Enhanced displacement of a liquid pushed by a viscoelastic fluid

Abstract

We consider the displacement, in a rectangular channel, of a Newtonian oil pushed by different types of liquids (Newtonian, shear-thinning, viscoelastic) of slightly higher apparent viscosity. In the absence of viscoelastic effects the interface between the two fluids becomes sharper at larger velocities, so that the thickness of the lateral film left behind increases with the flow rate. On the contrary, with a viscoelastic fluid, the shape of the interface is almost independent of the velocity so that the thickness of the lateral film is approximately constant. Moreover this thickness decreases when the ratio of normal to tangential stresses increases, suggesting that this effect can be attributed to normal stress differences. A heuristic theoretical approach tends to confirm this statement.

Viscoelastic effects on residual oil distribution in flows through pillared microchannels

“…Our recent simulations of viscoelastic flow through symmetric and asymmetric set of cylinders and through a random porous medium show that the origin of these instabilities are more related to the viscoelastic shear stress than to extensional contributions [25,43]. Recent findings by Clarke et al [18] , Avendano et al [44] and Nilsson et al [45] show the possible effects of viscoelasticity in enhanced displacement. Rodriguez de Castro et al [46] very recently showed effects of shear thinning fluids on residual oil formation.…”

Pore‐Scale Flow Characterization of Polymer Solutions in Microfluidic Porous Media

“…Several proposed mechanisms rely on a potential influence of polymers on the immiscible fluid interface. For example, it has been speculated that polymer solution viscoelasticity alters the shape of the fluid displacement front in a porous medium . However, how this process impacts macroscopic fluid recovery is unclear.…”

“…For example, it has been speculated that polymer solution viscoelasticity alters the shape of the fluid displacement front in a porous medium. [199] However, how this process impacts macroscopic fluid recovery is unclear. In another mechanism, it is speculated that the extensional viscosity of polymer solutions suppresses nonaqueous globules from breaking up as they transit through the tortuous pore space.…”