为了解决新源煤矿在近距离煤层群赋存条件下采用倾向穿层钻孔抽采邻近煤(岩)层卸压瓦斯,抽采瓦斯浓度低,抽采率不达标,回采工作面上隅角瓦斯超限严重等问题。通过采用UDEC软件模拟采动覆岩移动破坏规律,获得开采2号煤层时上覆岩层裂隙带范围9-16m,确定倾向穿层钻孔合理布孔参数,钻孔倾角:21°~26°,孔深:44~47m。经在2219工作面试验考察,与原始参数钻孔抽采效果相比,钻孔平均瓦斯抽采浓度增加6倍多,抽采纯量增加15倍多,有效抽采距离增加3倍多,倾向穿层钻孔抽采率从20%提高到56.8%,回采期间上隅角瓦斯浓度能够控制在0.5%以下,保障了矿井安全生产。
In order to solve the problems that the gas extraction concentration was low,the extraction rate could not meet the standard and the gas exceeded the limit seriously in the upper corner of the working face in Xinyuan mine,which adopted the inclining layer- through borehole to extract the relief gas from adjacent seams under the geological condition of close distance coal seam group,the movement and damage rules of overlying strata were simulated by using UDEC software,and the range of fractured zone in overlying strata when mining No. 2 coal seam was 9 ~16m. The reasonable hole arrangement parameters of inclining layer- through borehole were determined,the inclination of borehole was 21°- 26°,and the depth of borehole was 44- 47 m. Through the experimental investigation in the 2219 working face,compared with the gas extraction effect of original parameter borehole,the average gas extraction concentration increased more than 6 times,the gas extraction amount increased more than 15 times,and the effective gas extraction distance increased more than 3 times. The extraction rate of inclining layer- through borehole improved from 20% to 56. 8%,and the gas concentration in the upper corner could be controlled within0. 5%,so as to ensure the work safety of mine.