低透气性高瓦斯煤层CO2相变致裂强化增透技术

CO2 Phase-Transition Fracturing Technology for Enhanced Permeability in Low Gas Permeability and High Gas Coal Seams

如何提高煤层透气性是低透气性高瓦斯矿井煤与瓦斯安全高效共采的关键.本文基于液态CO2相变致裂工作原理,分析了爆破煤岩致裂与增透机理.结合陕西蒋家河煤矿ZF201工作面低透气性高瓦斯煤层地质生产条件,进行了爆破钻孔设计,确定了合理爆破有效影响半径等工艺参数.现场试验结果表明,采用液态CO2爆破致裂增透技术后,提高瓦斯抽采纯量1.71倍,共抽采瓦斯105.4万m^3,瓦斯抽采率提高到38.9%,促进了低透气性高瓦斯煤层工作面煤与瓦斯安全高效共采.

How to improve the coal seam permeability is the key to safe and efficient co-production of coal and gas resources for low permeability and high gascoal seams. Based on the liquid CO2 phase-transition fracturing operating principle,this paper analyzes the blasting coal rock fracturing and enhanced permeability mechanism. Combined with the geological and production conditions of low permeability and high gascoal seam in ZF201 working face of Jiangjiahe Coal Mine in Shaanxi Province,the blasting drilling boreholes design is carried out,and the process parameters such as the effective influence radius of blasting boreholes are reasonably determined.The field test results show that after the application of liquid CO2 phase-transition fracturing and enhanced permeability technology,the gas extraction is increased by 1. 71 times,the total gas extraction is1.054×10^4 m^3,and the gas drainage rate is increased to 38.9%,hence the safe and efficient co-production of coal and gas is achieved in the conditions of low gas permeability and high gas coal seams.