Spatially Distributed Wettability Characterization in Porous Media
Journal:
arXiv
Published Date:
Jul 2, 2025
Abstract
An enhanced geometric algorithm for automated pore-by-pore contact angle
measurement from micro-CT images, is presented that achieves superior accuracy
compared to existing methods through robust fluid-fluid and solid-fluid
interface extrapolation. Using this high resolution data, we generate spatially
distributed contact angle maps that reveal previously hidden wettability
heterogeneity. Our analysis of mixed-wet systems demonstrates the severe
limitations of averaged metrics: a sample with a mean contact angle of 64.7
degrees, conventionally classified as uniformly weakly water-wet, exhibits 40%
of its pore space in the intermediate-wetting regime (70-110 degrees). This
heterogeneity explains the presence of minimal surface interfaces and
fundamentally different pore-filling mechanisms operating within the same
sample. By providing open-source tools for spatially-resolved wettability
characterization, this work enables more accurate predictions of multiphase
flow behavior in heterogeneous porous materials, essential for optimizing
subsurface energy storage and recovery processes.
