Investigating Wormlike Micelle Behavior Under Flow in Porous Media

Abstract

Wormlike micelles or “worms” are flexible and elongated structures comprised of surfactants that exhibit viscoelastic behavior resembling polymer solutions. Due to their surface-active nature, worms tend to interact with fluid interfaces, resulting in a reduction of surface tension compared to polymer solutions. This property suggests that worms could be more effective than polymers in applications such as enhanced oil recovery, where oil is typically mobilized by injection of a wetting fluid. Furthermore, worms possess the ability to break and reform, which allows for complete recovery of viscosity and elasticity, improving sustainability and efficiency in applications such as transport of heating and cooling fluids. While wormlike micelles hold promise for solving problems involving energy, sustainability, and our environment, the dynamic and transient nature of their microstructure, along with torturous pore space geometries renders relating microscopic worm behavior with bulk fluid properties a difficult challenge. My research addresses these challenges by demonstrating the design of an optically transparent 3D porous medium, allowing for imaging of in situ pore-scale flow of worms in a porous medium for the first time. Using this innovative 3D porous medium, my work provides insights into worm flow behavior at various flow conditions, demonstrating where flow fluctuations like shear banding and dead zones begin to occur. Using this understanding, we can design better systems that effectively utilize worm flow properties.