双重孔隙介质中水平井两相渗流

本文研究了双重孔隙介质中水平井两相渗流问题,在流线不变的假定下,给出了水驱油二维渗流含水饱和度分布和见水时间公式。由于亲水岩块的吸渗作用,裂缝系统中含水饱和度沿特征线按指数规律下降,从而双重孔隙介质的见水时间较均质介质的较晚,采油量较多。     

水气二相渗流与双重介质变形的流固耦合数学模型

为了真实反映地质岩体系统内孔隙、裂隙对发生于其中的物理过程的控制与影响,基于岩体渗流水力学和多相渗流力学理论,将工程地质体简化为孔隙一裂隙双重介质,建立了水气二相渗流与双重介质变形的流固耦合数学模型,采用Galerkin有限元方法推导了相应的有限元方程,编制出三维有限元计算程序。算例表明：双重介质模型能够比较准确地描述地质体的结构;在进行注水井数值实验模拟时,考虑耦合与不考虑耦合时的孔隙压力的差别随时间的推移会越来越大。     

双重介质二维不定常渗流

本文用积分变换和分离变量等方法,求得了弱压缩液体在双重孔隙介质中,二维不定常渗流的Laplace变换空间解,用数值反演的公式研究了非稳态变换双重介质裂缝储量比ω和介质间传输系数λ对无限导流垂直裂缝井压力动态的影响。     

化学浆液在岩土介质中的非混溶流动过程

化学浆液在岩土双重孔隙介质中的流动是一个二相驱替过程。对这一过程建立方程描述并求解，结果显示了化学浆液在孔隙系统中的吸渗速度远小于在裂隙系统中的流动速度。     

化学浆液在岩土介质中的非混溶流动过程

化学浆液在岩土双重孔隙介质中的流动是一个二相驱替过程。对这一过程建立方程描述并求解，结果显示了化学浆液在孔隙系统中的吸渗速度远小于在裂隙系统中的流动速度。     

考虑裂隙的几何-力学特性的双重孔隙介质水-应力耦合模型及其有限元分析

建立了一种双重孔隙介质水-应力耦合模型,其特点是可考虑裂隙的组数、间距、方向、连通率、开度、刚度及应力水平对介质的弹性模量、孔隙率及渗透系数的影响,并研制出相应的二维有限元程序.以模拟饱和的双重孔隙岩体在外荷载作用下产生沉降为算例,针对岩体的孔隙率与渗透系数分别是常数及按照本文中所述规律变化的两种工况,考察了不同岩体中的变形、孔隙水压力与裂隙水压力及流速、主应力等的分布与变化.结果表明:将岩体的孔隙率与渗透系数作为应力的函数,与将其作为常量的方法相比,二者对岩体的变形及应力的影响不大,但前者对孔隙水压力、裂隙水压力及流速的影响强烈.     

考虑裂隙的几何-力学特性的双重孔隙介质水—应力耦合模型及其有限元分析

建立了一种双重孔隙介质水—应力耦合模型，其特点是可考虑裂隙的组数、间距、方向、连通率、开度、刚度及应力水平对介质的弹性模量、孔隙率及渗透系数的影响,并研制出相应的二维有限元程序。以模拟饱和的双重孔隙岩体在外荷载作用下产生沉降为算例，针对岩体的孔隙率与渗透系数分别是常数及按照本文中所述规律变化的两种工况，考察了了岩体中的变形、孔隙水压力与及裂隙水压力及流速、主应力等的分布与变化。结果表明：将岩体的孔隙率与渗透系数作为是应力的函数以及是常量的两种方法相比，二者对岩体的变形及应力的影响不大，但前者对孔隙水压力、裂隙水压力及流速的影响强烈。     

双重介质中有限导流垂直裂缝井试井模型求解的新方法

在T.A.Blasingame等人提出的均质油藏中有限导流垂直裂缝试井模型（TPR）的基础上采用Laplace变换与反演技术,完成了双重孔隙介质中有限导流垂直裂缝井试井模型的求解新算法.讨论了介质间窜流、弹性储容比、裂缝导流能力及外边界条件对压力动态的影响,结果表明：用该方法计算的结果与经典的双重介质垂直裂缝井模型一致.这种算法计算速度快,精度满足要求,可用于现代试井分析的自动拟合中.     

裂缝性地层中水质对流模型

一、水质对流模型 被普遍发育的宏观均匀裂隙系所切割的孔隙地层称裂缝性地层,它可用双重介质模型来描述.双重介质中岩块孔隙系统的渗透系数比其裂缝系统的小得很多,但孔隙度却比裂缝系统的大得很多.因而裂缝系统主要起渗流通道的作用,而岩块系统被看作储存、补给源.地下污水在双重介质中渗流时,其溶质(污染物、离子等)在裂缝系统中     

岩土破损力学与双重介质模型

建议了一种新的岩土材料力学分析理论－岩土破损力学，并将岩土抽象为由结构块和结构带组成的双重介质材料。通过两个具体的双重介质模型说明理论能解释许多结构性岩土材料所特有的力学现象。     

COUPLING SIMULATION OF SURFACE FLOW AND SUBSURFACE FLOW OVER POROUS MEDIA

Mathematical model of water flow over porous media is developed, the computer program is compiled , and an example is given to verify the validity of the model. The results of the calculation show that the model is very useful and worth going further study in practical engineering.     

