关键词: 页岩油气, 陆相, 沉积, 层序, 储层, 中国

Abstract: To address the key scientific problems involving diverse types of continental shale oil and gas deposition, complex reservoir space and unclear reservoir genesis in China, this paper systematically reviews the domestic and foreign research progress of continental deepwater sedimentary sequence, deposition system and shale oil and gas reservoirs, especially in China in the past 10 years. More importantly, in combination with the geological researches conducted by the authors' team in recent years on the deposition and reservoirs of continental shale oil and gas, the continental deepwater fine-grained sedimentary rocks are classified into four genetic types, i.e., terrestrial, endogenous, volcanic-hydrothermal, and hybrid-source types. Meanwhile, the paper proposes a comprehensive classification scheme for fine-grained sedimentary rocks based on inorganic mineral content (i.e., three end-members of carbonate minerals, felsic minerals and clay minerals), organic matter content (TOC contents ranges between 2.0% and 4.0%), and sedimentary structure (lamellar, thin-layered, and massive), and also summarizes a high-frequency cyclostratigraphic study method based on the Milankovitch astronomical orbital period, which is applicable for the subdivision and comparison of continental deepwater fine-grained sedimentary strata. Further, based on the high-frequency cyclostratigraphic correlation, a method is proposed for the industrial mapping of microphase planes of continental deepwater fine-grained sedimentary rocks, which is of important applicable value for the evaluation and prediction of favorable shale sedimentary reservoir lithologies. According to the matrix type for pore occurrence, pores in the continental shale oil and gas fine-grained sedimentary rock reservoir are divided into three categories:mineral matrix pore (or inorganic pore), organic pore, and fracture pore. Among them, the mineral matrix pore related to organic dissolution is an important storage space for shale oil and gas, and the development degree of organic matrix pore is mainly related to the degree of thermal evolution of organic matter. In general, the high degree of thermal evolution is conducive to the development of organic matter pores, and fracture pore is an important seepage channel for shale oil and gas. Moreover, the paper points out the problems requiring further studies and development directions regarding the deposition of fine-grained sedimentary rocks, formation mechanism and sweet spot evaluation of shale oil and gas reservoirs, and high-precision shale stratigraphic correlation methods.

Key words: shale oil and gas, continental, deposition, sequence, reservoir, China