Tectonic and Sedimentary Evolution and Hydrocarbon Accumulation in the Outeniqua Basin, South Africa

The degree of oil and gas exploration of Outeniqua Basin in South Africa is extremely low. The successive natural gas discoveries in 2019 and 2020 attracted extensive attention from oil and gas companies at home and abroad. Based on IHS database, assessment results of new ventures and literatures, comprehensive analysis shows that: The Outeniqua Basin experienced four evolutionary stages since the Permian period: pre-rift stage, syn-rift stage, transitional stage and post-rift stage; It mainly deposited continental clastic rocks in rift stage and marine clastic rocks in transitional stage and post-rift stage; The main source rocks in the basin are the marine shale of the Hauterivian period and Barremian-Aptian period; Two sets of important reservoirs, namely, the shallow marine sandstone at the top of the Valanginian in the syn-rift stage and the marine deep-water clastic rock of the Albian during the early drift period are developed, and the reservoir-seal combination conditions are superior; Four sets of reservoir-forming assemblages (plays) are formed, including Barremian-Albian sandstone, Valanginian-Hauterivian sandstone, Upper Jurassic-Lower Cretaceous sandstone and basement; The distribution of oil and gas is "more in the west and fewer in the east". At present, the exploration focus should be on Cretaceous lenticular turbidite sandstone in deep-water area of the continental margin of the Bredasdorp Sub-basin.