A finite volume framework for flow in karstified porous media

Resumo

Karst conduit systems exhibit complex geometries, where networks of channels, cavities, or vugs coexist within a porous matrix. Accurately simulating fluid flow in such heterogeneous environments remains a challenge that often limits the reliability of predictions. This study presents a conservative finite volume framework that ensures mass conservation while coupling the karst conduit and porous matrix domains to simulate coupled 1D/3D flows in carbonate rocks. The method is designed to handle intricate networks of karst conduits, including cases in which individual branches have distinct properties—particularly differing permeabilities and size ratios. The karst subdomain is embedded within the matrix grid to ensure geometric consistency and alignment, while mass exchange between the two domains is governed by a transmissibility factor. Numerical experiments include a sensitivity analysis of key parameters, such as permeability contrast and branch ratio, to examine their effects on pressure and velocity fields and to assess the model’s ability to capture these variations.