近距离突出煤层群首采面瓦斯综合治理技术应用

针对依兰三矿极复杂地质条件下近距离突出煤层群开采时面临的瓦斯突出和回采工作面瓦斯超限、自然发火等问题,从保护层开采影响范围、开采后的残余瓦斯压力、回采面瓦斯涌出量、煤层自然发火角度分析了各煤层开采顺序,确定了首采面布置在上1煤层,从上至下依次开采较为合理。回采前确定采用千米定向钻机预抽中煤层巷道区域瓦斯+中煤层穿层钻孔预抽上1煤层条带瓦斯的区域消突方法;回采期间工作面采用高位钻孔+顺层钻孔的瓦斯治理方法,从而实现卸压抽采、条带消突预抽、实施防灭火工程等。采用以上瓦斯治理方法能够有效解决工作面瓦斯超限,达到了区域消突的目的,千米钻机长钻孔钻孔抽放浓度维持在80%以上,回风流瓦斯体积分数基本稳定在0.4%以下。

Application of comprehensive gas control technology in the first working face of close outburst coal seams

Aiming at gas outburst,disallowed gas concentration,spontaneous combustion and other problems at working face during close outburst coal seams mining under complicated geological conditions in Yilan No.3 Mine,the mining sequence of each seam was analyzed from the protective layer mining influence scope,residual gas pressure after mining,gas emission in working face and coal seam spontaneous combustion,the first working face was located at upper-1 coal seam,and it was reasonable to mine from top to bottom.Before actual mining,regional outburst elimination methods were determined by using kilometer directional drilling machine to pre-pump the gas of middle coal seam roadway area and crossing hole of middle coal seam to pre-pump the gas of the stripe area of upper-1 coal seam,and during actual mining,the gas control methods with high borehole and bedding borehole were adopted at working face,so as to realize pressure-relief gas extraction,stripe outburst elimination pre-extraction,fire preventing and extinguishing engineering,etc.These gas treatment methods could effectively solve the disallowed gas concentration at the working face and achieve the aim of regional outburst elimination.The gas extraction concentration of the long drilling hole of the kilometer drill kept over 80%,and the volume fraction of gas in the return air was basically stable below 0.4%.