Abstract: Through data analysis such as seismic, drilling, core,testing data, and etc, the reservoir characteristics in Chad BS block were analyzed. The results indicate that the BS block belongs to the fan delta sedimentary system and the hydrocarbon is from P group of hydrocarbon source rock in Mimosa sag. Affected by dual factors of sedimentary evolution and tectonic activities, the optimal source–reservoir–seal association was formed in sedimentary evolution of rifting period, the late stress reversal effect on accumulation damage area is small, which promotes the oil and gas migration.