Division of Geological Exploration Engineering, Huainan Mining Industry Group Corporation Limited Xi'an
Research Institute, China Coal Technology and Engineering Group

针对常规下向穿层钻孔松软煤层卸压、增透和抽采效果差的问题,优选了下向穿层钻孔水力割缝配套装备,研究了下向钻孔水力割缝施工流程、工艺和下向钻孔“分组分排吹”的排水排渣工艺。在潘三煤矿1672(1)运输巷进行了60个下向穿层水力割缝钻孔的效果考察。应用结果表明:水力割缝后煤孔段等效直径增大至370 mm,钻孔煤壁暴露面积比未割缝的钻孔增加了2.3倍;水力割缝钻孔百孔抽采瓦斯纯量达0.5~0.7 m~3/min,比未割缝钻孔的百孔抽采纯量提高了70%以上;下向钻孔“分组分排吹”的排水排渣能有效排出水力割缝残留在孔内的煤(岩)渣和积水,为钻孔抽采提供有利条件,下向穿层钻孔水力割缝技术为煤矿下向孔条带抽采消突提供了有效手段。

According to the poor effect of a soft seam pressure released, improved permeability and gas drainage with a conventional downward drilling passed thr ough strata borehole, a hydraulic slotting matched equipment was optimized for the downward drilling through strata borehole. The paper had a study on the hydraulic S lotting construction process and technique of the downward drilling borehole and the water and cutting discharging technique with " air blowing in group and row" for the downward drilling borehole. In No.1672 ( 1) transportation gateway of Pansan Mine, an effect investigation was conducted on 60 downward passed through strata hydr aulic slotting boreholes. The application results showed that after the hydraulic slotting completed, an equivalent diameter of the borehole at the seam section was incre ased to 370 mm and the coal wall exposed area of the borehole was 2.3 times larger than the borehole without a slotting. The pure gas drainage volume from 100 boreh oles with the hydraulic slotting was 0.5 ~ 0.7 m3/min and was 70% higher than the pure gas drainage volume from 100 boreholes without slotting. The water and cutting discharging of the downward borehole drilling with " air blowing in group and row" could effectively discharge the coal ( rock) cutting and water in the boreholes by the h ydraulic slotting, could provide a favorable condition to the borehole gas drainage and could provide an effective means to the gas drainage and the mine pressure bum p elimination in the mine downward borehole strip zone with the hydraulic sloting technology of the downward passed through strata borehole.