AUTHOR=Yu Wei , Zhou Xianmin TITLE=Experimental and modeling study of foam coarsening kinetics in porous media JOURNAL=Frontiers in Energy Research VOLUME=10 YEAR=2022 URL=https://www.frontiersin.org/journals/energy-research/articles/10.3389/fenrg.2022.1012728 DOI=10.3389/fenrg.2022.1012728 ISSN=2296-598X ABSTRACT=

The geometric confinement significantly affects the foam coarsening dynamics in porous media. We present the experimental and modeling studies of coarsening-induced foam structural evolution in a porous microfluidic chip. The findings are expected to shed light on predicting the foam structure in many applications, such as foam-assisted enhanced oil recovery process and CO2 geological sequestration. It is shown that, in porous media, small bubbles are constantly consumed by large bubbles due to inter-bubble gas diffusion until most bubbles grow to the pore or throat size. The coarsening of edge bubbles (bubbles contacting the boundary) dominates the foam coarsening process, showing a linear increase in the average area of edge bubbles with time in a steady-state growth state. A mass transfer model is proposed to fit the foam coarsening rate of edge bubbles, including critical parameters such as liquid film permeability, gas-liquid interfacial tension, the molar volume of the dispersed phase, and the polydispersity of bubble size distribution. We emphasize that, under the same experimental conditions, foams with a broader size distribution exhibits a faster coarsening rate due to higher capillary pressure differences among the bubbles as the mass transfer driving force.