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Molecular thermodynamics of asphaltene precipitation in reservoir fluids
Author(s) -
Wu Jianzhong,
Prausnitz John M.,
Firoozabadi Abbas
Publication year - 2000
Publication title -
aiche journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.958
H-Index - 167
eISSN - 1547-5905
pISSN - 0001-1541
DOI - 10.1002/aic.690460120
Subject(s) - asphaltene , precipitation , colloid , van der waals force , chemistry , thermodynamics , crude oil , dispersion (optics) , chromatography , chemical engineering , molecule , petroleum engineering , organic chemistry , geology , physics , engineering , meteorology , optics
A previously described molecular‐thermodynamic framework, based on colloid theory, is used to correlate experimental asphaltene‐precipitation data at high‐temperature and pressure conditions. In this framework, asphaltenes and resins are represented by pseudopure components, and all other components in a crude oil are presented by a continuous medium that affects van der Waals attractions among asphaltene and resin molecules. Model parameters are evaluated systematically from average properties of asphaltenes and resins in crude oils, and from dispersion‐force properties of the oil medium. Given the composition of the medium, and asphaltene and resin concentrations, the molecular‐thermodynamic model described here can be used to identify the onset of asphaltene precipitation, and the total amount of precipitation at the given operation conditions. Calculated results for the effects of oil composition and pressure on asphaltene precipitation are in good agreement with at least some experimental measurements for four reservoir fluids, including Texaco, Shell, Weyburn, and North‐Sea crude oils.