Modelagem termodinâmica da permissividade elétrica da mistura de CO2 e n-dodecano através da equação de estado cubic plus association

Abstract

There is a significant need to evaluate the performance of the technologies used in Multiphase Flow Meters (MPFM) has been intensified by the large-scale exploitation of pre-salt wells, a region characterized by a high CO2 content in the multiphase mixture of gas, oil, and water. Therefore, almost all multiphase meters require precise fluid properties as part of their configuration, such as pressure, volume, and temperature (PVT). In this context, electrical permittivity stands out as a fundamental property for the development of phase sensors that characterize the phases of multiphase flows. Thus, this work proposes to adapt a theoretical methodology from the literature to thermodynamically model the electrical permittivity of the binary mixture consisting of CO2 and n-Dodecane. The modeling will be carried out using the CPA (Cubic-Plus-Association) equation of state, covering temperatures in the range of 9°C to 70°C, pressures up to 98 bar, and variations in the solubility of CO2 in the range of 0% to 100%. The generated results for the thermodynamic properties were compared with previously published experimental data and commercial reference software. In both situations, the proposed methodology was found to provide satisfactory results, characterized by average deviations of less than 10% for most of the evaluated properties, reinforcing the validity and applicability of the methodology in contexts with high CO2 content.