Concepts for the development of super-hot resources

In GEMex we aim to develop and verify concepts and technologies to access and exploit super-hot reservoirs (>300°C, including conditions above the critical point of water in the reservoir). In particular, we summarize the existing knowledge and the knowledge gained within the project and derive steps necessary for the development of such a resource. This summary includes know-how derived with project partners at other super-hot locations, especially in Iceland (IDDP1 and 2, IMAGE, DEEPEGS), Italy (DESCRAMBLE), New Zealand (HADES) and Japan (Japan Beyond Brittle).

The work on the concepts for the SHGS development will also benefit from the geophysical detection of deep structures , where we locate the brittle-ductile transition below the current reservoir at Los Humeros, and from the characterisation of the reservoir , where the physical properties of the fluid/rock system are investigated at the relevant conditions.

To come up with a concept for potential development of the deep reservoir it is crucial to consider the site specific acting forces. The stress field and especially its anisotropy have to be known before drilling and designing the thermal water loop. Very little experience and few examples exist on how to approach the brittle-ductile transition (BDT). It is therefore necessary to investigate and determine the potential stress conditions in different geological environments in the zone between brittle ductile transition zone and the magma chamber.

The concept for the development will also include material issues related to thermal stresses, corrosion and scaling all of which are known to be showstoppers for deep drilling utilization of super-hot systems. This is for both: subsurface and surface installations, as these are critical for testing and validation of the concepts and finally to utilize the energy.