Geology of shale oil occurring in Chang7 of the Triassic Yanchang Formation in Binxian-Yijun area at the south margin of the Ordos Basin

Oil shale occurring in Chang7 of the Triassic Yanchang Formation in Binxian-Yijun area at the south margin of the Ordos Basin was accumulated in sedimentary environment of shallow-semi-deep lakes, belonging to a lake phase oil shale. The oil shale exploration in Binxian-Xunyi area shows that the distribution area of oil shale in the study area is about 1,496km2, with a thickness ranging between 1.43m and 32.75m and a overall burial depth ranging between 0 and 440m. Oil shale is rich in organic matter of type I and type Ⅱ 1, featuring in low maturity-mature and good hydrocarbon characteristics with average oil content ranging between 3.88% and 9.03%, and the overall medium grade oil shale.. The average oil content of oil shale is between 3.88-9.03%, belonging to medium grade oil shale.