Drilling Into the Roots of the Reykjanes Geothermal Field – the IDDP-2 Drilling Project

Abstract

Drilling of RN-15/IDDP-2 in the Reykjanes geothermal field in southwest Iceland, was carried out in 2016 and 2017. With a total measured depth of 4650 m the well RN-15/IDDP-2 marks the deepest well drilled in Iceland to date. Drilling was completed in 168 days by deepening the pre-existing production well RN-15, which had previously been drilled in 2004 down to 2507 m. During drilling of RN-15/IDDP-2 a total loss of circulation occurred between 2507 and 3000 m and below 3200 m. In addition, 13 core runs were conducted during drilling of phase 4 and 5. In order to construct a geological model for the deep well, drilling performance and data is evaluation, which is validated with core observation. Further, feed zones are identified and related to the structural framework of the Reykjanes geothermal field. The high-temperature conditions indicate by core observations was confirmed by a temperature and pressure log reaching supercritical fluid conditions that was carried out on January 3rd, 2017, yielding a minimum temperature of 426°C and pressure of 340 bar.