Well Performance and Artifical Lift Rev 3
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Transcript of Well Performance and Artifical Lift Rev 3
INTRODUCTION TO WELL PERFORMANCE
& ARTIFICIAL LIFT
November 2001
by Russ Gilbert & Justin Gilmour
= $$$$$
the well
What is a well?Why is it important ?
WHY BOTHER WITH WELL PERFORMANCE ?
• Basic Well Configuration
• Reservoir Inflow Performance
• Tubing Outflow Performance
• Improving Well Performance
INTRODUCTION TO WELL PERFORMANCE
CONCEPTS COVERED
BASIC WELL CONFIGURATIONXMAS TREE
Hydrocarbon Flow
CASING
TUBING OUFLOW
PERFORATIONS
RESERVOIR
RESERVOIR INFLOW
Gas Export
Oil Export= $$$$
Separator
RESERVOIR INFLOW
oil rate
PRESSURE DROP
Reservoir pressure(Pres)
Inflow Performance Principle:
Pre
ssu
re
As pressure drop increases rate increases!
Can we model this principle?
pres
sure
BHP
Pres
ΔP ΔP
Wellbore Damage (Skin)
BHPBottomhole pressure
(BHP)
Higher Pressure(Driving Force)
RESERVOIR INFLOWMathematical Model
Flow Rate (Q) varies with: - Inflow Pressure Drop? (ΔP)- Thickness of the Reservoir? (h)- Permeability of the Reservoir Sand? (k)- Phase of the Moon? (x)- Skin Damage around the Well? (S)- Reservoir Pressure? (Pres)- Fluid Viscosity? (µ)- Hours of Sunshine? (y)- Wellbore Radius (rw)
pres
sure
BHP
Pres
ΔP
BHP
ΔP
Q = f ?
RESERVOIR INFLOWMathematical Model
Various inflow equations are used to model reservoir inflow in software such as Prosper
Flow Rate (Q) varies with: - Inflow Pressure Drop? (ΔP)- Thickness of the Reservoir? (h)- Permeability of the Reservoir Sand? (k)- Phase of the Moon? (x)- Skin Damage around the Well? (S)- Reservoir Pressure? (Pres)- Fluid Viscosity? (µ)- Hours of Sunshine? (y)- Wellbore Radius (rw)
pres
sure
BHP
Pres
ΔP
BHP
ΔP
Q = fK h ΔP rw
µ S
TUBING OUTFLOW
Tubing Performance Principle:
pres
sure
oil rate
PRESSURE LOSS
Higher Pressure(Driving Force)
Lower Pressure
BHP
WHP
As rate increases pressure loss increases!
Can we model this principle?
Bottomhole pressure(BHP)
Well Head pressure(WHP)
TUBING OUTFLOW
BHP
WHP
Mathematical Model
Flow Rate (Q) varies with: - Fluid Weight/Type? (ρ)- Friction Losses - Fluid Viscosity? (μ)- Friction Losses - Tubing Length? (L)- Phase of the Moon? (x)- Friction Losses - Tubing diameter ? (d)- Friction Losses - Tubing roughness ? (f)- Hours of Sunshine? (y)- Well Head Pressure? (WHP)
Q = f ?
Note: The acceleration term (velocity increasing due to gas expansion) has been assumed to be negligible for this presentation.
TUBING OUTFLOW
BHP
WHP
Mathematical Model
Flow Rate (Q) varies with: - Fluid Weight/Type? (ρ)- Friction Losses - Fluid Viscosity? (μ)- Friction Losses - Tubing Length? (L)- Phase of the Moon? (x)- Friction Losses - Tubing diameter ? (d)- Friction Losses - Tubing roughness ? (f)- Hours of Sunshine? (y)- Well Head Pressure? (WHP)
Various correlations are used to model tubing outflow in software such as Prosper
Q = f1
Fluid Weight . Friction Losses . Wellhead Pressure
Note: The acceleration term (velocity increasing due to gas expansion) has been assumed to be negligible for this presentation.
