Work

Ostwald Ripening in Underground Gas Storage

Year: 2026

Type: article

Abstract: Underground gas storage supports the energy transition, enabling long‐term sequestration and seasonal storage. A key process shaping the fate of injected gases is Ostwald ripening—the curvature‐driven mass transfer between trapped ganglia—yet its behavior in confined porous structures remains poorly constrained. We present ultra‐high‐resolution microfluidic experiments that track residually trapped hydrogen for weeks in realistic heterogeneous pore networks. The data show rapid local equilibration among neighboring bubbles, followed by slow global depletion driven by long‐range diffusion. We develop a continuum model that couples pore‐scale capillary pressure–saturation relationship, derived using the pore‐morphology method, with macroscopic diffusion. The model predicts saturation evolution without fitting parameters and collapses results across diverse conditions. Reservoir‐scale estimates indicate that local equilibration far outpaces convective dissolution for and occurs on timescales comparable to seasonal storage. Because minimal redistribution is required to reach local capillary equilibrium, residual trapping remains stable in the absence of sinks.

Source: Geophysical Research Letters

DOI: 10.1029/2025gl120691

Authors: Mohammad Salehpour, Tian Lan, Nicolas Bueno, Md Zahidul Islam Laku, Yashar Mehmani, Benzhong Zhao

Institutions: McMaster University, Pennsylvania State University

Language: English

Topic: CO2 Sequestration and Geologic Interactions

Subfield: Environmental Engineering

Field: Environmental Science

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $3,190

Funders: National Science Foundation, Natural Sciences and Engineering Research Council of Canada