小纪汗井田地层介质渗透特性及煤层为主含水层成因机制

发布时间：2018-09-11 18:23

【摘要】：以陕北榆横矿区特殊地质背景为基础,通过瞬态渗透试验研究小纪汗煤矿煤系地层的渗透力学特性,基于采集的岩样两端孔隙压差时间序列,通过差分得到渗流速度及其变化率的时间序列,基于最小二乘法计算得到了各层岩样在不同围压下全应力应变过程中的渗透率、非达西流因子及加速度系数,比较了不同岩层的最大渗透率及最小渗透率。研究表明:1随着压缩应变的增加,煤样应力峰值滞后于渗透率峰值;2应力峰后阶段,煤样非达西流因子及加速度系数先急剧增加后显著下降,两者峰值滞后于应力峰值;3洛河组中粒长石砂岩与2号煤层岩样峰后的最高渗透率显著高于其他岩层;4煤样的渗透率峰后约为1×10-15m2量级,普遍高于一般煤矿煤层的渗透率;5所有岩层中,富县组砂质泥岩的渗透率最低,可视为隔水层。
[Abstract]:Based on the special geological background of Yuheng mining area in northern Shaanxi, the permeability mechanics characteristics of coal measure strata in Xiaojihan coal mine were studied by transient permeation test, based on the time series of pore pressure difference between the two ends of the collected rock samples. Based on the least square method, the permeability, non-Darcy flow factor and acceleration coefficient of rock samples under different confining pressures are calculated by using the time series of seepage velocity and rate of change. The maximum permeability and minimum permeability of different formations are compared. The results show that with the increase of compressive strain, the peak stress of coal sample lags behind the peak stress peak of permeability and the non-Darcy flow factor and acceleration coefficient of coal sample increase sharply and then decrease significantly. Their peak values lag behind the peak value of stress, which is about 1 脳 10-15m2 after peak permeability of medium-grained feldspar sandstone and No. 2 coal seam samples. The permeability of sand mudstone in Fuxian formation is the lowest, which can be regarded as water-separating layer.
【作者单位】：江苏师范大学江苏圣理工工程学院;中国矿业大学深部岩土力学与地下工程国家重点实验室;
【基金】：国家重点基础研究发展计划(973)资助项目(2013CB227900) 国家自然科学基金资助项目(51574228,51674241)
【分类号】：TD821;TD163.1

【相似文献】