Study on Gas Drainage Technology in Goaf of Steep Seam

Aiming at the problem of gas control in the upper corner of steeply inclined coal seam, taking 3103 working face of a mine as an example, this paper determines the height range of fracture zone by combining theoretical empirical formula with on-site investigation of microseismic monitoring technology, designs the parameters of drainage borehole during production, and analyzes the gas drainage effect of long-strike borehole through on-site experiments. The results show that the average gas extraction concentration of the long borehole along the strike of 3103 working face is 53.55%, and the average gas extraction purity is 5.37 m3/min. After treatment, the gas concentration in the upper corner is about 0.4%, and the concentration in the return air roadway is about 0.3%, which ensures the control effect of gas extraction quantity