| Solvent-based recovery (VAPEX) is one of the most promising alternatives to thermal techniques to enhance heavy oil/bitumen recovery. Knowledge of the phase behavior and diffusion coefficients of gases in heavy oil is very important when designing recovery operations and facilities. In this work, a gravimetric microbalance was used to measure the solubility of carbon dioxide, ethane, propane and butane in a Lloydminster heavy oil and its fractions. Measurements were carried out on carbon dioxide and ethane at (290, 298 and 313) K over a pressure range from (200 to 2000) kPa. Similar measurements were performed on propane and butane below their vapor pressures. The Peng-Robinson equation of state was used to correlate the experimental results. The Solubility Parameter Theory was used to predict the solubility of CO2 and propane in heavy oil/bitumen over a wide range of pressures and temperatures. The associated Henry's Law constants for carbon dioxide, ethane and propane in heavy oil, its saturate fractions and aromatic fractions, were also determined from the absorption data. The gases had higher solubilities and the strongest interactions at lower temperatures in the heavy oil and its fractions. The diffusion coefficients of carbon dioxide, ethane and propane in heavy oil, its saturate and aromatic fractions were calculated using a simple diffusion model. The diffusion coefficient of carbon dioxide, ethane, propane and butane in heavy oil were calculated at different pressures. Estimated values were in agreement with published results and were found satisfactory. |
