TITLE:
Pore Structure Characteristics of Taiyuan Formation Shale in Qinshui Basin
AUTHORS:
Hongyue Duan, Wenkai Zhang, Xinquan Wang, Kaizi Jiang, Tingting Huang
KEYWORDS:
Qinshui Basin, Taiyuan Formation, Shale, Pore Structure, Mercury Intrusion Method, Liquid Nitrogen Method
JOURNAL NAME:
Journal of Geoscience and Environment Protection,
Vol.8 No.7,
July
27,
2020
ABSTRACT: Qinshui Basin is located in the southeast of Shanxi Province, China. Taking the shale of Taiyuan Formation in Qinshui Basin as the research object, the study analyzed the pore size of the shale of Taiyuan formation in detail from micropore to macropore by the methods of mercury injection, liquid nitrogen analysis and combination of liquid nitrogen and mercury injection. The results show that: 1) the visible pores and macropores are poorly developed and distributed unevenly in the shale of Taiyuan formation, and the micropores are well developed in the shale, and there are more open pores in the pore diameter range, and the pore connectivity is good; 2) the liquid nitrogen experiment shows that the pores of Taiyuan Shale are relatively developed between 15 nm and 20 nm, and the formation of hysteresis loop may be caused by some narrow slit pores with similar layered structure; 3) the comprehensive analysis of liquid nitrogen and mercury injection experiments shows that the shale of the Taiyuan formation mainly develops micropores, the Mesopores is not developed, the pore volume at 10 - 100 nm is more developed than other parts, and the specific surface is mainly contributed by micropores, which can improve the efficiency of shale gas resolution; at the same time, it provides a channel for Shale gas migration, which is beneficial to the development of shale gas.