顶板穿层钻孔带压封孔方法

Roof Crossing Strata Borehole with Pressure Sealing Hole Drilling Method

钻孔抽采瓦斯的效果主要取决于钻孔封孔质量,带压封孔技术能够提高抽采钻孔的封孔质量,提高钻孔抽采效果。但是,在现场应用过程中,经常出现封孔水泥浆漏浆导致钻孔报废的情况。新河煤矿通过地面模拟试验,找出了导致封孔水泥浆漏浆的原因,提出了"五段四管三步"带压封孔法,给出了封孔的主要技术参数,解决了顶板穿层钻孔带压封孔漏浆导致钻孔报废的问题,提升了抽采钻孔的封孔质量,提高钻孔抽采浓度、抽采纯量,达到了带压封孔提高抽采效果的目的。通过井下两个相邻钻场进行试验对比,单孔抽采浓度平均提高2.5倍,单位时间内抽采纯量增加1.8～2.2倍。

Drill gas drainage effect mainly depended on the quality of sealing borehole, pressurized sealing technology can improve the drainage borehole sealing quality and gas drainage effect. But, in the field application process, sealing grout leakage caused drilling scrapped. Through the test, the author found the causes of sealing cement slurry leakage, put forward the ＂five sections four tubes three steps＂ borehole sealing method, gave the main technical parameters of hole sealing, solved pressurized sealing grout leakage for borehole in coal seam roof, improved the drainage borehole sealing quality, extraction concentration and net amount, achieved with pressure sealing and improved the extraction effect. Through comparing the two adjacent drill field experiment, single hole drainage concentration increased an average of 2.5 times, time unit drainage net amount increased 1.8-2.2 times.