Methodical principles of experimental-analytical research into the influence of pre-drilled wells on the intensity of gas-dynamic phenomena manifestations

Abstract

Purpose.The research aims to substantiate the general provisions on coordination of the experimental-analytical research results of the influence of pre-drilled wells on the intensity of gas-dynamic phenomena manifestations (using the example of the mining-geological conditions of the phenomena at the PJSC Mine Administration Pokrovske, Ukraine). Methods. The research uses an integrated methodology consisting of indirect experimental methods for studying the adjacent rock mass state and tendencies. Findings. It has been proven that indirect experimental indicators of the rock mass state around the tunneling face are related to the peculiarities of the distribution of its stress-strain state components. Based on this research, the well lengths of up to 10-15 m has been determined to effectively and safely de-stress the rock mass. The experimental research validity is confirmed by conducted computational experiments, in the course of which the dependence of the propagation parameters of the stress-strain state component concentrations on the degree of hardness of the lithotypes is revealed, and a geomechanical substantiation to the tendencies of propagation of rock pressure anomalies near stoping and tunneling faces is given. The new knowledge obtained is the basis for creating a method for calculating rational parameters for the location of de-stressing pre-drilled wells. Originality. An objective assessment of the degree of adequacy and reliability of the computational experiment results has been made under the condition of using a new geomechanical model with mine studies of seismic-acoustic signal parameters and the initial gas release velocity. The main tendencies of vertical σу, horizontal σх and σz, as well as stress intensity propagation have been identified. The obtained results of exploring the bottom-hole mass are aimed at substantiating the parameters of anti-outburst measures for all preparatory mine workings. Practical implications. The conducted research is implemented in creation of a calculation method and recommendations for the selection of rational parameters for the location of de-stressing pre-drilled wells for the purpose of weakening the rock mass, surrounding the tunneling face, and reducing the probability of gas-dynamic phenomena occurrence due to the controlled weakening of adjacent rocks.