by: gatut widianoko ( weatherford ) herry subekti ( bp – indonesia )
DESCRIPTION
CASING HEAD PRESSURE FINE TUNING in Dual String Gas Lift Well With Injection Pressure Operated Valve. ASME – WORK SHOP - KUALA LUMPUR 2003. By: Gatut Widianoko ( Weatherford ) Herry Subekti ( BP – Indonesia ) Wahyu Jatmiko ( BP – Indonesia ). Abstract. - PowerPoint PPT PresentationTRANSCRIPT
CASING HEAD PRESSURE FINE CASING HEAD PRESSURE FINE TUNING inTUNING inDual String Gas Lift WellDual String Gas Lift WellWith Injection Pressure Operated ValveWith Injection Pressure Operated Valve
CASING HEAD PRESSURE FINE CASING HEAD PRESSURE FINE TUNING inTUNING inDual String Gas Lift WellDual String Gas Lift WellWith Injection Pressure Operated ValveWith Injection Pressure Operated Valve
By: Gatut Widianoko ( Weatherford )Herry Subekti ( BP – Indonesia )Wahyu Jatmiko ( BP – Indonesia )
By: Gatut Widianoko ( Weatherford )Herry Subekti ( BP – Indonesia )Wahyu Jatmiko ( BP – Indonesia )
ASME – WORK SHOP - KUALA LUMPUR 2003
Abstract
After two ( 2 ) years gas lift optimization performed with concentrated in gas lift change out, starting this year 2003, Bp -Indonesia begin to focus on Casing Head Pressure Tuning.
The first year, the gas lift optimization had made 3500 bopd oil gain, and the second year had made 4000 bopd oil gains. This year, up-to the second quarter 2003, BP had made 4500 bopd oil gains. This total gains is came from 40 % gas lift change out, and 60 % from Casing Head Pressure Tuning.
Today we are going to talk about the steps of casing head pressure tuning of the BP-Indonesia gas lift optimization on dual string gas lift well as follow :
1) Identify the gas lift well problems ;
2) Nodal analyzing to determine the well potential ;
3) Optimize point of injection of both string by gas lift change out ;
4) Perform Tuning Casing Head Pressure to optimize both string.
Offshore North West Java Oil Field
JAKARTA
BIMA
ARDJUNA
AV
AVS
AA
MX
MQ
MR
MM
MB
LL
L BZZ
B
K
U
E
F
ZU
P
0 25 50 KM
X
KLXKLY
KNA
KL
KK
APN
O
CILAMAYA
•KALIMANTAN
•SULAW
ESI
•SUMATERA
•J A V A
GG
GG Gas
Accumulation
“O” AREA POD
ARIMBI
CIREBON
Old Oil Field with more than 30 years old High FGOR with 1000 : 1 or more Low PI with only about 1 – 3 blpd / psi Low Production with about 200 - 500 blpd Low Static Pressure with average ~ 600 psi Limited Casing Pressure with ~ 600 psi only Flowing Tubing Pressure is about 180 psi Shallow well - reservoir depth ~ 3000 ft TVD Limited data (SBHP and PI is normally unknown) Old wells - may have leaking valve or tubing Some gas lift valves installed 5-10 years ago Some gas lift header choke stuck open/close
BP Wells General Conditions
ECHO - WELLs COMPLETION DIAGRAM
NOT TO SCALE
9-5/8” Shoe @ 4285’ MD
2-7/8” SSSV @ 286’
Packer @ 3111’ MD
Packer @ 3504’
EZ-27 ( 4016’ - 4021’ ) ( 4025’ – 4031’ ) ( 4035’ – 4043’ ) ( 4050’ – 4062’ )
1050’
3032’
2-7/8” SPM 2-7/8” SPM
1012’
2625’
3007’
2-7/8” WB-1D SSD @ 3383’
2-7/8” WB-1D SSD @ 3183’
2-7/8” SSSV @ 248’
EZ-22B ( Squeezed-Off ) Packer @ 3340’
2-7/8” WB-1D SSD @ 3584’
2-7/8” WB-1D SSD @ 3100’
EZ-23 ( 3389’ - 3406’ )
EZ-24B ( 3590’ - 3609’ )
PBTD @ 4205’ MD
Packer @ 3900’
2-7/8” WB-1D SSD @ 3164’
1898’
2652’
1866’
Find CHP problems
Adjust CHP , Reduce / increase
Slowly until get best
production rate. Repeat it if
needed. Keep best this CHP as
operating pres.
