Simulação de reservatório de petróleo utilizando o modelo Black-oil em conjunto com malhas não-estruturadas

Abstract

From several methodologies available, the Element based Finite Volume Method (EbFVM), in conjunction with unstructured meshes, is a methodology that deserves large attention in the petroleum reservoir simulation. After the initial step of discretization, each element is divided into sub-elements and the mass balance for each component is developed for each sub-element (sub-control volumes). This work presents an investigation of an element-based approach using the black-oil model based on pressure and global mass fractions. In this approach, even when all gas phase is dissolved in oil phase the global mass fraction of gas will be different from zero. Therefore, no additional numerical procedure is necessary in order to treat the gas phase appear/disappearance. In this work, the above mentioned approach is applied to multiphase flows involving oil, gas, and water. The mass balance equations in terms of global mass fraction of oil, water and global mass fractions are discretized through the EbFVM using a fully implicit procedure. In order to validate the numerical results of the proposed methodology, the results obtained with the IMEX simulator (Implicit-Explicit Black Oil Simulation) from CMG (Computer Modeling Group) are presented for some of the chosen case studies.