Evaluation of gas evolution outside the extraction section at the activation of coal-bearing stratum displacement

Abstract

The object of research is the processes of gas evolution from undermined sources within the exploited extraction section and beyond its boundaries under the influence of activation of rock displacement. To date, no quantitative dependencies have been established for gas evolution from the worked out (treatment workings) of the carbonaceous stratum when its movement is activated. Difficulties in studying gas evolution in the case under consideration lie in the need to carry out the necessary measurements of methane consumption in the workings and degassing wells of the mine field section and wing over the entire period of time working out the extraction column. The purity of the experiment is ensured by the operation of only one lava in the wing of the mine field. The ventilation scheme of the extraction section and the location of the measurement points in the mine workings make it possible to establish methane emission zones in the worked out space of the exploited and stopped lavas. The paper presents an analysis of the change, currently little studied, of gas evolution outside the exploited extraction section into the worked out space of stopped lavas. The main factors affecting the change in the level of gas evolution are determined, both within the extraction section and beyond its borders.

The methodology of the experiments is assumed that the level of gas evolution from the undermined coal-bearing stratum is determined by coal mining and the degree of development of treatment works in the extraction section. On the basis of experimental data, the dependences of gas evolution on coal production and the degree of development of treatment works within the extraction section are established. Out of the extraction section, gas evolution from the worked out space of stopped lavas occurs when the development of the minefield wing is sufficiently developed and is determined by the intensity of coal mining in the exploited section. When the Earth’s surface and the coal-bearing stratum are fully developed, the gas evolution from the mined-out space of the stopped lavas during the initial period of operation of the next lava can be several times higher than the methane emission within the existing extraction section.

Studies have shown that the mechanism of the process of gas evolution within the extraction section and beyond its boundaries proceeds under the influence of various influencing factors.