The Iceland Deep Drilling Project at Reykjanes - 4.5 km Deep Drilling Into Supercritical Conditions

Abstract

In 2016 and 2017 the geothermal well RN-15/IDDP-2 was drilled in the Reykjanes geothermal field, in southwest Iceland. With a total measured depth of 4650 m the well RN-15/IDDP-2 marks the deepest well drilled in Iceland to date and the hottest geothermal well (more than 426°C) reaching supercritical fluid conditions. Drilling was completed in 168 days by deepening the pre-existing production well RN-15, which was drilled in 2004 to a depth of 2507 m. In total 13 core runs were conducted during drilling of phase 4 and 5. Nine core runs retrieved core material with a total core length of 27.31 m and a core recovery of 63%. The high-temperature conditions of the predicted amphibolite facies was confirmed by a temperature and pressure log that was carried out on January 3rd, 2017, yielding a minimum temperature of 426°C at a pressure of 340 bar, but the well had not recovered from cooling during drilling.