| Title | De-risking Geothermal Heat Extraction from Tight Hot Sedimentary Aquifers (GEOGUARD) |
|---|---|
| Authors | Nathaniel Forbes Inskip |
| Year | 2026 |
| Conference | World Geothermal Congress |
| Keywords | Low permeability, Hot Sedimentary Aquifers, Stimulation, Data uncertainty, Europe |
| Abstract | Many major European population centres lie above Hot Sedimentary Aquifers (HSAs) that contain water at temperatures suitable for direct-use heating. Cities like Paris and Munich already harness low-carbon heat from HSAs, but many regions remain untapped. A major challenge is that many target formations lack sufficient permeability to sustain economic flow rates. Techniques to enhance flow are costly, not well understood, and face low public acceptance. To help address these challenges, the GEOGUARD project aims to develop a toolbox for assessing technical and economic options to improve flow rates. It will also prepare stakeholders for necessary dialogue on induced seismicity and other manageable risks. The project will focus on three country case studies: Lithuania, Scotland, and Ireland. Another key theme of GEOGUARD is managing uncertainty in subsurface data, including seismic, well logs, and rock properties. The three case studies differ significantly in data quality: Lithuania has abundant seismic and well data; Scotland has poor-quality seismic and minimal well control; Ireland has almost no relevant seismic and only limited well data from target formations. High-quality models from Lithuania’s data-rich case study will be used to develop an exploration and development strategy for geothermal heat production. This will then be adapted for the more data-limited settings in Scotland and Ireland. Through GEOGUARD, we aim to create methodologies and workflows that help manage key risks linked to uncertainties in subsurface data, ultimately supporting the expansion of geothermal heat projects across Europe. |