Pore structure characteristics and impact factors of laminated shale oil reservoir in Chang 73 sub-member of Ordos Basin, China

作者：Qi-liang Mei, Ruiliang Guo, Xinping Zhou, Guofeng Cheng, Shixiang Li, Yubin Bai, Jiangyan Liu, Weitao Wu, Jingzhou Zhao · 发表于：Journal of Natural Gas Geoscience · 年份：2023 · DOI：10.1016/j.jnggs.2023.07.003 · 被引用次数：15 · 研究领域：Hydrocarbon exploration and reservoir analysis、Coal Properties and Utilization、Hydraulic Fracturing and Reservoir Analysis

This research paper focuses on the laminated shale oil reservoir in the third sub-member of the seventh member of Yanchang Formation (Chang 73 sub-member) in the Ordos Basin. The study aims to comprehensively analyze the lithofacies type, micro qualitative and quantitative pore structure parameters, and the main controlling factors of the pore structure in laminated shale. The analysis involves various techniques, including a comprehensive analysis of TOC, rock-eval, X-ray diffraction, polarized light and fluorescence microscope observation, field emission scanning electron microscope observation, and low-pressure N2 adsorption analysis. Based on the sedimentation characteristics, geochemistry, and mineral composition differences, the Chang 73 laminated shale can be classified into three lithofacies types: tuffaceous-organic matter binary laminated shale, clayey-organic matter binary laminated shale, and felsic-clayey binary laminated shale. The pore network consists primarily of organic hydrocarbon generation pressurization fractures, clay mineral felsic intergranular composite pores, and felsic plasmid intergranular pore fracture systems. Mesopores are the most developed pore type. The pore volume and specific surface area increase in the order of “tuffaceous-organic matter”, “clayey-organic matter”, and “felsic-clay”, while the heterogeneity of the pore network gradually weakens, and the roughness of the pore surface enhances. The overall development of organic matter pore...