定向高位长钻孔上隅角瓦斯治理技术

针对常规顶板高位钻孔因钻孔方位及倾角无法控制而难以钻进至设计层位,且有效抽采孔段较短、易出现抽采盲区、抽采不连续等问题,以王家岭煤矿上隅角瓦斯治理为研究背景,在20103综采工作面回风巷布置1组定向高位长钻孔与4组常规高位钻孔进行瓦斯抽采,对比分析了这2种高位钻孔的瓦斯抽采效果,结果表明:定向高位长钻孔有效抽采孔段长,抽采盲区少,能实现连续抽采;定向高位长钻孔单孔平均瓦斯抽采纯量为2.11m^3/min,最大可达2.9m^3/min,与常规高位钻孔相比平均瓦斯抽采纯量提高了约2.77倍,工作面瓦斯抽采率提高了近2倍,有效抽采时间提高了约3.15倍;仅接抽常规高位钻孔时上隅角瓦斯体积分数为1.0%以上,仅接抽定向高位长钻孔时降至0.6%以下,表明定向高位长钻孔治理工作面上隅角瓦斯具有明显优势。

Gas control technology of directional high-level long borehole at upper corner

For problems that normal roof high-level borehole hardly drilled to design position because borehole direction and dip-angle cannot be controlled,and had short effective extraction hole segment,many drainage blind areas,discontinuous drainage and so on,taking upper corner gas control of Wangjialing Coal Mine as research background,agroup of directional high-level long borehole and four groups of normal high-level borehole were constructed for gas drainage in return airway of 20103 fully mechanized working face.Gas drainage effect of the two kinds of high-level boreholes were compared and analyzed.The results show that the effective drainage hole section of the directional high-level long borehole is long,the blind area of gas drainage is few,meanwhile,continuous drainage can be achieved.The average gas drainage flow from the directional high-level long borehole is 2.11 m^3/min and the maximum value achieves 2.9 m^3/min.Compared with normal high-level borehole,the average gas drainage flow from the directional high-level long borehole increases about 2.77 times,the gas drainage rate of working face increases nearly 2 times,and the effect drainage time increases about 3.15 times.The gas volume fraction at upper corner is reduced from more than 1.0% under the condition of only draining gas from normal high-level borehole to less than 0.6% only draining from the directional high-level long borehole,which verifies that the directional high-level long borehole has obvious technical advantages of controlling upper corner gas on working face.