Numerical Simulation of Multiphase and Multicomponent Fluid Flow in Petroleum Reservoirs Using an IMPEC Compositional Formulation and a Second Order MUSCL Type Finite Volume Method

Resumo

The numerical modeling of multiphase and multicomponent fluid flow in petroleum reservoirs is ex-
tremely complex and computationally demanding. Frequently, simpler black-oil models are not suitable for cases

in which the reservoir fluid is volatile and composed by several pseudo-components with distinct characteristics.
For those cases, the use of a compositional simulation based in Equations of State (EOS) is of utmost importance.
In this work, we present an Implicit Pressure Explicit Composition (IMPEC) formulation using cartesian grids for
the compositional reservoir simulation based on an EOS approach. Diffusive terms in flux and transport equations

are discretized by the Two-Point Flux Approximation (TPFA) finite volume method. Besides, to improve front res-
olution and accuracy, we discretize the advective terms of the transport equations by the second-order Monotonic

Upstream-centered Scheme for Conservation Laws (MUSCL) method. So far, the implemented model considers
isothermal flow, up to three-phase flow and that there is no mass transfer between water and hydrocarbon phases.
Physical dispersion is neglected. Our IMPEC formulation is evaluated by solving a benchmark problem found in
literature. The accuracy of our approach is evaluated comparing our results with those obtained by a commercial
reservoir simulator (CMG-GEM).