Petroleum geological characteristics and exploration potential of Kerio Basin in East African Rift System

Since the oil and gas exploration breakthrough has been made in South Lokichar Basin of eastern East African Rift System (EARS) in 2012, the EARS has become a hot spot for research and exploration. However, there were barely good exploration results in peripheral basins, which is worthy to be analyzed deeply. Kerio Basin is adjacent to South Lokichar Basin with lower exploration degree, and there were few domestic researches and achievements in this area. Based on the latest seismic and geological integrated achievements, the petroleum geological characteristics and exploration potential of the basin were expounded. The results show that Kerio Basin is an active rift and half graben with steep slope in the west and gentle slope in the east. Five sedimentary sequences in the basin from Oligocene were developed and the maximum thickness of total deposit is about 6 500 meters. A good source rock was confirmed, but the thickness is about 20 meters. Fluvial and deltaic sandstones with good porosity and permeability were also developed in the basin. The basin can be divided into four sags and five structure zones. The central gentle slope zone and the eastern structural inversion zone are the favorable zones for oil and gas prospecting with two possible hydrocarbon accumulation models. The basin is confirmed to have certain exploration potential, while source rock is the main geological risk in the exploration.