Hydrogen storage in porous geological formations – onshore play opportunities in the midland valley (Scotland, UK)

Abstract

Hydrogen usage and storage may contribute to reducing greenhouse gas emissions by decarbonising heating and transport and by offering significant energy storage to balance variable renewable energy supply. Underground storage of hydrogen is established in underground salt caverns, but these have restricted geographical locations within the UK and cannot deliver the required capacity. Hydrogen storage in porous geological formations has significant potential to deliver both the capacity and local positioning. This study investigates the potential for storage of hydrogen in porous subsurface media in Scotland. We introduce for the first time the concept of the hydrogen storage play. A geological combination including reservoir, seal and trap that provides the optimum hydrogen storage reservoir conditions that will be potential targets for future pilot, and commercial, hydrogen storage projects. We investigate three conceptual hydrogen storage plays in the Midland Valley of Scotland, an area chosen primarily because it contains the most extensive onshore sedimentary deposits in Scotland, with the added benefit of being close to potential consumers in the cities of Glasgow and Edinburgh. The formations assessed are of Devonian and Carboniferous age. The Devonian storage play offers vast storage capacity but its validity is uncertain due to due to a lack of geological data. The two Carboniferous plays have less capacity but the abundant data produced by the hydrocarbon industry makes our suitability assessment of these plays relatively certain. We conclude that the Carboniferous age sedimentary deposits of the D'Arcy-Cousland Anticline and the Balgonie Anticline close to Edinburgh will make suitable hydrogen storage sites and are ideal for an early hydrogen storage research project.

Cyclic CO2 – H2O injection and residual trapping: Implications for CO2 injection efficiency and storage security

“…The injection and storage of CO2 into deep saline aquifers could make a significant contribution to reducing global greenhouse emissions (Bachu and Adams, 2003;Benson and Cole, 2008;Edlmann et al, 2015;Heinemann et al, 2018;IEA, 2004;Koide et al, 1992;Metz, Davidson, de Coninck, 2005). Current field experience (Alcalde et al, 2017;Hosa et al, 2011) suggests that a single well can inject in excess of 1MT of CO2 per year with numerical simulations indicating that during constant CO2 injection, these injectivity rates can be maintained (Heath et al, 2014;Jikich et al, 2003;Rutqvist et al, 2008;Zoback and Gorelick, 2012).…”

Thermodynamic and transport properties of hydrogen containing streams

“…To enable hydrogen as a low carbon energy pathway, gigawatt-scale storage will be required 2 – 5 . Geological gas storage in underground salt caverns, depleted oil and gas fields and deep aquifers are proven technologies that could provide the necessary scales for hydrogen storage 6 – 8 . Hydrogen-rich town gas mixtures have been stored in geological formations since the 1970’s 9 and currently, over 1,000,000 m 3 of hydrogen is stored in underground salt caverns 10 , 11 .…”

Low-carbon GeoEnergy resource options in the Midland Valley of Scotland, UK

“…The technology for gas injection and storage in porous media is well established. Gas is injected into a porous and permeable reservoir formation, such as an aquifer or a depleted hydrocarbon field, via injection wells, and displaces the in-situ pore fluid, usually brine, and spreads out underneath an impermeable caprock (Mouli-Castillo et al, 2019;Heinemann et al, 2018;Edlmann et al, 2019). Since thick salt formations are absent in the Midland Valley, storage in porous media has to be investigated.…”

“…Small research projects in suitable potential storage sites of Carboniferous age could be investigated to test the feasibility of the technologies in the Midland Valley. Bigger projects could be implemented in Devonian sandstones, such as the Knox Pulpit Formation, once confidence in the technology has increased (Heinemann et al, 2018). Hydrogen storage is a particularly attractive GeoEnergy resource because it offers potential to reduce emissions across three energy sectors: replacing fossil fuels in vehicles, replacing natural gas for industry and domestic heating, and provide seasonal storage to replace existing fossil fuel-based energy storage.…”