Heavy crude oil mesoscopic modeling to predict interfacial tension

Abstract

Heavy crude oils represent a significant percentage of oil reserve available in the world, part of which are located in Venezuela. Nevertheless, they have a high level of complexity due to the asphaltenes, heavy metals, and heteroa-toms presence which converts these crudes into highly viscous fluids. These properties make difficult its theoretical and experimental study. Despite the computational power today, it is not feasible to represent and study these sys-tems, expressing their principal constituents at the atomistic level. Considering this fact, the study of a heavy crude from Venezuela was carried out, at a mesoscopic scale, based on theoretical and experimental data, modeled by ap-plying Dissipative Particle Dynamics (DPD), and the coarse-graining technique. DPD beads correspond to the heavy crude oil main fractions, for which a super- grain of each fraction was made, implying a new approach in a heavy crude oil system representation. The models' validation was done by studying the behavior of the systems at the interface, evaluating the interfacial tension evolution, density profiles, and images obtained from the dynamic performed, according to the variations of the concentrations of the heavy crude oil, their fractions, and solvents used. The results successfully reproduced the behavior and trends reported for these systems, under similar condi-tions, and support the validity and advantage of the approach of the present study, as an alternative for the analysis, prediction and understanding of the behavior in the interface of this type of systems.