Upload
jhony-chilon
View
71
Download
11
Embed Size (px)
DESCRIPTION
descargalo de www.chilonunellez.blogspot.com
Citation preview
Copyright 2007, , All rights reserved
NODAL ANALYSIS
Copyright 2007, , All rights reserved
NODAL ANALYSIS
Separator
Tubing
Psep
Q
Pwf
FlowlinePwh
ΔPtubing
ΔP flowline GAS
OIL+WATER
ΔPres
Pr, IPR, K
Reservoir
IS A METHODOLOGY TO ANALYZETHE PRODUCTION SYSTEM AS ANUNIT TO CALCULATE ITS CAPACITYWITH THE OBJECTIVE OF:
• DESIGNING EACH COMPONENT OF THE PRODUCTION SYSTEM
• DETECTING PRODUCTION IMPEDIMENTS
• CALCULATING THE EFFECT OF CHANGINGONE OR MORE COMPONENTS ON THECAPACITY OF THE PRODUCTION SYSTEM
ΔP = f(Q)
Copyright 2007, , All rights reserved
pp88= = PPwhwh--PPsepsep
PPwfswfs--PPwfwf = = pp22
PPrr PPeePPwfswfsPPwfwf
PPurur
PPuvuv
PPdvdv
PPwhwh PPdsdsPPsepsep
gasgas
SeparatorSeparator
TankTank
ReservoirReservoir
FlowlineFlowline
WellWell
pp11=P=Prr--PPwfswfs
pp33= P= Purur--PPdrdr
pp44= P= Puvuv--PPdv dv
PPdrdr
pp66= P= Pdsds--PPsep sep PPwhwh--PPdsds = = pp55
pp 77
= P
= P w
fw
f-- PPw
h w
h
Surface chokeSurface choke
Safety valveSafety valve
RestrictionRestriction
pp11=P=Prr--PPwfswfs Loss in porous mediumLoss in porous mediumpp22=P=Pwfswfs--PPwfwf Loss across the completionLoss across the completionpp33=P=Purur--PPdrdr ”” ”” restrictionrestrictionpp44=P=Puvuv--PPdvdv ”” ”” safety valvesafety valvepp55=P=Pwhwh--PPdsds ”” ”” chokechokepp66=P=Pdsds--PPsepsep ”” in flow linein flow linepp77=P=Pwfwf--PPwhwh Total loss in tubingTotal loss in tubingpp88=P=Pwhwh--PPsepsep Total loss in flowlineTotal loss in flowline
POSSIBLE PRESSURE LOSSES IN A PRODUCTION SYSTEM
Copyright 2007, , All rights reserved
NODE
Pn
INFLOW OUTFLOW
UPSTREAM COMPONENTS
DOWNSTREAMCOMPONENTS
Q Q
Pu Pd
Pnode = Pu – ΔPupstream components (1) = f1(Q)
Pnode = Pd + ΔPdownstream components (2) = f2(Q)
ΔPuΔPd
NODAL ANALYSIS CONCEPT
ΔP = f (Q)
Copyright 2007, , All rights reserved
FLOW RATE, Q
NO
DE
PRES
SUR
E, P
node Outflow from node
Inflow to node
SYSTEM FLOW CAPACITY
GRAPHICAL SOLUTION OF THE PROBLEM
NODE PRESSURE
(1)
(2)
Copyright 2007, , All rights reserved
EXERCISEILUSTRATION OF NODAL ANALYSIS CONCEPT
Use the following equation to calculate the pressure drop in a pipe
L Q2
ΔP = 3.8 x 10 - 7 x ; D5
where, ΔP is the pressure drop in psi, L is the pipe length in feet, D is the pipe diameter in inches and Q the flow rate in BPD.
Calculate:
1) Actual capacity of the system in BPD.2) Capacity of the system when the diameter of the 2” pipe is increased to 3”.
Select the node at the point where the pipe diameter is reduced from 3” to 2”. Assume flow rates of 2500, 3000 y 3500, 5000, 5500, 6000 BPD.
