Measurements and calculations of hydrocarbon mixtures liquid density by simple cubic equations of state

Abstract

The continuing importance of pressure-volume-temperature (PVT) property calculations of reservoir fluids mixtures in design of equipments used for storage, transportation and separation processes need considerable experimental and theoretical attempts to present a simple, accurate and theoretical based equation of state to replace the existing empirical based equations of state. The first author and his co-workers previously presented two parameters cubic theoretical based equation of state (MMM). This equation was used in PVT and vapour-liquid-equilibrium (VLE) calculations of pure and fluid mixtures. The comparisons for the different pure and mixture fluids calculations indicated the advantages of this equation of state over the well-known empirical-based two parameters cubic equation of state (RK EOS). In this study, PVT data for binary, ternary, quaternary and multicomponent oil mixtures at the different temperature and ambient pressure are measured, and reported. The measured PVT data were compared with those obtained by using the simple cubic equations of state. The calculated results by MMM EOS are compared with SRK and PR EOSs which are the commonly used three parameters cubic EOSs in the oil and gas calculations. The comparisons indicate that, although the SRK and PR EOSs needs an additional parameter (acentric factor, ω), the MMM equation of state is more accurate than both SRK and PR equations for the PVT calculations of oil mixtures.