Exploration on gas drainage technology and equipment of fracture zone in coal seam roof
YAN Baoyong CAO Liu ZHANG Jiagui
采空区与回风巷上隅角瓦斯超限情况亟待解决。为了对采空区裂隙带内瓦斯进行抽采,降低瓦斯浓度。提出了采用高位定向长钻孔代替传统高抽巷对采空区上隅角瓦斯进行治理的方案,分析了高位定向钻孔的直径大小、层位高低、深度等对裂隙带瓦斯抽采效果的影响,并以大直径定向钻机ZYWL-13000DS在双柳煤矿33(4)13工作面钻进为案例进行验证。结果表明:①定向钻孔直径对瓦斯抽采效率影响较大,因此应在地质条件与钻机性能允许的情况下,选择尽可能大的钻孔直径;②煤层顶板5~8倍采高内为定向钻孔较为适合的施工层位;③在不塌孔的情况下,随着定向钻孔的深入,瓦斯抽采效果逐渐提升,且随着煤矿的回采,高位钻孔涌出的瓦斯会呈平衡状态。实例分析表明:在定向钻进4个孔,且1孔失效的情况下,瓦斯抽采总量仅比高抽巷抽采量低2m3/min,但采用高位定向长钻孔工艺进行瓦斯抽采能使成本降低70%以上,使有效施工周期缩短75%以上。
The gas over-limit issue in the upper corner of the gob and the return air entry needs to be solved urgently. In order to drain the gas in the fractured zon e of the gob and reduce the gas concentration,a high-position directional long borehole is proposed to replace the traditional high-drainage roadway to control the gas i n the upper corner of the gob. The effect of high-position directional dilling diameter,layer height,depth,etc. on the gas drainage effect in the fractured zone is verified b y a case study of the large-diameter directional drilling machine ZYWL-13000 DS drilling in the 33( 4) 13 working face of Shuangliu Coal Mine. The results show that:① The diameter of the directional borehole has a great influence on the efficiency of gas drainage. Therefore,the largest possible borehole diameter should be selected wh en the geological conditions and the performance of the drilling rig permit; ②The 5 ~ 8 times the mining height of the coal roof is a more suitable construction level for directional drilling; ③Without collapsing the hole,with the depth of the directional drilling,the gas drainage effect gradually improves,and with the mining of the coal min e,the gas gushing from high-level drilling will be in a balanced state. The case analysis shows that: in the case of directional drilling of 4 holes and 1 hole failure,the tot al amount of gas drainage is only 2 m3/min lower than that of the high-drainage roadway,but the application of high-position directional long drilling technology for gas d rainage can make the cost reduce by more than 70%, and the effective construction period is shortened by more than 75%.
high-position dilling; directional drilling rig; gas drainage; fracture zone;
主办单位:煤炭科学研究总院有限公司 中国煤炭学会学术期刊工作委员会