薛湖煤矿超高压水力割缝工艺参数优化试验

Optimization test of ultra-high pressure hydraulic slotting process parameters in Xuehu Coal Mine

薛湖煤矿二2煤层瓦斯含量高、透气性差,采用顺层钻孔治理煤层瓦斯存在瓦斯抽采效果差、抽采达标时间长等问题,将超高压水力割缝技术应用于该煤层钻孔瓦斯抽采中。通过单因素试验确定了适用于薛湖煤矿二2煤层的超高压水力割缝优化工艺参数:割缝压力为60~70 MPa,割缝时间为25 min,割缝转速为80 r/min,割缝间距为2 m。现场应用采用该工艺参数的超高压水力割缝技术后,割缝钻孔与普通钻孔相比,前者日均瓦斯抽采体积分数约为后者的1.75倍,日均瓦斯抽采纯量为后者的3.25倍,瓦斯抽采达标时间缩短了约42%,残余瓦斯含量小。

Due to high gas content and poor gas permeability in No.2 coal seam of Xuehu Coal Mine,coal seam gas is treated by borehole along the bed,which has problems such as poor gas drainage effect and long time to reach standard.For the above problems,an ultra-high pressure hydraulic slotting technology was applied to borehole gas drainage of the coal seam.Single-factor test was carried out to determine optimum process parameters of ultra-high pressure hydraulic slotting applicable to the No.2 coal seam of Xuehu Coal Mine:slotting pressure is 60-70 MPa,slotting time is 25 min,slotting speed is 80 r/min and slotting spacing is 2 m.After field application of ultra-high pressure hydraulic slotting technology with the optimized process parameters,average daily gas drainage volume fraction of slotting borehole is about 1.75 times that of ordinary borehole,average daily gas drainage pure volume is 3.25 times,time of gas drainage to reach standard is shortened by about 42%and residual gas content is small.