Analysis of Petroleum Systems and its Implication for Exploration in the Senegal Basin
The Senegal Basin in West Africa is one of the most active frontier basin for oil and gas exploration in the world. The basin has recently made a series of major discoveries, including the giant Tortue giant gas field with a proven original in-place gas volume of 15.0 Tcf, Sne and Fan giant oil fields with a proven original in-place 630.0 MMboe(million barrel oil equivalent) and 950.0 MMboe, respectively. The discoveries of these oil and gas fields not only exemplified the successful application of the new Cretaceous turbidite fan and channel sandstone plays in the frontier basin, but also provided an excellent analog for other similar basins exploration such as Guyana Basin, Aaiun-Tarfaya Basin and Essaouira Basin in North Atlantic passive margin deep-water areas. Based on the newest geological database, with an approach of integrated geological investigation and petroleum system analysis, this paper focuses on the oil and gas distribution patterns, hydrocarbon accumulation characteristics and the main controlling factors in the Senegal Basin and discusses the hydrocarbon exploration potentials and the main exploration domains in the future. Three petroleum systems are recognized, including the Silurian petroleum system, the pre-salt Triassic petroleum system and the Cretaceous petroleum system, and the last petroleum system is of great significance. Regionally, the discovered oil and gas reserves are largely confined to the Mauritania sub-basin and Northern sub-basin. Stratigraphically, they are mostly reservoired in the Cenomanian, Albian and Miocene. The petroleum reserves are largely reservoired in two intervals of burial depths: 1500~2000m and 2000~2500m. The turbidite channel on the continental shelf and the turbidite fan in the slope are the main reservoirs development areas. The controlling factors of the hydrocarbons in the Senegal Basin include effective source-reservoir-seal assemblages, high-quality reservoirs and traps as well as salt tectonic movement in salt sub-basin. The results of petroleum resources assessment show that undiscovered oil, gas and condensate resources amount to 1508.3×106 bbl, 36.3Tcf and 327.0×106 bbl, respectively in the Senegal Basin. This study proposes two favorable exploration plays: Cenomanian play and Albian play of the Cretaceous petroleum system.
AAPG Datapages/Search and Discovery Article #90332 © 2018 AAPG International Conference and Exhibition, Cape Town, South Africa, November 4-11, 2018