Added: 25th November 2020 by CGG
CGG are providing research funding and support for two E4 DTP PhD projects in the School of Geosciences at the University of Edinburgh investigating the underground storage of hydrogen in porous rocks.
Large-scale hydrogen storage can help to alleviate the energy supply problems brought about by the dependence of renewable energy on seasonally fluctuating atmospheric events, i.e. sunlight level & intensity and wind force. Excess renewable energy can be converted to hydrogen, which can be stored for use when there is a dearth of energy.
Hydrogen storage in salt caverns is well established in the UK, but this type of geology only occurs in Teesside and Cheshire, which means long and costly transport to consumers in other areas. Natural gas in the UK however is already stored onshore in porous reservoirs and offshore in re-purposed natural gas fields.
Hydrogen can be stored in a suitable geological storage complex, featuring a porous and permeable reservoir formation, a caprock and a trap structure. However, there are no guidelines for suitable hydrogen storage sites, neither in terms of preferred rock formations nor for storage depth. One project will investigate and identify the key characteristics for safe and efficient large-scale storage in the subsurface, which is likely to be key for enabling a global hydrogen economy.
The other project will investigate to what extent conventional and emerging geophysical monitoring techniques, used for example in CO2 storage, will be able to reliably and rapidly track the spread of hydrogen in the subsurface, within and potentially outside the target reservoir in the event there is a loss of containment. Hydrogen has higher buoyancy and mobility than CO2, so it is currently expected that novel seismic monitoring approaches will be required to monitor its injection.
The image shows the model resulting from a joint inversion of different geophysical measurements overlaid on a seismic image. A range of different techniques may be needed to identify and monitor hydrogen gas storage sites.