Hydrogen Geostorage
As the transition towards renewable energy sources intensifies, hydrogen emerges as a promising energy carrier. The potential to use partially depleted gas shale reservoirs as large-scale geological storage for hydrogen has become an increasingly important resource for a future hydrogen economy.
Current research on subsurface hydrogen geostorage focuses on the use of salt caverns, saline aquifers, and depleted sandstone gas reservoirs. A novel alternative is to geostore green hydrogen in partially depleted unconventional gas shale reservoirs, for its proximity to renewable energy production, vast existing storage capacity, and access to pipeline infrastructure.
Challenges with Hydrogen Geostorage
- When to stop producing methane and start injecting hydrogen for storage?
- How to predict the geostorage efficiency of hydrogen in the various pore systems?
- How to avoid hydrogen gas leakage from unintended fracture extensions?
- How to predict the evolution of the hydrogen/methane ratio during hydrogen recovery?
- How to optimize the energy yield from hydrogen to predict the return on investment?
Carbon Utilization/Geostorage
The extraction of unconventional gas shale reservoirs, driven by hydraulic fracturing, has significantly altered global energy dynamics. Natural gas, of which methane is the principal component, is by far the cleanest burning of fossil fuels and can serve as a bridge to a low-carbon future.
Standard reserve assessments overlook dissolved gas in the kerogen matrix, potentially underestimating the recovery potential of unconventional gas shale reservoirs. Carbon dioxide injection offers promise for enhancing recovery rates, while at the same time geostoring carbon dioxide emissions captured by nearby surface facilities and pipelines.
Challenges with Carbon Utilization/Geostorage
- Will injection of carbon dioxide displace & produce the dissolved gas in kerogen?
- Will the increased recovery factor justify the cost of carbon dioxide injection?
- Can the injected carbon dioxide be simultaneously stored in the kerogen?
- Can unintended fracture extensions be avoided to minimize carbon dioxide leakage?