10000
FOURTH VALVE
OPEN
12000
14000
TUBING PRESSURE
SIBHP
CASING PRESSURE
© Schlumberger, 2001
TO SEPARATOR/STOCK TANK
PRESSURE PSI
0 1000 2000 3000 4000 5000 6000 7000
INJECTION GAS
CHOKE OPEN
2000
TOP VALVE OPEN 4000
DEPTH FTTVD
6000
SECOND VALVE
OPEN
8000
THIRD VALVE
OPEN
10000
FOURTH VALVE
OPEN 12000
14000
TUBING PRESSURE
SIBHP
CASING PRESSURE
© Schlumberger, 2001
TO SEPARATOR/STOCK TANK PRESSURE PSI
0 1000 2000 3000 4000 5000 6000 7000
INJECTION GAS
CHOKE OPEN
2000
TOP VALVE OPEN 4000
DEPTH FTTVD
6000
SECOND VALVE
OPEN
8000
THIRD VALVE
OPEN
10000
FOURTH VALVE
OPEN 12000
14000
TUBING PRESSURE
SIBHP
CASING PRESSURE
© Schlumberger, 2001
TO SEPARATOR/STOCK TANK PRESSURE PSI
0 1000 2000 3000 4000 5000 6000 7000
INJECTION GAS
CHOKE OPEN
2000
TOP VALVE OPEN 4000
DEPTH FTTVD
6000
SECOND VALVE
OPEN
8000
THIRD VALVE
OPEN
10000
FOURTH VALVE
OPEN 12000
14000 DRAWDOWN
TUBING PRESSURE
CASING PRESSURE FBHP SIBHP
© Schlumberger, 2001
TO SEPARATOR/STOCK TANK PRESSURE PSI
0 1000 2000 3000 4000 5000 6000 7000
INJECTION GAS
CHOKE OPEN
2000
TOP VALVE OPEN 4000
DEPTH FTTVD
6000
SECOND VALVE
OPEN
8000
THIRD VALVE
OPEN
10000
FOURTH VALVE
OPEN 12000
14000
DRAWDOWN
TUBING PRESSURE
CASING PRESSURE FBHP SIBHP
© Schlumberger, 2001
TO SEPARATOR/STOCK TANK PRESSURE PSI
0 1000 2000 3000 4000 5000 6000 7000
INJECTION GAS
CHOKE OPEN
2000
TOP VALVE CLOSED
4000
DEPTH FTTVD
6000
SECOND VALVE
OPEN
8000
THIRD VALVE
OPEN
10000
FOURTH VALVE
OPEN 12000
14000
DRAWDOWN
TUBING PRESSURE
CASING PRESSURE FBHP SIBHP
© Schlumberger, 2001
TO SEPARATOR/STOCK TANK PRESSURE PSI
0 1000 2000 3000 4000 5000 6000 7000
INJECTION GAS
CHOKE OPEN
2000
4000
TOP VALVE CLOSED
DEPTH FTTVD
6000
SECOND VALVE
OPEN
8000
THIRD VALVE
OPEN
10000
FOURTH VALVE
OPEN
12000
14000
DRAWDOWN
TUBING PRESSURE
CASING PRESSURE FBHP SIBHP
© Schlumberger, 2001
TO SEPARATOR/STOCK TANK PRESSURE PSI
0 1000 2000 3000 4000 5000 6000 7000
INJECTION GAS
CHOKE OPEN
2000
4000
TOP VALVE CLOSED
DEPTH FTTVD
6000
SECOND VALVE
CLOSED
8000
THIRD VALVE
OPEN
10000
FOURTH VALVE
OPEN
12000
14000 DRAWDOWN
TUBING PRESSURE
CASING PRESSURE FBHP SIBHP
© Schlumberger, 2001
FIGURE 3-8: Example of the Unloading Sequence
Casing Operated Valves and Choke Control of Injection Gas
2000
1800
1600
1400
1200
Pressure psi
1000
800
600
400
200
0
12:00 AM 03:00 AM 06:00 AM 09:00 AM 12:00 PM 03:00 PM 06:00 PM
T ime
PRESSURE CA SING PRESSURE TUBING
© Schlumberger, 2001
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!
© Schlumberger, 2001
RUNNING AND PULLING GAS LIFT VALVES
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.
© Schlumberger, 2001
GAS LIFT VALVE CHANGEOUTS!
• Methodical
• Equalise pressure
• Valve catcher
• Latches
• Running / pulling tools
• Pressure tests
• Experience
• Risk
© Schlumberger, 2001
© Schlumberger, 2001
© Schlumberger, 2001
GAS LIFT VALVE LATCHES
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.
• Explain the operation of a latch.
© Schlumberger, 2001
GAS LIFT MANDRELS
SIDE POCKET
MANDRELS
CONVENTIONAL
MANDREL
© Schlumberger, 2001
5 1/2” MMRG-4, 1 1/2” POCKET
ROUND MANDREL DESIGN CAMCO
Orienting Tool ‘G’ Latch Polished
Sleeve Discriminator Lug Seal Bore
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
TENSILE STRENGTH (EOEC) 490,000 LBS
CAMCO 1996
© Schlumberger, 2001
GAS LIFT MANDREL NOMENCLATURE
BASIC DESIGN FEATURES
KB 1ST IDENTIFIER 1" POCKET
M 1ST IDENTIFIER 1-1/2" POCKET
M 2ND IDENTIFIER OVAL BODY PIPE
M 3RD IDENTIFIER MACHINED POCKET W/TOOL DISCRIMINATOR
G TOOL DISCRIMNINATOR AND ORIENTING SLEEVE
R CAMCO DESIGN - ROUND BODY PIPE
T TRUGUIDE DESIGN - ROUND BODY PIPE
A A POCKET PROFILE
U REDUCED O.D. AND I.D.