TUBING OUTFLOWFluid Weight/Type
0 5000 10000 15000 200000
1000
2000
3000
4000
5000
6000
VLP (TUBING) CURVES ( 20 Nov 01 16:11)
Liquid Rate (STB/day)
Pre
ssur
e (
psig
)
FluidOilFlow TubingTypeProducer
Lift NoneCompCased HoleCorrlnHagedorn Brown
Bottom Measured Depth 10000.0(feet)Bottom True Vertical Depth 10000.0(feet)
Variables1:Water Cut (percent)2:First Node Pressure (psig)3:Tubing/Pipe Diameter (inches)
1 2 30=0 0=50.0 0=1.99
1=50.000 1=200.0 1=2.752=90.000 2=400.0 2=3.83
3=4.89
002
102
202
Mixture
All Wtr
50/50
All Oil
Tubing Length=10,000ft; Tubing Diameter=4 1/2”OD;WHP=50psig
TUBING OUTFLOWFriction Losses
Tubing Length=10,000ft; All Oil; WHP=50psig
0 5000 10000 15000 200000
1000
2000
3000
4000
5000
6000
VLP (TUBING) CURVES ( 20 Nov 01 16:11)
Liquid Rate (STB/day)
Pre
ssur
e (
psig
)
FluidOilFlow TubingTypeProducer
Lift NoneCompCased HoleCorrlnHagedorn Brown
Bottom Measured Depth 10000.0(feet)Bottom True Vertical Depth 10000.0(feet)
Variables1:Water Cut (percent)2:First Node Pressure (psig)3:Tubing/Pipe Diameter (inches)
1 2 30=0 0=50.0 0=1.99
1=50.000 1=200.0 1=2.752=90.000 2=400.0 2=3.83
3=4.89
000
001
002
003
Tubing OD
2 3/8”
4 1/2”
5 1/2”
3 1/2”
TUBING OUTFLOWWell Head Pressure
0 5000 10000 15000 200000
1000
2000
3000
4000
5000
6000
VLP (TUBING) CURVES ( 20 Nov 01 16:11)
Liquid Rate (STB/day)
Pre
ssur
e (
psig
)
FluidOilFlow TubingTypeProducer
Lift NoneCompCased HoleCorrlnHagedorn Brown
Bottom Measured Depth 10000.0(feet)Bottom True Vertical Depth 10000.0(feet)
Variables1:Water Cut (percent)2:First Node Pressure (psig)3:Tubing/Pipe Diameter (inches)
1 2 30=0 0=50.0 0=1.99
1=50.000 1=200.0 1=2.752=90.000 2=400.0 2=3.83
3=4.89
002
012
022
Tubing Length=10,000ft; All Oil; Tubing Diameter=4 1/2”
Well Head Pressure
400 psig
200 psig
50 psig
THE OIL RATE
Determined for specific fluid, specific tubing & specific reservoir by intersection of the reservoir inflow & tubing outflow curves
oil rate
pres
sure
from tubing outflow
surface pressure - WHP
from reservoir inflow
reservoir pressure - Pres
THE OIL RATE
0 5000 10000 15000 200000
1000
2000
3000
4000
5000
6000
Inflow v Outflow Curves ( 20 Nov 01 17:04)
Liquid Rate (STB/day)
Pre
ssur
e (
psig
)
FluidOilFlow TubingTypeProducer
Lift NoneCompCased HoleCorrlnHagedorn Brown
