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1.
弹塑性变形油藏中多相渗流的数值模拟   总被引:17,自引:0,他引:17  
基于流固耦合力学理论,建立了弹性变形油藏中多相渗流的数学模型,该模型考虑了渗流与变形的耦合作用,以及注采交变载荷作下油藏多孔介质的弹性变形特征,给出了耦合数值模拟方法和算例。  相似文献
2.
The purpose of this study is to analyze the effects of the soil air flow on the process of water infiltration in a 93.5 cm deep vertical column for varied boundary conditions at the surface - positive time constant head; time constant fluxes smaller and greater than saturated soil hydraulic conductivity.Several experiments conducted on a sandy soil column with and without a possible air flow through the wall are presented. Continuous and simultaneous measurements of water content and air and water pressure heads at different depths allow the analysis of the air and water movements within the soil and the determination of the capillary pressure and relative permeability for each phase as functions of the volumetric water content.A numerical solution of the equations describing the simultaneous flow of air and water is compared with the experimental data and with the traditional one-phase flow modeling. The results show that the air movement may significantly affect water flow variables such as infiltration rates, water content profiles, and ponding times.Furthermore, some basic assumptions used in two-phase flow modeling, such as the hydrodynamic stability of the wetting fronts and the pertinence of the relative permeability concept, are discussed in the light of the experimental data.  相似文献
3.
刘大有 《力学进展》1994,24(1):66-74
本文分析了单相流、二相流和多相流等概念上的差异,也分析了单流体模型、双流体模型和多流体模型等概念上的差异,指出前面三种概念是按流动介质的客观物理构成划分的,而后者是按主观采用的研究方法划分的.目前这些概念在使用中存在一些混乱,如二相流与多相流,多相流与多流体模型等.本文还研究了扩散模型、非牛顿流模型和颗粒流模型等,指出前两种模型在分类上属于单流体模型,分析了非牛顿流模型、扩散模型和双(多)流体模型的特点和应用范围,最后,以泥石流为例讨论了以上概念的应用.  相似文献
4.
A numerical method as well as a theoretical study of non-Darcy fluid flow through porous and fractured reservoirs is described. The non-Darcy behavior is handled in a three-dimensional, multiphase flow reservoir simulator, while the model formulation incorporates the Forchheimer equation for describing single-phase or multiphase non-Darcy flow and displacement. The non-Darcy flow through a fractured reservoir is handled using a general dual-continuum approach. The numerical scheme has been verified by comparing its results against those of analytical methods. Numerical solutions are used to obtain some insight into the physics of non-Darcy flow and displacement in reservoirs. In addition, several type curves are provided for well-test analyses of non-Darcy flow to demonstrate a methodology for modeling this type of flow in porous and fractured rocks, including flow in petroleum and geothermal reservoirs.  相似文献
5.
Dual Mesh Method for Upscaling in Waterflood Simulation   总被引:4,自引:0,他引:4  
Detailed geological models typically contain many more cells than can be accommodated by reservoir simulation due to computer time and memory constraints. However, recovery predictions performed on a coarser upscaled mesh are inevitably less accurate than those performed on the initial fine mesh. Recent studies have shown how to use both coarse and fine mesh information during waterflooding simulations. In this paper, we present an extension of the dual mesh method (Verdière and Guérillot, 1996) which simulates water flooding injection using both the coarse and the original fine mesh information. The pressure field is first calculated on the coarse mesh. This information is used to estimate the pressure field within each coarse cell and then phase saturations are updated on the fine mesh. This method avoids the most time consuming step of reservoir simulation, namely solving for the pressure field on the fine grid. A conventional finite difference IMPES scheme is used considering a two phase fluid with gravity and vertical wells. Two upscaling methodologies are used and compared for averaging the coarse grid properties: geometric average and the pressure solve method. A series of test cases show that the method provides predictions similar to those of full fine grid simulations but using less computer time.  相似文献
6.
多相流动的直接数值模拟进展   总被引:4,自引:0,他引:4       下载免费PDF全文
多相流动的直接数值模拟的讨论就是把流场中颗粒周围计算网格缩小到颗粒尺寸以下 进行流动的计算,颗粒的受力不是通过模型计算,而是通过积分表面的黏性力与压力获得. 直接模拟方法的出现标志着人们对多相流动的认识从宏观扩展到微观层次.主要介绍了 几种先进的直接模拟的方法:基于体适应的非结构化移动网格方法;基于固定网格方法;其 它方法.  相似文献
7.
