4b - IPO GL Design

7/21/2019 4b - IPO GL Design

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Valve Mechanics


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Valve Mechanics

Upon completion of this section you will be able to:

Calculate the opening and closing pressures for an IPO

gas lift valve.

Calculate the opening and closing pressures for a PPO

gas lift valve.

Understand the relationship that tubing pressure and

casing pressure have on the operation of GLVs.


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Force Balance Theory forIPO Valves


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Pressure Regulator

Diaphragm/

Atmospheric Bellows

Spring

Stem

Stem Tip

Port

Downstream

Upstream

Spring Operated Gas Lift Valve

Upstream/

Casing

Downstream/Tubing


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Opening Forces

Dome

(Loading Element)

Bellows

(Responsive Element)

PC, Casing Pressure

Area

of

Bellows

APArea of Port

P1Tubing

Pressure

PdAB= Pt(Ap) + Pc (ABAp)Force Balance at Opening


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Closing Forces

Force Balance at Closing

PdAB = PC(AB)

Pd

AbPc

ApP1


7/53UNBALANCED VALVE

F = P X A

Pc1

Pd

Pt

WHEN THE VALVE IS CLOSED

TO OPEN IT..

Pd x Ab= Pc1(Ab - Ap) + Pt Ap

Pd

Pc2

WHEN THE VALVE IS OPEN

TO CLOSE IT..

Pd x Ab = Pc2 (Ab)

Valve Opening and Closing Pressures


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CLOSING FORCE (IPO VALVE) Fc = PdAb =PcAb

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 = Pc Ab

Pd - Pt (Ap/Ab)

SOLVING FOR Pc Pc = --------------------------

1 - (Ap/Ab)

WHERE: Pd = Pressure in dome

Pt = Tubing pressure

Pc = Casing pressure

Ab = Area of bellows

Ap = Area of port



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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)



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0

2000

6000

8000

10000

12000

14000

4000

1000 2000

DEPTHF

TTVD

TUBING PRESSURECASING PRESSURE

1500500 2500

DRAWDOWN

3000 3500

FBHP SIBHP

Gas lift valves close in sequence


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Test Rack Opening Pressure

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

1 - (Ap/Ab)

TRO

Pd @ 60F 0

Pd @ 60FTRO = ----------------------

1 - R

R

Note: Pd @ 60F = (Tc) (Pd @ Depth)


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Calculation Summary

Pd = Pcsg(1-R) + Ptbg(R)Psc= Pd - DPc

Pso= Pcsg- DPc

Pd @ 60F = Tc (Pd) TRO = (Pd @ 60F)/(1-R)


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INJECTION GAS

PRODUCED FLUID

CASING P.

TO OPEN

CASING P

TO CLOSE

AT SURFACE

VALVE # 1

VALVE # 2

VALVE # 3

DOME P.

1200 PSI

1260 PSI

1300 PSI

NOTE : ALL VALVES 3/16 R-20R = 0.038 1-R = 0.962

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

TUBING P.

@ DEPTH

890 PSI

740 PSI

560 PSI

? PSI

? PSI

? PSI

1340 PSI ? PSI


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Force Balance Theory for PPO

Valves


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Production Pressure Operated

Valves

Also known as fluid valves Most commonly used in dual GL

wells

Primarily sense tubing pressure Achieved through use of cross-overseat


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F = P X A

Pc

Pt1

WHEN THE VALVE IS CLOSED

TO OPEN IT..

Fs= Pt1(Ab - Ap) + Pc Ap

Fs

Pc

WHEN THE VALVE IS OPEN

TO CLOSE IT..

