CHALLENGEReduce skin and improve the productivity index (PI) in new wells to increase overall field productivity for Petronas Carigali Sendirian Berhad (PCSB).
SOLUTIONUse the PURE* clean perforations system to achieve greater productivity than is possible with conventional static under-balance perforating.
RESULTSCompared with other wells in the region that had been perforated conventionally, the well perforated using the PURE system enabled additional production and significantly reduced the production payback period.
PCSB wanted to improve the PI in new off-shore wells to increase field productivityA field in the PMO region was put into comm-ercial operation with initial total production rates of 15,000 bbl/d oil and 60 MMcf/d gas.
Because the field is one of the biggest oil producers in Malaysia—contributing one- sixth of the total national oil production— its development is considered essential to meeting the nation’s rapidly increasing need for hydrocarbons.
Previously, all the region’s wells had been perforated using conventional static under-balance to clean damage and debris from the perforations. The results had been high skin values and, therefore, lower-than-desired PIs.
PCSB sought to maximize field recovery and meet production forecasts by improving the deliverability of new expansion wells.
Schlumberger proposed PURE system to maximize productivityFor the second expansion phase in the field, Schlumberger proposed using the PURE system. Unlike conventional perforating, which relies on a large static pressure differential between the wellbore and the formation to remove perforation debris and crushed-zone damage, the PURE system fully exploits the transient underbalance that occurs immediately after perforating. It creates a large dynamic underbalance, then absorbs perforation debris into the gun chambers, minimizing skin and leaving an obstruction-free path for flow from the reservoir to the wellbore.
The PURE system planner software was used to specify the unique perforating system based on full consideration of the completions geometry, reservoir fluids, and formation characteristics SPAN* Schlumberger perforating analysis was used to select the most suitable gun configura-tion, shot density, and charges and to simulate operation performance. A tubing-conveyed perfo-rating system was used to perforate the well, allowing perforating and testing in a single trip.
CASE STUDY
Perforating
Recovery Optimized with Dynamic Underbalance PerforatingPURE system for underbalance perforating helps PCSB achieve targeted production in offshore field
Manado
Samarinda
Rabaul
Iloilo
Nong Khai
Lhasa
Imphal
Banjarmasin
Jayapura
Kupang
Pontianak
Mandalay
Sittwe
Lae
Madang
Wewak
Bacolod
Baguio
Cagayan De Oro
Laoag
Zamboanga
Chiang Mai
Chumphon
Khon Kaen
Songkhla
Can Tho
Da Nang
Vinh
Monywa
Chittagong
Changsha
Chongqing
Dukou
Fuzhou
Guangzhou
Guiyang
Jingdezhen
Kunming
Nanning
Ningbo
Pingxiang
Shang Rao
Shantou
Shaoguan
Wenzhou
Xiamen
Zhanjiang
Medan
Surabaya
Kaohsiung
Taipei
Hai Phong
Ho Chi Minh City
Nanchang
YueyangZigong
Bandung
Palembang
Semarang
Ujungpandang
Davao
Quezon City
Dhaka
Agana
Hong Kong
Jakarta
Phnom Penh
Vientiane
Kuala Lumpur
Rangoon
Saipan
Kokor
ManilaBangkok
Bandar Seri Begawan
Port Moresby Honaira
Hanoi
Darwin
CHINA
MYANMAR
THAILAND
KAMPUCHEA
BHUTAN
VIETNAM
LAOS
BANGLADESH
WEST MALAYSIA
PAPUANEW GUINEA
BRUNEI
SINGAPORE
PHILIPPINES
TAIWAN
MALAYSIA
INDONESIA
AUSTRALIA
Bay of Bengal
Andaman Sea
Gulf of Thailand
Indian Ocean
Java Sea
South China Sea
Timor Sea
Philippine Sea
Arafura Sea
Gulfof
Carpentaria
North Pacific Ocean
Coral Sea
Pacific Ocean
PMO region
The field offshore West Malaysia.
PCSB was able to be certain its expansion wells would have higher PIs than previous wells in the regionA pressure buildup survey was conducted shortly after Well A was put into production. The calculated skin of 0.3 was significantly lower than skins measured in earlier field wells perforated using conventional tech-niques. No acid treatments or perforation washes were required.
Production from the layer perforated with the PURE system was significantly higher than production from neighboring wells. No water was produced for almost two years after startup.
The production payback period was only three days, and the total incremental value was determined to be USD 2.5 MM/month. This economic impact convinced PCSB to use the PURE system dynamic underbalance perforating in other fields it operates.
slb.com/PURE
*Mark of SchlumbergerOther company, product, and service names are the properties of their respective owners.Copyright © 2014 Schlumberger. All rights reserved. 14-TS-0173
CASE STUDY: PURE system dynamic underbalance enables higher PIs and production, Malaysia
Closed chamber with 3,965 psi trapped pressure
Gun detonated
Transient pressure,
psi
4,500
4,000
3,500
3,000
2,500
2,000
1,500
1,000
500
0
Time, ms
PURE system creates dynamic underbalance of 1,662 psi
0 400 800 1,200 1,600 2,000 2,400 2,800
Reservoir pressure: 2,137 psi
Oil rate, bbl/d
Gas rate, Mcf/d
Tubing-headpressure, psi
Tubing-head pressure
Oil �ow
Gas �ow
Choke size
Water cut
4,000
3,500
3,000
2,500
2,000
1,500
1,000
500
0
160
140
120
100
80
60
40
20
0
Choke size, 1/64 in
Water cut, %
Date
Jan. 1, 2007 Jan. 1, 2008 Jan. 1, 2009
Fast gauge measurement showing the large dynamic underbalance created by the PURE system.
Optimized production history for Well A.