低透气性煤层深孔聚能水压爆破增透瓦斯抽采技术

Permeability Improvement Gas Drainage Technology with Deep Borehole Accumulated Energy Hydraulic Blasting of Low Permeability Seam

针对高瓦斯低透气性煤层抽采率低、普通深孔爆破效果差的技术难题,提出了深孔聚能水压爆破增透技术,分析了深孔聚能水压爆破增透的4个关键技术:钻孔定向保直钻进、超长距离输药、双液浆固结封孔和双雷管双导爆索正向起爆。在东保卫煤矿41煤层的现场试验表明:深孔聚能水压爆破与普通深孔爆破相比,煤层透气性系数增大了4倍,瓦斯抽采率提高了15%,瓦斯压力由1.28~2.12 MPa下降到0.47~0.63 MPa,煤层瓦斯含量减少为4.8~5.8 m3/t,工作面推进度提高了45%,为提高低透气性煤层的瓦斯抽采率提供了有效的技术途径。

According to the problems of low gas drainage rate in high gassy and low permeability seam and poor blasting effect of a conventional deep borehole,a deep borehole permeability improvement technology with the accumulated hydraulic blasting was provided and four key technologies for permeability improvement with deep borehole accumulated hydraulic blasting were analyzed, including the borehole with directional vertical drilling,overlong distance explosive transportation,double grouts consolidated borehole sealing and forward detonation with double detonators and double primacords.The site trial in No. 41 seam of Dongbaouei Mine showed that compared to the conventional borehole blasting,the deep borehole accumulated energy hydraulic blasting could make the seam permeability coefficient increased by four times,the gas drainage rate increased by 15%,the gas reduced from 1. 28~2. 12 MPa to 0. 47~0. 63 MPa,the gas content of the seam reduced to 4. 8~5. 8 m3/t,the advancing rate of the coal mining face increased by 45% and the deep borehole accumulated energy hydraulic blasting technology could provide an effective technical access to improve the gas drainage rate of the low permeability seam.