integrated sand management strategy

Ikatan Ahli Teknik Perminyakan IndonesiaIkatan Ahli Teknik Perminyakan IndonesiaIkatan Ahli Teknik Perminyakan IndonesiaIkatan Ahli Teknik Perminyakan Indonesia

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Ikatan Ahli teknik Perminyakan Indonesia Simposium Nasional dan Kongres X

Jakarta, 12 – 14 November 2008

Makalah Profesional

IATMI 08 - 007

Integrated Sand Management Strategy for Mature Field West Java

by Achmad Soendaroe, Angga P.R., and Wahyu J. BP Indonesia

Abstract

Sustaining production on a mature field like West Java would require a holistic view on both production and integrity aspects. After 35+ production years of West Java field, we observe that sand problem results in production as well as integrity problems. Therefore an integrated sand management strategy that fits and applicable for mature field is required to optimize production and to provide maximum field values toward the contractor and the government. This paper addresses an example of sand management strategy in the mature asset to sustain the production and reduce integrity problem.

Beside production losses issue, the sand problem is also increase erosion rate of facilities. It results in higher operation cost to repair facilities damage and in many respect results in unintended environments issues. There are two main areas of focus to manage sand problem properly, which are upstream and downstream of the production choke. Ideally we should stop sand production all the way from the reservoir face as its source. However in reality we often need to considered the implication such strategy, because stopping sand production in early at reservoir face sometimes restrict reservoir productivity and also increase well cost.

Effective sand management is determined by how good it can reduce its negative impact. An appropriate sand control plan should be consisted of sand production prediction method, sand problem preventing & monitoring system, and also the best practices of remediation techniques. Through zone reviews we identified typical zones that potentially produce sand problem. Then follow up by building a list of wells that are predicted to have sand problem. Preventive works such as bean up choke strategy, and regular monitoring should be performed to minimize sand impact and provide effective tool for early detection of sand production prior the sand creating a furthering problem. A best option of remedial works should be chosen based on evaluation of previous implemented techniques.

Introduction West Java field located at offshore North West Java island of Indonesia. The field is in offshore environment with water depth 40-160 feet. The field produced since 1971 with peak production are 175 mbopd and 350 mmcfd. Current production is 25 mbopd and 260 mmcfd from 171 productive platforms and 10 flow-stations. It consist around 316 production strings and 571 shut-in potential strings. Those


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platforms and flow-stations connected together by 350 pipelines with total length of 1700 kms and collect all liquid is processing at single Central - Plant.

West Java field consist of 5 productive formations:

• Talang Akar – Oligocene sandstone

• Baturaja - reefal carbonate rock

• Main – Middle Miocene sandstone

• Massive – late Miocene sandstone

• Parigi - Late Miocene carbonate build up The Main-Massive sandstone are the most contributing oil producer, while Parigi carbonate is the most contributor of free gas production. Current cumulative production is 1207 MMBO oil + 2.86 TCF gas, with remaining reserve: Proved 83 MMBO + 0.498 TCF and Non Proved 276 MMBO + 1.298 TCF.

After producing the field more than 35 years there are several challenges such as:

• Depleted reservoir pressure (Pr ~ 500 – 650 psia)

• High watercut production that required higher pressure drawdown to produce oil and gas rate

• Sand problem that introduce significant production losses and also additional facilities cost due to eroded impact on equipments

• Remaining reserve that spread out of the field that required fit and proper technology to access

Recently sand problem is becoming the root cause of significant production losses, and environmental issues. Therefore integrated review was conducted to improve sand management strategy and cover both subsurface and surface aspects.

