Oil displacement in capillary tubes using viscoelastic fluids

Capillary invasion of liquid is a spontaneous phenomenon that occurs at length scales smaller than the capillary length. By means of capillary action, numerous applications have been developed. We investigate the time-dependent displacement of a Newtonian oil using viscoelastic polyethylene oxide solutions. The setup implies a capillary tube in a horizontal configuration that was partially prefilled with oil. We emphasize the prefilling liquid’s role in the dynamics of the system and show the influence of the displacing liquid’s viscoelastic properties. We find significant changes in the capillary regime as the displacing liquid’s viscoelastic properties change.