Shale Oil Occurrence Mechanisms: A Comprehensive Review of the Occurrence State, Occurrence Space, and Movability of Shale Oil

Shale oil resources are important supplements for the gradually decreasing production from conventional reservoirs. Although exploitation and development of shale have achieved considerable progress in last decade, commercial extraction hydrocarbons shales is still difficult, especially lacustrine sedimentary basins China. One key points controlling successful systems understanding occurrence mechanism oil. This study comprehensively summarizes theories techniques to characterize state, space, content, movability systems. Sophisticated instruments, such as high-resolution scanning electron microscopy high-energy ray imaging, were utilized qualitatively analyze pore networks shales. Advanced physical experiments numerical simulation techniques, including step-by-step rock pyrolysis, solvent extraction, NMR, introduced adsorption movability. By comparative analysis it found that image observation technique focuses on concentrated pores, organic matter-hosted pores. The fluid injection technology yields particular size information, which should be calibrated using other information. 3D digital core, demonstrating spatial distribution minerals an effective input flow simulation. Geological controls about retention organic-rich has inorganic matter pores fractures probably “sweet spot” oil, due low high light content. Many measure total free content but neglect hydrocarbon–rock interaction sequential migration hydrocarbon compounds. Thus, micro-scaled measuring adhesion forces needed uncover future.