Geologic Setting, Stratigraphy and Hydrocarbon Habitat of the Douala Basin, Cameroon

Simon F. Tamfu, Marcel Batupe, Robert J. Pauken, Dan C. Boatwright

The Douala Basin is the northernmost of a series of Aptian-age Salt Basins along the coasts of West Africa and Brazil in the South Atlantic. These extensional basins developed in response to the northward, progressive rifting of South America from West Africa, initiated approximately 130 Ma. Within the boundaries of the Douala Basin proper are the northern and the southern subbasins both of which are characterized by horst, grabens and half-grabens. Although oil as well as gas has been discovered in the basin, production of the hydrocarbon reserves has not yet taken place. Components of one or more petroleum systems are present in the basin. The viability of these critical components is an ongoing concern to explorationists.

Extensive seismic data coverage in the basin shows that over 6000m of sediment is present in the central portion of the basin. The tectono-stratigraphic history of the basin can be subdivided into four phases: syn-rift, transitional, early drift and late drift. Compared to the other marginal basins around the South Atlantic, the Douala Basin lacks massive Albian carbonates and thick regional salt. It also has a unique retrogradational sequence stacking pattern in the interval from Albian through Oligocene.

Recent geochemical analysis data on oil samples from seeps and well tests indicate that generation has occurred from both lacustrine and marine sources. Mature source rock intervals have not been drilled in the basin. It is hypothesized that Cretaceous and/or Tertiary age marine and lacustrine Type II/III kerogen sources are located in a seaward, downdip position toward the center of the basin where there are no exploration wells.

AAPG Search and Discovery Article #91020©1995 AAPG Annual Convention, Houston, Texas, May 5-8, 1995