Materiały konferencyjne SEP 2023

The development of continuous acoustic emission (CAE) in its intensity differs from the CAE when opening the seams with crosscuts and in nature corresponds to the process of crack formation during GDP. The effect of crack formation in the zone of array processing is explicit, the intensity of the degassing process and the volume of gas emission through the boreholes (more than 3400 m 3 ) increase sharply (Fig. 4). 1 – two-stage mode of the HDI; 2 - three-stage mode of the HDI Figure 4. The nature of the process of gas release through the borehole 1 - Dwustopniowy tryb OHD; 2 - Trójstopniowy tryb OHD Rys. 4. Charakterystyka procesu emisji gazu przez odwiert The control of the methane content in the outgoing stream of the stoping face during the extraction of coal in the processed and adjacent s (Fig. 5) showed that there were no signs of GDP in the processed lower part of the strip. This confirms that the HDI was effective, but the coal extraction criterion k rec was less than 5%. Based on the obtained results, it follows that when evaluating the effectiveness of HDI, it is necessary to consider not only the effect of layer-by-layer destruction of coal, but also the process of gasdynamic destruction of the array with crack formation and intensive (active) degassing of the "coal-gas" system. This approach makes it possible to expand the field of research and establish new parameters for evaluating the effectiveness of HDI-based methods. The established distinctive features of the process of destruction of the coal massif made it possible to develop new principles for the degassing of steeply dipping coal and gas deposits [9]. The paper shows that when provoking and maintaining gasdynamic destruction of coal (crack formation) in the "coal-gas" system and partial extraction of coal (layer-by-layer separation), regardless of the impact mode a rapid increase in the intensity of gas release is observed, exceeding the initial velocity of gas release by several tens of times. The process of gas release after HDI continues until the seam is opened or until the borehole is crossed by the frontal unit.