First Node Pressure 50.0(psig)Bottom Measured Depth 10000.0(feet)
Bottom True Vertical Depth 10000.0(feet)
IPR PI EntryRes Temp200.0 (degrees F)Res Pres 3000.0 (psig)
Variables1:Reservoir Pressure (psig)
1 2 30=3000.01=4000.02=5000.0
2
2
IPR Curve
VLP Curve
Tubing Length=10,000ft; All Oil; Tubing Diameter=4 1/2”; WHP=50psig, Pres=5000psig, k.h=10000mdft, rw=8.5”, Wellbore Skin=5
Reservoir Pressure
5000 psig
Initial Conditions
6500 bopd
THE OIL RATEPressure Depletion
0 5000 10000 15000 200000
1000
2000
3000
4000
5000
6000
Inflow v Outflow Curves ( 20 Nov 01 17:04)
Liquid Rate (STB/day)
Pre
ssur
e (
psig
)
FluidOilFlow TubingTypeProducer
Lift NoneCompCased HoleCorrlnHagedorn Brown
First Node Pressure 50.0(psig)Bottom Measured Depth 10000.0(feet)
Bottom True Vertical Depth 10000.0(feet)
IPR PI EntryRes Temp200.0 (degrees F)Res Pres 3000.0 (psig)
Variables1:Reservoir Pressure (psig)
1 2 30=3000.01=4000.02=5000.0
0
0
1
1
2
2
IPR Curve
VLP CurveReservoir Pressure
5000 psig
4000 psig
3000 psig
6500 bopd2500 bopd
Tubing Length=10,000ft; All Oil; Tubing Diameter=4 1/2”; WHP=50psig, Pres=depleting, k.h=10000mdft, rw=8.5”, Wellbore Skin=5
THE OIL RATEPressure Depletion & %Water Increase
Tubing Length=10,000ft; %wtr increasing; Tubing Diameter=4 1/2”; WHP=50psig, Pres=depleting, k.h=10000mdft, rw=8.5”, Wellbore Skin=5
0 5000 10000 15000 200000
1000
2000
3000
4000
5000
6000
Inflow v Outflow Curves ( 20 Nov 01 17:04)
Liquid Rate (STB/day)
Pre
ssur
e (
psig
)
FluidOilFlow TubingTypeProducer
Lift NoneCompCased HoleCorrlnHagedorn Brown
First Node Pressure 50.0(psig)Bottom Measured Depth 10000.0(feet)
Bottom True Vertical Depth 10000.0(feet)
IPR PI EntryRes Temp200.0 (degrees F)Res Pres 3000.0 (psig)
Variables1:Reservoir Pressure (psig)
1 2 30=3000.01=4000.02=5000.0
0
0
1
1
2
2
IPR Curve
VLP CurveReservoir Pressure
5000 psig
4000 psig
3000 psig
%Water
100%
50% (Now)
0%Now 4500 psig
3000 bfpd
THE OIL RATEPressure Depletion & %Water Increase
What can we do to stop oil rate falling ?
Was 6,500 bopd, now 1500 bopd
IMPROVING WELL PERFORMANCE
pres
sure
Oil rate can be increased by:• Shifting reservoir inflow up • Shifting tubing outflow curve down
oil rate
Tubing outflow
surface pressure - WHP
Reservoir inflow)
reservoir pressure - Pres
How Do You Do That Then ?
