Abstract: In order to determine the shale oil resource potential of Da’anzhai Member, Jurassic Ziliujing Formation of Sichuan basin, the hydrocarbon generation potential, reservoir property, oil content, and shale oil mobility conditions were comprehensively evaluated by FE-SEM, CLSM, He-measured porosity and permeability, N2 adsorption, and rock pyrolysis experiments. The results show that the hydrocarbon generation potential is poor, reaching mature to high mature stage, and oil and gas coexist in the Da’anzhai Member. The intercalated limestone is dense. The inter-calite pore connectivity is poor. The foliation fracture, interlayer fracture, and calcite cleavage constitute the main occurrence space of shale oil. The oil content of foliated clay shale is good, and fracture development is the premise of shale oil mobility and high yield. Vertically, the fractures of the interbedded combination of shale and limestone are relatively developed, making it the preferred sweet spot for shale oil. Layered structures are conducive to the formation of bedding planes. Layered shale has exploration potential in areas with high levels of thermal evolution. Based on the organic matter abundance, oil property, and lithofacies combinations, it is proposed that the northern Yilong and southern Dazhou are favorable exploration areas for interlayer type shale oil. While the areas between Yilong and Dazhou are favorable exploration areas for pure shale type shale oil.

Key words: shale oil, enrichment mechanism, hydrocarbon generation potential, favorable area, Da’anzhai Member, Ziliujing Formation, Sichuan basin