Generation and application of adaptive PEBI grid for numerical well testing(NWT)

Abstract

Several methods have been investigated on how to generate PEBI (Perpendicular Bisection) grid such as static property based method, flow based method and the combination of them. However, these methods are not suitable for NWT. In this paper, an adaptive gridding method is proposed for NWT based on the locations of the wells. First we divide the reservoir into several areas which each has one well in it. Then, PEBI grid points are placed in each area separately according to isobars which are derived from analytical solutions of the well in that area. At the end of this paper, proposed adaptive PEBI grid was compared with uniform coarse and fine grid. Numerical results in this paper showed that adaptive grid reduced two thirds of grid number and saved two thirds of computation time while kept almost same accuracy compared with fine grid.