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Termit盆地是西非裂谷系中典型的海相沉积盆地,海陆过渡相沉积特征对于盆地烃源岩、储层、盖层及油气生成、聚集的影响巨大。Moul凹陷白垩系Yogou组是Termit盆地海相油气勘探的典型成功实例。受构造沉降与海平面变化控制,Moul凹陷白垩系Yogou组发育曲流河三角洲、辫状河三角洲、远岸水下扇、混积陆棚及滨浅海等5种沉积相类型;凹陷东部发育辫状河三角洲—远岸水下扇沉积体系,凹陷西部发育曲流河三角洲—混积陆棚沉积体系,凹陷中心则以浅海和远岸水下扇沉积体系为主;Yogou组沉积相序演化垂向呈“浅海—远岸水下扇—三角洲”进积序列叠加的特点,平面具有“盆缘三角洲—盆内重力流—混积陆棚”多相匹配的特征,使烃源岩与储层呈“纵向叠置相邻、平面广泛分布”的分布格局,形成了多套“三明治”式优质生储盖组合,为油气成藏奠定坚实的基础;Yogou斜坡、Koulele帚状带及Trakes斜坡油气运聚条件优越,保存条件良好,是勘探重点区带;YSQ1、YSQ2高位域及YSQ3低位域生储盖组合条件好,是主要目的层段。在地质认识基础上,优化井位部署,多口井获工业油流,有力推动了盆地油气勘探的进程。
The Termit Basin is a typical marine sedimentary basin in the West African Rift System. The sedimentary characteristics of the transitional facies between the sea and the land have a great influence on the formation and accumulation of source rocks, reservoirs, cap rocks and hydrocarbons in the basin. The Mogo Cretaceous Yogou Formation is a typical example of successful marine oil and gas exploration in the Termit Basin. Under the control of tectonic subsidence and sea level change, the Mogo Cretaceous Yogou Formation developed five types of sedimentary facies: meandering delta, braided river delta, afar submarine fan, alluvial continental shelf and coastal shallow sea; Deltaic-oceanic fan-delta fan depositional system in the western part of the sag, meandering deltaic-alluvial continental shelf sedimentary system in the sag, and shallow sag and far offshore subaqueous fan sedimentary systems in the sag; the sedimentary facies evolution of the Yogou Formation The characteristics of the sedimentary sequence superimposed on the submarine-delta “submarine fan-delta” are that the plane has the characteristics of multi-phase matching of “basin margin delta-basin gravity flow-alluvial cover” and the hydrocarbon source The distribution of rocks and reservoirs is “vertically adjacent to each other and the plane is widely distributed”, forming a combination of multiple sets of “sandwich” high quality reservoirs and reservoirs, laying a solid foundation for oil and gas accumulation. Yogou slope, The Koulele broom and Trakes slope have favorable hydrocarbon migration and accumulation conditions and good preservation conditions, and are the key exploration zones. The combined conditions of YSQ1, YSQ2 high zone and YSQ3 low zone are good and are the main target intervals. On the basis of geological understanding, optimizing the well location deployment and obtaining multiple oil wells by industrial wells have effectively promoted the exploration of oil and gas in the basin.