Hot solvent injection is an in-situ technology which uses heated solvent for efficient and sustainable viscous oil (VO) recovery (cf. 93 kg per barrel less GHG emission than SAGD technology). The process reduces the oil viscosity via mass and heat transfer so that the combined effect of heating and solvent dilution yields a better result than in steam (SAGD) or cold solvent injection (VAPEX) cases.
In this case, the injection of the solvent in gaseous state reduces the amount of solvent required per unit volume of produced oil, and takes advantage of higher rate of solvent diffusion. The solvent will not remain in gaseous state but will condense downstream and release a latent heat making easier its mixing with the VO in-place due to the local temperature increase. Recently the hot solvent injection technology (known also under the name NSolv) had its first successful pilot project designed to recover bitumen from oil sands.
Physically speaking the VO displacement in the solvent-based process is a complex combination of dynamic energy and mass transport and phase transformation phenomena. The rapidly emerging experimental technique of fluid dynamical measurements and observations on micromodels (MM) is proved to be a powerful mean providing quantitative information on multiphysical processes in porous media.
The numerical simulation of solvent injection for VO displacement in a MM setup has demonstrated its feasibility and usefulness both for model design and experimental results analysis. This includes first a pore-scale imaged-based study of micromodel transport properties. Then the Darcy-scale model has been developed and applied for dynamic displacement study. It
has been shown that although being not capable to reproduce in detail the fluid- and thermodynamic diversity of the displacement (especially at pore scale), the developed numerical model has indicated the process key parameters and offered the framework for their quantitative determination.
Finally the dedicated study of process dynamics and corresponding adaptation of the numerical model parameters has been presented and discussed.
|Acceptance of Terms and Conditions||Click here to agree|