Experimental study on multi-scale pore structure characteristics of tar-rich coal in Yushenfu mining area

Authors

SHEN Yanjun, School of Geology and Environment, Xi'an University of Science and Technology, Xi'an 710054, China; Shaanxi Provincial Key Laboratory of Geological Support for Coal Green Exploitation, Xi'an 710054, China
WANG Xu, School of Architecture and Civil Engineering, Xi'an University of Science and Technology, Xi'an 710054, China
ZHAO Chunhu, Xi'an Research Institute Co. Ltd., China Coal Technology and Engineering Group Corp., Xi'an 710077, China
WANG Shengquan, School of Geology and Environment, Xi'an University of Science and Technology, Xi'an 710054, China; Shaanxi Provincial Key Laboratory of Geological Support for Coal Green Exploitation, Xi'an 710054, China
GUO Chen, School of Geology and Environment, Xi'an University of Science and Technology, Xi'an 710054, China; Shaanxi Provincial Key Laboratory of Geological Support for Coal Green Exploitation, Xi'an 710054, China
SHI Qingmin, School of Geology and Environment, Xi'an University of Science and Technology, Xi'an 710054, China; Shaanxi Provincial Key Laboratory of Geological Support for Coal Green Exploitation, Xi'an 710054, China
MA Wen, School of Geology and Environment, Xi'an University of Science and Technology, Xi'an 710054, China

Abstract

Extracting oil and refining gas from oil-rich coal is an important measure to make up for the shortage of oil and gas supply in China. The research on pore development characteristics and permeability of tar-rich coal will help to better develop and utilize tar-rich coal. Taking the tar-rich coal in Yushenfu mining area as the research object, this paper studies the multi-scale pore structure and the whole segment pore characterization of tar-rich coal by such methods as low-temperature liquid nitrogen adsorption, mercury intrusion porosimetry, nuclear magnetic resonance and gas permeability measurement method. Based on the test results of multi-scale pore structure of tar-rich coal, this paper discusses the differences between the pore characteristics of tar-rich coal and traditional low-rank coal. The results show that the micropores of tar-rich coal in Yushenfu mining area is extremely well-developed, accounting for over 70% of the total pores, while the macropores and mesopores are relatively underdeveloped, accounting for only 25%-30%. By comparing the results of the nuclear magnetic resonance test with the combined characterization results of low temperature liquid nitrogen adsorption and mercury intrusion porosimetry, it is found that the latter can better characterize the whole segment pores of coal samples. Compared with traditional low-rank coal, tar-rich coal has a larger pore specific surface area of 27.48 m²/g and low-temperature nitrogen adsorption capacity of 40-50 cm³/g, providing an advantage to extract oil and gas for tar-rich coal.

Keywords

tar-rich coal, pore structure, low-temperature nitrogen adsorption, mercury intrusion porosimetry, nuclear magnetic resonance, gas permeability measurement method

DOI

10.3969/j.issn.1001-1986.2021.03.005

Recommended Citation

SHEN Yanjun, WANG Xu, ZHAO Chunhu, et al. (2021) "Experimental study on multi-scale pore structure characteristics of tar-rich coal in Yushenfu mining area," Coal Geology & Exploration: Vol. 49: Iss. 3, Article 6.
DOI: 10.3969/j.issn.1001-1986.2021.03.005
Available at: https://cge.researchcommons.org/journal/vol49/iss3/6

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