oa Composition and Source Analysis of Jurassic Shale Oil in Sichuan Basin: Evidence from Molecular Geochemistry

Using the sample liquid nitrogen freezing-sealed thermal desorption and chromatographic online detection method, shale samples of different lithology from shale oil drilling in the Sichuan Basin were analyzed. The experimental results obtained complete hydrocarbon composition information in different shale samples. Among them, the fingerprint parameters of light hydrocarbons in mudstones and sandy mudstones are similar, indicating the characteristics of self-generation and self-storage of this set of formations. The shale oil in sandstone mudstones mainly comes from the supply of overlying mudstones. There are differences in the composition of shale oil in organic-rich shales of different lithofacies. The relatively dense mudstone shale accounts for a high proportion of light components, and the pores and fractures of sandy shale are relatively developed. The existing shale oil has undergone short-distance migration, and the light hydrocarbon components are severely lost, and the shale oil components are mainly heavy hydrocarbons.