2000 feet, Ø= 3” 1000 feet, Ø=2”
P1= 200 psi P3= 60 psi
Pnode
WATERSOURCE WATER
SINK
ΔP1 ΔP2
Copyright 2007, , All rights reserved
GRAPHICAL SOLUTION OF THE PROBLEM
(1) Pnode = P1-ΔP1
(2) Pnode = P3+ΔP2
2000 feet, Ø= 3” 1000 feet, Ø=2”
P1= 200 PSI P3= 60 PSIPnode
WATERSOURCE
WATERSINK
ΔP1 ΔP2
FLOW RATE, Q
NO
DE
PRES
SUR
E, P
node
Outflow performance
Inflowperformance
Actual system flow capacity
Pnode
(1)
(2)2”
Copyright 2007, , All rights reserved
GRAPHICAL SOLUTION OF THE PROBLEM
(1) Pnode = P1-ΔP1
(2) Pnode = P3+ΔP2
2000 feet, Ø= 3” 1000 feet, Ø=2”
P1= 200 PSI P3= 60 PSIPnode
WATERSOURCE
WATERSINK
ΔP1 ΔP2
FLOW RATE, Q
NO
DE
PRES
SUR
E, P
node
Outflow performance
Inflowperformance
Actual system flow capacity
Pnode
(1)
(2)2”
3”
new system flow capacitySOL
Copyright 2007, , All rights reserved
1A
876
5
4
3 21
1B
NODE LOCATION
1 SEPARATOR2 SURFACE CHOKE3 WELLHEAD4 SAFETY VALVE5 RESTRICTION6 Pwf7 Pwfs8 Pr
1A GAS SALES1B STOCK TANK
LOCATION OF VARIOUS NODES
Copyright 2007, , All rights reserved
Inflow to node:Pr – ΔPres – ΔPtubing = Pwh (1)
Outflow from node:Psep + ΔPflowline = Pwh (2)
Gas
Flow through porous media
Vertical or inclined tubing
HorizontalFlowline
Separator
Tank
Pr, k, IPR
PwhNODEPsep
ΔPtubing
ΔPres
ΔP flowline
NODAL ANALYSIS APPLICATION IN A SIMPLE PRODUCTION SYSTEM(NODE SELECTED AT THE WELLHEAD)
Copyright 2007, , All rights reserved
EFFECT OF THE FLOWLINE SIZE(NODE SELECTED AT THE WELLHEAD)
FLOWRATE, Q
WEL
LHEA
D P
RES
SUR
E, P
wh
d1
d2 > d1
INFLOW
OUTFLOW
Copyright 2007, , All rights reserved
Inflow to node:Pr – ΔPres = Pwf (1)
Outflow from node:Psep + ΔPflowline +
ΔPtubing = Pwf (2)
(NODE SELECTED AT THE BOTTOMHOLE)
NODAL ANALYSIS APPLICATION IN A SIMPLE PRODUCTION SYSTEM
Gas
Flow through porous media
Vertical or inclined tubing
HorizontalFlowline
Separator
Tank
Pr, k, IPR
Pwh
NODE
Psep
ΔPtubing
ΔPres
ΔP flowline
Pwf
Copyright 2007, , All rights reserved
EFFECT OF THE TUBING SIZE(NODE SELECTED AT THE BOTTOMHOLE)
FLOWRATE, Q
BO
TTO
MH
OLE
FLO
WIN
G P
RES
SUR
E, P
wf
INFLOWIPR
Pr
00
OUTFLOW
d1
d2>d1
Copyright 2007, , All rights reserved
TUBING DIAMETER, d
FLO
W R
ATE
, Q
UNSTABLE REGION
DIAMETER FORMAXIMUM FLOW RATE
FINDING OPTIMUM TUBING SIZE
Copyright 2007, , All rights reservedFLOW RATE, Q
BO
TT
OM
OL
E F
LO
WIN
G P
RE
SSU
RE
, Pw
f Pr
00 PRODUCTION INCREASE
1
2
d1
d2>d1
2**
2*
WELL WITHSKIN EFFECT
WELL WITHOUT SKIN EFFECT
SIMULTANEOUS EFFECT OF MINIMIZING FLOW RESTRICTIONSIN THE RESERVOIR AND IN THE PIPING SYSTEM
(NODE AT THE BOTOMHOLE)
Copyright 2007, , All rights reserved
LIQ
UID
PR
OD
UC
TIO
N R
ATE
, QL
GAS INJECTION RATE, Qgi
Available gasvolume
Economic Optimum
Maximum liquid production
LIQUID PRODUCTION RATE, QL
BO
TTO
M H
OLE
FLO
WIN
G P
RES
SUR
E, P
wf
Inflow PerformanceIPR
Pr
GLR
Excessive GLR
GAS LIFT WELL PERFORMANCE
(a) Gas lift well analysis (b) Effect of gas injection rate
Copyright 2007, , All rights reserved
FLOWRATE, Q
BO
TT
OM
HO
LE
FL
OW
ING
PR
ESS
UR
E, P
wf
Pr
00
EFFECT OF PERFORATING DENSITY ON INFLOW
N1
N1>N2
N3>N2
N = NUMBER OF PERFORATIONS PER FOOT
OUTFLOW
INFLOW
Copyright 2007, , All rights reserved
NUMBER OF PERFORATIONS PER FOOT, N
FLO
WR
AT
E, Q
EFFECT OF PERFORATING DENSITY ON FLOW RATE
Copyright 2007, , All rights reserved
NODAL ANALYSIS APPLICATIONS
•Selecting tubing size.•Selecting Flowline size.•Gravel pack design.•Surface choke sizing.•Analyzing an existing system for abnormalflow restrictions (production impediments).
