Successful Exploration of the Outer Pinda Trend of Offshore Cabinda, Angola

Abstract

Areas B and C offshore Cabinda cover 675,050 ac (2,732 km) and are held by Cabinda Gulf Oil Company (Operator), Sonangol, Agip Angola, and Elf Petroleum Angola. Recent exploration has been very successful. Over 5 x 10[sup 9] bbl of oil in place and over 10 x 10[sup 12] ft[sup 3] of gas have been discovered in the Lower Cretaceous Pinda Formation. The first discovery was the N'Dola field in 1972, but the discovery of the Sanha field in 1987 led to the recognition of the potential of the trend. The hydrocarbons are found primarily in eight fields situated in water depths ranging from 255 to 425 ft (68 to 130 m) and located 50 to 65 km from the onshore Malongo terminal. The Pinda Formation is approximately 4000 ft (1220 m) thick and is a cyclic, carbonate-siliciclastic sequence, deposited in a sabkha to shallow-marine environment. The best reservoirs are in fine- to medium-grained subarkosic sandstones deposited in a nearshore environment. Diagenesis is important in determining reservoir quality. The structure of a typical field is a fault-bonded antiformal raft, containing one or more rotated fault blocks, separated from neighboring blocks through gravity sliding on the underlying salt decollement surface. Hydrocarbonmore » columns range from 1000 to about 2500 ft (305 to 760 m). First production from the Kokongo field, which will become the gathering station for all area B and C production, is scheduled for 1994.« less