The Association Thermodynamics Modeling of Asphaltene Precipitation

摘要

In this work, the authors introduce an association asphallene deposition modeling through application of continuous thermodynamics for crude oil mixture. It is assumed that a binary system forms consist of a nonprecipitaling crude oil solvent system and a precipitating asphaltene component in which pure asphaltene component only participate in deposition phase. A simple association factor as an association term has been incorporated in set of equations for minimization of Gibbs free energy, which was obtained from molecular weight distribution (fractional molecular weight) and association ability of system. For characterization of asphaltenes, asphaltene segment distribution function and the association term are applied at equilibrium condition. The association parameters of asphaltene component are adjusted with the experimental data at different conditions. In this study, experimental data from the Iranian crude oil reservoir was used to examine the proposed asphaltene model. It has been shown that the calculated results are in good agreement with experimental data.