| Author's Name: WANG Hongping, XU Zhicheng, YU Xinghe, LIU Yanhong, YAN Chun, Lü Fuliang, FAN Guozhang, ZHANG Yonggang |
| Based on the study of the formation and evolution of coastal basins in West Africa, the petroleum geological characteristics of each basin are summarized, the reservoir-forming assemblages of each basin are divided, and the resource potential is evaluated. Finally, the direction of oil and gas exploration is put forward. West Africa coastal basins are mainly consisted of 17 basins and can be divided into 5 provinces: the North salt basin province, the Gulf of Guinea province, the Niger Delta province, the Aptian salt basin province and the South basin province. The formation and evolution of West Africa coastal basins can be divided into 3 stages: pre-rift stage, syn-rift stage, and post-rift stage. Controlled by basin evolution, 6 reservoir-seal assemblages developed in West Africa coastal basins. With reservoir-cap assemblages as the core, 27 reservoir-forming assemblages have been divided in the 17 basins in West Africa. Taking reservoir-forming assemblage as the basic unit of resource evaluation, analogy method, discovery process method and subjective probability method are used to calculate and predict the undiscovered recoverable resource of conventional oil and gas. The results show that the total amount of the resources in these basins is 146,175 MMBOE. The conventional oil and gas resources to be discovered are mainly distributed in the Aptian salt basin province and Niger Delta Basin, and mainly in the Cretaceous, Paleogene and Neogene in the vertical. The 17 basins in West Africa are classified as type I, type II and type III basins according to their exploration potential from large to small. The key exploration targets in West Africa are deep-water turbidite and pre-salt carbonate rocks. The most favorable exploration zones in each basin are the areas where the main reservoir-forming assemblages overlap most. |
