The aim of the research is to develop a 3D fluid flow model predicting the effect of discontinuities on hydrogen storage and recovery within different facies of the Sherwood Sandstone Group (SSG).
Three research questions will be addressed:
1. What are the key pore scale characteristics within the discontinuities of the SSG that affect the reservoir scale H2 storage properties?
2. What are the influential fluid flow properties of the SSG that are needed to parameterise, develop, test and validate a 3D probabilistic geological model for H2 storage and recovery?
3. How can the sensitivities of the variables and uncertainties of the model be quantified and characterised so that they can be communicated to policymakers and industry?
The SSG is important to the UK as a hydrocarbon reservoir and as a significant source of groundwater. It also has potential to help with some of the imminent climate challenges by potentially acting as a storage reservoir for CO2 or reservoir for the temporary storage of hydrogen, thereby supporting the energy transition and Net Zero 2050 goals by the UK government . However, discontinuities, such as deformation bands, have the potential to restrict the advantages of the SSG. For instance, clusters of cataclastic bands may limit lateral flow and porosity may be reduced , . Further understanding of the effect of discontinuities on storage and recovery capabilities of different facies at field scale is needed to better model reservoir capacity and its response to cyclic perturbations so that we can manage our resources effectively, avoiding potential hazards and costly and disruptive interventions, such as those created by anomalous pressure increases at SnÃƒÂ¸hvit . A better comprehension of SSG properties will further our understanding of other sandstone formations and improve our ability to use geological resources globally.
Potential impacts of this research are:
– Improved UK subsurface strategy. It will provide a scientific foundation for the UK Government regarding the extent of our resources and their geographical locations, impacting upon hydrogen transportation costs and the proximity of large industrial processes to storage sites, enabling them to create clear policy about the hydrogen network and focus resources toward building an integrated infrastructure with other technologies such as carbon capture and storage .
– Removal of some barriers to a hydrogen economy, one of the UK Government’s three pathways towards achieving its emissions goals  with recent substantial investment . Storage and effective retrieval is an essential part of this relatively immature technology.
– Newly identified geological domains for hydrogen storage. Currently hydrogen is stored in solution-mined caverns in halite; understanding the potential for pore space storage could allow additional geological units to be identified as hosts, increasing the geographical extent of potential sites in areas of projected hydrogen demand remote from suitable accumulations of bedded halite.
– Reduction in hydrogen storage costs. Identification of storage sites and their fluid properties will cut research and exploration costs of industry, allowing resources to be targeted at areas with maximum chance of success, and provide companies and clusters with a more realistic understanding of the costs involved.
The overall effect will be to accelerate the UK industrial, domestic and transport sectors towards the Net Zero targets  by reducing information and cost barriers to their implementation. This research will also be relevant to energy storage for other technologies with potential in the SSG, including aquifer thermal and compressed air storage.