Gas hydrates in coal seams and their impact on gas-dynamic processes in underground mining

This paper deals with the development and analysis of the method of predicting gas-dynamic phenomena due to the gas hydrates in coal seams. With the help of the method of mathematical modelling the rate of dissociation of gas hydrates depending on the size of particles was determined as well as the correlation between the speed of moving the boundary line of the dissociation of gas hydrates in the pore space of coal and that of extending of the wave of crushing. The regularity of gas pressure distribution in a coal seam marginal zone after dissociation of gas hydrate depending on its saturation capacity and taking into account the changing coefficient of permeability of this zone was stated. It was also found that this kind of gas-dynamic processes in the presence of gas hydrates in the pore space of coals depends on critical value of permeability of a coal seam marginal zone.