Analogy between Melut Basin of Central Africa and Rift Basins of East China and Implication

Shi Zhongsheng; Fang Lehua; Xue Luo; Wang Guolin; He Weiwei; Ma Lun

Abstract：Melut Basin is an important petroliferous passive rift basin of Central Africa, and now it is in the midst of transformation from negional structure exploration to new formations, new domains and new areas exploration without very clear understandings of hydrocarbon accumulation.By analogy between Melut passive rift basin and active rift basins of East China, the geological understandings of hydrocarbon accumulation in Melut Basin are deepened, and the exploration transformation will be promoted.The analogy shows that, the North Melut Sub-basin has typical passive rift basin character, and developed large oilrich sag with the primary"far-source"play of Paleogene and secondary"near-source"play of Cretaceous.The"far-source"lithological reservoir of Upper Yabus Fm.in Paleogene and Cretaceous faulted block reservoirs of Galhak Fm.near source rock are two important domains of fine exploration in North Melut Sub-basin.The Central-South Melut Sub-basins experienced overlapping tectonic evolution process of passive and active rift basin, with the sediments filling and play features of small faulted depression, which is similar with the Hailar Basin, and the"near-source"reservoir-caprock assemblages are favorable exploration targets, inherited low uplifts in sags, faulted uplifts between sags, and faulted slope break belts in gentle slope are favorable hydrocarbon accumulation structural zones.The study deepens the understandings of hydrocarbon accumulation in MelutBasin, and it is suggested that the North and Central-South Melut Sub-basins have different basin forming mechanisms and hydrocarbon accumulation characteristics, which is of great importance to promote the fine exploration in mature exploration areas of North Melut Sub-basin and exploration breakthrough in low exploration areas of Central-South Melut Sub-basins.