By an OGJ Online Correspondent
BANGKOK, Apr. 27 -- Moving quickly to arrest a significant production decline, the Bongkot consortium plans to start the next development stage of Thailand's largest natural gas field in the middle of this year.
Initially estimated to cost $40 million-50 million, Phase 3C will help the Thai-European development group sustain gas and condensate output at 635 MMcfd and 15,000-16,000 b/d of condensate from Bongkot, about 600 km south of Bangkok in the Gulf of Thailand.
Bongkot's cumulative gas sales to the Petroleum Authority of Thailand (PTT) since it was put on stream in mid-1993 hit 1 tcf Feb. 1. In addition, the field also yielded 24 million bbl of condensate during the period. The combined gas and condensate production is 165 million boe.
With more than 30% of the most likely reserves (3.7 tcf) already produced and about 10% of remaining reserves being drained out each year, the field's gas production potential is falling 1 MMcfd, said PTT Exploration & Production PLC (PTTEP), the field operator.
The development phase calls for installation of an additional well platform and a new gas processing platform to treat sour gas. Maroot Mrigadat, PTTEP senior vice-president for operation, said basic engineering design and economic study of Phase 3C are in the advanced stage, and final approval from consortium members -- including TotalFinaElf SA and BG International Ltd. -- is expected in June.
Phase 3B development, involving drilling 47 wells and installing two additional well platforms, is scheduled for completion in August 2002. Phase 3B development also is meant to help sustain gas and condensate production from Bongkot (OGJ Online, June 12, 2000).
The development supports the consortium's recent study that it makes more economic sense to develop significant sour gas reserves in the concession area rather than first developing all the sweet gas reserves. The study also pointed out that sour gas reserves justify the installation of H2S removal facilities.
Maroot said the consortium does not plan to engage in exploration activities in the Bongkot concession until 2005-6 because of the expected stagnation of Thai gas demand.
Much of the Bongkot consortium's activities will be geared toward drilling of delineation wells in Bongkot and satellite fields, including Ton Koon and Ton Nok Yoong.
More than 130 wells have been drilled in the Bongkot concession, with $1.6 billion capital outlay spent for the project. Gas and condensate production has generated sale revenues of $2.2 billion for the consortium.