Citation

Wu X, Li B, Gao Z, Xu J, Fu J. China Saf. Sci. J. 2022; 32(4): 129-134.

Copyright

(Copyright © 2022, China Occupational Safety and Health Association, Publisher Gai Xue bao)

DOI

10.16265/j.cnki.issn1003-3033.2022.04.019

PMID

unavailable

Abstract

In order to study coal deformation and gas seepage behaviors caused by pressure reduction in gas extraction process, based on seepage test and triaxial compression test of gas pressure reduction, coal deformation and seepage characteristics were obtained. Then, matrix shrinkage deformation was modified by considering adsorption damage, and a permeability model was constructed before its rationality was verified by experimental results. The results show that with the decrease of gas pressure, coal permeability presents a "V" shaped change trend. The axial and radial deformation increase linearly, and coals injected with CO2 produce larger deformation than that with CH4, with radial deformation being 1. 89 times of axial deformation. Moreover, the elastic modulus and peak principal stress difference in coal with CO2 are lower to different extent than those with CH4. In order to ensure safe production, attention should be paid to the issue of coal strength reduction caused by CO2 injection into coal seam when using CO2 displacement or CO2 fracturing anti⁃reflection technology. © 2022 China Safety Science Journal. All rights reserved.

Language: zh