NUMERICAL SIMULATIONS OF VISCOELASTIC FLOWS THROUGH ONE SLOT CHANNEL

In this article,the Modified Upper-Convected Maxwell equation (MUCM) is proposed. The viscoelastic polymer solution flow characteristics are described by the numerical method. The stream function contour,velocity contour and stress modulus contour of fluid in slot channel are drawn. The non-Newtonian power law property and viscoelasticity of MUCM fluid influence on the stream function are analyzed. The velocity contour move towards dead oil area with the viscoelasticity increase,flow area increase and the sweep area enlarges,so the sweep efficiency is enhanced.     

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.     

EXPERIMENTAL STUDY OF MICROSCALE FLOW FOR MICRO MOLECULE LIQUID AND POLYMER SOLUTION

The flow performances of water, white oil and Hydrolyzing Polyacrylamide (HPAM) solution in fused quartz channels and the effect of wettability on the microscale flow shave been studied respectively in this paper. The adaptability of classical fluid mechanics in channels with different sizes has been discussed. The results show that water flows in channels of 2μm diameter also have few size effects and white oil flow accord with classical fluid mechanics theory in channels of 25μm diameter too, but polymer solution appears an obvious size effect as diameters of channels decrease to 16μm. The wettability does not produce any influences on the water or white oil flows in channels of 25μm or 50μm diameter. The experimental technology of microscale flows has been first applied for studying the flow performances of pores in low permeability reservoir. This study found a base for deep investigating the percolation mechanism in low permeability reservoirs.     

THE INFLUENCE OF THE SECONDARY NORMAL STRESS DIFFERENCE OF VISCOELASTIC FLUID ON ECCENTRIC CAPSULE FLOW

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AN UNSTEADY SEEPAGE FLOW MODEL OF VISCO-ELASTIC POLYMER SOLUTION

With the consideration of the visco--elasticity, the adsorption effect and the variation of rheological parame ters, a seepage flow model of visco-elastic polymer solutions was established. The model was numerically treated with the finite difference method. Then curves of Bottom Hole Pressure (BHP) and formation pressure were drawn. The influences of the relaxation time, the injection rate, the permeability reduction co,efficient, the consistency coefficient and the power-law exponent of the injected fluid on pressure performance were analyzed. This study shows that it is necessary to consider the visco elasticity of non-Newtonian fluid in analyzing of pressure performance in the polymer flooding.     

UNSTEADY FLOW OF POLYMER FLUID BETWEEN COAXIAL CYLINDERS

In the present paper an unsteady flow of polymer fluid,i.e.non-Newtonianfluid is studied.The constitutive equation of upper-convected Maxwell fluid is used.The varia-tional approach due to Kantorovich is used for the unsteady problem of the fluid.A special com-puter program“MACSYMA”is used to get the different approximation of the method of Kan-torovich.The present method developed is called Computational Analytical Method which isavailable for the scientific research.     

NUMERICAL SIMULATION OF STEADY FLOW FOR VISCOELASTIC FLUID IN AN ECCENTRIC ANNULUS WITH INNER ROD MOVING AXIALLY

1. INTRODUCTION Compared with water-flood, polymer-flood has increased the recovery ratio by 12 %in Daqing oil field,and it’s economic profit is very promi- nent ,but severe well rod eccentric wear appears in the polymer-flood well , and rod breaking occurs someti mes , whichis a new problemthat should be solvedi mmediately in the polymer-flood well pro- duction. Experi ment[1]shows that the inner rod moving in polymer-water solution in the eccentric annulus will lean to outer pipe , whic…     

NUMERICAL SIMULATION OF FLOWS FOR SECOND-ORDER VISCOELASTIC FLUID COUPLED WITH HEAT TRANSFER BY DIFFERENTIAL QUADRATURE METHOD

The problem of two-dimensional steady flow of an incompressible second-order viscoelastic fluid coupled with heat transfer between parallel plates was considered. A viscous dissipation function was included in the energy equation.When the elastic property of the fluid is weaker, the zerothorder and first-order approximate governing equations were obtained by means of the perturbation method. To understand the behavior of flow near the tube wall, the half-domain was divided into two sub-domains, in which one is a thin layer near the wall called the inner domain and the remainder is called the outer domain. The governing equations in the inner domain and in the outer domain were discretized respectively by using the Differential Quadrature Method (DQM). The matching conditions at the interface between the inner and outer domains were presented. An iterative method for solving these discretized equations was given in this paper. The numerical results obtained agree with existing results.     

粘弹性流体在盲端孔隙中的流场

以带有盲孔的流道模拟油藏中的盲端孔隙，应用数值方法研究了上随体Maxwell流体在盲端孔隙中的流动特性。着重分析了流体流变性和盲端倾角对流场的影响规律。计算结果表明，驱替液的粘弹性是影响盲端波及效率的重要因素；在较大的盲端倾角范围内，低雷诺数（Re）流动条件下，流体的威森博格数（We）越大，孔隙盲端中的流动区域越大，滞留区越小。     

岩石孔隙结构与渗流特征核磁共振研究综述

准确评价岩石的孔隙结构与渗流特征对于制定安全高效的能源开采实施方案具有重要的指导意义。以分析核磁共振技术在研究岩石孔隙结构和渗流特征方面的应用现状和发展方向为目标,在简要介绍传统测量方法的基础上,通过对大量文献的研究分析,综述了使用核磁共振技术(NMR)测量岩石孔隙结构与渗流特征的发展历史、研究成果及研究现状等内容,分析了核磁共振技术的基本原理、适用范围及优缺点,指出了目前研究的局限性及需要进一步研究的内容。结果表明:核磁共振技术在能源地质、生命科学、航空航天等众多领域均有广泛应用。在岩土工程领域,该技术可以快速、准确的测定岩石的孔隙率、渗透率、可动流体饱和度等基本物性参数,当岩芯中有流体时,能直观地观测到岩芯内流体的渗流过程,为后续多孔介质微观孔隙结构的研究提供了新思路;在岩石孔隙结构与渗流特征研究方面,核磁共振技术与传统研究方法相比具有其独特优势,但是岩芯中顺磁物质及含氢物质的存在使得测量结果与实际情况存在一定的误差。因此,今后的研究应致力于减小这些因素对测量结果的影响,同时建立渗流过程中不同时刻流体渗流量与渗流特征的函数关系。