The Migration of Coalbed Methane under Mining Pressure and Air Injection: A Case Study in China

Table 2

Numerical model boundary conditions.

Coal seam deformation	Value	Methane migration	Value
Upper boundary (MPa)	14 transition to 21	Pressure of methane extraction borehole (kPa)	20
Lower boundary	Fixed boundary
Left boundary	Roller support
Right boundary		Methane pressure (MPa)	2
Borehole boundary	Free deformation
Initial displacement	0	Others (MPa)	0