基于CO_2爆破致裂增透的瓦斯治理技术与实践

Practices on gas control based on CO_2 blasting and permeability improvement technology

为解决利民煤矿09114综采工作面坚硬顶板难以垮落，从而造成工作面上隅角瓦斯和有毒有害气体浓度超限的问题，采用CO2爆破致裂技术，配合注水压裂和退锚辅助措施对采空区顶板岩层进行预裂爆破，以避免顶板突然垮落造成人员伤亡。通过优化09114综采工作面上隅角钻孔设计参数和注水压力，实践结果表明：CO2预裂爆破前，生产时瓦斯体积分数为1．5％～2．0％，检修时瓦斯体积分数为1．0％～1．5％；CO2预裂爆破后，生产时瓦斯体积分数可控制在0．3％～0．4％，检修时瓦斯体积分数可控制在0．2％～0．3％，瓦斯体积分数下降了80％左右；CO2爆破致裂技术增加煤层的透气性53％以上．有利于瓦斯的提前排粟．

In order to solve the difficult falling of the hard roof in No. 09114 fully-mechanized coal mining face of Limin Mine and to solve the gas and harmful gas concentration over limit at the top corner of the coal mining face, with the study determination, a CO2 blasting frac- turing technology with the water injection pressurized fracturing and the bolt withdrawn auxiliary measures of the roof strata above the goal was applied to the pre-fracturing blasting to the roof strata above the roof in order to eliminate the personal casualties coursed by the sud- den roof falling down. With the continued optimizations of the borehole designed parameters and water injection pressure size and practices on the top corner of No. 09114 fully-mechanized coal mining face in Limin Mine conducted,the results showed that before the CO2 pre- fracturing blasting conducted,the gas fractional volume during the coal production was 1.5%-2. 0% and the gas fractional volume during the equipment maintenance was 1.0%- 1.5%. After the CO2 pre-fracturing blasting conducted,the gas fractional volume during the coal production could be controlled at 0.3%- 0.4% and the gas fractional volume during the equipment maintenance could be controlled at 0.2%- 0.3%. The gas concentration decreased by 80%, affter used the CO2 blasting fracturing technology,the permeability of the seam im- proved by 53%,and it could be favorable to pre-drainage gas.