松软煤层瓦斯抽采孔PVC管护壁技术应用研究

Application Study on Wall Protection Technology with PVC Pipe in Gas Drainage Hole in Soft Seams

摘要:

针对晋城煤业集团赵庄煤业矿区地质构造复杂、煤层松软及透气性差，瓦斯抽采孔由于煤层松软引起孔壁稳定性差，成孔提钻后，短时间内孔壁坍塌，导致瓦斯抽采通道堵塞，抽采率低，抽采效果差的问题。利用在钻孔施工完成后不提钻杆，先在钻杆内部下入抽采筛管进行护壁，提钻后形成瓦斯抽采通道，应用结果表明：该技术与传统提钻后下套管工艺相比，下管效率大幅提高，下管深度达到孔深的98%以上，有利于提高瓦斯抽采效率，对煤矿安全具有重要意义。

Abstract:

Geological structure is complex with soft seams and poor permeability in Zhaozhuang coal mine of Shanxi. Wall collapse of gas drainage hole caused by unstability leads to gas drainage channel blocking, low extraction rate and poor drainage effect. By the technology that drill pipe is kept at the completion of drilling construction and in which gas extraction screen liner is lowered to protect the wall, gas drainage channel can be formed after drill pipe is lifted. The application results show that the pipe lowering efficiency is largely improved comparing with that of traditional drill casing technology. The pipe length is up to more than 98% of the hole depth, which is helpful to improve the efficiency of gas drainage and has great significance for coal mine safety.