Pore Scale Modeling of Rate Effects in Imbibition   总被引:3,自引:0,他引:3  
We use pore scale network modeling to study the effects of flow rate and contact angle on imbibition relative permeabilities. The model accounts for flow in wetting layers that occupy roughness or crevices in the pore space. Viscous forces are accounted for by solving for the wetting phase pressure and assuming a fixed conductance in wetting layers. Three-dimensional simulations model granular media, whereas two-dimensional runs represent fracture flow.We identify five generic types of displacement pattern as we vary capillary number, contact angle, and initial wetting phase saturation: flat frontal advance, dendritic frontal advance, bond percolation, compact cluster growth, and ramified cluster growth. Using phase diagrams we quantify the range of physical properties under which each regime is observed. The work explains apparently inconsistent experimental measurements of relative permeability in granular media and fractures.  相似文献
8.
环境力学与可持续发展   总被引:3,自引:0,他引:3       下载免费PDF全文
李家春  吴承康 《力学进展》1998,28(4):433-441
展望21世纪,环境问题是人类面临的最具有挑战性的课题,环境力学是力学学科新的生长点,本文概述了环境力学的历史沿革,还根据社会和经济可持续发展的需要和我国国情,提出了环境力学的研究方向与关键性基础研究问题,并以若干实例说明进行环境力学研究的途径.  相似文献
9.
Multiphase flow with a simplified model for oil entrapment   总被引:3,自引:0,他引:3  
A computationally simple procedure is described to model effects of oil entrapment on three-phase permeability-saturation-capillary pressure relations. The model requires knowledge of airwater saturation-capillary pressure relations, which are assumed to be nonhysteretic and are characterized by Van Genuchten's parametric model; scaling factors equal to the ratio of water surface tension to oil surface tension and to oil-water interfacial tension; and the maximum oil (also referred to as nonwetting liquid in a three-phase medium) saturation which would occur following water flooding of oil saturated soil. Trapped nonwetting liquid saturation is predicted as a function of present oil-water and air-oil capillary pressures and minimum historical water saturation since the occurrence of oil at a given location using an empirically-based algorithm. Oil relative permeability is predicted as a simple function of apparent water saturation (sum of actual water saturation and trapped oil saturation) and free oil saturation (difference between total oil and trapped oil saturation), and water relative permeability is treated as a unique function of actual water saturation. The proposed method was implemented in a two-dimensional finite-element simulator for three-phase flow and component transport, MOFAT. The fluid entrapment model requires minimal additional computational effort and computer storage and is numerically robust. The applicability of the model is illustrated by a number of hypothetical one- and two-dimensional simulations involving infiltration and redistribution with changes in water-table elevations. Results of the simulations indicate that the fraction of a hydrocarbon spill that becomes trapped under given boundary conditions increases as a nonlinear function of the maximum trapped nonwetting liquid saturation. Dense organic liquid plumes may exhibit more pronounced effects of entrapment due to the more dynamic nature of flow, even under static water table conditions. Disregarding nonwetting fluid entrapment may lead to significant errors in predictions of immiscible plume migration.  相似文献
10.
In-situ air sparging (IAS) is used for the clean-up of soil and groundwater that are contaminated with volatile organic compounds in relatively permeable subsurface environments. In this study, we investigated the secondary groundwater and gas flow fields that develop in the vicinity of single and multiple air sparging wells. The purpose is to evaluate their effects on contaminant plume migration and thus, remediation. Governing equations describing multiphase flow and contaminant transport in a three-dimensional domain were formulated and solved using the Galerkin finite element technique. Trichloroethylene was selected as a target contaminant. The increase in air injection contributed to an increase in the size of the IAS cone of influence and the gas saturation levels within the cone. This reduced the groundwater velocity within the cone and increased the zone of detour of groundwater around the air sparging wells. This outcome was quantified and compared under several IAS operations. Different soil permeability characteristics also affected the groundwater and gas flow patterns, and this impacted the remedial performance of the IAS system. Under high ambient groundwater velocity, an air sparging system that uses a single injection well caused the detour of contaminant plumes around injection wells, regardless of air injection rates, and failed to meet the remedial goal specified here. This system was successful for relatively low ambient groundwater velocity environments used here. An IAS system with multiple injection wells was effective in capturing and remediating the detoured contaminant plume, and showed superior performance when compared to a single injection well IAS system. Using IAS simulation, we also analyzed the impact of injection rates on site remediation using single or multiple wells. Design criteria that are based on the results of this study would be useful in enhancing the performance of the IAS systems.  相似文献
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