Organic Geochemical Characteristics of Source Rock in Doseo Depression of Central African Rift System

Summary Doseo depression is an underexplored frontier onshore zone, belonging to Central African Rift System. To evaluate the source rock of the depression, we took 112 shale cuttings and 6 oil samples for pyrolysis, elements analysis, vitrinite reflectance, macerals identification, carbon isotopes and mass spectrometry analysis. The results show that three sets of high-quality lacustrine oil-prone source rocks are continuously developed in the Lower Cretaceous of Doseo depression. The organic matter type of three source rock are mainly I-II1, of which Kedeni source rock has the best quality. The maturity of Kedeni source rock is low to medium in the edge of the depression, but in the center of the depression it probably reach the high mature level. Based on the widespread effective source rock in the Doseo depression, the resource potential is considerable in the interbedded sandstone reservoirs of Lower Cretaceous.