RESOURCE POTENTIAL OF THE CONTINENTAL SHALE OIL IN CHINA

Shale oil refers to oil stored in organic-rich shale. It is an important part of unconventional oil and provides a large amount of resources. Based on the systematic study of the geological characteristics of shale oil in China's major continental basins, the geological connotation of the “sweet area (section)” in shale oil is proposed, and it refers to target zones (sections) that can be preferentially explored and developed in oil-bearing shale formations under current economic and technical conditions. The formation conditions and distribution characteristics of continental shale oil in China are analyzed with a focus on the geological properties of the Triassic Yanchang Formation in the Ordos Basin, the Cretaceous Qingshankou Formation in the Songliao Basin and the Permian Lucaogou Formation of the Jimusar Sag in the Junggar Basin. It is found that the “sweet areas” of shale oil with medium-high maturation are mainly located in thick shales with a R_o greater than 0.9 %, and the “sweet sections” are mainly located in the middle and lower parts of the shale formation. The geological resources of continental shale oil in the major continental basins in China are estimated to be approximately 3,700×10⁸ tons. The in situ conversion process (ICP) may be a key technology for the effective development of medium- to low-mature shale oil. The scale, maximum burial depth and present depth of the organic-rich shale are proposed as the three key parameters for the optimization of pilot sites by taking the Triassic Yanchang Formation in the Ordos Basin as an example. Using ICP, it is expected that the recoverable resources of China's continental shale oil will be approximately (400-500)×10⁸ tons. Continental shale oil may be another revolutionary source of unconventional oil and is expected to be first successfully produced in China.