Abstract
Microfluidics allow for investigation and visualization of multiphase flow behavior at small scales. Micromodels are microfluidic porous media that can can tailored geometry and heterogenity. In this work, we investigate enhanced oil recovery mechanisms using microfluidic devices over several scales, from a single channel to core-flood on a chip with hundreds of thousands of pores and throats. We show analytically, numerically, and experimentally the conditions under which snap off occurs in 2D channels and develop a new fabrication technique with glass to develop 2.5D microfludic channels and micromodels that have channel depths different than pores. We also fabricate a new “coreflood on a chip” micromodel which is the length (30-40 cm) of a typical coreflood, has 3D properties (2.5D), and allows for coating of the grains to control the surface chemistry. Heterogenity is included by adapting a computer-generated geostatistical model used in network models.
Applications of nanoparticles, viscoelastic polymer flooding, and alkali-surfactant polymer flooding (ASP) are investigated. It is shown that for purely viscous fluids, the trapped non-wetting fluid droplet at a constriction scales with L ~ Ca-1/3. However when the wetting fluid is viscoelastic, the droplet vibrates and oscillates. As the velocity inreases, the oscillation wavelength increases and the droplet does not pass through. In micromodels, swelling of the oil droplets occurs in the presence of low salinity, viscolelastic polymers which can lead to impreoved sweep efficiency. Finally, the corelfood-on-a-chip micromodel is used to investigate ASP floods and visualize oil banks and surfactant at several scales. Surprisingly, surfactant is observed in pores ahead of the oil bank.
Bio
Matthew T. Balhoff is the Department Chair and a Professor in the Hildebrand Department of Petroleum and Geosystems Engineering at UT-Austin. He co-leads the Industrial Affiliate Program on Chemical Enhanced Oil Recovery. Dr. Balhoff received his BS (2000) and PhD (2005) in chemical engineering from Louisiana State University. He became an SPE Distinguished member in 2017 and is a winner of the 2022 SPE Lester C. Uren Award, 2014 SPE International Young Member Service Award, and 2012 SPE International Teaching Fellow Award. Dr. Balhoff has 96 peer-reviewed publications and 39 conference papers in the areas of enhanced oil recovery, carbon storage, unconventional resource production, and fundmental processes of flow and transport through porous media.