Capturing dissolution wormhole growth dynamics in partially saturated porous media

Wormholes, intricate finger-like channels, may form fluid flows through soluble porous media. An example of such instability is a acidic water flow through porous rocks leading to formation of karst. In experimental setups such conditions are analyzed using rock cores injected with acid. A variety of flow and acid conditions lead to varying wormhole geometry, with well known links between them for single phase flows. When a second, non-wetting phase is added, new geometrical and time scales are introduced to the system changing its dynamical properties. However, studies reveal contradictory effects of the second phase on wormholes depending on the type of second phase and how it arises. These contradictory effects can be resolved by observation of the dynamics of the second phase in the rock/wormhole. Injecting acid and nitrogen into a rock core to form wormholes while being scanned would allow to observe how steady state multi-phase flow interacts and changes wormhole dynamics.