Impact of Wettability and Gravity on Fluid Displacement and Trapping in Representative 2D Micromodels of Porous Media (2D Sand Analogs)

The combined effects of gravitational forces and wettability on displacement trapping have not previously been investigated experimentally in realistic 2D porous media. Here we report the first use representative micromodels that accurately reproduce characteristic geometric, morphological, topological properties 3D sand packs. We these to compare dependence front morphology processes using selected fluid pairs at capillary numbers between 10?6 10?5. contact angles studied ranged from 30° (normal imbibition) 150° (strong drainage). impact gravity was dramatic: In horizontal flow case, only one finger developed, is longitudinal always favored, whereas created a more compact with broad lateral extension, this movement loops, leading by-pass trapping. As result, efficiency rose 7% 29%. observed universal scaling cluster size distribution demonstrating our are statistically representative. 2D-scaling exponent 2.05 obtained an acceptable error smaller than 5%. Our experimental results by fluorescence microscopy showed (a) precursor corner for weak imbibition ? = 51°, above critical angle ?c 45° (Zhao et al., 2016, https://doi.org/10.1073/pnas.1603387113), (b) new wetting transition full duct under neutral conditions, ?c ? 90°; (c) second angle, strong drainage again (specifically, core-annular flow).