InterPore2026

X-ray CT Imaging of Gas Dispersion in Porous Media for Underground Hydrogen Storage Applications

21 May 2026, 10:05

1h 30m

Poster Presentation (MS10) Advances in imaging porous media: techniques, software and case studies Poster

Speaker

Ianna Gomez Mendez (Pennsylvania State University)

Description

Large‑scale underground hydrogen storage (UHS) in porous formations requires the presence of a cushion gas to maintain reservoir pressure, but miscible mixing between hydrogen and the cushion gas reduces withdrawal purity. Quantifying dispersion and flow instabilities controlling this mixing is therefore essential for evaluating the viability and performance of UHS in porous reservoirs, which will be critical to expanding hydrogen economies. This study presents in situ miscible core flooding experiments using X‑ray computed tomography to measure dispersion coefficients and visualize gas‑gas displacement and mixing in homogeneous porous media. Radiopaque analog pairs (Helium–Xenon) were selected to reproduce the viscosity ratios of hydrogen and typical cushion gases (Carbon Dioxide and Methane) under relevant reservoir pressure and temperature. Helium was injected into a Xenon-saturated vertical Gray Berea sandstone core (5.08 cm diameter, 15.24 cm length) across multiple thermodynamic conditions, and time‑resolved 2D CT images were used to extract concentration fields and estimate dispersion parameters. The resulting dispersion coefficients capture the influence of viscosity contrast and flow regime on miscible gas mixing and provide relevant inputs for reservoir‑scale UHS simulations. Furthermore, the experimental setup developed in this research enables safe, effective investigations of hydrodynamic phenomena in UHS and expands our capabilities of evaluating processes controlling hydrogen retention and purity at relevant reservoir conditions. Outcomes of this research improve our fundamental understanding of gas‑gas displacement and mixing behavior in porous media and support feasibility assessments and operational optimization of UHS systems.