Fs = Pt2 (Ab)

PPO Valve Mechanics

Pt2

THE REVERSE OF AN IPO VALVE

Fs

Fs = Ps.t. X Ab


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CLOSING FORCE (PPO VALVE) Fc= Fs= Ps.t.* Ab

OPENING FORCES (PPO VALVE) Fo1= Pt (Ab- Ap)

Fo2= Pc Ap

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

JUST BEFORE THE VALVE OPENS THE FORCES ARE EQUAL

Pt (Ab - Ap) + Pc Ap = Ps.t.*Ab

Ps.t.- Pc (Ap/Ab)

SOLVING FOR Pt Pt = --------------------------

1 - (Ap/Ab)

WHERE: Pb = Pressure in bellows

Pt = Tubing pressure

Ps.t. = Spring tension effectPc = Casing pressure

Ab = Area of bellows

Ap = Area of port



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Ps.t.- Pc (Ap/Ab)Pt = ----------------------

1 - (Ap/Ab)

Where R = Ratio Ap/Ab

Pt - Pc (R)OP = ----------------------

1 - R

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

Valve opening and closing

pressures


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Test Rack Opening Pressure

Ps.t. - Pc (Ap/Ab)

Pt = ----------------------

1 - (Ap/Ab)

TRO

Pvc 0

Pvc

TRO = ----------------------

1 - R

R


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Calculation Summary

Pvc @ L = Pt(1-R) + Pc(R) TRO = Pvc@ L /(1-R)


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Operation

In the closed position, tubing pressure is acting on the bellowsand casing pressure is acting on the ball. When the combined forces of tubing pressure and casing

pressure are greater than the spring tension the valve opens.

When the valve opens, tubing pressure is acting on the ball and

the bellows. The valve closes on a drop in tubing pressure. Test rack opening pressures should generally increase as you

get deeper on the design sheet. This is due to increase in tubing

pressure as you go downhole.


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Characteristics

Advantages Not temperature sensitive

Suitable for dual installations

Each valve is operated at the same casing pressure so

higher casing pressure is maintained in deep wells.

Disadvantages Difficult to troubleshoot

High back pressure holds the valves open

Not suitable for wells with IPO spacing

Dependant on the parameter over which we have the leastcontrol


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Example: Operating Pressure

Calculation

Using the supplied calculation worksheet,derive the Operating Pressure equation for an

injection pressure operated (IPO) gas lift

valve.


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Section 4a: Gas Lift Design


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Constant Casing Pressure Drop Method

#1


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0 1000 2000

0

1000

2000

3000

4000

5000

6000

7000

8000

9000

10000

PRESSURE (PSIG)

DEPTH

FTTVD

DEPTH OF WELL (MID PERFS)

TEMPERATURE F

100 150 200


#1.

#2


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0 1000 2000

0

1000

2000

3000

4000

5000

6000

7000

8000

9000

10000

PRESSURE (PSIG)

DEPTH

FTTVD


TEMPERATURE F

100 150 200

S.I.B.H.P.

#2.


#3


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0 1000 2000

0

1000

2000

3000

4000

5000

6000

7000

8000

9000

10000

PRESSURE (PSIG)

DEPTH

FTTVD


TEMPERATURE F

100 150 200

S.I.B.H.P.F.B.H.P.

#3.


#4


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0 1000 2000

0

1000

2000

3000

4000

5000

6000

7000

8000

9000

10000

PRESSURE (PSIG)

DEPTH

FTTVD


TEMPERATURE F

100 150 200

S.I.B.H.P.F.B.H.P.

#4.


#5


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0 1000 2000

0

1000

2000

3000

4000

5000

6000

7000

8000

9000

10000

PRESSURE (PSIG)

DEPTH

FTTVD


TEMPERATURE F

100 150 200

S.I.B.H.P.F.B.H.P.

MANDREL #1

#5.


#6


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0 1000 2000

0

1000

2000

3000

4000

5000

6000

7000

8000

9000

10000

PRESSURE (PSIG)

DEPTH

FTTVD


TEMPERATURE F

100 150 200

F.B.H.P. #1

S.I.B.H.P.F.B.H.P.

MANDREL #1

#6.


#7


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0 1000 2000

0

1000

2000

3000

4000

5000

6000

7000

8000

9000

10000

PRESSURE (PSIG)

DEPTH

FTTVD


TEMPERATURE F

100 150 200

MANDREL #2

F.B.H.P. #2 S.I.B.H.P.F.B.H.P.

MANDREL #1

#7.


#8


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0 1000 2000

0

1000

2000

3000

4000

5000

6000

7000

8000

9000

10000

PRESSURE (PSIG)

DEPTH

FTTVD


TEMPERATURE F

100 150 200

MANDREL #2

MANDREL #3


MANDREL #1

#8.


