摘要
为高效评价近距离突出煤层群水力冲孔卸压瓦斯抽采效果,基于弹性力学、渗流力学和Klinkenberg效应等理论,建立了包含煤岩变形、瓦斯运移、孔隙率和渗透率演化数学方程的低透气性含瓦斯煤气固耦合模型,采用COMSOL Multiphysics数值模拟软件模拟分析了近距离突出煤层群水力冲孔钻孔周围煤体瓦斯压力与孔径之间的时空演化规律;基于质量守恒定律建立了近距离突出煤层群瓦斯抽采有效影响半径理论计算公式,并在贵州盘江煤电集团公司松河煤矿进行了工程试验及应用。得到以下结论:1)水力冲孔后,近距离煤层群各煤层的瓦斯抽采变化规律基本同步,水力冲孔的孔洞半径越大,影响半径越大,瓦斯抽采效果越好;2)现场试验结果显示,水力冲孔显著地改善了煤层瓦斯卸压抽采效果,且距离水力冲孔的孔洞越近,增透与卸压效果越好,瓦斯抽采体积分数和流量越大,考察孔对比结果确定了松河煤矿水力冲孔卸压抽采70 d的有效影响半径为4~5 m;3)将现场数据代入近距离突出煤层群瓦斯抽采有效影响半径理论公式中,得到的结果与数值模拟结果近似表明该理论公式的可行性。研究结果对近距离低渗透煤层群的瓦斯治理及效果评价具有良好的指导意义。
In order to effectively evaluate the effect of pressure relief and gas drainage of hydraulic punching, based on elastic mechanics, seepage mechanics and Klinkenberg effect, a solid-gas coupled model containing deformation equations of coal and rock, equations of gas migration and evolution equations of porosity and permeability was established, the spatio-temporal evolution law between diameter of borehole with hydraulic punching and gas pressure in the coal seam around borehole with hydraulic punching was simulated and analyzed with COMSOL Multiphysics, and the theoretical calculation formula of effective influence radius of gas extraction in short-distance coal seams group with the risk of outburst was established based on the law of conservation of mass, which was applied in Songhe Coalmine. Studies have shown that, 1) The gas drainage changes of each coal seam in the short-distance coal seams group are basically synchronous after hydraulic punching. The effect of gas extraction and influence radius increase with the increase of borehole size of hydraulic punching. 2) The effect of pressure relief and gas drainage in the coal seam are significantly improved after hydraulic punching according to the field test result. The closer it is to the borehole of hydraulic punching, the better the effect of pressure relief effect and permeability improvement is, so are the concentration and flow rate of gas extraction. According to the comparison results of inspection boreholes, the effective influence radius of pressure relief and gas drainage are 4-5 m on the 70 days after hydraulic punching.3) The results are similar to those of numerical simulation after substituting field data into the effective influence radius theoretical formula of gas extraction in short-distance coal seam group, which shows the feasibility of the theoretical formula. The research results have good guiding significance for the gas control and effect evaluation of the short-distance coal seams group with low permeability.
作者
曹佐勇
王恩元
何学秋
汪皓
刘泉霖
张光辉
罗飞
王聪
徐佑林
CAO Zuoyong;WANG Enyuan;HE Xueqiu;WANG Hao;LIU Quanlin;ZHANG Guanghui;LUO Fei;WANG Cong;XU Youlin(Key Laboratory of Coal Methane and Fire Control,Ministry of Education,China University of Mining and Technology,Xuzhou,Jiangsu 221116,China;Institute of Mining Engineering,Guizhou Institute of Technology,Guiyang,Guizhou 550003,China;Guizhou Administration of Coal Safety,Guiyang,Guizhou 550004,China;School of Safety Engineering,China University of Mining and Technology,Xuzhou,Jiangsu 221116,China;School of Civil and Resources Engincering,University of Science&Technology Beijing,Beijing 100083,China;Guizhou Panjiang Coal and Electricity Giroup Co Ltd,Guiyang,Guizhou 550081,China;Guizhou Songhe Coal Mine Development Co Lid,Panzhou,Guizhou 553526,China)
出处
《采矿与安全工程学报》
EI
CSCD
北大核心
2021年第3期634-642,共9页
Journal of Mining & Safety Engineering
基金
国家自然科学基金项目(51574231,51764010)
安全生产重大事故预防关键技术科技项目(guizhou-0001-2017AQ)。
关键词
气固耦合模型
近距离煤层
水力冲孔
卸压瓦斯抽采
有效影响半径
gas-solid coupling model
short-distance coal seam group
hydraulic punching
pressure relief and gas drainage
effective influence radius
