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潘一东矿低透气性煤层穿层钻孔掏穴增透技术研究
Study on Coal Layer Anti-reflection Technology of Low Gas Permeability Coal Seam in Pan Yidong Coal Mine
【作者】 程昊;
【导师】 戴广龙;
【作者基本信息】 安徽理工大学 , 安全技术及工程, 2012, 硕士
【摘要】 本文主要通过对煤与瓦斯突出机理、钻孔周围瓦斯的流动规律、穿层钻孔预抽瓦斯技术等理论知识的学习研究,结合数值模拟技术及现场工业测试等多种方法,对潘一东矿煤层透气性差、瓦斯难以抽放等问题开展了底板穿层钻孔掏穴扩孔强化增透技术的研究。首先,从理论上分析了钻孔瓦斯流动规律、穿层钻孔抽采瓦斯消突机理等;然后,对现场潘一东矿11-2煤层瓦斯基础参数等进行了测试,并建立了穿层钻孔抽采瓦斯的几何模型,利用FLUENT软件对原始钻孔和掏穴钻孔周围瓦斯压力的变化情况进行了数值模拟,从理论上得出掏穴扩孔前后钻孔的抽采影响范围:扩孔前为2m,扩孔后达到了3m。采用示踪气体法在现场对掏穴扩孔前后钻孔的抽采影响范围进行了测试,测得的结果与数值模拟的情况基本致。根据得到的抽采半径对钻孔进行了优化布置:将11-2煤层穿层钻孔布置由4m×4m优化为为6m×6m网格化进行,既减小了钻孔施工量,又提高了瓦斯抽放效率。最后对潘一东矿穿层钻孔掏穴增透技术的消突效果进行了考察验证,通过预抽煤层瓦斯,其有效控制范围内的瓦斯含量、瓦斯压力、煤体坚固性系数f、最大钻屑量Smax、Δh2、瓦斯放散初速度△p均低于《防治煤与瓦斯突出规定》中的临界值,消突效果良好,为后期煤巷掘进提供了保障,保证了矿井的安全高效生产。
【Abstract】 This article mainly study the problem of the gas drainage in low permeability coal seam in Pan Yidong coal mine. It researched about borehole gas drainage strengthening antireflection technology by cutting hole through the study of mechanism of coal and gas outburst, gas flow pattern around the borehole, pre-drainage gas technology, combined with the computer numerical simulation technology and industrial test in Pan Yidong coal mine. First of all, it lays the theoretical basis by studying of borehole gas flow rule, borehole drainage to prevent gas and coal outburst mechanism. Then, we tested the gas basic parameters of coal-bed of11-2, build a geometric model of the borehole gas drainage, investigated the change of the pressure around the original drilling and cutting hole drilling by FLUENT numerical simulation and analysised the influence radius of the drilling before and after cutting hole. Conclusion:the original borehole effect radius is2m and the cutting hole influence range reached3m. It tested the effective drainage radius of borehole before and after cutting hole reaming by the method of tracer gas of actual conditions. The measured results were according to the numerical simulation results. According to the borehole effective drainage radius, the optimization design of borehole spacing and drilling field arrangement is carried out. Though calculating:the arrangement of11-2Grossmeasures boreholes in coal seam is according to the6m*6m grids. Last of all,it studied about the cutting hole reaming antireflection effect and drainage effect of the Pan Yidong coal mine.Though a cutting hole of borehole gas drainage, the gas pressure, gas content, the largest drilling cutting weight Smax, coal firmness coefficient f,△h2, coal initial velocity of gas△p during the tunnel excavation process in the area of influence shall not exceed the "coal and gas outburst prevention provisions stipulated by the prominent" index critical value; the outburst eliminating effect is good, thereby successfully protect the coal lane tunneling, guarantee safe production of the coal mine.
【Key words】 coal and gas outburst; pre-drainage gas mechanism; drilling layoutoptimization; cutting hole drilling;