Glossary

HDR-systems refer to dry rocks with the absence of natural water. To enable a subsurface circulation, necessary to sustain a cycle of injected water, hydraulic stimulations (hydraulic fracturing) produce artificial fractures within rock bodies.

For petro-thermal heat exploitation, fluids are injected in wells under high pressure to connect existing fractures, to bifurcate or to create new fractures within a particular exploitation zone.

Precondition of any heat exploitation in hydrothermal geothermics is water with sufficient flow rate and temperature. This water is found in pores of sedimentary rocks or it circulates in small fractures originated in geological processes.

Via a production well thermal water is conveyed to the surface and then fed into a geothermal plant converting thermal energy. An injection well brings the cooled water back into the heat reservoir.