Pore-scale modeling of foam in porous and fractured media
Dr. Maša Prodanović is Frank W. Jessen Professor and Associate Department Chair in Hildebrand Department of Petroleum and Geosystems Engineering, The University of Texas at Austin.
Abstract: Foams are dispersions of gas bubbles within a liquid. They often generate in porous and fractured media during co-injection of gas and liquid in the presence of surfactants that stabilize foam bubbles. Since foam viscosity is much higher than the constituent gas and liquid phases, they are used for diverting fluid to less permeable subsurface formations in applications such as enhanced oil recovery or carbon dioxide storage. Pore geometry, thermodynamic conditions, molecular structure and behavior of stabilizing agents such as surfactants or nanoparticles near fluid/fluid or fluid/solid interfaces are some important factors affecting stability and regeneration of foam during its transport in porous media. The transport behavior of foam at pore scale in the porous media has thus far been mostly studied using micromodels (i.e. experimentally) and pore-scale numerical models have lagged behind. The work I will present is mostly developed by PhD student Xuesong (Cedar) Ma as well as Bernard Chang in my research group. We have developed and validated a new 2D and 3D model for foam propagation that incorporates fundamental mechanisms within the detailed geometry of a porous medium. The foam propagation is modeled using a lattice Boltzmann model that couples the momentum equation for liquid flow and the advection-diffusion equation for gas diffusion. To our knowledge, this is the first model with the foam flow driven by pressure gradient in a fractured / porous medium, gas diffusion through liquid phase and the interface changes as a result due to both of those mechanisms at pore scale. The model is validated against microfluidic experiments from the literature. We quantify, for the first time, detailed pressure and velocity spatial changes that lead to foam bubbles splitting or wiggling while moving through the complex pore scale geometry. Depending on the injection conditions, we correctly capture foam bubble wiggling or splitting (into multiple bubbles) through pore throats. We describe individual bubble behavior in parametric space and ultimately derive foam rheology in porous media from the first principles. The foam apparent viscosity is inversely related to the capillary number and we fit the data to a power law. Some results we will show are published , and some are very recent (publication is in
review).
About: Maša Prodanović is Frank W. Jessen Professor and Associate Department Chair in Hildebrand Department of Petroleum and Geosystems Engineering, The University of Texas at Austin. She has expertise in direct simulation of flow and particulate transport in porous and fractured media, porous media characterization especially based on 2D and 3D images of rock microstructure, unconventional resources and data curation. Notably, she manages open data repository Digital Rocks Portal (https://www.digitalrocksportal.org/). She is a recipient of multiple awards such as SPE Regional Data Science and Engineering Analytics Award in 2024, InterPore Medal for Porous Media Research in 2022, SPE Distinguished Member Award in 2021 and EAGE Alfred Wegener Award in 2021 among others. Most recently, she was elected Interpore Society Council member, SIAM Geosciences Program Director 2021-22, SIAM Geosciences Chair 2023-24 and Gordon Conference on Flow and Transport in Permeable Media Co-Chair 2024-26.