Oil and gas production often involves two-phase flow in pipes, making accurate estimation of these complex systems crucial for designing facilities, optimizing production, and minimizing risks. This work presents the development and application of a transient, thermal, compositional two-phase simulator that uses the Drift-flux model to account for phase slip. The simulator can be applied to model flow in wellbores and pipelines, particularly in cases requiring a rigorous thermodynamic description, such as the flow of mixtures with high concentrations of carbon dioxide. The proposed model includes a mass conservation equation for each component, a momentum equation for the mixture, an energy equation for the mixture, and the Peng-Robinson equation of state to calculate thermodynamic properties and phase equilibrium. Heat transfer between the fluid mixture and the surrounding geological formation is also considered. The system of equations is solved implicitly using Newton-Raphson’s method for enhanced numerical stability. Numerical results are presented, including comparisons with widely used methods in the oil industry, such as those based on empirical correlations, as implemented in commercial simulators.