深部突出煤层采动断裂带发育高度确定研究

Study on determination of development height of mining-induced fissure zone in deep outburst coal seam

采用高位定向长钻孔抽采瓦斯技术代替高抽巷抽采采动卸压瓦斯不仅能够大幅缩减岩石巷道掘进量,有效缓解矿井采掘接替紧张局面,而且瓦斯治理效果显著,但高位定向长钻孔抽采瓦斯技术在实际应用中经常会出现因采动覆岩“三带”发育高度范围确定失准,定向长钻孔布置层位过高或过低导致应用效果不佳的问题。针对该问题,以河南平顶山天安煤业股份有限公司八矿己_(15)−15050工作面为研究背景,采用经验公式法和数值模拟实验法确定该工作面煤层采动断裂带发育高度,得到了垮落带最大发育高度为13.2 m,断裂带最大发育高度为48 m。利用千米定向钻机在己_(15)−15050工作面施工高位定向长钻孔对所得的断裂带发育高度进行验证,结果表明:距煤层顶板20 m处上覆岩层岩性较为破碎,断裂带高浓度瓦斯区在距顶板23 m以上;当己_(15)−15050工作面推进至105 m时,高位定向长钻孔与采空区断裂带已充分沟通;己_(15)−15050工作面上隅角及回风流瓦斯均保持在0.47%,且高位定向长钻孔单孔最大瓦斯抽采体积分数达13.2%,日抽采纯量保持在3~4 m^(3)/min,配风量按2500 m^(3)/min计算,高位定向长钻孔抽采瓦斯量可达风排瓦斯量的25.5%~34.0%,期间未出现瓦斯超限,高位定向长钻孔布置在当前层位内能够成功治理上隅角和回风流瓦斯,验证了综合2种方法确定断裂带发育高度的正确性。

The use of high-level directional long borehole gas extraction technology instead of high-level extraction roadway to extract mining pressure relief gas can greatly reduce the amount of rock roadway excavation.And it can effectively relieve the tension situation of mine mining replacement.Moreover,it can achieve remarkable gas control effect.But the high-level directional long borehole gas extraction technology often has problems in practical application.Due to inaccurate determination of the development height range of the upper"three zones"of mining overburden,the directional long borehole layout horizon is too high or too low.The application effect is poor.In order to solve this problem,taking the Ⅵ_(15)-15050 working face of No.8 Coal Mine of Henan Pingdingshan Tian'an Coal Mining Co.,Ltd.as the research background,the development height of mining-induced fissure zone in the coal seam of the working face is determined by using empirical formula method and numerical simulation experiment method.The maximum development height of the caving zone is 13.2 m,and the maximum development height of the fissure zone is 48 m.The kilometer directional drilling rig is used to construct high-level directional long borehole in the Ⅵ_(15)-15050 working face,and the fissure zone development height is verified.The results show that the lithology of overburden is relatively broken at 20 m from the roof of the coal seam,and the high concentration gas area in the fissure zone is more than 23 m from the roof.When the Ⅵ_(15)-15050 working face is pushed to 105 m,the high-level directional long borehole and the fissure zone in the goaf have been fully communicated.The gas in the upper corner and return air flow of the Ⅵ_(15)-15050 working face is kept at 0.47%.The maximum gas extraction volume fraction of a single hole of the high-level directional long borehole is 13.2%.The daily net gas extraction volume is kept at 3-4 m^(3)/min,and the air distribution volume is calculated as 2500 m 3/min.The gas extraction volume of high-level directional long boreholes can reach 25.5%-34.0%of the air exhaust gas volume.During this period,there is no gas overrun,and the high-level directional long boreholes arranged in the current layer can successfully control the gas in the upper corner and return air flow.The correctness of the development height of the fissure zone obtained by the two methods is verified.