Escoamento bifásico em reservatórios petrolíferos heterogêneos.

Abstract

This assignment says respeet to modeling and simulation of the recovery process of oil in a petroliferous reservoir, in which the model of arrangements of injection wells and production wells of five-spot was used, being the mesh base formed by a square with a producing well in the center and the remain in the vértices of the same. In this study, it was considered that the distribution of the absolute permeability in 1/4 (a quarter) of this mesh was equal to the others 3/4 (three fourths). The mathematical modeling used to describe the two-phase flow (water-oil) through a porous way with geologic heterogeneity is correspondent to a modification in the model used by WENDLAND et al. (2001), in which, basically, it separates the equation of advection and diffusion in a hyperbolic part and in a parabolic one. The differential equations that compose the model were discrete by the method of finite volumes and the systems of resultant equations were solved with assistance of an explicit scheme for the hyperbolic part and the ADI method (Alternating Direction Implicit) for the parabolic part, both being executed in a computational program developed in MatLab. Three distinct situations of distribution of the permeability of the petroliferous reservoir were evaluated: the first one with uniform permeability; the second one constituted of two different regions of permeability, being it a shaped square region and located in the center of the reservoir and, finally, the third situation in which was defined a permeability of the random rock varying between l,0.10-12m2 the l,0.10~8m2. The results presented demonstrate the applicability of the considered method and also demonstrated to be capable to foreseeing the water advance in the petroliferous reservoir in those distinct evaluated situations. In special, in the case of the fortuitous distribution of the absolute permeability of the rock reservoir, in which was evidenced the presence of the imprisoned residual oil in the regions of low permeabilities, and as consequences they affect in the curves of accumulated production.