Viscosity enhancement In non-Newtonian flow of dilute polymer solutions through crystallographic porous media

In many practical flow situations solutions of flexible polymers are found to exhibit a well-known non-Newtonian viscosity enhancement effect. This is likely to be due to extensional components in the flow field, which can cause flexible polymer molecules to stretch and orientate, causing an increase in the extensional viscosity. This viscosity enhancement is important in many industrial applications, including food technology, paint and cosmetic formulation and enhanced oil recovery (EOR). Potential EOR applications based upon polymer solution flooding depend upon studies of porous media flow of polymer solutions in order to optimise the use of polymers as additives in the solutions used for oilfield flooding. One essential ingredient is the achievement of effective viscosity matching at the oil-solution interface. Remarkably, this can be achieved with low concentrations of ultra-high molecular weight polymers in water or brine. However the large viscosity enhancement that occurs when polymer solutions flow through porous media, which can be exploited for EOR, is not well understood, mainly due to difficulties defining the complex random geometry of the flow field and probing the molecular response of the polymers within the porous medium. Porous media are usually modelled experimentally by randomly packed beds of spheres. The flow of Simon J. Haward Jeffrey A. Odell Viscosity enhancement In non-Newtonian flow of dilute polymer solutions through crystallographic porous media