凤凰山矿15#煤层U型通风工作面高位钻场钻孔瓦斯抽放技术研究

Research on high-level drilling site for gas drainage at U-type ventilation mining face in No.15 coal seam of Fenghuangshan Coal Mine

针对凤凰山矿151304综采工作面U型通风系统下开采初期瓦斯超限实际,结合矿井煤层赋存情况,经论证得出其上覆9#煤层的瓦斯涌出是151304工作面瓦斯涌出的主要来源;根据9#煤层存有272m实体煤且原始瓦斯含量大的特点,实施高位钻场钻孔瓦斯抽放。现场应用结果表明,该条件下高位钻场具有布置钻孔多、抽放浓度高等优点,可有效抽采和拦截9#煤层卸压瓦斯向15#煤层采空区的涌入,并有效改变15#煤层采空区瓦斯流态。

In view of gas overrun during the initial mining period at No. 151304 fully mecha- nized mining face with U-type ventilation system in Fenghuangshan Coal Mine and the conditions of coal seam occurrence, the gas emission amount in No. 9 overlying coal seam was calculated, accounting for 73% of overall gas emission amount of No. 151304 mining face, which is the main source of gas emission. According to the characteristics of No. 9 coal seam in thickness of 272 m and high initial gas content, the gas drainage was carried out at high-level drilling site with 24 boreholes. The application results showed that the high-level drilling site, characterizing of such advantages of much more boreholes and high concentration of drained gas, achieved effective gas drainage and avoided pressure relief gas to rush in goaf from No. 15 coal seam. The gas flow re- gime in goaf of No. 15 coal seam was effectively changed, solving the big problem of gas overrun at mining face caused by large quantity of gas rushing in goaf in instant from overlying adjacent coal seam.