Prediction of CO2 solubility in bitumen using the cubic-plus-association equation of state (CPA-EoS)

The ability to accurately predict the solubility of CO2 in bitumen is essential to the design of bitumen and heavy oil recovery processes. We applied the cubic-plus-association equation of state (CPA-EoS) to calculate the solubility of CO2 in bitumen and the Soave-Redlich-Kwong (SRK) equation of state was applied to treat the physical molecular interactions. The proposed thermodynamic model was verified against the experimental data for CO2 solubility in bitumen over wide ranges of temperature and pressure for four different bitumens from Alberta reservoirs. The CPA-EoS was able to predict the solubility with less deviation from the experimental data than the regular cubic equations of state and the statistical association fluid theory (SAFT). Our results suggest that the CPA-EoS is an effective method of conducting solubility calculations for solvent assisted bitumen recovery processes. (C) 2015 Elsevier B.V. All rights reserved.