The Reykjanes Geothermal System - an Extended Conceptual Model

Abstract

The geothermal system at Reykjanes, SW Iceland, is the landward extension of the North Atlantic Ridge. HS Orka commisioned a geothermal power plant in May 2006 with capacity of 100 MWe utilizing a two-phase reservoir from ~1000 m b.s.l down to ~2500 m b.s.l. At 1500 m b.s.l. the reservoir is ~280-290°C. Seismic data had revealed the brittle-ductile boundary in the area to be at 5,5 – 6 km depth and an aseismic body between 3-6 km depth underneath the main geothermal field. The Horizon 2020 project „Deployment of deep enhanced geothermal systems for sustainable energy business (DEEPEGS)“ aims at demonstrating the feasibility of deep enhanced geothermal systems (EGS) as a competitive energy alternative for commercial use. As a part of the Horizon 2020 DEEPEGS project well RN-15/IDDP-2 was deepened from 2500 m down to 4650 m total measured depth from August 2016 to January 2017 to explore and investigate the roots of the Reykjanes geothermal system. During drilling 13 core runs were made and in total 27,3 m of core was recovered, permeability was encountered during drilling below 3000 m measured total depth and induced seismicity occured along the drilling path of the well. The well reached a reservoir with estimated temperatures of