松软煤层瓦斯抽采钻孔高压气体循环修复增透技术研究  

Research on high pressure gas circulation repair and permeability enhancement technology for gas drainage boreholes in soft coal seam

作　　者：覃木广[1,2] Qin Muguang(State Key Lab of Gas Disaster Monitoring and Emergency Technology,Chongqing 400037,China;China Coal Technology and Engineering Group Chongqing Research Institute,Chongqing 400037,China)

机构地区：[1]瓦斯灾害监控与应急技术国家重点实验室,重庆400037 [2]中煤科工集团重庆研究院有限公司,重庆400037

出　　处：《能源与环保》2021年第7期38-43,共6页CHINA ENERGY AND ENVIRONMENTAL PROTECTION

基　　金：国家重点研发计划资助项目(2018YFC0808305)。

摘　　要：针对松软煤层瓦斯抽采钻孔煤粉堵塞煤层裂隙、煤渣堵塞抽采管路等瓦斯运移通道不畅问题,研究高压气体循环修复增透机理,合理确定循环修复增透气体压力,改造完善高压气体循环修复增透装置,并在赵家寨煤矿进行了现场试验。结果表明:高压气体作用下,煤体解吸收缩产生的拉伸应力是煤体新裂纹生成的主要原因;高压气体对煤体的破壁冲刷作用打通了瓦斯流动通道,实现了抽采钻孔的修复增透;确定了循环修复增透的气体压力的最小值,即解吸收缩产生的拉伸应力应大于煤体的最大抗拉强度;试验钻孔实施修复增透措施后,瓦斯抽采钻孔的瓦斯浓度为修复增透前的1.92倍,瓦斯纯流量为修复增透前的3.24倍,瓦斯抽采效果提升显著。In view of the problems of unsmooth gas migration channel such as coal dust blocking coal seam fissure and cinder blocking drainage pipeline in soft coal seam gas extraction drilling hole,the mechanism of high-pressure gas circulation restoration and anti-reflection was studied,the gas pressure of circulating restoration and anti-reflection was reasonably determined,the high-pressure gas circulation restoration and anti-reflection device was improved and field test was carried out in Zhaojiazhai Coal Mine.The results showed that the tensile stress caused by coal desorption shrinkage under the action of high pressure gas is the main reason for the formation of new cracks.The wall-breaking and scouring effect of high-pressure gas on coal body opens up the gas flow channel and realizes the repair and anti-reflection of drainage borehole.The minimum value of gas pressure for cyclic repair and anti-reflection was determined,that is,the tensile stress caused by desorption shrinkage should be greater than the maximum tensile strength of coal.The gas concentration and pure gas flow rate of the test borehole are 1.92 times and 3.24 times as high as those before the repair and anti-reflection,and the drainage effect of the gas drainage borehole was significantly improved.

关 键 词：松软煤层 瓦斯抽采钻孔 高压气体 循环修复 增透技术 

分 类 号：TD712.6[矿业工程—矿井通风与安全]