工作面顺层钻孔瓦斯抽采掏穴工艺技术研究

Research on the Technology of Bedding Borehole Enlarging for Gas Drainage in Working Faces

2014年6月,煤科集团沈阳研究院有限公司编制的《2号煤层区域突出危险性预测报告》中确定九龙矿开拓区域第Ⅰ、第Ⅳ、第Ⅴ地质单元为突出危险区。矿井为突出矿井,为了更好地治理该区域瓦斯,确保矿井安全生产,作者在平巷间隔4~8 m施工了顺层钻孔预抽瓦斯,并采用掏穴钻头将钻孔从94 mm提升到220 mm,通过对比普通钻孔和掏穴钻孔的瓦斯抽采参数,研究了掏穴钻孔的瓦斯抽采效果。研究结果表明,相比没有掏穴钻孔,掏穴后钻孔中瓦斯浓度达到原来的1.97倍,瓦斯抽采量明显增大,混合量达到原来的1.73倍,抽采纯量达到原来的3倍。掏穴工艺可以增大钻孔煤层暴露面积和钻孔周围煤体卸压范围,增强煤层透气性,使瓦斯流动场扩大,增加了单孔抽采半径,提高瓦斯抽采效率,因此九龙矿瓦斯灾害治理具有非常重要的实际意义。

In June 2014,the Prediction Report on the Outburst Risk of Coal Seam 2 prepared by CCTEG Shenyang Research Institute determined that the geological units I,IV and V in the development area of Ji⁃ulong Mine are outburst risk areas.The mine is an outburst mine.In order to better control the gas in this area and ensure the safe production of the mine,the author adopted the bedding borehole at the interval of 4~8 m in the drift for gas pre-drainage,and used the borehole enlarging bit to enlarge the borehole from 94 mm to 220 mm.By comparing the gas drainage parameters of the ordinary borehole and the enlarging borehole,this article studies the gas drainage effect of enlarging boreholes.The results show that compared with the non-enlarging borehole,the gas concentration in the enlarging borehole is 1.97 times the original,the gas drainage volume increases significantly,the mixing volume is 1.73 times the original,and the pure drainage volume is 3 times the original.The borehole enlarging technology can increase the exposed area of the drilled coal seam and the pressure relief range of the coal around the borehole,enhance the permeabili⁃ty of the coal seam,expand the gas flow field,increase the single borehole drainage radius and improve the gas drainage efficiency.Therefore,this research has an important practical significance for the gas disas⁃ter control of Jiulong Mine.