类保护层抽采瓦斯机理及模式研究

Research on gas drainage mechanism and mode of similar protective layer

针对当前我国软煤层存在着钻进难、护孔难、增透难等问题,提出了在煤层顶/底板施工抽采钻孔的类保护层抽采瓦斯方法。通过岩体加载试验,研究了岩石的应力—渗透率—时间之间的定性关系,分析了岩石的破裂压力;探讨了软、硬煤层在类保护层开采模式下瓦斯的运移产出机理;构建了类保护层钻孔采前、采中、采后抽采模式。通过在鹤壁中泰矿业公司进行类保护层单孔抽采试验并使用CYT技术进行强化范围探测,结果表明,类保护层抽采钻孔单孔强化范围可达1601m2,在抽采计量的近5个月内,单孔抽采纯量平均328m3/d,最大661m3/d。

In view of the current problems of difficulties in drilling, borehole supporting and the enhancement of permeability in soft coal seams in our country, the gas drainage of similar protective layer during the construction of coal seam roof and floor was proposed. Through the loading test of rock mass, the quantitative relationship of rock stress-permeability-time was stud- ied, the fracture pressure of rock was analyzed, the gas migration and emission mechanism dur- ing the similar protective layer mining for soft or hard coal were discussed, and the gas drainage modes before, during and after drainage were established. The gas drainage from a single bore- hole in similar protective layer was tested in Hebi Zhongtai Mining Company and the CYT tech- nique was adopted to strengthen the detection range. The results show that the strengthening range of single borehole is up to 1601 m2 , the average amount of gas drainage is 328 m3/d, and the maximum amount is up to 661 m3/d in the past 5 month.