摘要
The lack of research on the effect of diffusion on methane extraction leads to low methane concentration and low utilization.The Comsol Multiphysics software is used to solve the numerical gas and solid coupled model which considers the diffusion of coal matrix,fracture seepage,permeability evolution and coal deformation.The simulation results reveal the effect of diffusion process on methane migration.The gas diffusion rate is relatively high in the initial stage.With the increase in time,the difference between coal fractures and coal matrix blocks becomes lower and the gas diffusion rate decreases gradually.The gas seepage rate decreases significantly near the borehole and the decrease degree becomes small when it is far away from borehole.The influence of diffusion time on gas drainage rate is not obvious.
基金
This study is sponsored by the National Natural Science Foundation of China(no.51679199)
the Initiation Fund of Doctor’s Research(no.107-451117008)
the Special Funds for Public Industry Research Projects of the Ministry of Water Resources(no.201501034-04 and 201201053-03)
the Key Laboratory for Science and Technology Coordination&Innovation Projects of Shaanxi Province(no.2014SZS15-Z01).References。
