An eos-based numerical simulation of thermal recovery process using unstructured meshes

Abstract

In the past thirty years, the development of compositional reservoir simulators using an equation of state (EOS) has been addressed in the literature. However, the development of compositional thermal simulators in conjunction with the EOS formulation, in particular, has not been addressed extensively. In this work, a fully implicit, thermal, compositional EOS-based simulator in conjunction with unstructured meshes has been developed. In this model, an equation of state is used for equilibrium calculations among phases. Also, the physical properties are calculated based on an EOS, hence obviating the need for using steam tables for calculation of water/steam properties. The governing equations for the model comprise fugacity equations, material balance, pore volume constraint and energy equation. The governing partial differential equations are solved using the EbFVM (Element based Finite Volume Method). Results for several case studies consisting of 2D and 3D reservoirs are presented in order to demonstrate the applicability of the method.