#9


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0 1000 2000

0

1000

2000

3000

4000

5000

6000

7000

8000

9000

10000

PRESSURE (PSIG)

DEPTH

FTTVD


TEMPERATURE F

100 150 200

MANDREL #4

MANDREL #2


MANDREL #1

MANDREL #3

#9.


#10


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0 1000 2000

0

1000

2000

3000

4000

5000

6000

7000

8000

9000

10000

PRESSURE (PSIG)

DEPTH

FTTVD


TEMPERATURE F

100 150 200

MANDREL #4

MANDREL #2

MANDREL #5

F.B.H.P. #5

S.I.B.H.P.F.B.H.P.

MANDREL #1

MANDREL #3

#10.



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End Day 3


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Agenda

Day 1: Introduction & Objectives; ALTechnology; Gas Lift Overview;Field TripLufkin

Day 2: Gas Lift Equipment Day 3: Well Performance; Gas Lift Design Day 4: GL Design (cont.); Computer Based

Applications

Day 5: GL Trouble-shooting andOptimization


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Day 4Delivery Duration Begin End

Review Day 3 Lecture 0:30 8:00 AM 8:30 AMIPO Gas lift design Individual Activity 1:30 8:30 AM 10:00 AM

Break 0:15 10:00 10:15

Design Bias

Overview of design bias. Lecture 1:00 10:15 AM 11:15 AM

IPO Gas lift design w/ design bias Individual Activity 0:45 11:15 AM 12:00 PM

Lunch 1:00 13:30 14:30

PPO Gas Lift Design

PPO design methodology. Lecture 0:45 12:00 PM 12:45 PM

PPO Gas lift design Individual Activity 0:45 12:45 PM 1:30 PM

Section 5: Computer Based ApplicationsComputer Based Applications

Introduction to SNAP Demo 0:30 1:30 PM 2:00 PM

Break 0:15 14:00 14:15

IPO Gas lift design using SNAP Individual Activity 1:15 2:00 PM 3:15 PM

PPO Gas lift design using SNAP Individual Activity 0:45 3:15 PM 4:00 PM

Topics


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Gas Lift Design Example #1Design a continuous flow gas lift installation for the well described below.

Use the provided calculation sheet and determine the following informationfor all valves: setting depth, port size, test rack opening pressure.

English Metric

Tubing Size 2-7/8" 6.5 ppf 62 mm

Desired Producing Rate 600 BPD 100 M3

Percent Water 50% 50%

Water Specific Gravity 1.08 1.08

Gas Specific Gravity 0.65 0.65

Oil Gravity 35API 0.85 rel dens

Static Fluid Gradient (Gs) 0.465 10.5 kPa / mtr

Depth of Perforations 5257 ft. 1600 meters

Depth of Packer 5000 ft. 1500 meters

Wellhead Pressure (Pwh) 100 psig 700 kPa

Static Bottom Hole Pressure (Pws) 1600 psig 11,000 kPa

Flowing Bottom Hole Pressure (Pwf) 1160 psig 8000 kPa

Temperature at Surface (T@S) 90F 32 C.Temperature at Bottom Hole (T@bh) 136F 58 C

Operating Injection Pressure (Pi@S) 800 psig 5600 kPa

Kickoff Pressure (Pko) 850 psig 5900 kPa

Suggested IPO Valve R-20 R-20

Suggested Valve Port Size 1/4" 6.35 mm

Voluma of Gas Available 1200 MCFD 30,000 M3

Formation GLR 100:1 20 M3/kltr

Solution
http://sptupstream.conocophillips.net/sites/learning/prd/gaslift_gregstephenson_Mar2013/Sept%202011/GL%20Design%201.ppthttp://sptupstream.conocophillips.net/sites/learning/prd/gaslift_gregstephenson_Mar2013/Sept%202011/GL%20Design%201.ppt


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Design Bias


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Design Bias in Gas Lift Designs

Tubing head pressure

Tubing pressure / minimum gradient Casing pressure drops to close valve systematically

(disadvantage?) Re-opening valves / Valve interference

Differential at bottom point Casing pressure available Design bias will vary depending on condition Gas passage Well coming in Add some more mandrels? Usually called safety factors


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Transfer Point Bias

Accounts for uncertainty in flowing gradient Affects spacing Affects valve calculations

Options Percentage of tubing pressure

% (PcsgPtbg)

Bracketing

Design Line

User defined per station


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Design Lines

0 1000 2000

0

1000

2000

3000

4000

5000

6000

7000

8000

9000

10000

PRESSURE (PSIG)

DEPTH

FTTVD


MANDREL #4

MANDREL #2

MANDREL #5

F.B.H.P.

