Surface tension plays a critical role in controlling fluid flow in porous media. By measuring surface tension interactions under multiphase conditions, relative permeability curves, which describe how multiple fluids interact within a porous media, can be derived. These curves are essential for modeling multiphase flow in subsurface systems, including carbon sequestration, hydrocarbon recovery, and groundwater remediation. Accurate characterization of the distribution of relative permeability in the subsurface is therefore vital.
While empirical formulas for estimating relative permeability from capillary pressure are well established, they often lack the flexibility needed to match laboratory-measured data. By expanding on existing methods, we show that both two-phase and three-phase relative permeability curves can be generated directly from capillary pressure data.
In this study, mercury intrusion capillary pressure (MICP) data from multiple lithologies, combined with interfacial tension and contact angle measurements, were used to generate relative permeability curves. These model-derived curves were calibrated against a limited set of laboratory-measured data to identify common fitting parameters. These parameters were then applied to the method to create relative permeability curves from MICP datasets lacking laboratory-derived counterparts, enabling characterization of multiphase flow behavior in a broad range of formations.