Effect of Asphaltene on Phase Behavior and Thermophysical Properties of Solvent/Bitumen Systems

Solvent-aided bitumen production from oil sands has shown promise as an alternative to thermal recovery methods. Phase behavior studies of solvent/bitumen mixtures are necessary for reservoir simulation of recovery methods, process design and operation of surface facilities, anti transportation. Bitumen and heavy crudes comprise a different weight fraction of asphaltene. In this study, the effect of asphaltene on. phase behavior, viscosity, and density of solvent/bitumen systems is studied. Ethane (C2H6) and carbon dioxide (CO2) are considered as solvents. Phase behavior studies and. property measurements are conducted on solvent/bitumen and: solvent/deasphalted bitumen systems. Solubility of C2H6 and CO2 in the original and deasphalted bitumen are measured. The viscosity and density of the liquid phase are also measured by inline viscometer and densitometer at temperature and pressure ranges of 70-130 degrees C and 2-8 MPa, respectively. The measured data showed that the asphaltene has no significant effect on C2H6 solubility in bitumen. However, the solubility of CO2 in the original bitumen differs from that of the deasphalted bitumen. The significant effect of asphaltene on density and viscosity of bitumen is also quantified. Mixing rules are also employed to estimate the density and viscosity of asphaltene using the density and viscosity of bitumen and deasphalted bitumen.