Great savings of time &
efforts
Dual Completion
CHP Fine Tuning Candidates Wells( Gas Lift Optimization )
Suddenly production rate drop Suddenly the well dead Casing Head Pressure unstable Suddenly gas injection rate increase/decrease Inaccurate gas rate measure Robbing, and cause one (1) string dead or drop The well shutdown under maintenance The well shut-in while service status Gas lift Change out is being perform Suddenly Casing Head Pressure Increase Suddenly Casing Head Pressure decrease Suddenly Flowing Tubing Head Pressure increase
Casing Head Pressure TuningSteps in Dual Gas Lift well
Use graphical method to construct the well condition. Draw the static and flowing pressure gradient, etc.
Select Kick Off and best Operating pressure available.Use 90% (max) off Kick Off as Operating pressure.
Select best point of injection of both string ( close or same depth ) and operating port size (close or same size).
Use same surface opening and closing pressure for both string valve.
Perform gas lift well performance by software on each
string to determine optimum condition . Perform CHP tuning by open the Gas Lift Header Choke
and set at the kick off pressure selected. Adjusts the CHP slowly to reach the Best Surface
Operating Pressure selected. Record the Rates. Select the best rate and keep best CHP.
Graphical Method
0 500 1000
1000
1500
2000
3000
4000
DEPTH
Ft
TVD
PRESSURE (p s i)FTP CHP
1200 p s i
Casing Pressure
Echo- Wells
Mid Perforation
Tubing Pressure
#1
#2
#3
#7
0.45 p s i / ft
0.1 p s I / ft
FL
FBHP
Kick OffOperating Pres.
(To determine best Point of Injection, KO and OP)
Gas Lift Well Performance
Gas Injection Rate Vs Production Rate
Q l
Q i
Q I : Gas in Rate mscfd Q l : Prod. Rate blpd
Optimum Point
Why Do
Casing Head Pressure tuning
instead of
Gas Injection Rate Tuning ?
Gas Measurement Problems
Not each platform has a good measurement
facilities
Some Gas Measuring inaccurate
Gas Injection rate not recorded
Gas in VS CHP does not make sense
We Decided Using CHP as parameter to optimize gas injection
Adjust CHP to find a best production rate of both
String
Measure Gas In, after best CHP reached / selected
Record and keep best CHP of each Well
WHAT IS BEST CHP
Where is the existing CHP ? Is it too high ? Any un-loader valve reopen? Is the existing gas in too much ? Do We need to decrease it ? OR Is it too low ? Is the existing gas in too low ? Can the existing CHP pressure reach the
operating valve ? Do we need to Increase it ? Any actions needs to be done ?
Back to The Original Operating Pressure Design
Decreasing CHP
0 500 1000
1000
1500
2000
3000
4000
DEPTH
Ft
TVD
PRESSURE (p s i)FTP CHP
1200 p s i
Casing Pressure
Echo- Wells
Mid Perforation
Tubing Pressure
#1
#2
#3
#7
0.45 p s i / ft
0.1 p s I / ft
FL
FBHP
Kick OffBest Operating Pres.
(To determine Best Operating Pressure)
Existing CHPToo High
Increasing CHP
0 500 1000
1000
1500
2000
3000
4000
DEPTH
Ft
TVD
PRESSURE (p s i)FTP CHP
1200 p s i
Casing Pressure
Echo- Wells
Mid Perforation
Tubing Pressure
#1
#2
#3
#7
0.45 p s i / ft
0.1 p s I / ft
FL
FBHP
Kick OffOperating Pres.
