Mirny Polytechnic Institute (Branch), Ammosov North-Eastern Federal University, Mirny, Russia

V. I. Gavrilov, Professor, Doctor of Engineering Sciences, gawrilov.slawick@yandex.ru

Polyakov Institute of Geotechnical Mechanics, NAS of Ukraine, Dnepropetrovsk, Ukraine

K. K. Sofiyskiy, Head of a Department, Professor, Doctor of Engineering Sciences

The mine survey of the influence of the hydrodynamic method through long technological wells on the intensification of degassing of low-permeable gas-saturated flat coal seams in various geological conditions confirmed its effectiveness. The experience of the degassing and extraction of methane from the unloaded coal bed and the coal bed shows a close relationship between the geological, geomechanical and technological aspects of the combined mining of coal and methane. According to modern concepts, methane in a coal seam is contained in three states: free, adsorbed, and in the form of a solid carbon-gas solution. As a result of drilling a well, a redistribution of stresses occurs in its vicinity, and an increase in gas pressure in a cleavage results in a compression of the coal matrix and a decrease in adsorption. With increasing depth, the proportion of methane in the composition of the solid carbongas solution increases and the condition for its extraction is unloading of the formation from mechanical stresses. Degassing of a gas-saturated reservoir occurs mainly in the zone of influence of the working face and degassing wells function (methane is sucked out of a suitable concentration for disposal) for only a short period of time. The intensification of degassing by hydrodynamic effects leads to an increase in the flow rate of degassing wells and a reduction in the processing time of the formations. According to the research results, rational parameters were established for laying technological wells and for the modes of the most hydrodynamic impact on low-permeable gas-saturated flat coal seams. It was established that when extracting the destroyed coal from a technological well during exposure in an amount of not less than 1% of its mass in the treated zone, intensification of gas release during the first three to four months is 1.8–2.6 times ensured and the required level of degassing is achieved in 3 to 6 months. This allows to exclude the stopping of the mine by the gas factor and thereby increase the load on the breakage face.

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