Complex fluids, such as polymer solutions and dispersions, are frequently injected for well conformance and as an enhanced oil recovery method. The research being developed in this area is focused on understanding the fundamentals of flow of complex liquids, such as viscoelastic polymer solutions, oil-water emulsions and suspension of flexible microcapsules, in porous media and their application as EOR agent.
We combine core-flooding experiments, pore-scale flow visualization using optical and confocal microscopy and x-ray micro tomography, capillary network model and continuous model to understand these complex flows and how the microscopic phenomena relates to the observed macroscopic flow behavior.
Early field tests have shown the potential of emulsion flooding for EOR. Application of emulsion injection for increasing sweep efficiency has been reported in the literature. One difficulty in designing an EOR process based on emulsion flooding lies on having a better understanding of the displacement mechanisms in porous media. Established filtration models fail to accurately predict the transport process of these complex fluids in a porous medium, including the observed pressure drops and recovery factors. This research is being extended to flow of suspensions of flexible micro capsules.
In the same way, polymer solution injection is used in the industry as an alternative to water injection. The common wisdom is that the higher viscosity reduces the mobility of the water phase and improves the amount of oil displaced. However, polymer solutions may present viscoelastic behavior that can change the pore scale flow, reducing the residual oil saturation of areas swept by the water phase. The fundamental understanding of the pore level effect are still not well established.
Current research also covers polymer adsorption and condensate formation in retrograde gas reservoirs.