Numerical Simulation of CO2-ECBM Based on Multi-Physical Field Coupling Model

In this paper, heat injection and CO2 are combined, the influence of coal seam parameters on CO2-ECBM is analyzed to improve production CH4 reserves effective control both greenhouse gases. A multi-physical field coupling model was established based Darcy’s law, Fick’s law diffusion, extended Langmuir for adsorption, equation state. Numerical simulation under different carried out by COMSOL Multiphysics. The results show that increasing pressure well initial can effectively increase gas concentration gradient, which has a positive effect improving extraction sequestration in seam. temperature will promote desorption diffusion binary elemental gas, resulting decrease coalbed methane displacement effect. process displacement, greater permeability, fracture opening seam, more conducive seepage transport gas. closer position well, better lower permeability rate ratio.