松软煤层群穿层钻孔全程筛管下放瓦斯抽采技术

Gas Drainage Technology by Putting down Screen Pipes along Full-length Boreholes Crossing Soft Coal Seams

针对松软煤层群穿层钻孔施工过程中成孔率低、易塌孔堵塞瓦斯抽采通道、抽采效果差等问题,分析了穿层钻孔全程筛管下放瓦斯抽采技术原理及施工工艺,并在神华宁煤集团石炭井焦煤公司进行了现场试验,结果表明：全程筛管下放瓦斯抽采技术在松软煤层群穿层钻孔中的钻孔施工成孔率达到100%,筛管下放成功率为93%;相比未下放筛管瓦斯抽采技术,单孔平均瓦斯抽采浓度提高了0.2 -3. 5 倍,平均瓦斯抽采流量提高了0. 7-7. 2 倍.该技术在穿层钻孔瓦斯抽采中的应用提高了钻孔成孔率,保证了钻孔瓦斯抽采效果.

To aim at the problems of lower hole-forming ratio,easy blockage of gas drainage channels and poor drainage effect in gas drainage process by crossing borehole in the soft seams with low permeability,analysis was carried out on the technical principles and construction process of gas drainage by putting down screen pipe along the full length of the crossing boreholes in the soft coal seams,and site tests were conducted in Shitanjing Coke Corporation of Shenhua Ningxia Coal Industry Group Co.,Ltd. The results showed that the hole-forming rate in crossing hole drilling in the soft coal seam was up to 100%,the success rate of putting down the screen pipe along the crossing borehole was is 93% and the success rate of putting the screen pipe into the crossing borehole was 100%. Compared with the traditional gas drainage technology without putting down screen pipes,when this new gas drainage technology was applied,the average gas drainage concentration of a single hole increased 0. 2 ~ 3. 5 times and the average gas drainage flow increased 0. 7 ~ 7. 2 times. The application of this technology in gas drainage by crossing boreholes improved hole-forming rate and ensured the gas drainage effect by boreholes.