A Fluid-Solid Coupling Mathematical Model of Methane Driven by Water in Porous Coal

Table 1

Parameters of the numerical simulation.

Symbol	Physical significance	Value	Unit
	Elastic modulus of the coal rock	2713	MPa
	Elastic modulus of the coal skeleton	8469	MPa
	Poisson’s ratio of the coal rock	0.32	1
	Initial porosity	0.09	1
	Dynamic viscosity of the methane		Pa·s
	Dynamic viscosity of the water		Pa·s
	Density of the coal skeleton	1470	kg/m^3
	Density of water	1000	kg/m^3
	Absolute permeability of the coal rock		m^2
	Langmuir ultimate adsorption capacity of the methane	0.036	m^3/kg
	Langmuir adsorption equilibrium constant of the methane	3.304	MPa
	Bound water saturation	0.2	1
	Residual methane saturation	0.1	1
	Relative permeability of the water endpoint	0.83	1
	Relative permeability of the methane endpoint	1	1
	Outlet pressure	0.1	MPa
	Initial pore pressure	0.5	MPa