InterPore2026

Buoyancy-driven leakage through high-permeability channels in porous media: experimental investigation of various flow regimes

19 May 2026, 15:05

1h 30m

Poster Presentation (MS08) Mixing, dispersion and reaction processes across scales in heterogeneous and fractured media Poster

Speaker

Anoop Rathore (Indian Institute of Technology Kanpur)

Description

This study investigates the complex phenomenon of buoyancy-driven leakage through a high-permeability channel (HPC) in a porous medium. In nature, such buoyancy-driven flows may be observed in several contexts, including underground hydrogen storage, CO$_2$ sequestration, and water infiltration in soil. For our study, we used a transparent acrylic rectangular tank for performing the experiments. The tank was filled with glass beads of different diameters to create the HPC and a low-permeability porous medium (LPPM) around it. In this setup, we performed experiments to examine the flow behavior of a low-density fluid, i.e. injected at the bottom, through the HPC embedded within the LPPM, and saturated with ambient fluid of higher-density. We obsered two distinct flow scenarios: (a) the low-density fluid leakages remains confined within the HPC while leaking through it upward with no-gravity current (NGC) formation, and (b) the fluid leaks through the HPC into the LPPM and subsequently forms a gravity current (GC) underneath the impermeable layer (caprock). The objective of this study is to determine the critical injection rate of the low-density fluid for which we can separate out these two distinct behaviors. This critical discharge depends on various parameters, including the permeability ratio between the HPC and LPPM, the width of the HPC, the discharge rate, and the density difference between the injected and ambient fluids. For a permeability ratio of 9, experiments were conducted with injection rates ( q ) between 0.09 to 1.76~cm$^{3}$/s and density differences ranging from 0.5\% to 10\%. Figure~1 illustrates the two flow scenarios: Exp-1, figures~1(a) and~1(b) correspond to the NGC case, while Exp-2, figures~1(c) and~1(d) show the GC case. Figure~2 shows the delineating line separating the two scenarios for setup with various discharge and density difference values. The curve exhibits a negative slope of 0.172. Future work will include additional experiments with higher permeability ratios and the validation of these experimental findings using both numerical and analytical models.