Characteristics and controlling factors of marine source rocks in the basins on the two sides of South Atlantic

Oil and gas resources are rich in drifting stages in the basins on both sides of South Atlantic. Comparative researches on main marine source rocks, including hydrocarbon generation potential, seismic facies and distribution patterns suggest that there are 2 sets of main source rocks, of which the upper is more widely distributed. In a general perspective, the geochemical indexes of main source rocks in the north and Equatorial South Atlantic basins are better than those in the central basins, while the source rocks in South American basins are also better than those in West African basins. Study of typical well data, sedimentary facies and paleogeography of main marine source rocks suggest that high-quality marine source rocks are mainly distributed in confined bays and related sedimentary facies. The first priority of exploration targets should be the deep-water deposited sandstones intercalated in the matured marine source rocks. The sandstones deposited in the drifting stages close to the salt mini-basin are also recommended.