Petroleum geology and hydrocarbon accumulation pattern in the Lake Albert Basin of East African rift system

The evolution and tectonic-sedimentary stratigraphic features of the Lake Albert Basin in the East Africa were studied using geological, seismic and drilling data. The petroleum geology features and the accumulation pattern and enrichment conditions were summarized. The basin was mainly affected by the tectonic movement of the East Africa rift system, forming a long and narrow (semi-) graben with deep faults on both sides. The sedimentary strata are dominated by Neogene clastic rocks, including mudstone, sandstone and conglomerate. Depositional fill is characterized by a river-(fan) delta-lacustrine sedimentary system. The Upper Miocene organic-rich shale, Miocene-Pliocene fluvial-(fan) delta sandstone and fine lacustrine mudstone formed a favorable source-reservoir-cap assemblage vertically. There are a large number of structural traps. Hydrocarbon generated in depressions, migrated vertically and laterally, and finally accumulated in upper formations, resulting in multiple sets of stacked reservoirs. High-quality sand bodies and vertical faults controlled the effective migration of oil and gas, and structural traps developed by fault control are the main sites for oil and gas accumulation.