低透气性煤层深孔聚能爆破增透技术及实践

Permeability Improved Technology and Practices with Deep Borehole Energy Accumulation Blasting in Low Permeability Seam

针对松树镇煤矿低透气性煤层瓦斯抽采率低的问题,在矿井瓦斯地质研究基础上,分析了聚能爆破煤体致裂机理,将爆破裂隙划分为粉碎区、裂隙发育区和裂隙扩展区,同时对爆破钻孔、装药及封孔工艺进行了设计,并现场应用了深孔聚能爆破增透技术。结果表明,聚能爆破后抽采钻孔平均瓦斯浓度是爆破前的1.70～3.21倍,爆破影响区平均瓦斯体积分数均值为11.26%,是非影响区的2.21倍,而且装药长度越大,爆破增透效果越显著。

According to the low gas drainage rate of the low permeability seam in Songshuzhen Mine, based on the study on the mine gas geology, the paper analyzed the seam fracturing mechanism with the energy accumulation blasting and blasting fracture was divided into crush zone, crack developed zone and crack propagating zone. Blast hole, charging and sealing technology were designed, and energy ac- cumulation blasting and permeability improving technology of deep borehole was applied. The site application results showed that, after the energy accumulation blasting conducted, the average gas drainage density of the borehole was increased by 1.70~ 3.21 times higher than before the blasting conducted. In the blasting influence zone, the average gas drainage density value was 11.26%, which was 2. 21 times higher than the no blasting influence zone. With the explosive loading length increased, the blasting and permeability improving effect would be more obvious.