Enrichment and accumulation characteristics and prospect analysis of the Permian marine conticental multiphase shale gas in China

In China, the marine and continental multiphase shale systems of Permian are widely distributed, mainly including coal bearing formation in the coastal shallow water environment represented by Shanxi formation, Taiyuan Formation and Longtan Formation, and siliceous bearing formation represented by Gufeng formation and Dalong formation. Based on the comparison and comprehensive evaluation of a large number of shale gas enrichment evaluation parameters, two types of organic rich shale that have the characteristics of "high organic matter content, moderate thermal evolution, high gas content and high porosity", which can be compared with the marine shale parameters of Silurian Longmaxi formation in Sichuan Basin are confirmed. According to the three main controlling factors of shale gas enrichment and accumulation, which are lithofacies controlling carbon, diagenesis controlling hydrocarbon and structure controlling reservoir, the shale gas exploration prospect areas such as the eastern margin of Ordos Basin, Qinshui Basin, the north of South China Basin, Kaijiang-Liangping trough, Chengkou-Exi trough, Wanjiang trough, Central Hunan and South Sichuan-Qianxi are comprehensively evaluated and optimized. These shale gas exploration prospect areas will provide support for exploration and development of Permian marine continental multiphase shale gas of China.