关键词: PEBI网格, 笛卡尔网格, 两相流, 数值模拟, 网格取向效应, 差分方程, 自动生成

Abstract: The widely used Cartesian grid has some disadvantages in the description of geologically complex reservoirs.In addition,finite difference method based on Cartesian grid causing significant orientation effects.PEBI grid takes advantages of finite elements of flexible approximation of reservoir geometry,and reduced orientation effects by using window techniques.It is easy to be refined and be applied in finite differente simulators.This paper presents the differente equation of control volume finite elements,with a method of automatic triangulation and PEBI grid generation.2-D single-phase model and two-phase model were designed to test the feasibility of the PEBI grid.The numerical results indicated that PEBI grid could simulate radial flow near the well bore with high accuracy.The results are consistent with the analysis solution and PEBI grid reduces grid orientation effects greatly comparing with 5-point finite-difference method.

Key words: PEBI grid, Cartesian grid, two-phase flow, numerical simulation, grid orientation effects, difference equation, automatic generation