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

Anthony Nigel Bremner, Anthony J. Lomando, Robert J. Minck

Areas B and C offshore Cabinda cover 675,050 acres (2,732 km²) and are held by Cabinda Gulf Oil Company (Operator), Sonangol, Agip Angola, and Elf Petroleum Angola. Recent exploration has been very successful. Over 5 × 10⁹ barrels of oil in place and over 10 × 10¹² cu ft of gas have been discovered in the Lower Cretaceous Pinda Formation. The first discovery was N'Dola Field in 1972, but the discovery of Sanha Field in 1987 led to recognition of the potential of the trend. The hydrocarbons are found primarily in 9 fields situated in water depths ranging from 255 ft (68 m) to 425 ft (130 m) and located 50 km to 65 km from the onshore Malongo terminal.

The Pinda Formation is approximately 4,000 ft (1,220 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 sub-arkosic sandstones deposited in a nearshore environment. Diagenesis is important in determining reservoir quality.

The structure of a typical field is a fault-bounded antiformal raft, containing one or more rotated fault blocks, separated from neighboring blocks through gravity sliding on the underlying salt decollement surface.

Hydrocarbon columns range from 400 ft (130 m) to about 2,700 ft (820 m). First production from Kokongo Field, which will become the gathering station hub for all Areas B and C production, is scheduled for 1994.

AAPG Search and Discovery Article #90986©1994 AAPG Annual Convention, Denver, Colorado, June 12-15, 1994