The South Qilian Basin Yanchang Formation Hydrocarbon Source Rock And Reservoir Characteristics

South Qilian Basin is located in the south side of the Qilian Mountains, the middle of Qilian Mountain Block is in the north of it, West Qinling Mountains is in the south of it, Northwest of the basin is controlled by the Altyn Tagh fault, southwest of the basin adjacent to the Qaidam Basin. The whole basin is pressed from the Qilian Mountains, West Qinling and the Altyn Tagh fault. South Qilian Basin are researched early, but the research mainly focus on the Early Palaeozoic and Cenozoic, Mesozoic study is relatively small. The Triassic of South Qilian basin have had few research. The predecessors have not conducted the sampling and analytical testing research. In this paper, laboratory rock pyrolysis data and thin section observation as the basis, we did characteristics of hydrocarbon source rock evaluation and evaluation of reservoir characteristics, as well as the analysis of the factor of reservoir properties. The significance and destination of this study is:To analyze the hydrocarbon source rocks carbon content and hydrocarbon potential of the Triassic in South Qilian Basin and evaluate the degree and distribution of hydrocarbon source rocks; evaluate the reservoir property features of Triassic in South Qilian Basin, analysis the main influencing factors; as the basic information of oil and gas resource evaluation in South Qilian Basin, and can be further researched.Conclusions:According to the hydrocarbon source rocks characteristics, in Triassic of South Qilian Basin,Jianghe group, Dajia Lian group, Qieer Ma group are poor source rocks levels, only hydrocarbon source rocks of Karamanid Temple group reach the medium to good level; according to the characteristics of kerogen, soluble organic matter characteristics, gas chromatography analysis of saturated hydrocarbons, the type of organic matter in South Qilian Basin Upper Triassic Karamanid Temple group and the Middle Triassic Dajia Lian group belong to sapropel humic (Ⅱ2type); According to the comprehensive evaluation of clastic reservoir, western Triassic reservoir properties of the basin are relatively good. According to the comprehensive evaluation of carbonate rock reservoir, it is mainly refers to the Dajia Lian group carbonate rock section,it have good porosity and permeability characteristics and belong to good reservoir layer; Triassic clastic reservoir in South Qilian Basin have low porosity and permeability characteristics, the main reason is it contain more volcanic clastic components and clay.