Characterization of crude oils and asphaltenes using the PC-SAFT EoS: A systematic review

Abstract

In this paper, we present a systematic review of the perturbed-chain statistical associating fluid theory equation of state (PC-SAFT) EoS for thermodynamic modeling with application in asphaltene phase behavior simulation. The SAFT EoS and its modified version known as the PC-SAFT EoS is briefly introduced. Then, uses of the PC- SAFT EoS as a tool for asphaltene phase behavior modeling is highlighted. Crude oil characterization methods and modeling procedures are described with a focus on SARA-based method of modeling. The effects of varia-tions in temperature and pressure on the PC-SAFT asphaltene precipitation models are discussed, as well. An erroneous behavior of PC-SAFT models at low temperatures was noted in the literature for a number of crudes. To address this issue, a summary of approaches developed to deal with such problems is presented. The effect of other modeling aspects on accuracy such as binary interaction parameters, inclusion of association term, and asphaltene polydispersity are discussed. The interaction parameters have a profound effect on modeling of precipitation envelope. Inclusion of association term seems to be especially promising in developing more ac-curate asphaltene phase behavior models. Modeling asphaltene fraction as polydisperse entities greatly improves the quality of models that aimed at calculation of the amount of precipitated asphaltenes. Finally, a summary of comparative studies between the PC-SAFT and some other thermodynamic models is provided.