低透气性煤层顺层钻孔有效抽放半径测定

Determination of Effective Drainage Radius of Low Permeability Coal Seam

五矿贵石沟井由高瓦斯矿井变为煤与瓦斯突出矿井后,按照相关规定在15号煤层具有突出危险性的区域必须采取钻孔预抽措施,钻孔预抽效果的好坏取决于抽放半径是否合理,阳煤五矿需要尽快查明15号煤层顺层钻孔的有效抽放半径。通过在四采区8421进风顺槽内,采用钻相对压力指标法对矿井15号煤层抽采半径考察工作,对瓦斯压力下降曲线进行拟合,得出在抽放时间为73 d内,采用Φ75mm钻头施工钻孔对15号煤层进行抽放。试验结果显示:有效抽放半径可以达到1.5 m;当抽放时间为90 d时,抽放影响距离可达5.5 m,有效抽放半径为1.8 m,抽采钻孔间距取3.6 m较为符合五矿15号煤层实际情况。

Minmetals Guishigou wells by the high gas coal mine for coal and gas outburst mine, with the outburst risk in coal seam No. 15 in accordance with the relevant provisions of the region must take drainage measures, drainage effect depends on the drainage radius is reasonable, Yang coal mine needs as soon as possible to identify effective pumping 15 no seam drilling on the radius. In four mining area by 8421 into Fengshun groove, the drill relative pressure index method of mine No. 15 coal seam drainage radius of investigation work, the gas pressure drop curve fitting, the time in smoking for 73 days, adopting 75mm bit drilling of No. 15 coal seam pumping On the test results show that the effective drainage radius can reach 1.5m; when the drainage time was 90 days, drainage distance up to 5.5m, the effective drainage radius 1.8m, drainage borehole spacing was 3.6m more in line with the actual situation of Minmetals No. 15 coal seam.