Understanding supercritical resources in continental crust

The DESCRAMBLE project, which developed a proof-of-concept test of reaching deep geothermal supercritical resources, has been an occasion to improve knowledge of deep chemical-physical conditions for predicting and controlling future drilling activities. The test site has been an existing dry well in Larderello, Italy, already drilled to a depth of 2.1 km and temperature of 350 °C, which was deepened to intersect a seismic marker at almost 3 km depth. Down at the final depth of 2.9 km, in the middle of the seismic reflections, an unexpected extremely high temperature was measured (507- 517°C at 2.9 km). This value, associated with the geological conditions of the rocks, with a leak off pressure of about 30 MPa (300 bar), can pave the way for a further utilization of this well for an EGS system, producing supercritical fluids from reinjected water.