IMPROVING WELL PERFORMANCEShifting Reservoir Inflow Curve Up - How To
Q = fK h ΔP rw
µ S
Increase
Decrease
Increase: Kh, ΔP rw Decrease: µ S
IncreaseReservoirPressure
Re-Perf.,Acidise,Fracture,Dissolve
Heat-UpFracture,Horizontal
Well
DrillBiggerHole
IMPROVING WELL PERFORMANCEShifting Tubing Outflow Curve Down - How To
Q = f1
Fluid Weight . Friction Losses . Wellhead Pressure
Reduce: Fluid Weight, Friction Losses, Wellhead Pressure
Isolate WtrProdn orAdd gas
via gas lift(aka artificial lift)
BiggerTubing
LowerSeparatorPressure
No Action:Rate = 3000bfpd
Well Will Die Soon
0 5000 10000 15000 200000
1000
2000
3000
4000
5000
6000
Inflow v Outflow Curves ( 20 Nov 01 17:04)
Liquid Rate (STB/day)
Pre
ssur
e (
psig
)
FluidOilFlow TubingTypeProducer
Lift NoneCompCased HoleCorrlnHagedorn Brown
First Node Pressure 50.0(psig)Bottom Measured Depth 10000.0(feet)
Bottom True Vertical Depth 10000.0(feet)
IPR PI EntryRes Temp200.0 (degrees F)Res Pres 3000.0 (psig)
Variables1:Reservoir Pressure (psig)
1 2 30=3000.01=4000.02=5000.0
0
0
1
1
2
2
IPR Curve
VLP CurveP res
5000 psig
4000 psig
3000 psig
%Water
100%
50%
0%
Shifting Reservoir Inflow Curve UpIMPROVING WELL PERFORMANCE
Increase: Kh, ΔP rw Decrease: µ S
IncreaseReservoirPressure
Re-Perf.,Acidise,Fracture,Dissolve
Heat-UpFracture,Horizontal
Well
DrillBiggerHole
Actions: (1) N/A N/A Later Re-perf N/A
4000 bfpd
0 5000 10000 15000 200000
1000
2000
3000
4000
5000
6000
Inflow v Outflow Curves ( 20 Nov 01 17:04)
Liquid Rate (STB/day)
Pre
ssur
e (
psig
)
FluidOilFlow TubingTypeProducer
Lift NoneCompCased HoleCorrlnHagedorn Brown
First Node Pressure 50.0(psig)Bottom Measured Depth 10000.0(feet)
Bottom True Vertical Depth 10000.0(feet)
IPR PI EntryRes Temp200.0 (degrees F)Res Pres 3000.0 (psig)
Variables1:Reservoir Pressure (psig)
1 2 30=3000.01=4000.02=5000.0
0
0
1
1
2
2
IPR Curve
VLP CurveP res
5000 psig
4000 psig
3000 psig
%Water
100%
50%
0%
50% +G/L
Shifting Tubing Outflow Curve Down
No Further Action:Rate = 4000bfpd
Well Will Still Die Soon
IMPROVING WELL PERFORMANCE
Reduce: Fluid Weight, Friction Losses, Wellhead Pressure
Isolate WtrProdn,
Add gasvia gas lift
BiggerTubing
LowerSeparatorPressure
Actions: (2) Add G/L N/A N/A
7500 bfpd
Shifting Reservoir Inflow Curve Up
No Further Action:Rate = 7500bfpd
Well Will Still Die, But Later
0 5000 10000 15000 200000
1000
2000
3000
4000
5000
6000
Inflow v Outflow Curves ( 20 Nov 01 17:04)
Liquid Rate (STB/day)
Pre
ssur
e (
psig
)
FluidOilFlow TubingTypeProducer
Lift NoneCompCased HoleCorrlnHagedorn Brown
First Node Pressure 50.0(psig)Bottom Measured Depth 10000.0(feet)
Bottom True Vertical Depth 10000.0(feet)
IPR PI EntryRes Temp200.0 (degrees F)Res Pres 3000.0 (psig)
Variables1:Reservoir Pressure (psig)
1 2 30=3000.01=4000.02=5000.0
0
0
1
1
2
2
IPR Curve
VLP CurveP res
5000 psig
4000 psig
3000 psig
%Water
100%
50%
0%
50% +G/L
IMPROVING WELL PERFORMANCE
Increase: Kh, ΔP rw Decrease: µ S
IncreaseReservoirPressure
Re-Perf.,Acidise,Fracture,Dissolve
Heat-UpFracture,Horizontal
Well
DrillBiggerHole
Actions: (3) N/A N/A Wtr Injector N/A N/A
10000 bfpd
IMPROVING WELL PERFORMANCE
Actions to improve well performancehave almost returned oil rate to initial condition
SUMMARY• Basic Well Configuration
• Reservoir Inflow Performance
• Tubing Outflow Performance
• Improving Well Performance
Q = f K h ΔP rw
µ S
Q =f1
Fluid Weight . Friction Losses . Wellhead Pressure
Shifting Reservoir Inflow Curve Up
Shifting Tubing Outflow Curve Down