South Korea has taken another step toward the ranks of countries with commercial hydrocarbon production.
State-owned Korea National Oil Corp. (formerly PEDCO) is preparing to bring on stream Donghae-1 (formerly known as Gorae) gas field in the Ulleung basin 60 km off Ulsan.
The field, on Block 6-1 on the Korean continental shelf, was confirmed as commercial after two appraisal wells were drilled.
Donghae-1 is estimated to have 250-300 bcf of gas in place. Reserves are pegged at 170-200 bcf-the equivalent of 4-5 months of South Korea's consumption of LNG imports.
First commercial production of natural gas is slated to begin in July 2002, according to KNOC. Production plans include the design and construction of a production platform and related facilities, a pipeline to shore, and an onshore underground storage facility. KNOC plans to supply the gas to southeastern South Korea's Kyounsangnamdo region-enough to meet that region's for 15 years.
Block history, future plans
A Royal Dutch/Shell unit acquired Block 6-1 rights in 1970. It drilled one well and later withdrew from the block in 1976. During 1983-95 KNOC drilled 10 wells with 5 of 6 wildcats yielding noncommercial gas shows.
KNOC re-evaluated the block with an integrated-team task force during 1996-99. The team studied the block, then applied a new play concept that targeted a less-deformed geological formation of an earlier age. KNOC then discovered Gorae V (Donghae-1) gas field in 1998 with the Doo Sung semisubmersible drilling rig (see cover photo, this issue).
Development plans for the field include a geotechnical survey of the area to be completed by July 2000. Following the survey, front-end engineering design and detail design are slated for completion by February 2001. After a period of testing of the platform's development wells, the field is expected to come on stream after June 2002.
KNOC also is conducting 3D seismic surveys of other prospects within a 15-km radius of Donghae.
The company noted that the field is geologically analogous to the Subei basin and to Pinghu gas and condensate field in the East China Sea (OGJ, Aug. 9, 1999, p. 80).
