DECLINE IN GAS PRESSURE INFLUENCES THE DEFORMATION AND PERMEABILITY OF COAL-CONTAINING METHANE
Yunqi Tao1, 2, Dong Liu2, 3, Jie Cao3, Jiang Xu3
1School of Energy Science and Engineering, Henan Polytechnic University, Jiaozuo, Henan Province, China
2Yongcheng Coal & Electricity Holding Group Co. Ltd., Yongcheng, Henan Province, China
3State Key Laboratory of Coal Mine Disaster Dynamics and Control, Chongqing University, Chongqing, China
The development and utilization of coal-bed methane, as an unconventional gas, is not only beneficial to the reduction of environmental pollution caused by fossil fuels, but also conducive to the prevention of disasters during coal mining. In this paper, a dynamic permeability model of coal body is established and discussed by means of experimental tests, which measure the deformation and gas permeability of coal-containing methane in the process of gas pressure reduction under different temperatures. The results show that, when gas pressure decreases, the strain of coal-containing methane increases linearly. With temperature increases, the variation of radial strain decreases. Under the same temperature, the permeability of coal decreases first and then increases again during gas pressure reduction. The changing point of gas pressure is approximately 1.2 MPa in the study. In the initial stage of gas pressure decrease, the radial strain of coal-containing gas has a significant effect on its permeability.