(To determine Best Operating Pressure)
Existing CHPToo Low
Some Wells Sample of CHP tuning at BP-Indonesia
Gas Lift Optimization at EC-2ST well
Status CHKFTP (Psi)
BOPD BFPDW/C (%)
TOTAL GAS (Mscfd)
GLR (SCF/STB)
GL GAS (Mscfd)
CHP (psi)
Remark
Pretest 64/64" 140 691.2 768 10 552.7 719.66 551.41 580
Test 1 64/64" 140 864 960 10 548.43 571.28 546.23 560
Test 2 64/64" 140 777.6 864 10 543.6 629.17 540.3 540
Test 3 64/64" 140 972 1080 10 542.31 502.14 532.7 520
Post test 64/64" 140 950.4 1056 10 545.87 516.92 528.59 520
Oil Gains : 250 b o p d
Sample : A
Best CHP
Best CHP : 520 p s i
Some Wells Sample of CHP tuning at BP-Indonesia
Gas Lift Tuning at FFB-7
StatusCHK
1/64 inFTP (Psi)
BOPD BFPDW/C (%)
TOTAL GAS (Mscfd)
GLR (SCF/STB)
GL GAS (Mscfd)
CHP (psi)
Remark
Pre well test 72 120 216 864 75 - - - 200 Prior tuningTest 1 72 120 225 898 75 - - - 300
Test 2 72 120 231 924 75 - - - 400
Test 3 72 120 288 1152 75 - - - 440 Optimum rateTest 4 72 120 252 1008 75 - - - 460
Post well test 72 120 288 1152 75 - - - 440 After TuningGain 72
Oil Gains : 70 b o p dSample : B
Best CHP440
Some Wells Sample of CHP tuning at BP-Indonesia
Gas Lift Optimization at EF-5 well
Status CHKFTP (Psi)
BOPD BFPDW/C (%)
TOTAL GAS (Mscfd)
GLR (SCF/STB)
GL GAS (Mscfd)
CHP (psi)
Remark
Pretest 64/64" 130 1101.6 1224 10 1658 1355 650
Test 1 64/64" 130 1110.5 1233.9 10 864 700 624 630 Gas lift optimizationTest 2 64/64" 130 1145 1272 10 816 642 552 610 with GFC-200 runningTest 3 64/64" 130 1209.6 1344 10 744 615 516 590 test to measure gas inTest 4 64/64" 130 1166.4 1296 10 672 576 432 570 and gas outTest 5 64/64" 130 1123.2 1248 10 624 500 360 550
Post test 64/64" 130 1188 1320 10 720 546 504 590
Oil Gains : 80 b o p dSample : C
Best CHP
Best CHP : 590 p s i
Sample of One PlatformCHP Tuning Results
FFB- 1 15-Jul-03 610 220 468 70 85 - - - 16-Jul-03 630 220 723 110 85 40
FFB- 2L 16-Jul-03 360 120 952 190 80 - - - 17-Jul-03 340 120 1101 220 80 30
FFB- 2S 17-Jul-03 360 120 682 68 90 - - - 18-Jul-03 340 120 684 68 90 0
FFB- 3S 18-Jul-03 380 120 1284 128 90 - - - 18-Jul-03 380 120 1284 128 90 0
FFB- 6L 20-Jul-03 600 100 480 72 85 - - - 20-Jul-03 580 100 552 83 85 10
FFB- 7 19-Jul-03 200 120 864 216 75 - - - 19-Jul-03 440 120 1152 288 75 70
COMPLETE DATE
POST WELL TEST AFTER TUNINGPre-testCOMPLETE
DATE
TOTAL GAINS (Bopd)
GLR (scf/stb)
FTP (Psi)
GL GAS (Mscfd)
CHP (Psi)
WELL FLUID (Bfpd)
OIL (Bopd)
W/C (%)
FLUID (Bfpd)
OIL (Bopd)
W/C (%)
TOTAL GAS
(Mscfd)
CHP (Psi)
FTP (Psi)
* Total Gains for one platform by CHP tuning : 150 b o p d* Gas gains is not recorded* Working Days : 10 days.
