A review of analogue case studies relevant to large-scale underground hydrogen storage Nikolaos Diamantakis, Anna Peecock, Omid Shahrokhi, Sudhagar Pitchaimuthu, John M. Andresen (2024) review case studies of hydrogen, helium, and natural gas storage in the subsurface to identify challenges affecting large-scale underground hydrogen storage (UHS). They highlight the importance of containment security, hydrogen reactivity, and well integrity. The study identifies 32 depleted offshore hydrocarbon reservoirs in the UK Continental Shelf (UKCS) as potential storage formations based on technical screening criteria. These fields are evaluated for their hydrogen storage capacity, low cushion gas requirements, and proximity to offshore wind farms, indicating their potential for efficient UHS in the UKCS. The study also proposes that analysis of existing helium concentrations and investigation of local tectonic settings are key site-specific criteria for identifying containment security of depleted fields for stored hydrogen. The review discusses various UHS storage options, including salt and lined rock caverns, and porous media. Salt caverns are commercial and efficient for short-term hydrogen storage, while porous media offer large storage capacities and are suitable for long-term storage. The study also examines pilot UHS projects, such as H2STORE, HyUNDER, HyINTEGER, HyCHICO, and others, to assess the feasibility of UHS in depleted reservoirs, aquifers, and caverns. The study highlights the challenges associated with hydrogen storage, including chemical and microbial reactions, diffusion losses, and viscous fingering effects. It also discusses the importance of cushion gas in UHS, and the influence of geological factors on hydrogen storage. The study also examines the experience from underground helium storage and helium injection experiments, which provide insights into hydrogen storage, particularly in terms of gas mobility, diffusivity, and containment. The study highlights the importance of well integrity in UHS, and the potential risks associated with hydrogen leakage. It also discusses the geological setting of various UHS sites, including the Lobodice Aquifer, Ketzin Aquifer, Beynes Aquifer, and the Diadema Wind Park and Hydrogen Plant. The study concludes that the experience from these case studies is essential for the development of site-specific screening criteria for UHS.A review of analogue case studies relevant to large-scale underground hydrogen storage Nikolaos Diamantakis, Anna Peecock, Omid Shahrokhi, Sudhagar Pitchaimuthu, John M. Andresen (2024) review case studies of hydrogen, helium, and natural gas storage in the subsurface to identify challenges affecting large-scale underground hydrogen storage (UHS). They highlight the importance of containment security, hydrogen reactivity, and well integrity. The study identifies 32 depleted offshore hydrocarbon reservoirs in the UK Continental Shelf (UKCS) as potential storage formations based on technical screening criteria. These fields are evaluated for their hydrogen storage capacity, low cushion gas requirements, and proximity to offshore wind farms, indicating their potential for efficient UHS in the UKCS. The study also proposes that analysis of existing helium concentrations and investigation of local tectonic settings are key site-specific criteria for identifying containment security of depleted fields for stored hydrogen. The review discusses various UHS storage options, including salt and lined rock caverns, and porous media. Salt caverns are commercial and efficient for short-term hydrogen storage, while porous media offer large storage capacities and are suitable for long-term storage. The study also examines pilot UHS projects, such as H2STORE, HyUNDER, HyINTEGER, HyCHICO, and others, to assess the feasibility of UHS in depleted reservoirs, aquifers, and caverns. The study highlights the challenges associated with hydrogen storage, including chemical and microbial reactions, diffusion losses, and viscous fingering effects. It also discusses the importance of cushion gas in UHS, and the influence of geological factors on hydrogen storage. The study also examines the experience from underground helium storage and helium injection experiments, which provide insights into hydrogen storage, particularly in terms of gas mobility, diffusivity, and containment. The study highlights the importance of well integrity in UHS, and the potential risks associated with hydrogen leakage. It also discusses the geological setting of various UHS sites, including the Lobodice Aquifer, Ketzin Aquifer, Beynes Aquifer, and the Diadema Wind Park and Hydrogen Plant. The study concludes that the experience from these case studies is essential for the development of site-specific screening criteria for UHS.