%A Feng Xiaolong, Ao Weihua, Tang Xuan %T Characteristics of Pore Development and Its Main Controlling Factors of Continental Shale Gas Reservoirs: A Case Study of Chang 7 Member in Ordos Basin %0 Journal Article %D 2018 %J Journal of Jilin University(Earth Science Edition) %R 10.13278/j.cnki.jjuese.20160332 %P 678-692 %V 48 %N 3 %U {http://xuebao.jlu.edu.cn/dxb/CN/abstract/article_10810.shtml} %8 2018-05-26 %X The Yanchang Formation is one of the most promising area for shale gas exploration in the Ordos basin. The Chang 7 Member of the Yanchang Formation in the eastern Ordos basin was selected as the research object. Based on the nitrogen isothermal adsorption, field emission scanning electron microscopy (FESEM) in combination with the laboratory tests on mineralogy, maturity and TOC, the pore types, structures as well as their controlling factors were analyzed respectively. As shown in the results, the pore structure of Chang 7 Member shale gas reservoir is complex, and can be divided into 2 types according to the adsorption loop morphology. TypeⅠloops mainly correspond to the parallel plate-like holes or micro-cracks with a pore structure of 2.6-4.2 nm in diameter or in a wedge structure, and can be classified into clay-mineral intergranular pores, organic-matrix-like pores, and matrix microcracks; typeⅡloops are mainly open-ended cylindrical boreholes in 2.3-3.1 nm, 3.5-3.8 nm, and 4.3-5.2 nm, including organic pores and residual intergranular pores. Mesopores and micropores are major contributors to total volume and specific surface area,which is controlled mainly by TOC with a positive correlation with both total volume and specific surface area. Neither Ro nor mineral contents show any influences on the pore structure; however, clay minerals contribute a lot to the volume of micropores, which is supported by the relatively positive correlation between illite contents and the total volume and specific surface area.