Sand Management Sand production can occur at any point during field life; during first flow, later when reservoir pressure depleted, or when water breaks through. Degrees of severity of sand problem depend on the reservoir type and completion methods. Sand management is an operating

concept where traditional sand control means are not normally applied and production is managed through monitoring and control of well production and sand influx. With the above term of sand management it can produce the well in lower skin and higher productivity index, and avoided an expensive installation sand control devices in early life of wells. However there is also risk that sand production might exceed of prediction, therefore need in some cases need to put remedial actions, including well re-completion. Effective sand management is determined by how good it minimized negative impact of sand problem within favorable well productivity and cost. Ideally sand management should consist of the following process:

• sand production prediction, which are covered sand failure models, rock properties determination, formation strength evaluations

• sand problem preventing that describe about maximum sand free rate, allowable drawdown pressure, maximum productivity, formation stabilization, and sand control techniques

• monitoring system utilized to optimize production without significant negative impact of sand problem

• best practices of remediation techniques selected to cure sand problem effectively

This paper will share the West Java approach to reinforce sand management strategy with objective to minimize impact of sand problem in late life of field production. This sand management strategy will give West Java Operations an integrated plan to manage impact of sand problem within economically framework

West Java Sand Management Strategy

There are two main locations that need to be focused on regarding sand problem (Figure 1), which are upstream and downstream of the production choke. At the upstream production choke sand problem can be accumulated inside tubing or below end of tubing, then restricted or even stop the production due to sand bridging or integrity problem on well equipments. At the downstream production choke, sand could be


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accumulated at separator and/or pipeline (Figure 2) then reducing capacity of equipment, and also created potentially sand erosion problem.

In mature of life production like West Java, there is available well history database that can be utilized to identify and predict the behavior of sand production wells. Identification typical zones from a well that have sand problem at certain conditions were applied to predict sand production for the other wells. Then thru zones review, a list of wells potentially have sand problem can be predicted. Preventive works such as bean up choke strategy, follow with regular monitoring should be performed to minimize sand impact and provide effective tool for early detection of sand production prior the sand creating a furthering problem. Bean up and bean down choke strategy (Figure 3) philosophy is best practices to apply many small DPs (Delta Pressure) with short time in between rather than a few big steps with long pauses when we bring online or shut-in a well. By apply this as SoP (Standard of Procedure), it can maintain the rock consolidated strength (Figure 4) and reduce the risk of sand problem or sand control failure. Regular monitoring of sand production either from regularly BS&W (Base Sediment & Water) sampling or thru special equipments i.e. Clamp-On portable sand detector (Figure 5) would help us to optimize production level of wells within sand free condition. In order to choose the best option of sand control, need to perform evaluation previous implemented techniques of sand control including remedial work in West Java. For further development of new applicable technology for the field, several pilot project like Thru Tubing Gravel Pack (TTGP) technique and resin sand consolidation has been analyzing. Based on the evaluation, advantage and disadvantage of each method can be understood as showed in the table 1. Best method was selected based on well condition and considered cost and simplicity on operation. Thru thorough process well-work it was selected two candidates, which are EB-5 and EB-7 for at TTGP installation. The jobs were performed in

early 2008 with result the EB-5 TTGP installation was postponed due to wellbore mechanical restriction. However TTGP (Figure 6) was successfully installed in EB-7 after wellbore restriction problem can be resolved. Then the well can be brought online sand free with rate 200 bopd. This success considered as good progress of trial, considering the EB-7 was 2 years shut–in due to sand problem. Based on the evaluation and the trial, regular sand clean out and TTGP are best practice sand control methods for West Java. In the surface side choke management was successfully applied in APN and EA wells to produce the wells on optimum production without having sand problem. The execution of BNA separator clean out project gave positive result on facilities efficiency; reduce on back pressure on system, and improve integrity the vessel. First campaign portable sand monitoring utilized Clamp On was performed on Foxtrot area. The result of threshold velocity chart based on allowable erosion rate (Figure 7), indicated there is room to bean up choke of Foxtrot wells with potential additional production rate around 400 bopd.

