Although Yingzijie area is near the hydrocarbon generation center, because of its simple structure and the lack of structural traps, traditionally, the exploration potential is considered not great. In order to overcome the exploration obstacles, the sedimentary evolution and the facies types are studied in this paper. Based on the dominant sand-body types, the hydrocarbon source rock pressure and the subtle traps, the main controlling factors in the hydrocarbon accumulation of lower Sha 3 in Yingzijie area are analyzed. It is shown that there are two kinds of dominant sand-bodies: The sheet sand and the turbidite fan sand. These sand-bodies are surrounded by the source rock with the reservoir types being subtle lithologic, where the hydrocarbon accumulation factors are controlled by the overpressure of the source rock and the effective reservoirs. The oil fullness degree of the reservoirs are controlled by the overpressure of the source rock and the oil scale is controlled by the effective reservoirs in the region of the overpressure of the source rock, and the accumulation model can thus be built, as the self-source and the self-reservoir and the overpressure controlling accumulation.

overpressure of source rock  /  effective reservoirs  /  accumulation regularity  /  accumulation model  /  Yingzijie area  /  Linnan Sag