Analysis of oil-accumulation condition and exploration direction of the second member of Shahejie Formation in the western Chezhen Sag

Based on the tectonic and sedimentary characteristics,oil-accumulation condition and exploration direction of the second member of Shahejie Formation in the western Chezhen Sag are analyzed by means of the study on hydrocarbon source rocks, reservoirs, caprocks and hydrocarbon migration pathways. The results show that the second member of Shahejie Formation has a good condition for forming hydrocarbon reservoirs:The oil and gas mainly come from the hydrocarbon source rocks in the middle-lower submember of Es3; The reservoirs were developed in the study area and the fourth cycle is very important one; There are many kinds of caprocks with good sealing capacity which are in favor of protecting hydrocarbons; There are three types of hydrocarbon migration pathways, such as faults, unconformity surfaces, sand bodies, which are very important to the processof forming oil and gas reservoirs. Up to now, the tectoniclithologic reservoirs and tectonic reservoirs have been foundin the second member of Shahejie Formation, stratigraphic o-verlapped reservoirs may be in existence. Though it is difficult to make research on the second member of Shahejie Formation, it still has a good exploration potential, for example, the Cao Jiahzhuang fault step zone and overlapped zoneon the southern slope are more favorable areas for next ex-ploration in search of tectonic- lithologic reservoirs and stratigraphic overlapped reservoirs.