IDDP-1 Drilled Into Magma - World's First Magma-EGS System Created

The Iceland Deep Drilling Project (IDDP) is a research and development project that is investigating the possibility of greatly increasing the power output of geothermal wells by producing high-enthalpy supercritical geothermal fluid from 4-5 km depths. The aim is to increase the power output per well by an order of magnitude. IDDP is a collaboration project of three energy companies - HS Orka hf (HS), Landsvirkjun (LV) and Reykjavik Energy (OR), and Orkustofnun (OS) (the National Energy Authority of Iceland) that was established in 2000 to investigate the feasibility of utilizing geothermal fluid at substantially higher temperatures and from deeper wells than currently used today. From the onset of the IDDP, international collaboration has been one of the trade mark of the project. Scientists from at least 15 countries have contributed to the science program in various ways by participating in workshops and by publishing articles in international journals. Since 2005 ICDP (International Scientific Drilling Program) and NSF (National Science Foundation of USA) have supported the IDDP program. The international companies Alcoa (2006-2012) and Statoil (2008-2011) also participated in the IDDP-1 project in Krafla by direct financial and technical contributions. In the first serious attempt to reach 4-5 km by well IDDP-1 at Krafla, NE-Iceland, in 2009, the well had to be completed at only 2.1 km depth after entering into >900°C hot magma of rhyolite composition. In order to produce from the >500°C hot contact zone of the magma intrusion, the well was completed with a cemented 9 5/8” sacrificial casing to 1950 m depth, inside a 13 5/8” production casing to the same depth. A 9 5/8” slotted liner reached from 1,950 m to 2,072 m depth, with a barefoot 12 ¼” well from there to 2,096 m depth. Subsequently, during a two year-long flow test, well IDDP-1 became the world’s hottest producing geothermal well, with a wellhead temperature of 450°C, flowing dry superheated steam at high pressures (40–140 bar). Production tests indicate the well IDDP-1 was capable of producing up to 36 MWe depending on the design of the turbine system. Series of pilot tests for power production were undertaken during and after the flow tests yielding breakthrough results in dealing with a magma within a geothermal system. First of all, (i) the IDDP project managed to drill into molten rock at >900°C and get out of it; (ii) it produced high permeability by hydrofracking the contact aureole rocks with cold drilling fluid; (iii) it managed to insert a protective casing (sacrificial casing), cement it in, and a liner; (iv) it produced superheated dry steam from the contact aureole at world record temperature for a geothermal well; (v) it showed that hostile fluid chemistry could safely be dealt with by steam treatment, enabling the steam to be taken directly into conventional steam turbines, and finally, (vi) it proved beyond reasonable doubts that world’s first Magma-EGS system had been created, apparently confirmed by an injection tracer test after the discharge tests. While it would probably be more economical to use the steam directly from a well like IDDP-1 in superheat form, the process could evidently be reversed by using such wells for injection in an attempt to enhance the performance of the conventional geothermal system above. The IDDP-1 well had to be cooled down rather abruptly in 2012 due to valve failure and the pilot studies and flow test terminated. Many technical hurdles were met during drilling and the subsequent flow test of the IDDP-1 well and the lessons learned so far are very valuable for the continuation of the IDDP R&D program. We believe that proper engineering and geoscience carry the keys to breakthrough results in future utilization of high enthalpy geothermal systems worldwide. Preparation is well underway for the drilling and testing of well IDDP-2 at Reykjanes, SW Iceland, which is expected to be followed by IDDP3 at the Hengill volcano before 2020.