Alcorn (Production) Philippines Inc. has found a major oil field in the South China Sea off Philippines.
Alcorn's 1 West Linapacan wildcat recorded substantial flows of 30.1 oil with no water on three drillstem tests of Miocene-Oligocene Nido-Galoc platform carbonate rock at 5,350-5,896 ft.
Biggest flow was 6,708 b/d through a 2 in. choke on a test that covered a dolomite interval about 40 ft thick. The well also flowed at a stabilized rate of 5,051 b/d a through a 48/64 in. choke with 552 psi flowing wellhead pressure and 342:1 gas:oil ratio.
Site is in 1,150 ft of water, 250 miles southwest of Manila and northwest of Palawan Island, on Alcorn's Block C held under Service Contract 14 (see map, OGJ, July 10, 1989, p. 24).
Preliminary estimates place recoverable reserves in excess of 100 million bbl and oil in place at 1 billion bbl. Gruy Engineering Corp., Houston, will assess field reserves.
West Linapacan development plans are uncertain, pending study of final data.
Areal closure of the field is estimated at 4,500 acres.
Virgil A. Walston, Alcorn president and chief operating officer, said the formation is highly fractured, with 7.521% porosity and high permeability.
"On DST No. 1 we completely broke down the formation through fractures," Walston said. "We had 1 Darcy of permeability.
"When we acidized, pump pressure dropped from about 1,400 psi to zero."
The service contract held by Alcorn, a subsidiary of Vaalco Energy Co., Houston, sets a net profit tax of 35% and a remittance tax of 7.5%.
Alcorn produces about 5,000 b/d of oil from former major company acreage 30 miles south of the West Linapacan strike.
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