Unocal Corp. said Tuesday that it had made a new discovery, Ca Voi, in block 52/97 off southwestern Viet Nam. Unocal also said it had drilled four wells to confirm the earlier Kim Long gas find in Block B (OGJ, Dec. 22, 1997, p. 30).
In addition, Unocal announced that it and its coventurers in blocks B and 48/95 (also known as block A) recently signed a letter of intent for development of the blocks that anticipates gas production from block B will begin at 200 MMcfd of gas in 2005.
The letter establishes a basis for the negotiation of a gas purchase agreement, says Unocal, which also said the Kim Long and Ca Voi drilling program confirmed the first trillion cu ft in gross unrisked resource potential for the three blocks.
The Ca Voi discovery well, 52/97-CV-1X, in 215-280 ft of water about 175 miles west of Ca Mau, Viet Nam, found 107 ft of net gas pay, said Unocal, which called the find "significant."
Unocal said that since the Kim Long trend is within 10 miles of Ca Voi, the fields could be developed together, taking advantage of shared facilities.
Unocal said four successful wells in the Kim Long trend seem to imply the trend is gas-bearing for more than 21 miles over blocks B and 52/97. The wells averaged net pay of 136 ft, said the US company.
Three of the four wells have been tested. B-KL-1X well flowed 53 MMcfd of gas from two zones; B-AQ-1X had a maximum calculated flow of 39 MMcfd from three zones; and 52/97-AQ-3X flowed 54 MMcfd from five zones.
Unocal Vietnam Exploration Ltd. and its Block B and 48/95 coventurers are purchasing the interest held by Repsol Exploracion Vietnam SA of Spain. PTT Exploration & Production, a unit of Petroleum Authority of Thailand, is also joining the venture.
At the conclusion of those transactions, Unocal said, it will hold a 49.86% working interest in the PSC covering blocks B and 48/95; Moeco Vietnam Petroleum Co. Ltd., a subsidiary of Mitsui Oil Exploration Co. Ltd., will hold 30.14%; and PTTEP Kim Long Vietnam Co. Ltd., a subsidiary of PTTEP, will hold 10%. PetroVietnam PSC Supervising Co., a subsidiary of PetroVietnam, will hold 10% once final government approval is received. PetroVietnam also has an option to participate with an additional 15% interest. If exercised, PetroVietnam's option would reduce all participants' working interests proportionately.
PTTEP also expects to join the investors in the Block 52/97 PSC. Unocal Southwest Vietnam Exploration & Production Ltd. will hold a 62% working interest, while Moeco Southwest Vietnam Petroleum Co. Ltd. will hold 28%, and PTTEP Southwest Vietnam Co. Ltd. will hold 10% after PTTEP's entry receives final government approval. PetroVietnam has an option for a 30% interest, which would reduce other partners' interests proportionately.