Underground gas storage modelling

What we can help you with

Underground gas storage can balance variations in production and demand and provide reserve capacity for energy systems. For hydrogen, it is particularly important to understand how the gas moves, dissolves in formation water and interacts with other gases and microbial activity. These processes affect both the quantity and purity of the gas that can be recovered.

We work with industrial partners and research organisations to:

• Simulate hydrogen injection, storage and withdrawal in porous formations.
• Describe phase behaviour and fluid properties across different pressures, temperatures and salinities.
• Investigate how injection and withdrawal rates and storage cycle duration affect performance.
• Model microbial hydrogen consumption and changes in gas composition.
• Perform sensitivity analyses and develop simulation tools for specific storage questions.

Contact our Applied Computational Science research group to discuss a storage scenario, a modelling challenge or the need for new simulation capabilities.

Hydrogen, formation water and phase behaviour

Hydrogen density and solubility in formation water influence its distribution and transport through a reservoir. Models therefore need a consistent description of the relationships between pressure, temperature, salinity and gas composition.

We develop and apply thermodynamic models for hydrogen–brine systems. These are used to generate pressure–volume–temperature (PVT) tables that incorporate phase behaviour into efficient flow simulations. Our work includes both simplified descriptions of phase behaviour and compositional models that track several chemical components in the gas and aqueous phases.

Our research focuses particularly on storage in saline aquifers. We also contribute to interdisciplinary studies of hydrogen storage in depleted oil and gas reservoirs.

Microbial activity and hydrogen loss

Microorganisms can consume hydrogen and alter the composition of the stored gas. One example is methanogenesis, in which hydrogen and carbon dioxide are converted into methane and water:

4H₂ + CO₂ → CH₄ + 2H₂O

We couple models of microbial growth and reactions with compositional multiphase flow. This allows us to investigate how hydrogen and carbon dioxide availability, transport processes and operating conditions affect hydrogen loss and gas purity. The models also account for molecular diffusion and the effects of microbial clogging.

Sensitivity analyses help identify which assumptions and parameters have the greatest influence on the results. Simulations can therefore also indicate where improved data and experimental investigations would be particularly valuable.

Open simulation tools

A central part of our work is the development of the MATLAB Reservoir Simulation Toolbox (MRST). Two modules specifically address hydrogen storage:

• h2store provides models for hydrogen–brine systems, calculation and tabulation of PVT data, and simulation of storage and withdrawal. It includes the Redlich–Kwong equation of state, solubility data from ePC-SAFT and correlations based on Henry's law.
• H₂-biochem couples compositional flow with microbial growth and methanogenesis. The model includes water, hydrogen, carbon dioxide, methane and nitrogen, using a Søreide–Whitson equation of state fitted to experimental data.

Open source code makes the models and numerical methods available for inspection, reproducibility and further development. The tools can be adapted to new questions and used to compare the influence of different physical and biochemical processes.

Research collaboration

We contribute to HYDROGENi, a centre for environment-friendly energy research focused on hydrogen and ammonia. Collaboration with experimental researchers and geoscientists connects model development with questions about storage behaviour and the practical use of hydrogen as an energy carrier.

Publications and further reading

• Ahmed et al. (2025). Numerical Modeling and Sensitivity Analysis of Coupled Hydro-Biogeochemical Processes in Underground Hydrogen Storage. Conference contribution, GdR HydroGEMM; archived in HAL.
• Ahmed et al. (2025). Modeling and simulation of coupled biochemical and two-phase compositional flow in underground hydrogen storage. International Journal of Hydrogen Energy, 168, 150947.
• Masoudi et al. (2025). Feasibility of Hydrogen Storage in Depleted Hydrocarbon Reservoirs in Norway. 86th EAGE Annual Conference & Exhibition, Workshop Programme.
• Ahmed, Møyner, Raynaud and Nilsen (2024). Phase behavior and black-oil simulations of Hydrogen storage in saline aquifers. Advances in Water Resources, 191, 104772.