Conclusions

From this paper there are some following conclusions:

• Sand problem not only impact on production losses but also increased safety risk due to eroded subsurface and surface equipments

• Ideally sand problem should eliminate since in the formation, but considering the consequence of cost a detail evaluation to ensure the selected techniques is required

• Wellbore restriction (i.e. small tubing ID, scale deposit, etc) was the critical parameter of successful TTGP installation jobs. It is recommended to perform wellbore clean out prior install TTGP equipments

• Portable sand monitoring using “clamp on” indicated some of produced sand was accumulated on some remote facilities or pipelines. A further action like separator


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clean out or regular pigging are recommended

Further Work As part of BP Continuous Improvement Program to improve the West Java Sand Management Program the following are the plan that will be performed in the near time:

• Proceed the next campaign of TTGP, sand monitoring, and facilities clean out

• Progress the hopper of sand control management

• Continue sand monitoring campaign on Lima, Echo and Bravo area

• Implement bean up and bean down strategy for well start up and shut-in

• Determine the critical erosion rate for choke optimization on FFB wells

• Conduct external peer-review with BP’s well completion and sand expertise (BP-EPTI)

Acknowledgement The author would like to thank BP Management and BP Migas for permission to publish this paper.

Abbreviations bopd = barrels oil per day mmcfd = millions metric cubic feet per day kms = kilo metres MMBO = Millions Metric Barells Oil TCF = Trillion Cubic Feet Pr = Pressure reservoir TTGP = Thru Tubing Gravel Pack

References

1. BP Java Base Management Team, “Approach on Minimizing West Java Sand Problem”, Java Reservoir and Well Department, Jakarta, 2007

2. William K. Ott, P.E. and Joe D. Woods, “Modern Sandface Completion Practices Handbook”, World Oil magazines - Gulf Publishing Company, Houston - Texas, 2005.

3. EPTG Team, “Living With Sand – Process Treatment And Processing of Production Solids”, BP Exploration & Production Technology Group, Sunbury, UK, 2005.

4. Hans Vaziri, Robbie Allam, Gordon Kidd, Clive Bennett, Trevor Groose, peter Robinson, Jeremy Malyn, “Sanding: A Rigorous Examination of Interplay Between Drawdown, Depletion, Start-Up Frequency and Water Cut”, SPE89895, SPE Annual Technical Conference and Exhibition, Houston-Texas, USA, September 2004

5. EPTG D&CTeam, “Sand Control & Well Completion”, BP Exploration & Production Technology Group, Drilling and Completion Division, Sunbury, UK, 2003.

6. Schlumberger, “Sand Management Solution”, SC-03-049_0, Schlumberger Oilfield Services, September 2003

7. Mike Travis, Juan Tovar, John L.C. Chambers, “Integrated Approach to Sand Control Deliver Zero Sand”, SPE 81304, SPE Latin American and Caribbean Petroleum Engineering Conference, Ports Spain – Trinidad, West Indies, April 2003

8. Stephen P. Mathis, “Sand Management: A Review of Approaches and Concerns”, SPE 82240, SPE European Formation Damage Conference, The Hague-Netherlands, May 2003.

9. J. Tronvoll, M.B. Dusseault, F. Sanfilipo, and F.J. Santarelli, “The Tool Sand Management”, SPE71673, SPE Annual Technical Conference and Exhibition, New Orleans-Louisiana, USA, October 2001.


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Figure 1 Two main focus location of sand management

Sand accumulation at facilities

Figure 2 Sand accumulations in facilities

0

10

20

30

40

50

60

70

0 5 10 15 20 25 30 35

Choke Size, 1/64th

Cum

ula

tive F

low

Tim

e (

hrs

)

Conventional

Proposed

Conventional: large DP steps with redundant long wait time

Redundant ∆∆∆∆T

Unrealized Production

Conventional: longer ∆∆∆∆T, bigger ∆∆∆∆P →→→→ more fines

Figure 3 Bean Up Choke Strategy

Figure 4 Bean Up and Down Choke Impact

Upstream

Production

Choke

Downstream Production Choke

Separator


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NODE Sand Rate

FFB 2.33 gpd

FK 49.42 gpd

FWB trace gpd

HZEA trace gpd

FPRO 0.04 gpd

Figure 5 Sand Monitoring

�Based on history was hard to

retrieve

�Not applicable for heterogenic

sand grain distribution (Sc>10)

