NUMERICAL MODELLING OF METHANE GAS MIGRATION IN DRY COAL SEAMS

Abstract

This paper presents the development of a mathematical model for methane gas migration in coal seams. The major focus of this model is the coupling between the gas flow and deformation of solid coal. The effect of diffusion of adsorbed methane gas from the solid matrix to the voids has been taken into account. The adsorption of gas in the coal seam causes a two-phase state of gas flow. The governing equation for the two-phase gas flow is a non-linear partial differential equation with non-linear boundary conditions. A finite element model has been developed for simulation of the distribution of pressure and concentration of methane gas due to gas migration in coal seams.