ISSN 1000-3665 CN 11-2202/P
    张东, 刘晓丽, 王恩志. 非均匀多孔介质等效渗透率的普适表达式[J]. 水文地质工程地质, 2020, 47(4): 35-42. DOI: 10.16030/j.cnki.issn.1000-3665.202003065
    引用本文: 张东, 刘晓丽, 王恩志. 非均匀多孔介质等效渗透率的普适表达式[J]. 水文地质工程地质, 2020, 47(4): 35-42. DOI: 10.16030/j.cnki.issn.1000-3665.202003065
    ZHANGDong, . A universal expression of the equivalent permeability of heterogeneous porous media[J]. Hydrogeology & Engineering Geology, 2020, 47(4): 35-42. DOI: 10.16030/j.cnki.issn.1000-3665.202003065
    Citation: ZHANGDong, . A universal expression of the equivalent permeability of heterogeneous porous media[J]. Hydrogeology & Engineering Geology, 2020, 47(4): 35-42. DOI: 10.16030/j.cnki.issn.1000-3665.202003065

    非均匀多孔介质等效渗透率的普适表达式

    A universal expression of the equivalent permeability of heterogeneous porous media

    • 摘要: 多孔介质渗流是普遍的物理过程,涉及地下工程、地热开采、环境工程等各行各业,尤其是工程建设,常面临防渗问题。由于地质条件的复杂性,工程区域地层受到成岩、压实、风化、生物作用等各种影响,故渗流性质复杂,常需要对建设区域的渗流状况进行数值模拟,从而为工程的设计施工提供决策依据。数值仿真结果依赖于对地层介质关键参数的选取,但目前工程多将其视为均匀介质处理,对于介质的非均匀特性考虑较少。文章旨在研究非均质多孔介质渗透率空间分布与等效渗透率的关系。基于连续介质假定、达西定律以及非均匀多孔介质渗透率空间分布函数,建立一维到三维的达西渗流问题模型,通过求解偏微分方程和理论推导,得到基于渗透率空间分布函数的等效渗透率理论表达式,并与有限元计算的数值解进行对比分析,结果表明理论值和数值解误差很小,证明等效渗透率的表达式的合理性。利用该成果可通过多点局部渗透率的测定构建渗透率空间分布函数,从而对整体渗流区域的渗透性质进行快速计算和评估,从而简化异常复杂的工程地质模型以减少计算量需求,对于工程仿真的快速计算和结果评估有重要意义。

       

      Abstract: Flow and transport inside porous media is a common physical process, and it is related to subsurface engineering, geothermal energy extraction, environment engineering and so on. Due to the complexity of geological conditions, strata suffer diagenesis, compaction, weathering, biological effect, etc. The feature of permeability is rather complex, and numerical simulation is utilized to supply data and key information for engineering design and construction, with a larger amount of time and computation. However, the accuracy of simulation directly relies on the key parameters such as permeability. This paper aims to study the relationship of the equivalent permeability and permeability distribution function in the space of heterogeneous porous media. Based on the continuum assumption, Darcy’s law and permeability distribution function, the mathematical model of the Darcy seepage problem from 1D to 3D is established, and the theoretical solution of the equivalent permeability is obtained by solving the partial differential equation. Besides, the theoretical solution and the numerical solution are obtained by using finite element simulation. The results show that they are closed to each other, and the error is quite small, indicating that the expression of the equivalent permeability is correct and valid. The permeability distribution function can be established through multi-points permeability measurements of media, then the seepage properties of the whole porous media can be simulated and evaluated rapidly. The complex geological models are simplified to reduce the computation with the expressions. It is of great significance for the rapid simulation of engineering and the evaluation of simulation results.

       

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