摘要
为研究瓦斯压力对含水合物煤体渗透特性以及滑脱效应影响规律,借助应力–渗流–化学耦合作用含瓦斯水合物煤体三轴试验装置,分别测量不同饱和度、粒径以及瓦斯压力条件下含瓦斯水合物煤体渗透率;在此基础上,结合二次渗透率修正方程量化水合物饱和度与滑脱效应相互间的关系,并进一步定量评价滑脱效应对含瓦斯水合物煤体渗透率的影响程度。研究结果发现:(1)含瓦斯水合物煤体渗透率随瓦斯压力增加呈指数函数降低,下降幅度为14.6%~66.4%,渗透率变化可以分为加速减小变化阶段和平稳变化阶段2种阶段。(2)采用基于渗透率变化率B_(p)与瓦斯压力敏感系数C_(p)评价含瓦斯水合物煤体渗透率对瓦斯压力的敏感程度;瓦斯压力小于1.50或1.625 MPa时,渗透率变化率B_(p)随瓦斯压力增大而快速增大;瓦斯压力敏感系数C_(p)随瓦斯压力增大而快速减小,瓦斯压力敏感程度强。(3)水合物饱和度对滑脱效应有着重要影响,随水合物饱和度增加,滑脱因子呈减小趋势。(4)滑脱效应对含瓦斯水合物煤体渗透率的影响率为30.1%~98.2%,滑脱效应影响率随瓦斯压力增加呈指数函数降低。本试验可为瓦斯水合固化防突技术应用提供数据支撑。
To evaluate impacts of gas pressure on permeability and slippage effect of gas hydrate bearing coal,the permeability was measured for gas hydrate bearing coal under different gas hydrate saturations,particle sizes and gas pressures,by using triaxial testing machine for coupling action of stress,seepage and chemical effect.Then,the relationship between the gas hydrate saturation and the slippage effect was quantified by combining with the secondary permeability correction equation.Furthermore,the slippage effect was quantitatively evaluated on the permeability.The results show that:(1) The permeability of gas hydrate bearing coal exponentially decreases with the increase of the gas pressure with a reduction between 14.6% and 66.4%,and the permeability variation can be divided into two stages,including accelerated decrease stage and stable variation stage.(2) The permeability change rate B_(p) and the gas pressure sensitivity coefficient C_(p) are introduced to evaluate the sensitivity of the permeability of gas hydrate bearing coal to the gas pressure.The permeability change rate B_(p) and the gas pressure sensitivity coefficient C_(p) respectively increase and decrease rapidly with the increase of the gas pressure,if the gas pressure is less than 1.50 or 1.625 MPa,indicating that the sensitivity of the gas pressure is significant.(3) The hydrate saturation has significant influence on the slippage effect and the slippage factor decreases with the increase of the hydrate saturation.(4) The influence rate of the slippage effect on the permeability of the gas hydrate bearing coal ranges from 30.1% to 98.2%,and the influence rate of the slippage effect exponentially decreases with the increase of the gas pressure.The results can provide experimental reference for hydrate method application in coal and gas outburst prevention.
作者
张保勇
赵国建
高霞
吴强
张旭辉
ZHANG Baoyong;ZHAO Guojian;GAO Xia;WU Qiang;ZHANG Xuhui(School of Safety Engineering,Heilongjiang University of Science and Technology,Harbin,Heilongjiang 150022,China;School of Architecture and Civil Engineering,Heilongjiang University of Science and Technology,Harbin,Heilongjiang 150022,China;Institute of Mechanics,Chinese Academy of Sciences,Beijing 100190,China)
出处
《岩石力学与工程学报》
EI
CAS
CSCD
北大核心
2023年第11期2655-2667,共13页
Chinese Journal of Rock Mechanics and Engineering
基金
国家自然科学基金面上项目(51974112)
国家自然科学基金联合基金项目(U21A20111)。
关键词
采矿工程
煤与瓦斯突出
含瓦斯水合物煤体
渗透率
瓦斯压力
滑脱效应
mining engineering
coal and gas outburst
gas hydrate bearing coal
permeability:gas pressure
slippage effect
