Flow in Porous Media

We develop microfluidic systems to investigate the fundamentals of two-phase flow in porous media. These three-dimensional (3D) model systems allow us to fully visualize the multiphase flow, in 3D, at pore-scale resolution, using confocal microscopy. Moreover, we instrument these systems to simultaneously image the flow and probe their bulk transport properties. We also develop new materials that control the flow in the porous material. This work is motivated by the need to direct fluids for improved resource recovery.

Flow in Binary Colloidal Glasses: Glassy materials are of great importance both as a subject of scientific study and also for their enormous potential in engineering applications. Distinctive feature of glasses is the absence of long-range periodic order in their internal structure along with low atomic or molecular mobility. An essential unresolved question in the physics of glasses is a comprehensive understanding of their behavior under applied stress. How do the constituent molecules or atoms in a glass respond to an external force? Such a study would be highly challenging in a material like window glass. Molecular movement within a sheared window glass is too fast to be tracked easily by conventional microscopes. Therefore, a system with a much slower response time would be desirable. It is known that the time scale of the motion of colloids is slow enough to render their dynamics trackable in real time. Also, their size is large enough to make them visible in an optical microscope. Colloids can be synthesized with high precision and nearly perfect size dispersity with tunable inter-particle interactions. Therefore, in this study, we are aiming at making a glassy system based on two different colloidal particles, reminiscent of glassy alloys, which can be exposed to external shear with simultaneous investigation under optical microscope. This study is expected to provide more insights into the displacement of the glass constituents upon macroscopic deformation. Payam Payamyar

Hydraulic Fracture of Brittle Gels: Hydraulic fracture of oil and natural gas bearing rocks has rapidly grown over the last two decades into an integral tool for the extraction of these resources.  It has proven to be both very economically favorable as while also being cited as responsible for significant ecological damage.  In order to address both its efficacy and safety, one must understand more about the factors that control the growth of these hydraulic fractures that cannot be observed in nature.  Our goal is to study the behavior and control mechanisms of fractures produced in tough hydrogels where we can observe with far greater spatial and temporal accuracy than similar experiments performed on rocks.  By measuring the basic physics that governs hydraulic fracture propagation we hope to make oil and natural gas exploration both safer and more efficient. Will Steinhardt

Flow of multiple immiscible fluids in porous media: I study the dynamics of flow of multiple immiscible fluids in a 3D model porous medium. Using confocal microscopy we are able to visualize multiphase flow within the porous media. I am interested in understanding the underlying physical phenomenon that results in enhanced imbibition of the non-wetting phase due to flow of  Non-Newtonian wetting phase, a shear thinning polymer solution. Shima Parsa

 Understanding water-oil-solid interaction by visualizing two phase flow in porous media: Water-oil-solid interactions are abundant all around us, if it’s oil extraction from rock reservoirs, remediation of solvents from the soil or just percolating coffee. In essence the coffee analogy can serve well to exemplify different interactions; making coffee with a percolator is similar to extracting oil by replacing it with water under gravitational pressure. Making an espresso is similar to the process known as fracking where water with high pressure fracture the rock formation to reach untapped oil, in both cases the oil is trapped in pores at the porous medium. We can visualize the water-oil-solid interaction by matching the refractive index of all three while suspending fluorescent beads in the oil and the water. This procedure elucidates the underlying physics using high spatial-temporal imaging of the flow in both phases. Yaniv Edery