Modelling CO2 dissolution in brines for CO2 sequestration and enhanced oil recovery applications

Understanding the thermodynamic behavior of each flowing phase in a petroleum reservoir allows for accurate quantification of these phases. This work explains how to develop and run a thermodynamic model to reliably forecast the equilibrium behavior of oil-gas-brine systems across a reasonable pressure and temperature range. The 3-phase negative flash method is tested against previously published data in the literature. The multiphase flash approach is used to develop linearized physical operators utilizing an Operator Based Linearization (OBL) modeling technique that allows for the nonlinear solution of governing equations to include various complicated physics. To our knowledge, this is the first implementation to the coupling of 3-phase flash calculations for hydrocarbons and brines have been using fugacity-activity models with a a sophisticated, high-efficiency linearization technique. Such coupling improves the efficiency and flexibility of physical phenomena modeling of the fluid flow in porous subsurface reservoirs.