Fractured crystalline rocks (source: Deep-HEAT-Flows project)The Deep-Heat-Flows project’s principal researcher Dr. Alan Bischoff from the GTK’s geothermal energy group explains: “Our project involves unlocking the full potential of deep geothermal resources in low-enthalpy crystalline settings away from volcanic and rifting areas. Much of our current knowledge about geothermal systems comes from thermodynamically active areas where high-temperature fluids, intense tectonic and volcanic activity, and the presence of convective hydrothermal cells play a central role in forming geothermal reservoirs.”
Bischoff continues: “Today, it is broadly accepted that processes like rock fracturing and mineral alteration are key for defining the fluid flow properties of higher-enthalpy geothermal reservoirs, but fundamental knowledge about the processes that can form deep crystalline reservoirs at lower-enthalpy conditions is lacking. Our hypothesis centres on recent research that indicate that substantially large (>1 km3) geological structures can host highly permeable crystalline reservoirs suitable for deep geothermal energy production. The most promising geological structures that can deliver these geothermal prospects are crustal fault zones and the contact zone of ancient igneous intrusions. Both structures occur in great numbers in the Fennoscandian Craton and as such have significant potential to provide drillable targets for deep geothermal exploration.”
The project provides long-needed science-based R & D thinking to accelerate geothermal utilisation in Finland and other crystalline settings. “When I studied geology, the main theory was that the deeper one goes the fewer fractures and pores can be found. This frame has been overturned and now the Deep-Heat-Flows project will seek opportunities for geothermal heat utilisation from deeper resources with a new perspective,” says Dr. Teppo Arola, Chief Expert in geothermal energy at GTK.
More details, including the opportunity to join the project on a postdoc position, can be found on the project’s website at: Deep-HEAT-Flows – Discovering deep geothermal resources in low-enthalpy crystalline settings.
