Shaanxi Coal and Chemical Technology Research Institute Co. ,Ltd.

为解决高突矿井试验工作面未开采保护层区域瓦斯浓度超限难题,基于COMSOL数值模拟分析了抽采参数对煤层瓦斯预抽效果的影响规律,通过物理相似模拟明确了采动卸压瓦斯导流通道。结合工程实际采掘进度,划分“掘进期”和“回采期”,分别开展瓦斯防治工作,采用立体式瓦斯抽采技术开展“顺层+穿层”钻孔瓦斯抽采。分析了掘进期高负压顺层钻孔与穿层钻孔的预抽效果,对比回采期断层附近穿层钻孔瓦斯浓度,研究了瓦斯抽采效果与工作面推进距离的关系。研究结果表明:不同布孔条件下,钻孔外侧瓦斯有效抽采半径在5m左右,钻孔间距设置为10m较为合理。掘进期,通过底抽巷施工穿层钻孔抽采邻近层瓦斯,配合顺层钻孔抽采使煤层瓦斯含量由24.37m3/t降至6.76m3/t,煤层瓦斯压力由1.62MPa降至0.47MPa;回采期,进风巷施工低负压高抽钻孔抽采上层采空区瓦斯,最大瓦斯浓度仅为8.7%。未开采保护层区域瓦斯抽采结合卸压瓦斯抽采技术成功消除了M18煤层的煤与瓦斯突出危险性。

To solve the problem of gas concentration exceeding the limit in the unmined protective layer area of the high outburst mine test working face,the influence of extraction parameters on the pre extraction effect of coal seam gas was analyzed based on COMSOL numerical simulation. The gas diversion channel for pressure relief during mining was clarified through physical similarity simulation. Based on the actual mining progress of the project,the gas prevention and control work was divided into two steps:the “excavation period” and the “recovery period”. The three-dimensional gas drainage technology was adopted to carry out the “layer by layer+through layer” drilling combined gas drainage. The pre extraction effect of high negative pressure layer drilling and through layer drilling ( non depressurized area) during the excavation period was analysed. The gas concentration relationship of through layer drilling (replenishment) near the fault during the recovery period was compared,and the relationship between gas extraction effect and recovery mileage was studied. The results show that under different drilling conditions,the effective gas extraction radius on the outer side of the borehole is about meters,and the spacing between boreholes is set at meters. This could be more reasonable. During the excavation period,the gas content in the coal seam is reduced from 24. 37 m3 / t to 6. 76 m3 / t. The coal seam gas pressure decreased from 1. 62 MPa to 0. 47 MPa. During the mining period,low negative pressure and high pressure drilling were carried out on the side of the track to extract gas from the upper goaf,with a maximum gas concentration of only 8. 7%. The combination of gas extraction and pressure relief gas extraction technology in the unexplored protective layer area has successfully eliminated the risk of coal and gas outburst in the M18 coal seam.

国家自然科学基金青年科学基金项目(51904236)

赵泓超,王秦生.高突矿井未开采保护层区域瓦斯治理研究[J].矿业安全与环保,2024,51(3):56-64.

ZHAO Hongchao,WANG Qinsheng. Research on gas control in unexploited protective layer areas of high outburst mines[J].Mining Safety & Environmental Protection,2024,51(3):56-64.