Melut盆地为中非被动裂谷盆地,具有丰富的油气资源,盆地发育2种类型的高砂地比地层。其中,古近系Yabus组与Samma组区域性厚层砂岩与Adar组区域泥岩形成的区域性高砂地比地层为盆地勘探初期的主力成藏组合,主要形成各种反向断块、断鼻等构造油藏;上白垩统Galhak组近源局部性砂泥互层高砂地比地层为盆地中后期构造—岩性及岩性地层油气藏勘探的主要成藏组合,为盆地新的成藏组合和勘探层系。通过对Galhak组高砂地比地层油藏特征、富集规律、油藏评价与勘探方法的研究,首次提出“湖泛泥岩控藏”与“辫状河三角洲内前缘分流河道砂体控富”认识,指出湖泛泥岩是Galhak组高砂地比地层成藏主控因素,“高孔厚砂岩”是高产油层形成的储层条件,辫状河三角洲内前缘是高产油层发育的有利相带。同时,提出了以湖泛泥岩划分与对比为基础的分层系评价,提高大套高砂地比地层的垂向研究尺度和评价精度;及以测井、录井、油藏地质等多方法相结合的油水综合判识,提高大套高砂地比地层复杂断块油藏油水关系与油藏认识的合理性。该研究提升了Melut盆地局部性砂泥互层高砂地比地层的勘探潜力,拓展了盆地勘探空间,对中西非相似被动裂谷盆地高砂地比地层的勘探具有借鉴意义。 The Melut Basin is a passive rift basin in Central Africa with rich oil and gas resources. There are two types of high sand ratio formations in the basin. Among them, the Paleogene Yabus Group and Samma Formation regional thick sandstone and Adar Group regional mudstone formation of high-sand ratio stratigraphic basin for the early exploration of the main accumulation, the formation of a variety of reverse faulted block, broken nose, etc. Tectonic reservoirs. The Upper Cretaceous-sourced local sand-mud interbedded high-sand ratio formations are the major reservoir-forming assemblages of tectono-lithology and lithologic reservoir exploration in the mid- Exploration system. Based on the study of the characteristics, enrichment rules and reservoir evaluation and exploration methods of the high-sandstone ratio strata in the Galhak Formation, it is first proposed that the “lake-type mudstone control reservoir” and the “braided river delta front distributary channel sand body It is pointed out that the lake flooding mudstone is the dominant factor controlling the formation of high sand ratio in the Galhak Formation. ”High porosity thick sandstone" is the reservoir condition for the formation of high oil reservoirs. The leading edge of the braided delta is well developed Advantage phase belt. At the same time, the authors put forward the evaluation of stratified system based on the division and contrast of the mudflat in the lake and improve the vertical research scale and evaluation accuracy of the large set of high-sand sandstone than the strata; and by means of well logging, logging, reservoir geology, Combined with the integrated judgment of oil and water, it is reasonable to improve the relationship between oil and water in the large set of high-sandy sandstone and the understanding of reservoirs than the complex faulted block reservoir in the strata. This study enhances the exploration potential of the sand-mud interbedded high-sands and geologic strata in the Melut Basin and expands the exploration space of the basin, which is of reference significance to the exploration of the high-sands in the similar passive rift basins in central and western Africa.