Solvent-assisted heavy oil recovery methods have gained significance in recent years. The injected solvents can be of hydrocarbon and non-hydrocarbon chemicals or a mixture of both. The addition of a diluent, as a mixture of light and intermediate hydrocarbons, to bitumen has a significant effect on reducing the viscosity and density of bitumen. In this work, the experimental measurements and thermodynamic modeling of thermophysical properties of C 1 /bitumen, CO 2 /bitumen, C 1 /CO 2 /bitumen, C 1 /diluent/bitumen, and C 1 /CO 2 /diluent/bitumen systems are performed. The measured data includes liquid viscosity, liquid density, and mole fraction of components in vapor and liquid phases. Experimental data show that the addition of CO 2 into the injected gas mixture results in bitumen viscosity reduction, especially at lower temperatures. A diluent has a significant effect on the viscosity and density of the liquid mixtures in all cases. The results showed that the component Kvalues are nearly independent of the solvent composition. The consistency of K-values of the intermediate components was examined by the Hoffmann and Wilson plots. The obtained linear trends revealed that the K-values of the intermediate components are only a function of temperature and pressure. The thermodynamic modeling of phase equilibria is performed using the cubic plus association equation of state. The unknown parameters of the model, including binary interaction parameters and critical properties of C 6+ in the diluent, are tuned versus experimental liquid density and solvent solubility (i.e., the mole fraction of solvent in the bitumen-rich phase). The developed model is able to predict the liquid density, C 1 solubility, and CO 2 solubility with an absolute average relative deviation of 0.28, 11.41, and 12.22%, respectively.

We report new measurements and correlations of the density, viscosity, solubility, and K-values of multicomponent solvent/live bitumen systems with applications to the solvent-aided thermal recovery of bitumen. The density, viscosity, solubility, and K-values of live bitumen and a multicomponent solvent composed of n-C4, n-C5, n-C6, n-C8, and n-C10 were measured at a pressure range of 1−6 MPa and a temperature range of 343.15−503.15 K. A systematic approach is presented that can be adapted for the construction of input PVT models for thermal reservoir simulations. The measured data are correlated with the temperature-and pressure-dependent correlations used in commercial thermal reservoir simulators. Accepted agreements were found between all the predicted properties and experimental data of the multicomponent solvent/live bitumen system. The data and the parametrization approach find applications in the design and optimization of solvent-aided thermal recovery of bitumen.

The in situ solvent-aided thermal recovery processes are promising methods for recovering unconventional oil resources due to their higher efficiency, lower energy and water consumption, and reduced environmental impacts. The produced stream is often a highly stable water-in-oil emulsion, where the oil phase comprises bitumen and solvent. Separating water from such a sample is challenging because conventional approaches result in solvent loss and sample contamination and render the solvent content measurement techniques currently employed by the industry invalid. Developing analytical techniques for solvent detection without sample dehydration, solvent loss, and contamination is essential for production surveillance, monitoring, process optimization, and economic evaluation. Solvent recovery and concentration measurement in produced streams have been considered the most important issues associated with the success and commercialization of solvent-assisted recovery processes. In this work, we implement a comprehensive chromatographic technique to measure the solvent concentration of the actual bitumen/solvent/water emulsions produced during a large 3D physical model experiment of the solvent-aided recovery process. We used combined gel permeation chromatography (GPC) and gas chromatography (GC) to obtain the full characterization of bitumen/solvent/water systems. After characterizing four produced emulsion samples, actual and synthetic multicomponent solvents are used to establish the necessary calibrations for rapid and accurate determination of the organic solvent content in the produced emulsion samples. The results demonstrated that the automated GC/GPC can be applied to actual minute amount emulsion samples for fast detection of solvent content in the pilot and field-scale projects of solvent-aided thermal recovery processes without sample dehydration while solvent loss and sample contamination are entirely avoided.