Effect on permeability of anthracite subjected to cyclical microwave modification

Liankun ZHANG; Yuefang WANG; Xiaoyu ZHANG; Geng LI; Tianbai ZHOU; Bo YIN; Wentian MI

doi:10.13347/j.cnki.mkaq.20231225

Meikuang Anquan (Jun 2024)

Effect on permeability of anthracite subjected to cyclical microwave modification

Liankun ZHANG,
Yuefang WANG,
Xiaoyu ZHANG,
Geng LI,
Tianbai ZHOU,
Bo YIN,
Wentian MI

Affiliations

Liankun ZHANG: School of Resources and Environmental Engineering, Inner Mongolia University of Technology, Hohhot 010051, China
Yuefang WANG: Experimental Management Center(Testing Center), Inner Mongolia University of Technology, Hohhot 010051, China
Xiaoyu ZHANG: Research Institute of Mine Big Data, Chinese Institute of Coal Science, Beijing 100013, China
Geng LI: School of Resources and Environmental Engineering, Inner Mongolia University of Technology, Hohhot 010051, China
Tianbai ZHOU: Research Institute of Mine Big Data, Chinese Institute of Coal Science, Beijing 100013, China
Bo YIN: School of Resources and Environmental Engineering, Inner Mongolia University of Technology, Hohhot 010051, China
Wentian MI: School of Resources and Environmental Engineering, Inner Mongolia University of Technology, Hohhot 010051, China

DOI: https://doi.org/10.13347/j.cnki.mkaq.20231225
Journal volume & issue: Vol. 55, no. 6
pp. 30 – 39

Abstract

Read online

Increasing the permeability via microwaves is one of the potential feasible reservoir modification technologies to improve the efficiency of coalbed methane extraction. The microwave oven is used to conduct 3 cycles of microwave modification experiments on No.15 anthracite in Jincheng area of Qinshui Basin. The gas permeability of anthracite samples before and after each modification is tested using a self-built solid-gas coupling seepage platform. The pore properties are tested by micro CT scanning combined with image processing technology. In addition, the complexity index of pore-fracture network of coal samples before and after modification is discussed based on fractal theory. The results show that the gas permeability of anthracite sample increases with the increase of cycle times, and increases by 8.8 times after 3 cycles. The expansion and connection of pores/fractures in anthracite caused by microwave radiation is the fundamental reason for the increase of gas permeability. After three cycles, the total porosity of anthracite samples increases from 3.48% to 6.19%, in which the proportion of connected pores and fractures increases from 27.0% to 77.4%, and the proportion of isolated pores decreases from 73.0% to 22.6%. The pore number, pore volume, pore surface area and throat number, throat surface area and pore-throat coordination number of connected pores/fractures increase with the increase of cycle times, while the maximum throat length decreases, which confirms the “expansion and connection” effect of microwave modification on pores/fractures in anthracite. The two-dimensional fractal dimensions of pores/fractures of three typical sections in anthracite samples increase with the increase of cycle times, and increase from 1.25, 1.16, and 1.09 to 1.46, 1.54, and 1.37 respectively after three cycles, which clarifies that the cyclical microwave modification will make the pore-fracture network （gas seepage channel） in coal samples more complex.

Published in Meikuang Anquan

ISSN: 1003-496X (Print)
Publisher: Editorial Office of Safety in Coal Mines
Country of publisher: China
LCC subjects: Technology: Mining engineering. Metallurgy
Website: https://www.mkaqzz.com/indexen.htm

About the journal

Abstract

Keywords