MANDREL #1

MANDREL #3

Design line


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Casing Pressure Drop

Ensures injection through single valve Attempts to offset tubing pressure effect Relative to port size

Methodologies include:Constant pressure dropPtmaxPtmin

Valve-dependant (catalog-based)


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Temperature bias

Static pressure gradient

SBHP

Flowing temperature gradientStatic temperature gradient

Static fluid level

1stpotential operating point


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(Ptmax- Ptmin) Method

#1.


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Valve #1

Pressure

De

p

t

h

Pc1

Pt@L Pc @ L

30-50#

Differential

Pt

#2.


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#1

Pressure

De

p

t

h

Pc1

50#

Differential

Pt

Pt min Pt max

Point A

Pc2 = Pc1-[ (Pt max-Pt min) (TEF)]

#3.


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#1

Pressure

De

p

t

h

Pc1

50#

Differential

Pt

Pt min

Pt max

#2

Point A

Pc2=1000-[(750-425) (.104)]

Pc2=966 psi

(33.8 psi)

Pc1

#4.

Pc2


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#1

Pressure

De

p

t

h

Pc1Pt

#2

#3

Pc2

Pc3

Pc3=966-[(815-625) (.104)]

Pc3=946 psi

(19.76 psi)

Pc2#5.


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#1

PressurePc1Pt

#2

#3

Pc2

Pc3

D

ep

t

h

Pt min Pt max

Point A

Pc2#6.


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#1

PressurePc1Pt

#2

#3

Pc2

Pc3

D

ep

t

h

Pt min

Pc4= 946-[(925-750) (.104)]

Pc4= 928 psi

(18.2 psi)

Pc4

(.05 x Depth) + Pwh

#4


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Gas Lift Design Example #2Redesign the gas lift installation for example #1 using at least 2 forms of

design bias.

English Metric

Tubing Size 2-7/8" 6.5 ppf 62 mm

Desired Producing Rate 600 BPD 100 M3

Percent Water 50% 50%

Water Specific Gravity 1.08 1.08

Gas Specific Gravity 0.65 0.65Oil Gravity 35API 0.85 rel dens

Static Fluid Gradient (Gs) 0.465 10.5 kPa / mtr

Depth of Perforations 5257 ft. 1600 meters

Depth of Packer 5000 ft. 1500 meters

Wellhead Pressure (Pwh) 100 psig 700 kPa

Static Bottom Hole Pressure (Pbhs) 1600 psig 11,000 kPa

Flowing Bottom Hole Pressure (Pbhf) 1160 psig 8000 kPa

Temperature at Surface (T@S) 90F 32 C.Temperature at Bottom Hole (T@bh) 136F 58 C

Operating Injection Pressure (Pi@S) 800 psig 5600 kPa

Kickoff Pressure (Pko) 850 psig 5900 kPa

Suggested IPO Valve R-20 R-20

Suggested Valve Port Size 1/4" 6.35 mm

Voluma of Gas Available 1200 MCFD 30,000 M3

Formation GLR 100:1 20 M3/kltr

Well Data

Solution
http://sptupstream.conocophillips.net/sites/learning/prd/gaslift_gregstephenson_Mar2013/Course%20Materials/Presentations/GL%20Design%202.ppthttp://sptupstream.conocophillips.net/sites/learning/prd/gaslift_gregstephenson_Mar2013/Sept%202011/GL%20Design%202.ppthttp://sptupstream.conocophillips.net/sites/learning/prd/gaslift_gregstephenson_Mar2013/Course%20Materials/Presentations/GL%20Design%202.ppthttp://sptupstream.conocophillips.net/sites/learning/prd/gaslift_gregstephenson_Mar2013/Sept%202011/GL%20Design%202.ppt

4b - IPO GL Design

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