%A MU Hansheng, XUE Xinyu, JIANG Zaixing %T Shale oil and gas in the Mesozoic Basins, eastern Yanshan Orogenic Belt—exploration status and outlooks %0 Journal Article %D 2023 %J Earth Science Frontiers %R 10.13745/j.esf.sf.2022.2.72 %P 282-295 %V 30 %N 2 %U {https://www.earthsciencefrontiers.net.cn/CN/abstract/article_6472.shtml} %8 2023-03-25 %X

Continental basins in China possess abundant shale oil and gas resources and are an important strategic successor area for increasing oil and gas reserves and production in the future. The Mesozoic basin group in the eastern section of the Yanshan Orogenic Belt (western Liaoning) has rich yet unexplored shale oil and gas resources, therefore, petroleum prospecting in this area has become inevitable. Through field exploration and comparisons of basin’s geological conditions with that of typical domestic and foreign shale oil and gas basins, combined with comprehensive analysis of geochemical parameters for sedimentary systems and source rocks of the area, the shale oil and gas resource potential of the Mesozoic basin group is evaluated. The results show that (1) the Beipiao Formation of the Lower Jurassic and the Jiufotang Formation of the Lower Cretaceous are the main source rocks, with the extensive developments of thick and dark shales. (2) The source rocks are dominated by type II1/II2 kerogen; their total organic carbon (TOC) content is 1%-4% on average, and vitrinite reflectance (Ro), an indicator of source rock thermal maturity, is generally higher than 0.6%, indicating good petroleum generation potential. (3) The two sets of source rocks are both rich in volcanic clastic components, with high content of brittle minerals, and have good transformability. In view of the problems in shale oil and gas exploration in continental petroliferous basins, the multi-source genetic mechanism and oil and gas enrichment types of carbonate fine-grained sedimentary rocks, an important carrier of shale oil and gas, are first discussed, which suggests that volcanic hydrothermal fluids and mixed-source “sweet spot” are the main enrichment types in the study area; then the enrichment effect of volcano-lake interaction on organic matter is discussed, which indicates the volcanic ash input enhances the enrichment efficiency of organic matter. Meanwhile, based on previous exploration experience, it is proposed that the prototype basin restoration technology and the “space-earth-drilling” trinity technology are the key to solving many problems in the oil and gas exploration of complex orogenic belts (especially densely planted mountainous areas).