Solubility of carbon dioxide and ethane in Lloydminster heavy oil: Experimental study and modelling

Abstract Heavy oil reserves in the world represent 5.5 trillion barrels, which are equivalent to five times the conventional crude oil reserves. Heavy oil reserves will be the main petroleum source for the world's future demand for energy. To enhance the recovery of heavy oil/bitumen, solvent‐based recovery seems to be one of the most promising alternatives to costly thermal methods. Phase behaviour studies of light gases in heavy oil are therefore very important when designing surface facilities and for enhanced oil recovery operations. In this study, we present solubility data for carbon dioxide and ethane in Lloydminster heavy oil. Measurements were carried out using a microbalance at 290.2, 298.2, and 313.2 K and at pressures varying from 200–2000 kPa. Experimental data were regressed with the Peng‐Robinson (PR) equation of state. We also report results of the fractionation of the heavy oil and its characterization in terms of SARA (saturates, aromatics, resins, and asphaltenes) fractions. Henry's law constants for gaseous solvents were also regressed and reported. As expected, ethane had a higher solubility than CO 2 in the heavy oil at all temperatures.