Materiały konferencyjne SEP 2023

Analysis of the above results shows that the adopted criteria for control and evaluating the effectiveness of the HDI meet the requirements [8]. From the above, we can conclude that the effect of dynamic loading on the intensity of gas- dynamic destruction process of a coal massif remains little studied. For example, it is difficult to explain the occurrence of processes of coal seams self- destruction and the intensity of gas release in volumes that significantly exceed the calculated value of gas in coals of an average degree of metamorphism. To explain this process during HDI, we will use studies [1, 2]. With a sharp release of pressure in the hydraulic system, in the liquid-filled fractured-porous space of coal at the “solid-gaseous” interface, a pressure gradient ∆ Р =5-9 MPa is created by a reverse impulse to detachment. The globular structure of macromolecules of outburst-hazardous coals and low strength characteristics for detachment and shearing (no more than 2.0 MPa) contribute to the initiation of layer-by-layer detachment and intense crack formation. At the tip of a growing crack in a coal macromolecule, an instantaneous rupture of lateral single bonds between carbon, hydrogen, oxygen and other chemical elements occurs. In the supramolecular assembly (SMA) of a macromolecule, a phase transition of carbon molecules occurs. When they interact with hydrogen and oxygen, a macromolecule of a coal matter generates methane and water molecules. This process is similar to the transformation of coal matter at the stages of metamorphism, but, unlike it, proceeds almost instantly [2]. In an array of outburst-hazardous coal, the formation of a crack always leads to a new formation of substances from which the "coal-gas" system is formed. Such a system can also be considered as a coal-gas substance. The avalanche-like development of cracks, including in GDP, leads to the chain reaction development of the SMA components destruction of the macromolecule and the generation of methane by the coal-gas substance with the transition of potential energy into kinetic energy. This energy supports the process of self-destruction, changes the structure of the seam and moves into the depths of the array. In the absence of a gradient ∆Р at the interface the self-destruction process stops. However, the disturbed quiescent state (equilibrium) in the coal-rock massif, the formed near-borehole collector zone, the created open surfaces at the coal-gas interface continue to influence the change in the physical state of the coal massif. Therefore, after 6-18 hours of HDI with the effect of self-sustaining gasdynamic self-destruction, a highly porous fractured zone is formed around the borehole with dimensions of up to 7.5 m downdip, up to 10 m on the strike and up to 15 m up-dip. This zone (artificial collector) as a result of deformation processes and degassing is constantly increasing (see Fig. 4) and after 25-30 days it increases by 3-5 times. The insignificant period of technological boreholes existence (up to 3 months) did not allow for a given period of time to establish the limits of the effective influence of boreholes and the possible volumes of gas extraction using a degassing system. However, the research results and their analysis confirm the effect of methane generation by coal-gas substance during its gasdynamic self-destruction. Based on the analysis performed, it follows that a fundamentally new method has been developed on the basis of the HDI. In the process of industrial testing and implementation of HDI methods at the CDD mines, the parameters of the technology for active degassing of outburst-hazardous coal seams were studied and tested under industrial conditions. The method is based on the mechanism of a coal-gas massif destruction by a reverse impulse to detachment in a discrete mode of hydrodynamic destruction. The discreteness of the mode allows not only to provoke gasdynamic self-destruction of the coal-gas massif and technogenic generation of methane by the coal-gas medium, but also to move the destruction wave into the depths of the massif.