METHANE MIGRATION AND ACCUMULATION STATE AFTER SEAM MINING

The pathway of methane migration and methane accumulation space are varying with both of activities in overburden and the occurrence pattern of fractured zones after comprehensive mining in methane-rich thick coal seams.The influences of variation caused by mining operation in over key seams to pattern of fractured zone occurrence are analyzed.It is proposed that if the crush zone and separated bed zone were connected, a elliptic parabolic-shaped zone would be formed.The liftion diffusion theory of methane from relieved zone in the elliptic parabolic-shaped zone is explained, that will be served as scientific base for coal and gas production.