Hydrogen storage in the East Midlands (UK): The EMStor Project

The East Midlands (UK) is poised to become the largest inland hydrogen cluster in the UK, supplied via Cadent’s East Coast Hydrogen pipeline. The storage of hydrogen will become an important enabler, allowing the gas to be produced when renewable energy is abundant, stored, and then used by industry and power generators during times of energy needs.

Project East Midlands Storage (EMStor) is a Strategic Innovation Funded feasibility study on the development of hydrogen storage in repurposed hydrocarbon fields. In this project, we investigate the feasibility of one of the East Midland depleted oil reservoirs in close proximity to the proposed hydrogen pipeline network that could potentially be used to store hydrogen, subject to technical feasibility and further development work. Initial promising calculations predicted combined capacities in the TWh-scale of nearby fields, and current research focusses on unlocking meaningful storage capacity while ensuring safety and commercial success.  

Project EMStor will demonstrate at scale the technology readiness of underground hydrogen storage in the East Midlands and develop our understanding of technical, social and economic facets. A screening of available sites has resulted in the selection of the “Long Clawson” oil field for a pre-feasibility study. Oil-rich reservoirs are often not the primary targets for hydrogen storage due to the scientific complexities. Additionally, the field of the interest is relatively shallow (680m), has reservoir layers with an average thickness of ~10m, and have low oil depletion rates. Using an efficient black-oil simulator, reservoir modelling is used to test and optimise the feasibility of cyclic hydrogen storage in these reservoir layers, with a focus on cushion gas demand and dynamic storage capacity. 

Gas leakage via pre-existing reservoir wells poses a potential risk for hydrogen storage. An assessment of the integrity of Long Clawson’s operational and legacy wells, conducted using existing available data, including well schematics and reports, will determine the preliminary suitability of these wells for safe and reliable hydrogen storage.

To address questions around possible reaction between stored hydrogen and reservoir materials batch reactions are conducted on the nominal well cement as well as reservoir rock samples, together with synthetic formation brine and hydrogen gas at reservoir conditions, in order to characterise any reaction within the system. These experiments will provide a basis for demonstrating the long-term stability and safety of these stores for hydrogen from a geochemical point of view, where loss of stored hydrogen to reaction, generation of undesirable by-products (such as H2S) and infrastructure compatibility are of primary concern.

Additional research includes public’s perception of hydrogen storage in East Midlands (UK), an economic analysis, the approach to regulatory, permitting and planning for any subsequent demonstration and finally decisions on next steps and future phasing.

By showcasing the potential storage in the East Midlands, project EMStor may demonstrate the technical viability of underground hydrogen storage in a methodology that is widely replicable for other repurposed hydrocarbon fields.