Measurements and PR EoS Modeling of Thermophysical Properties at Vapor–Liquid Equilibrium Conditions for Natural Gas Condensate/Live Bitumen Mixtures

In response to the need for less energy-intensive and greener bitumen recovery techniques, the use of multicomponent diluents through the expanding solvent steam-assisted gravity drainage (ES-SAGD) technique has garnered significant interest in recent years. In this work, we report new comprehensive measurements and Peng–Robinson equation of state (PR EoS) modeling of thermophysical properties (saturation pressure, density, viscosity, and K-values) of multicomponent mixtures of methane-bitumen-solvent. The multicomponent solvent is a natural gas condensate comprised of C3, i-C4, n-C4, i-C5, n-C5, C6, and C7+. Density, viscosity, solubility, and K-values of live bitumen (bitumen with dissolved methane) and various multicomponent mixtures are measured in the pressure range of 1–4 MPa and the temperature range of 313.41–459.10 K. A systematic approach is utilized to model the measured data. The experimental data show that the saturation pressure of the live bitumen can be controlled by selecting an appropriate solvent (condensate) composition. Condensate also has a significant effect on reducing the density and viscosity of the system. The results also show that the K-values of the components are almost independent of the composition of the solvent. The new comprehensive data set and the EoS model parameters reported in this work find applications in reservoir simulation as well as the design and optimization of the ES-SAGD process.