Abstract:
Jining coal mine is a typical low-permeability coal mine, the controllable shock wave technology is one of an ideal measure for increasing the permeability of low-permeability coal seams.Parameters such as the controllable shock wave operating point spacing, the number of single-point operations, and the orifice retention depth that are suitable for the mine have not yet been resolved.In view of the problems, reasonable operating parameter design of controllable shock wave anti-reflection technology is carried out in the mining area and non-mining area of the low-permeability coal seam of Jining coal mine.Considering the factors of safety and operation effect, two kinds of orifice retention depths of 0-30 m and 0-40 m are designed.Two kinds of operating point spacings of 6 m and 9 m are designed considering the impact of shock wave superposition and single-hole operation efficiency.Three single-point operations with 6 times, 8 times and 9 times are designed considering the physical property gap of the coal seam.The 3
# anti-reflection hole in the non-mining area takes the operating point spacing of 9 m, and the single-point operation has 6 parameters.The average daily drainage volume of the anti-reflection boreholes in the mining area increased by 5.9 times; the effect of the retention depth of the orifice on the anti-reflection effect is irregular; the drainage volume of the 1-2
# observation hole at a distance of 60 m from the antireflection hole higher than this group.The results show that the controllable shock wave operating parameters of Jining coal mine are the best at 9 m operation point spacing and 6 single-point operations; the effect of retained hole depth on the anti-reflection effect is irregular and can be maintained at 0-40 m according to site construction experience.The maximum impact distance of controllable shock wave on the coal seam of Jining coal mine reaches about 60 m.