Characterization of reservoir fluids: A predictive model for interfacial and bulk phase equilibrium properties

In this contribution, a robust theoretical approach was applied to predict the interfacial and phase equilibrium properties of real reservoir fluids. The modeling approach was based on an improved version of the Peng-Robinson equation of state (EoS) and on the Density Gradient Theory (DGT) for fluid interfaces. All the EoS and DGT parameters were obtained from literature correlations or calculated through a group-contribution method, leading to the computation of all the fluid properties in a fully predictive manner. The good agreement with volumetric, phase composition and interfacial tension data of multiple contact tests confirmed the superior predictive capabilities of the present modeling approach for describing key PVT properties of reservoir fluids.