Using underground gas storage facilities for hydrogen involves an increased risk of leakage due to the small molecular size and high diffusivity of hydrogen.

In order to minimize this risk, hydrogen diffusion rates are to be measured using representative rock and material samples so that possible leakage rates can then be quantified with the aid of simulations and storage operations can be optimized.

Cyclic stress on reservoir and caprock formations potentially leads to risks such as material failure and leakage.

By developing hydro-geomechanical reservoir models that simulate the behavior of sandstone materials under cyclic stress alteration, the critical points in the stressed areas will be identified.

To achieve this goal, hydro-geomechanical experiments will be carried out to investigate the material behavior, determine the corresponding constitutive laws and integrate them into the mathematical models for reservoir simulation.

Completion as access to the storage system (cavern, pore storage) has been identified as a critical factor in gas storage.

The aim of this project is to comprehensively describe the critical near-wellbore factors for the safe storage of gases. Experimental investigations will be carried out to determine gas permeability and material compatibility.

Mathematical modeling of the transport processes in completion systems will be used to carry out additional analyses.

In this sub-project, an existing 3D model of the geological subsurface around the Burgwedel geothermal concession will be updated and expanded to include a deeper reservoir.

The deeper reservoir is a depleted natural gas horizon targeted to be explored for hydrogen storage.

As part of the project, new data from seismic surveys will be evaluated and incorporated into the model, and storage scenarios for a hydrogen storage facility will be simulated.