A Note to the Variable Sorptivity Infiltration Equation

A simplification for the variable sorptivity infiltration equation of Poulovassilis et al. (1989) is proposed. The resulting equation has three parameters S _x, c and K ₀. From these, S _x and c are considered as fitting parameters and K ₀ as a physical one. The new empirical infiltration equation is tested for precision, parameter time-dependence and applicability for soil surveys. The test was carried out by comparison with reference solutions i.e. infiltration data obtainedexperimentally, analytically or numerically for two different head conditionsat the infiltration surface. A good agreement is observed for all examinedcases. The dependence of the fitting parameters S _x and c on the initialand boundary conditions, as well as the error that arises by taking intoaccount different values of them, are examined. In fine textured soilsparameter c seems to be very small, so that one can easily suppose that the proposed equation reduces to the well-known Philip's infiltration equation (Philip, 1957).     

求解水动力弥散方程的多单元均衡法

本文给出一种多孔介质溶质输运方程的多单元均衡解法。该方法基于多孔介质溶质输运理论和物质守衡原理,在三角形单元的局部座标系中对溶质传输的物质流强度方程进行差分,直接形成未知函数离散后的系数矩阵。方法简易,形式简单,物理意义直观,实用方便。     

ANALYTICAL AND APPROXIMATE SOLUTION FOR SPHERICAL SYMMETRY DISPERSIVE TRANSPORT IN POROUS MEDIA

Spherical symmetry convective-dispersive transport of a tracer or contaminant from continue and slug injection well in semi-infinite porous media is of significance,especially for the tracer test in huge thick formation.The partial equation describing the transport process belongs to confluent hypergeometric equation.With variable substitution and Laplace transform,the partial equation may be coverted Weber equation and it's solution is represented by parabolic cylinder function.We found the analytical solution by analytical inversion.Besides,we also obtained the early-time and late-time approximate solution.In the paper we compared these solutions and investigated the basic characteristics of concentration distribution and change.In early-time and late-time the approximate solution is of significance.     

A variable sorptivity infiltration equation

Horizontal and vertical one-dimensional infiltration are compared when they both occur in a homogeneous isotropic porous body initially at a uniform low water content _n under constant concentration (₀) or constant pressure head (H ₀) conditions. From a consideration of the physics governing infiltration under such conditions, the conclusion is reached that the magnitude of the pressure head gradient atx=0, wherex=0 denotes the infiltration surface in the horizontal case, must be larger than the magnitude of the pressure head gradient atz=0, wherez=0 denotes the infiltration surface in the vertical case, for all finitet>0, so that for the hydraulic head gradient atz=0 to be greater than (1/2K ₀)S _x t ^–1/2 but smaller than [(1/2K ₀)S _x t ^–1/2+1],K ₀ being the hydraulic conductivity at ₀ andS _x the sorptivity during horizontal infiltration. On these grounds, it is further argued that if the sorptivityS _z is introduced for the case of vertical infiltration, then it must be equal toS _x fort=0 only and that it must decrease with time. Results obtained by solving soil-water flow equations for the infiltration conditions defined above, and from experiment, support the above conclusions. An equation for the relationship between cumulative infiltration and time during vertical infiltration is developed after assuming thatS _z decreases with time in an exponential manner. Cumulative infiltration versus time relationships given by this equation are compared with those obtained from the numerical solution of the soil-water flow equation and from experiment.     

多孔介质内非牛顿流体沿垂直平板的混合对流

本文研究了非牛顿流体在多孔介质内沿垂直等温平板的混合自然和强迫对流。以幂律型渗流规律和边界层近似为数学模型的主要理论依据,得到了问题的精确相似解和近似积分解。对于同向混合对流,近似解与相似解的误差只有3％;对于反向混合对流,两者之间的误差也不超过10％。本文还发现,流体的非牛顿特性对温度场、速度场及多孔介质内的流态转变范围等均有相当显著的影响。     

多孔介质壁面封闭腔体自然对流传热的数值模拟

多孔介质壁面封闭腔体的自然对流在太阳能暖房、蓄热腔体等中有重要的应用。该文针对左侧部分多孔介质壁面矩形封闭腔体,基于有限元法对封闭腔体的自然对流换热进行了数值模拟,得到了在不同Ra数、宽高比A以及不同壁面工况条件下腔体内空气的速度分布,同时获得右壁面的平均Nu数。研究结果表明:随着A的增大,腔体内的流动减弱,右壁面换热减弱;而左侧部分多孔介质壁面对腔体的流动换热产生很大的影响。     

RADICAL FLOW IN POROUS MEDIA WITH DISPERSION AND ADSORPTION

The radical transport of chemical concentration in porous media with dispersion and adsorption was studied in this paper. Using Langmuir‘s adsorption model, the numeri cal equation of concentration transport was derived. The flows with and without adsorption were simulated and analyzed. Comparison of the obtained solution with the known analytical solution for flow without adsorption shows the presented numerical method is correct and effective, which can be used in reservoir engineering