麦地掌煤矿2号煤层瓦斯抽采钻孔封孔工艺优化研究

Research on optimization of hole sealing technology for No.2 coal seam gas drainage in Maidizhang Coal Mine

为提高麦地掌煤矿2号煤层顺层钻孔瓦斯抽采浓度及抽采效率,采用“两堵两注”封孔工艺,保证钻孔封孔段两端的封堵效果,提高耐压强度。通过对比不同注浆压力下钻孔瓦斯抽采浓度分布、浓度衰减以及稳定情况,确定麦地掌煤矿2号煤层顺层钻孔注浆压力在1.0 MPa以上,能大幅度提高瓦斯抽采浓度,延长钻孔抽采衰减周期,为2号煤层长时间瓦斯预抽提供技术支撑。

In order to improve the gas drainage concentration and efficiency of the coal seam 2 in Maidizhang Coal Mine, the hole sealing process of "two plugging and two injection" is adopted to ensure the sealing effect at both ends of the hole sealing section and improve the pressure resistance.By comparing the concentration distribution, concentration attenuation and stability of gas extraction from boreholes under different grouting pressures, it is determined that the grouting pressure of the borehole along the seam 2 of Maidizhang Coal Mine is above 1.0 MPa, which can greatly increase the concentration of gas extraction, extend the attenuation period of borehole drainage, and provide technical support for long-term gas pre extraction of coal seam 2.