Petroleum geochemistry and oil and gas sources of the Lujing depression in western Yin'e basin,Inner Mongolia

Based on analyzing the geochemical characteristics of group composition, bulk oil isotopes, crude oil biomarkers, and components and isotopes of associated gas of crude oil, this paper discusses the types of source materials, sedimentary environments of crude oil in different strata, and evolution degree of hydrocarbon generation material of Late Variscan intrusive rock and Jurassic and Cretaceous hydrocarbon rock in Lujing depression of western Yin'e basin. An analysis of the environment of Upper Carboniferous-Lower Permian source rocks, the Jurassic and Cretaceous hydrocarbon rocks and the contrast of the biomarker of the oil with that of the Upper Carboniferous-Lower Permian Ganquan Formation show that the crude oil of different strata from Lujing depression has a close relationship with the source rocks in the Ganquan Formation. The difference of the geochemical characteristics and biomarkers of the crude oil might be mainly caused by the different contributions of the lower and upper parts of the Ganquan Formation.