针对乌兰煤矿低透气性煤层群瓦斯含量高、压力大的特点,为解决首采保护层工作面开采过程中瓦斯超限问题,提出穿层钻孔预抽首采层瓦斯、地面钻井抽采卸压瓦斯、走向高位钻孔和上隅角埋管抽采瓦斯的综合措施对突出煤层群开采下的矿井实施瓦斯灾害治理。结果表明:回采期间,抽采钻孔瓦斯浓度和流量随时间变化呈现比较稳定的规律、随工作面推进变化呈现先增加后减小的规律,工作面回风侧最大瓦斯浓度0.36%,上隅角最大瓦斯浓度0.5%,最大抽采瓦斯流量105.8m^3/min,有效地解决了工作面回采期间瓦斯超限问题,实现了工作面安全高效回采。
Aiming at the high gas content and high gas pressure in low permeability coal seams group of Wulan Coal Mine,and the gas overrun of working face in the first protective seam, we proposed the comprehensive gas control scheme comprising gas pre-drainage with crossing-seam drilling in the first mining seam,gas pressure relieving with surface drilling,gas drainage with high drilling along the strike and pipe laying in upper corner. The result showed that the time-varying trend of gas flow and gas concentration was stable,which increased first and then decreased with the working face advancement,the maximum gas concentration was 0. 36% near the air return way of working face,the maximum gas concentration was 0. 5% and the maximum gas drainage flow was 105. 8m^3/min in upper corner,which indicated the gas overrun was effectively solved,and safe and efficient mining was achieved.