松软煤层超高压水力压裂技术研究及应用

Research and application of ultra-high pressure hydraulic fracturing in soft coal seam

为了增大煤层透气性,提高煤层的瓦斯抽采效率,保障工作面的安全生产,在N3704西瓦斯巷设计了穿层钻孔超高压水力压裂实施方案,并对压裂效果进行初步考察。结果表明,通过在7号煤层进行煤岩合层压裂,得出压裂后瓦斯抽采纯量效率提高10倍以上,煤层由难以抽采煤层、可抽煤层变为易抽采煤层,煤层透气性系数提高50倍以上;同时,7号煤层在埋深750m条件下,水量达109.72m^3时,压裂之后的抽采半径可以达到50~70m,提高瓦斯抽采效率,改善由于瓦斯制约而不利于生产的被动局面。

In order to increase the coal seam permeability,improve the coal seam gas drainage efficiency,and ensure the safe production in working face,the ultra-high pressure hydraulic fracturing scheme is designed for N3704 west layer-crossing drilling gas drainage roadway,and the fracturing effect is investigated preliminarily.The results show that through the coalbed fracturing in No.7 coal seam,the pure gas drainage efficiency after fracturing is increased by more than 10 times,the coal seam is changed from hard-drainage to easy-drainage,and the coal seam permeability coefficient is increased by more than 50 times;at the same time,under the condition of 750 m buried depth and water volume of 109.72 m^3,the drainage radius after fracturing can reach 50~70 m,the gas drainage efficiency is improved,changing the passive situation caused by gas restriction in coal production.