北加蓬次盆成藏要素分析与油气分布规律

Analysis of reservoir forming factors and distribution regularities of North Gabon sub-basin

通过对北加蓬次盆区域构造背景的研究,综合分析各成藏要素条件,结合油气田类型、平面及纵向上的分布,认为北加蓬次盆地是典型的裂谷和被动大陆边缘叠合盆地,发育裂谷前、裂谷、过渡阶段和漂移阶段4套沉积地层。目前北次盆已发现油田数量多,已探明油气资源量较大且产量较高,证实具备较好的油气成藏条件:其中盐上Azile-Anguille组海相页岩为主力优质源岩,大型深水浊积扇体作为有利储层。盐岩活动形成了一系列盐构造作为规模型油气聚集圈闭。目前已发现油气田以构造型为主,油气田主要分布在海上,纵向上油气主要分布在森诺期浊积扇砂体。

By comprehensive study on the regional tectonic setting, reservior-forming factors and distribution regularities of North Gabon sub-basin, it is considered to be a rift and passive continental margin superimposed basin, in which four sedimentary forma- tions were developed： pre-rift period, rift period, transition period and drift period. At present, North sub-basin, in which a number of oilfields are found and large hydrocarbon resources and high yie}d are proved to be, is proved to have a better hydrocarbon accu- mulation conditions. The conditions have post-salt Azile-Anguille shale as the main mother rock for hydrocarbon generation, and large deep-water turbidite fan body as a good reservoirs. The activities of salt rocks have generated a series of salt structure which become the most important traps for hydrocarbon accumulation. The oil and gas reserviors are mainly structural type and mainly dis- tributed in the sea which are controlled by Senomian turbidite fan sand bodies vertically.