Assessing the well yield during methane drainage in coal mines

摘要

High gas bearing capacity of coal beds is a factor that restricts high level of production. This issue is especially urgent for the Kuznetsk Basin (Russia) where high methane release in production units significantly reduces the capacity of applied equipment performance of which could ensure a higher production level. The amount of methane in coal beds and host rocks can be reduced by methane drainage. However, it is difficult to assess the efficiency of planned measures due to absence of an opportunity to forecast the amount of methane delivered to methane drainage boreholes. This article suggests an approach to assess the yield of methane drainage boreholes drilled from the surface to the coal bearing rock mass. The approach is based on calculating the change of volumetric strains and the permeability coefficient of characteristic zones of the underworked coal bearing rock mass by using computational simulation. The obtained yield forecast of methane drainage boreholes allows assessing the drainage efficiency and making right decisions to apply proper drainage schemes in coal mines.