Numerical modeling of two- and three-phase equilibria of mixtures of hydrocarbons and carbon dioxide

In the modern oil and gas industry, there is an increasing interest in the technology of injecting carbon dioxide into the reservoir. This method has become widespread not only because of its positive impact on the environment, but also because of its effectiveness in increasing oil production. When dissolved, the gas is able to lower the viscosity of the oil and, consequently, accelerate its flow. However, the effectiveness of the method depends on the phase behavior of mixtures of carbon dioxide and oils, the density and viscosity of the phases, and much more. In this paper, the method of direct energy minimization is used, which consists in finding the minimum value of the Gibbs energy for a system at constant temperature, pressure and composition.