The economics of deep and medium depth geothermal projects rely to a great extent on cost-effective geophysical exploration techniques. How can these be designed and deployed with a fit-for-purpose approach to achieve more effectively a satisfactory image of the subsurface and its uncertainties? These are the questions at the core of the GECOS project.
The Geothermal Energy Chance of Success GECOS (Project n. 26728.1 PFIW-IW) project, co-funded by Innosuisse, Services Industriels de Geneve and Geo2X S.A., aims at improving exploration investigations which are designed and implemented for the development of geothermal resources and underground thermal energy storage (UTES) projects.
The GECOS project is based on the need of industrial partners to reduce the uncertainty of subsurface exploration and the risks associated with drilling operations. The Geneva Basin subsurface and the whole Swiss Molasse Plateau show favourable conditions for geothermal heat production (and storage where possible) from the fractured and karstified Mesozoic carbonates. These are potentially highly productive reservoirs, as demonstrated by the 744 metres deep GEo-01 well which has been recently completed in Geneva in 2018 in the framework of the Geothermie2020 programme.
However, the uncertainties related to fault architecture and fracture network might still be high despite investing in standard geophysical exploration (i.e. active seismic). Additionally, the Geneva Basin is an active petroleum system, which means that hydrocarbons such as natural gas are present in the subsurface. The occurrence of hydrocarbons is an element of risk that can hinder the development of geothermal projects if not properly constrained and managed.