Reservoir crude oil features of the Chang 10 layer in the north of Shaanxi province

Baed on crude oil features’s analysis of the Yanchang formation and the Jurrasic in the north of Shanxi province,the authors divide type of crude oil and mainly decide the origin of crude oil in the Chang 10.In research area,the pool in the Chang 10 layre is lithologic oil pool which is controlled by structure and dictribute in the region with good physical property in high position of structure noses.Crude oil has characteristics of low density,low viscsity and high wax content and there is an gradually reduceing content order of saturated hydrocarbon,aromatic hydrocarbon and non-hydrocarbon.According to biomarker composition including sterane and terpane,crude oils are divided into two types of A and B.In type A of oil,17α(H)-rearangement hopane17α(H),21β(H)-30-norhopane17α(H),21β(H)-hopane,content of 17α(H)-rearangement hopane is very low,Ts content is colse to Tm’s and tricycle terpane content is lower.Source rock of type A of oil is oil shale in the Chang 7 layer.In type B of oil,content of 17α(H)-rearangement hopane is higher and exceed 17α(H),21β(H)-30-norhopane sometimes,Ts content is higher obviously than Tm’s,tricycle terpane content is higher.Source rock of type B of oil is mudstone in the Chang 9 layer and partial of the Chang 10 layer.