E STANDARD POCKET PORTING - BOTTOM EXHAUST
EC POCKET PORTED TO TUBING - BOTTOM EXHAUST
W WATERFLOOD
BASIC DESIGN VARIATIONS
2 SLIGHTLY REDUCED MAJOR O.D.
3 SPECIAL THREADING CONSIDERATIONS
4 THREAD RECUTS
5 EXTERNAL GUARD DEVICES
7 SPECIAL INTERNAL MODIFICATIONS
8 SPECIAL POCKET MODIFICATION
9 BOTTOM LATCH ONLY
10 PLUGGABLE OR NO PORTS
LT SIDEPIPE POCKET PORTING
LTS SIDELUG TO ACCEPT INJECTION TUBE
V MULTIPLE POCKET
© Schlumberger, 2001
GAS LIFT VALVE MECHANICS
© Schlumberger, 2001
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 edged • Injection pressure (casing)
• Venturi (nova) operated valves
• production pressure (fluid)
operated valves
• Throttling/proportional response
valves
© Schlumberger, 2001
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
© Schlumberger, 2001
Diaphragm/
Atmospheric Bellows
Spring
Stem Upstream/
Casing
Stem Tip
Upstream
Downstream
Port
Downstream/Tubing
Pressure Regulator Spring Operated Gas Lift Valve
© Schlumberger, 2001
VALVE OPENING & CLOSING PRESSURES
F=PXA
WHEN THE VALVE IS CLOSED
TO OPEN IT…..
Pd 1 Pd
Pd x Ab= Pc (Ab - Ap) + Pt Ap
2
Pc
1
Pc
WHEN THE VALVE IS OPEN
TO CLOSE IT…..
2
Pd x Ab = Pc (Ab)
Pt
UN BALANCED VALVE
© Schlumberger, 2001
VALVE OPENING & CLOSING PRESSURES
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 bellows
Pt = Tubing pressure
Pc = Casing pressure
Ab = Area of bellows
Ap = Area of port
© Schlumberger, 2001
VALVE OPENING & CLOSING PRESSURES
Pb - Pt (Ap/Ab)
Pc = ----------------------
1 - (Ap/Ab)
Pb - Pt (R)
Pc = ----------------------
1-R
Pb = Pc (1 - R) + Pt (R)
Where R = Ratio Ap/Ab
© Schlumberger, 2001
PRODUCED FLUID
0 500 1000 1500 2000 2500 3000 3500
INJECTION GAS
2000
4000
DEPTH FTTVD
6000
8000
10000
12000
14000
DRAWDOWN
TUBING PRESSURE
CASING PRESSURE FBHP SIBHP
© Schlumberger, 2001
GAS LIFT VALVES CLOSE IN SEQUENCE
0 500 1000 1500 2000 2500 3000 3500
2000
4000
DEPTH FTTVD
6000
8000
10000
12000
14000
DRAWDOWN
TUBING PRESSURE
CASING PRESSURE FBHP SIBHP © Schlumberger, 2001
CASING P. CASING P
PRODUCED FLUID
TO OPEN TO CLOSE
DOME P.
INJECTION GAS
AT SURFACE 1200 PSI ? PSI
TUBING P.
@ DEPTH
VALVE # 1 1260 PSI ? PSI
560 PSI
VALVE # 2 1300 PSI ? PSI
740 PSI
890 PSI
VALVE # 3 1340 PSI ? PSI
Pd = Pc (1-
(1-R) + Pt (R)
NOTE : ALL VALVES 3/16” R-
R-20
R = 0.038 1-
1-R = 0.962 © Schlumberger, 2001
Pb Pb
Dome Dome
Chevron Chevron
Packing Packing
Stack Stack
Bellows Bellows
Stem Tip (Ball)
Square Edged
Pc
Seat Pc
Stem Tip (Ball)
Square Edged
Seat
Pt
Chevron Chevron
Packing Pt Packing
Stack Stack
Check Valve Check Valve
Nitrogen Charged Bellows Type Nitrogen Charged Bellows Type
Injection Pressure (Casing) Operated Gas Lift Valve Production Pressure (Fluid) Operated Gas Lift Valve 2001
© Schlumberger,
Dome Pb
Atmospheric
Spring Bellows
Chevron
Packing
Stack
Bellows
Chevron
Packing
Stack
Pc Pc
Spring
Adjustment
Large T.C. Ball Nut & Lock Nuts
Tapered
T.C. Seat
Stem Tip (Ball)
Square Edged
Chevron Pt Seat
Packing
Stack Chevron
Packing
Stack Pt
Check Valve Check Valve
Nitrogen Charged Bellows Type Spring Operated
Proportional Response Gas Lift Valve Injection Pressure (Casing) Operated Gas Lift Valve
© Schlumberger, 2001
© Schlumberger, 2001
© Schlumberger, 2001
GAS LIFT VALVE FEATURES
• Bellows protection
• Max dome charge
• Check valve
• Stem travel
• Metallurgy
• Elastomers
• Max fluid rate
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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
© Schlumberger, 2001
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.
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NOVA VALVE
© Schlumberger, 2001
