| The widely used Cartesian grid has some disadvantages in the description of the geologically complex reservoirs, and in some cases finite difference methods based on Cartesian grid cause significant grid orientation effects, especially it can't describe accurately complex boundary configuration of fracture .Because in China there are still not perfect theories and literatures on these problems, and theoretic researches just begin overseas. Under this situation, this paper studies unstructured grid (the way in which grids connect is arbitrary), PEBI grid application in manual fractured reservoir. According to actual terra model, this paper establishes three dimensional and three phases mathematical model, proposes a set of reservoir mathematical simulation methods based on unstructured grids and compiles programs, the content of study follows:1. Establishing three dimensional mathematical model of simulating fracture in terms of PEBI grids, writing partial differential equation and scattering it, finally gaining linear equation group.2. Proposing an automatic triagulation scheme based on advancing-front method and maximum-angle rule, PEBI grids are generated wheresoever. Usine this scheme, the triangle satisfies Delaunay condition, and the PEBI grids are optimized. Flexible grid nodes can more precisely describe the reservoir geometry. 3. All programs are written in FORTRAN90 language by the author herself, which include grid generation, calculation and storage of coefficient matrix formed by PEBI grids and relative equation group solutions. 4. The feasibility of the proposed method is proved by numerical examples, expectedresults are obtained.
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