A computational tool for parameter estimation in EoS: New methodologies and natural gas phase equilibria calculations

Samir S. Abunahman*, Letícia C. dos Santos, Frederico W. Tavares, Georgios M. Kontogeorgis

*Corresponding author for this work

Research output: Contribution to journalJournal articleResearchpeer-review


Brazilian pre-salt reservoirs represent the discovery of large amounts of light oil, but at high pressures and containing high concentration of CO2. Proper parameter estimation procedures are essential to perform more accurate predictions of their thermodynamic properties. Therefore, two new methodologies for such calculations have been implemented here: by applying simultaneously VLE and LLE to the metric;and by handling water content in dew point conditions. Utilizing the Cubic-Plus-Association (CPA) EoS, they were employed to obtain new parameters for water. Also, new parameters were obtained forH2O + CO2 mixtures, whose average absolute deviation in water content at high pressures fell from 24% to 3% compared to previous publications. The same procedure was performed for other aqueous mixtures containing H2S and light hydrocarbons. Finally, this study has been applied into a natural gas compressing simulation with CO2, studying streams properties comparing the parameters obtained in this work with the literature.
Original languageEnglish
Article number115437
JournalChemical Engineering Science
Number of pages13
Publication statusPublished - 2020


  • Equations of state
  • Parameter estimation
  • Computational tool
  • Natural gas production

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