Effect of hydraulic punching pore parameters on pressure relief of high gas outburst coal seam

The range of influence of hydraulic punching determines the arrangement of drilling holes.The rationality of layout drilling can significantly improve coal seam permeability.Therefore, it is very important to explore the impact range of punching.In this paper, the 15th coal seam of Pingdingshan No.8 mine was taken as the test object.Firstly, the high-pressure hydraulic punching equipment was introduced and simulated by FLAC^3D software.The pressure relief effect and the interaction between boreholes under different punching coal output were compared.The simulation data and field test results verified each other.The results show that the borehole diameter and borehole spacing affect the unloading conditions of the surrounding coal.The hole spacing of the coal holes is theoretically about 5 m, and the optimal range of coal output is 0.37-1 t/m.The results can provide technical references for drilling arrangement and hydraulic punching engineering application.