高强度开采综放工作面上隅角瓦斯联合抽采实践

针对传统单一的上隅角瓦斯治理技术不能有效解决高强度开采综放工作面上隅角瓦斯严重超限的问题,以王家岭煤矿为工程背景,提出了利用上隅角插(埋)管和高位定向钻孔对瓦斯进行联合抽采方案。上隅角插(埋)管抽采即在工作面回风巷铺设瓦斯抽采管路,管路沿回风巷走向延伸至上隅角,在管口位置形成稳定负压区抽采上隅角瓦斯,通过抽吸作用形成人工风流,扰动上隅角位置的回旋涡流,降低瓦斯浓度。同时在工作面回风巷开掘钻场,施工高位定向钻孔向工作面切眼方向钻进,通过定向钻进技术使钻孔轨迹在采空区裂隙带内延伸,抽采采空区高浓度瓦斯。应用结果表明,上隅角插(埋)管和高位定向钻孔联合抽采后,瓦斯抽采纯量稳定在3.40~6.20 m 3/min,平均为4.91 m 3/min;工作面上隅角瓦斯体积分数呈阶梯式下降,最终稳定在0.30%~0.52%,平均为0.42%,上隅角瓦斯治理效果显著。

Combined gas drainage practice at upper corner of high-intensity fully mechanized caving face

In view of traditional single upper corner gas control technology cannot effectively solve problem of severe over-limit of gas at upper corner of high-intensity fully mechanized caving face,taking Wangjialing Coal Mine as engineering background,the paper puts forward a scheme of combined gas drainage by use of upper corner inserted(buried)pipe and high-level directional boreholes.To insert(bury)pipe at upper corner,gas drainage pipe is laid in return air lane of working face.The pipe extends along direction of return air lane to upper corner and forms a stable negative pressure zone at the pipe mouth to extract gas at the upper corner.Artificial air flow is formed through suction to disturb cyclotron vortex at the upper corner and reduce gas concentration.At the same time,in drilling site of the return air lane of the working face,the high-level directional borehole is constructed to drill in direction of cutting holes of working face,and the borehole track is extended in fissure zone of goaf through directional drilling technology to extract high concentration gas in the goaf.The application results show that after the combined gas drainage of upper corner inserted(buried)pipe and high-level directional borehole,gas drainage pure volume is stable at 3.40-6.20 m 3/min,with an average value of 4.91 m 3/min;gas volume fraction in upper corner of the working face decreases in steps,and finally stabilizes at 0.30%-0.52%,with an average value of 0.42%.The gas control effect in upper corner is significant.