Monte Carlo Simulations for Multicomponent Phase Equilibria and Thermophysical Properties of Near-Critical Fluids

Abstract

Understanding phase equilibria and thermophysical properties of complex fluid mixtures is crucial to the oil and gas industry, particularly for exploration and production process design. Crude oil and natural gases in such processes are subjected to a very broad range of conditions, under which experimental measurement of physical properties can be quite challenging. To overcome this, the industry has made extensive use of traditional thermodynamic models, such as equations of state and activity coefficient models. However, these conventional tools often lack the necessary predictive power to accurately model fluid properties across the entire range of relevant conditions, especially at extreme conditions where experimental data is often limited. Hence, Monte Carlo simulations have been employed to determine the microscopic features required for improving current PVT modeling methods. Results have shown that these simulations provide remarkably accurate descriptions of phase equilibria and thermophysical properties of fluids relevant to petroleum processing across a wide range of conditions, showing the versatility of molecular simulations as a predictive modeling tool and for developing new modeling methods.