�Easy and less expensive

�Tubing inserted

�Theoretically retrievable

19

Stand Alone

Screen

“Poroplus”

�Very limited application

�Sensitive and complex

operation

�Low success ratio compare with

mechanical solution

�Not good for rock with

significant clay content

�Less expensive compare with TTGP

�No need to insert new

equipment at exeisting

completion

11Resin Sand

Consolidation

�More expensive compare with chemical solution

�Complicated in operation

�Tubing inserted

�Applicable for high perm +

high thickness reservoir


1

Thru Tubing

Gravel Pack

(TTGP)

�Previous method was sand

dumping into the sea

(environmental issue)

�Limited to seapub schedule

availability

�Lowering FTP (Increase

deliverability from wells)

�Minimize separator upset due to high level

control/ bottleneck

1

Separator

and Facilities

Clean Out

�Expensive

�Need to be installed at initial

completion


�Not retrievable

�Introduce skin effect

�Very effective to retain

sand

�No need to choke back the

well (limiting the flowrate)

51Gravel Pack

�Difficult to determine optimum choke size

�Limiting the flowrate

�Easy and low cost

�Quick execution

20 per

year

Choke

Management

Could not stop sand producing

Not cost effective


�Regular job (Not required

complex design prior to

execution)

15 per

year

Regular Sand

Clean out

DisadvantagesAdvantagesNumber

of JobsMethod

�Based on history was hard to

retrieve

�Not applicable for heterogenic

sand grain distribution (Sc>10)


�Tubing inserted


19

Stand Alone

Screen

“Poroplus”

�Very limited application

�Sensitive and complex

operation

�Low success ratio compare with

mechanical solution

�Not good for rock with

significant clay content

�Less expensive compare with TTGP

�No need to insert new

equipment at exeisting

completion

11Resin Sand

Consolidation

�More expensive compare with chemical solution


�Tubing inserted

�Applicable for high perm +

high thickness reservoir


1

Thru Tubing

Gravel Pack

(TTGP)

�Previous method was sand

dumping into the sea

(environmental issue)

�Limited to seapub schedule

availability

�Lowering FTP (Increase

deliverability from wells)

�Minimize separator upset due to high level

control/ bottleneck

1

Separator

and Facilities

Clean Out

�Expensive

�Need to be installed at initial

completion


�Not retrievable

�Introduce skin effect

�Very effective to retain

sand

�No need to choke back the

well (limiting the flowrate)

51Gravel Pack

�Difficult to determine optimum choke size

�Limiting the flowrate

�Easy and low cost

�Quick execution

20 per

year

Choke

Management

Could not stop sand producing

Not cost effective


�Regular job (Not required

complex design prior to

execution)

15 per

year

Regular Sand

Clean out

DisadvantagesAdvantagesNumber

of JobsMethod

Table 1 West Java Sand Control Methods Comparison

PACKER

BEFORE AFTER

Frac valve

Centralizer

Centralizer

Centralizer

Centralizer

Bull Plug

C Line

SSSV

PERMANENT

Casing shoe

GLM

E-29B E-29B

-E-29A2

E-29B2

E-29C2

EOT

Screen

Screen

Screen

Screen

Thru

Tubin

g G

ravel P

ack S

yste

m

ER Packer

San

d

TTGP Procedure

• Design proper gravel and screen

based Sand Sieve analysis from

core data

• Perform Wellbore clean out

• RIH GR-CCL

• Re-perforation

• RIH Screen equipments

• Set and test the packer

• Perform Injectivity test

• Pumping gravel until packed off

• Close Frac Valve

• Washout excess gravel pack

• Bring online the well

Equipment unit :

• CTU, pumping, seapub unit

• SCO tank, sand silo & blender,

WL tool, etc

Figure 6 Thru Tubing Gravel Pack Technique

Figure 7 Threshold velocity chart of FK-7 wells

integrated sand management strategy

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