Doctor of Philosophy (PhD)
Modeling particle transport and retention in porous media is important in fields such as hydrocarbon extraction, groundwater filtration, and membrane separation. While the continuum-scale (>1 m) is usually of practical interest, pore-scale (1-100 μm) dynamics govern the transport and retention of particles. Therefore, accurate modeling of continuum-scale behavior requires an effective incorporation of pore-scale dynamics. Due to current computational limits however, the large spatial and temporal discrepancies of these scales prohibit modeling an entire continuum-scale system as a single pore-scale model. Even if a pore-scale model could incorporate every pore contained in a continuum-scale system, an upscaling scheme that coupled pore- and continuum-scale models should in principle be more efficient and achieve acceptable accuracy. In this work, a continuum-scale model for particle transport and retention has been developed using the concurrent coupling method. In the model, pore network models (PNMs) were embedded within continuum-scale finite difference grid blocks. As simulations progressed the embedded PNMs periodically provided their continuum-scale grid blocks with updated petrophysical properties. The PNMs used a Lagrangian particle tracking method to identify particle dispersion and retention coefficients. Any changes in permeability and porosity due to particle trapping were also determined. Boundary conditions for the PNM simulations were prescribed by fluid velocity and influent particle concentration information from the continuum-scale grid blocks. Coupling in this manner allowed for a dynamic understanding of how particle induced changes at the pore-scale impact continuum-scale behavior.
Blears, John Rayner, "Coupled Pore-to-Continuum Multiscale Modeling of Dynamic Particle Filtration Processes in Porous Media" (2019). LSU Doctoral Dissertations. 5098.