Flow of polymer fluids through porous media
Résumé
Non-Newtonian fluids are extensively used in enhanced oil recovery. However, understanding the flow of such fluids in complex porous media remains a challenging problem. In the presented study, we use computational fluid dynamics to investigate the creeping flow of a particular non-Newtonian fluid through porous media, namely a power-law fluid with a newtonian behavior below a critical shear rate. We show that the nonlinear effects induced by the rheology only weakly impact the topological structure of the flow and that the non-Newtonian problem is a regular perturbation from the Newtonian case. We demonstrate that this transition results from a coupling between the multiscale nature of the porous medium and the specific non-Newtonian property of the fluid. We develop a theory that allows us to propose a general model for the macro-scale transition.