(550f) Characteristics Affecting Foam Stability in Microfluidics Porous Media

Foams play essential roles in industrial applications — as displacing fluids in enhanced oil recovery at production wells and as carriers for gas in carbon sequestration at hydraulic fracking cites. These applications generated great interest in understanding the fundamental physicochemical processes associated with foam to predict their flow in natural porous media environments. Microfluidics have been proven effective in visualizing small scale events and processes that would otherwise be difficult to observe in natural confined systems. In this study, a microfluidic device designed to mimic natural heterogenous sandstone porous media is employed to investigate the effects of gas types, surfactant concentration, and foam quality on gas trapping, foam generation, foam stability, and phase mobility. Phenomena such as lamella division and foam coarsening are directly observed in microfluidic devices and compared between different cases. We characterize pressure drops, apparent viscosities, variations in foam texture, and ratios of flowing and stationary foam across the model porous media. An in-depth picture of foam texture in relation to foam quality and flow rate is possible by combining real-time imaging and image processing technique.