THE OBSERVATION TODAY
The research effort is currently limited to pilot (or pre-industrial) projects, particularly in the field of geosciences. The approach is based on an empirical vision of the geological phenomena that determine the existence or not of a deep geothermal system.
As in all phases of exploration, the integration of new concepts and new technologies from scientific research is an essential vector of success, as oil exploration has shown for more than 60 years. The technological levers exist, and the methods for implementing and optimizing exploration programs (target selection, geophysical data acquisition, drilling) as well as knowledge have significant room for improvement compared to what has been undertaken by other industries.
THE CONTEXT OF R&D PROJECTS
The field concerned is primarily that of geosciences. The R&D approach is in fact very similar to that of the oil industry. Developing new technologies, integrating new knowledge to limit risks and therefore investments: first at the stage of studies, then of methodologies to be implemented and finally of innovative technologies to be developed.
UNCERTAINTIES
The criteria for selecting potential deep geothermal sites are not yet clearly established. The first-order geological parameters that govern their existence (origin and potential of heat flows, nature of the bedrock and hydrothermal potential) are poorly known and do not allow today to define the potential zones (drilling sites) with a sufficient level of risk.
As in the oil industry, these criteria are the discriminating parameters: identifying zones with high heat production, having the best image of the subsurface to pilot drilling, modeling deep structures to test and minimize risks (fracturing, induced seismicity), characterizing the host rock (level of fracturing of granitic or sedimentary bedrock), understanding the geological precursors on the surface (hydrothermal phenomena).