Geochemical Characteristics and Their Geological Significance of the Sterane in the Crude oil of Chang 2 Oil Group in Yanchang Formation in Xifeng area, Ordos Basin

AbstractXifeng area is a key oil and gas exploration and development area in the Ordos Basin. The Chang 2 oil group of Yanchang Formation is an important replacement oil‐bearing horizon in this area. The sterane compounds in the saturated hydrocarbons of crude oil contain abundant geochemical information and can reflect the source of parent materials and the maturity of crude oil, so they are important information carriers for oil source correlation(Huang et al., 1991; Duan, et al., 2001). In this paper, the crude oil samples were systematically collected from the reservoirs of Chang 2 oil group in 10 production wells in Xifeng area and the group compounds of crude oil were separated. The separated saturated hydrocarbon components were tested by chromatography‐mass spectrometry (GC‐MS) and the sterane compounds were identified and analyzed. The geochemical characteristics of the sterane in the saturated hydrocarbons of crude oil and their geological significance could provide a scientific basis for the oil source correlation of Chang 2 oil group at late stage.