Optimized Parameters and Forecast Analysis of High-position Hole for Goaf Gas Drainage

In order to obtain the ideal parameters and drainage quantity of high-position hole for gas drainage, the flow equation of high-position hole for goaf gas drainage is established, and No.1111 Fully Mechanized Coal Mining working face of Zhangji mine was taken as the field for simulating methane flow by Matlab software to gain high-position ideal drainage parameters. It showed that borehole interval should be 0.5 m, the drainage pressure should be in the range from 0.015 MPa to 0.025 MPa, the borehole diameter should be 108 mm. At the same time, in order to control working face air quantity and gas drainage quantity of goaf, the relation of methane quantity drained by wind and methane drainage quantity of high-position hole was analysed, and forecast model of high-position hole drainage quantity was established. The drainage parameters and forecast model of high-position hole can be introduced to the other similar mines of coal seam storage, which is beneficial to safety production for high methane mines.