Abstract: The displacement process of cement in annulus was simulated by volume of fluid(VOF) method and Fluent 6.0 software.The inner and outer diameters of the simulated wellbore are 0.089 meters and 0.112 meters respectively,and its length is 10 meters.The influences of eccentricities of casing and displacement velocity of cement on the stability of displacement interface and displacement efficiency under different conditions of flow states,Reynolds numbers and eccentricities were obtained.The results of numerical simulations are in good agreement with those of experiment.The simulated results indicate that lower eccentricity of casing and displacements of turbulent or laminar at a low speed are helpful for improving the displacement efficiency.

Key words: annulus wellbo re, drilling mud, displacement velocity, oi-lwater interface, stability, casing, eccentricity, numerical simulation

摘要： 借助计算流体力学(CFD)软件FLUENT6.0,利用流体体积法(VOF)对环空内水泥浆顶替进行了数值模拟,模拟环空井筒长为10m,外径为0.112m,内径为0.089m。在不同流态、不同流动雷诺数和不同环空无量纲偏心度的条件下进行了计算,得到了顶替速度及偏心度对顶替效率以及界面稳定性的影响规律。与实验数据对比表明,数值模拟得到的结果与实验结果相吻合。模拟结果表明,降低套管偏心度及进行湍流顶替或低速下的层流顶替有助于界面稳定和提高顶替效率。

关键词: 环空井筒, 钻井液, 顶替速度, 油-水界面, 稳定性, 套管, 偏心度, 数值模拟