Total Oil Gains by CHP Tuning YTD up to 2nd Qtr
Tuning Result As per June 30
0
500
1000
1500
2000
2500
3000
3500
Time
BO
PD
Tuning
Total Oil Gains by Gas Lift Change Out YTD up to 2nd Qtr’ 03
GLVCO Result as per June 30
0
200
400
600
800
1000
1200
1400
1600
1800
2000
04/0
1/20
03
11/0
1/20
03
18/0
1/20
03
25/0
1/20
03
01/0
2/20
03
08/0
2/20
03
15/0
2/20
03
22/0
2/20
03
01/0
3/20
03
08/0
3/20
03
15/0
3/20
03
22/0
3/20
03
29/0
3/20
03
05/0
4/20
03
12/0
4/20
03
19/0
4/20
03
26/0
4/20
03
03/0
5/20
03
10/0
5/20
03
17/0
5/20
03
24/0
5/20
03
31/0
5/20
03
07/0
6/20
03
14/0
6/20
03
21/0
6/20
03
28/0
6/20
03
Time
BO
PD
GLVCO
Total Oil Gains After Gas Lift Optimization YTD up to 2nd Qtr’ 03
GL Optimization Result
0
500
1000
1500
2000
2500
3000
3500
4000
4500
5000
04/0
1/20
03
11/0
1/20
03
18/0
1/20
03
25/0
1/20
03
01/0
2/20
03
08/0
2/20
03
15/0
2/20
03
22/0
2/20
03
01/0
3/20
03
08/0
3/20
03
15/0
3/20
03
22/0
3/20
03
29/0
3/20
03
05/0
4/20
03
12/0
4/20
03
19/0
4/20
03
26/0
4/20
03
03/0
5/20
03
10/0
5/20
03
17/0
5/20
03
24/0
5/20
03
31/0
5/20
03
07/0
6/20
03
14/0
6/20
03
21/0
6/20
03
28/0
6/20
03
Time
BO
PD Tuning
GLVCO
Tuning Results VS Gas Lift Change Out Results up to 2nd Qtr’ 03
Tuning vs GLVCO
0
500
1000
1500
2000
2500
3000
3500
Time
BO
PD GLVCO
Tuning
Well Work Percentage
46%
9%3%23%
19%
Total Wells analyzes : 190 wells
Completed by Wire line : 31 wells
: 87 Wells potential
: 18 Wells had optimum
: 5 New wells
: 44 Wells CHP Tuning
: 36 Wells Needs FGS & SBHP survey
TOTAL GAS LIFT JOB YTD UP TO 2nd Qtr’ 03
Total Oil Gains After Gas Lift Optimization YTD Up to 2nd Qtr’ 03
5703 9942
4815
0
500
1000
1500
2000
2500
3000
3500
4000
4500
5000
5500
6000
Pre-test, bopd Post-test, bopd Gain, bopd
CHP Tuning – Lessons Learned ( With Injection Pressure Valve )
Enough Kick Off (KO) and Operating (OP) Pressure to reach deepest point of injection is required
Differential pressure between KO and OP is ~10% of casing pressure, (or at least 50psi).
Use graphical method to select best point of injection and best draw down of both (200 – 500 psi) strings.
Surface opening pressure of both string are same. Use at least 10 psi less than the CHP available.
Surface closing pressure of both strings must be at least 20 psi above OP, and 30 psi less than KO
To avoid “gas robbing” - depth point of injection of both strings must be close or equal; same thing in the port size
Perform CHP tuning to reach Optimum Conditions Watch the CHP performance and Keep it at best CHP.