青龙煤矿11615工作面高位定向长钻孔瓦斯抽采分析

Study on gas drainage laws of high-level directional long drilling in 11615 working face of Qinglong coal mine

为解决青龙煤矿11615回采工作面上隅角瓦斯浓度超限难题,结合该工作面实际瓦斯赋存情况,采用高位定向长钻孔瓦斯抽采技术方法开展瓦斯抽采。对比了瓦斯抽采效果与钻孔距回风巷距离远近的关系,研究了瓦斯抽采效果与回采里程的关系,总结了高位定向长钻孔的瓦斯抽采规律。研究结果表明:回采过程中,通过高位定向长钻孔抽采采空区上覆岩层瓦斯,回采工作面上隅角瓦斯浓度降低到0.25%~0.35%,解决了该采空区上隅角瓦斯浓度超限问题;钻孔距回风巷距离为40m时,抽采瓦斯浓度基本稳定在18.5%左右,抽采效果最佳;随着回采里程的增加,钻孔抽采效果呈上升趋势,但在抽采末期有所下降。说明高位定向长钻孔对降低采空区及回采工作面上隅角瓦斯发挥了一定作用,提高了回采过程中瓦斯治理效率。

To solve the problem of over-limit gas concentration in the upper corner of the 11615 working face in Qinglong coal mine,gas extraction is carried out by using high-level directional long drilling gas drainage technology,combined with the actual gas occurrence of working face.The relationship between the drainage effect and the distance of borehole far away from the return airway is compared.And the relationship between the gas drainage effect and the mining distance is studied.Further,the gas drainage laws of the high-level directional long drilling are summarized.The research results showed that during the mining process,the gas in the overburden strata is drained by high-directional directional long drilling,and the corner gas concentration in the mining face is reduced from 0.25%to 0.35%,which solved the problem of corner gas concentration exceeding the limit in the working face;when the distance between the borehole and the return airway is 40 m,the drainage gas concentration is basically stable at about 18.5%;which indicated that the drainage effect is the best.With the increase of the mining mileage,the drilling drainage effect is also increasing,but it decreased at the end of drainage stage.The high-level directional long drilling has played a certain role in reducing the gas in the goaf and the upper corner of mining face,and improved the gas management efficiency during the mining process.