•Artificial lift system design.•Well stimulation evaluation.•Analyzing effects of perforating density.•Predicting the effect of depletion on productioncapacity.
•Allocating injection gas among gas lift wells.•Analyzing a multiwell producing system.
Copyright 2007, , All rights reserved
1. Determine which components in the system can be changed.
2. Select one component to be optimized.
3. Select the node location.
4. Develop expressions for the inflow and outflow.
5. Obtain required data to calculate the pressure drop versusflow rate fall components.
6. Determine the effect of changing the characteristics of the selected component by plotting inflow versus outflow and readin the intersection.
7. Repeat the procedure for each component that is to be optimized.
SUGGESTED PROCEDURE FORNODAL ANALYSIS APPLICATION
Copyright 2007, , All rights reserved
HISTORY CASENODAL ANALYSIS FOCUSED ON ARTIFICIAL LIFT
FLOW RATE, Q
BO
TT
OM
HO
LE
FL
OW
ING
PR
ESS
UR
E, P
wf
Pr
00 PRODUCTION
INCREASE
1
2
GAS LIFT
ELECTRICAL SUBMERSIBLEPUMP (ESP)
PbBUBBLE PRESSURE
ESP FAILED DUE TOEXCESSIVE GAS RATE
Pwf<<<<Pb
Pwf
Copyright 2007, , All rights reserved
Pr
00
1
2
GAS LIFT
Pb
PRODUCTION INCREASE
WELL WITH AVERY STRONGSKIN EFFECT
3
IPR IMPROVED BY REPERFORATION +STIMULATION JOB
ZERO GAS INTHE PUMP
Pwf > Pb
ELECTRICAL SUBMERSIBLEPUMP (ESP)
FLOW RATE, Q
BO
TT
OM
HO
LE
FL
OW
ING
PR
ESS
UR
E, P
wf
BUBBLE PRESSURE
HISTORY CASENODAL ANALYSIS FOCUSED ON ARTIFICIAL LIFT
Copyright 2007, , All rights reserved
Pr
00
2
BEAM PUMPING
WELL STIMULATED WITH STEAM SOAK
1
VERY SMALL INCREASEIN PRODUCTION WAS ACHIEVED
HISTORY CASENODAL ANALYSIS FOCUSED ON INFLOW RESERVOIR PERFORMANCE
FLOW RATE, Q
BO
TT
OM
HO
LE
FL
OW
ING
PR
ESS
UR
E, P
wf
Copyright 2007, , All rights reserved
Pr
00 PRODUCTION INCREASE
3
1
1000 BPD
BEAM PUMPING
FLOW RATE, Q
BO
TT
OM
HO
LE
FL
OW
ING
PR
ESS
UR
E, P
wf
ELECTRICAL SUBMERSIBLEPUMP (ESP)
HISTORY CASENODAL ANALYSIS FOCUSED ON INFLOW RESERVOIR PERFORMANCE
Copyright 2007, , All rights reserved
WELL RESTRICTED BY PIPING SYSTEM AND NEAR WELLBORE SKIN EFFECT
FLOW RATE, Q
BO
TT
OM
HO
LE
FL
OW
ING
PR
ESS
UR
E, P
wf
Pr
00
OUTFLOW
INFLOW
1
2
3
4
NEAR WELLBORE
RESTRICTION (SKIN)
TUBING OR FLOWLINE
RESTRICTION
BOTH
Copyright 2007, , All rights reserved
ANALYZING MULTIWELL SYSTEMS
• Working over individual wells• Placing some wells on artificial lift• Add new wells• Shutting in some of the existing wells• Changes in producing characteristics with time• Effect of surface line sizes• Instalation of pumps or compressors• Effect of the final outlet pressure
A change made in any component in the system would affect the producingcapacity of the total system, Some of the changes that could be consideredare:
Copyright 2007, , All rights reserved
Well 1
Well 2
A B
Well 3
Pwf2
Q2
Pwf3
Q3
Pwf1
Q1
QA=Q1+Q2+Q3
PASystemCapacity
ANALYZING MULTIWELL SYSTEMS