放顶煤工作面以孔代巷合理布孔参数

Reasonable Hole Distribution Parameters of High-location Directional Long Drilling Replacing Roadway

为了解决刘家梁矿2号煤层低含量赋存高强度开采引发工作上隅角瓦斯问题,缓解矿井因岩巷掘进造成采掘接替紧张的局面,提出了采用大直径高位走向长钻孔代替工作面低位岩石抽采巷的瓦斯治理技术,结合矿井2号煤层顶板煤岩物理力学参数,通过理论分析、UDEC、FLUENT数值模拟的方法,分别从工作面裂隙带发育、工作面采空区流场分布等不同的专业角度,分析、研究了瓦斯流通通道及赋存规律,为定向高位钻孔合理布孔层位选择提供理论支撑;结合1号钻场瓦斯抽采效果,修正工作面煤岩赋存资料,优化2号钻场抽采设计,调整钻孔布置参数,以工作面瓦斯抽采纯量、上隅角瓦斯浓度为指标,对不同条件下瓦斯治理效果进行对比,实践证明:走向高位长钻孔能够取代低位岩石抽采巷,用于低含量赋存、高强度开采的放顶煤工作上隅角瓦斯治理,治理效果显著,上隅角瓦斯浓度维持在0.6%以下。

To solve the problem of gas in the upper corner of the working face caused by low content and high intensity mining in No.2 coal seam of Liujialiang Mine,alleviate the situation of mining replacement caused by rock roadway driving.A gas control technology was proposed to replace the low rock extraction roadway of the working face with a major diameter high-location directional long drilling.Combining with the physical and mechanical parameters of the roof of No.2 coal seam,through theoretical analysis and numerical simulation,the gas flow channel and its occurrence rule were analyzed and studied from different professional perspectives such as the development of fractured zone in working face and the flow field distribution in goaf in working face,which provided theoretical support for the selection of reasonable layout of directional high level boreholes.According to the gas extraction effect of the No.1 drilling field,the coal and rock occurrence data of the working face were modified,the extraction design of drill yard No.2 was optimized and the drilling layout parameters was adjusted.Taking the pure amount of gas extraction in the working face and the concentration of gas in the upper corner as indicators,the effect of gas treatment under different conditions was compared.The practice proved that the long borehole towards the high position could replace the low rock extraction roadway and be used for the gas treatment in the upper corner of the top coal caving work with low content occurrence and high intensity mining.The treatment effect was remarkable,and the concentration of gas in the upper corner was maintained below 0.6%.