Study of the gas permeability of permeability of rock interplates after their undermining and overworking, taking into account geodynamic and geomechanical factors

The article presents a forecast of geodynamic and geomechanical processes during coal seam extraction that affect methane emissions in mines. An analysis of geomechanical processes has been conducted, and the periods of non-steady and steadystate displacements in the undermined and overworked strata of the rock mass have been identified. It has been established that if the dimensions of the unloaded zones along the strike and dip do not exceed the extent of the active zones, the entire surface of the satellite is an actively gas-emitting surface. The highest porosity and gas permeability of the undermined and overworked strata are observed in the active part of the displacement zone. An approximate analytical solution to the inverse filtration problem of methane flow from the undermined and overworked seams is presented. An equation has been derived to calculate the average values of the gas permeability coefficient of the surrounding rocks, depending on the thickness of the interlayer rocks, the advance rate of the working face, and other mining factors. The results of the calculations can be used to predict gas emissions from adjacent seams and in the design of degassing. A methodology for predicting methane content in development workings driven through overworked seams is provided, taking into account changes in methane content and filtration properties of the rock mass due to overworking. The methodology is based on initial data known at the design stage and considers the main parameters determining the methane content in development workings.