Geothermics 49 (2014) 76–82 Contents lists available at ScienceDirect Geothermics journal homepage: www.elsevier.com/locate/geothermics Pilot testing of handling the fluids from the IDDP-1 exploratory geothermal well, Krafla, N.E. Iceland Trausti Hauksson a,∗ , Sigurdur Markusson b , Kristján Einarsson b , Sigrún Nanna Karlsdóttir c , Ásbjörn Einarsson d ,Aðalsteinn Möller e , Þorsteinn Sigmarsson f a Kemía, Suðurlandsbraut 10, 108 Reykjavík, Iceland b Landsvirkjun, Háaleitisbraut 68, 103 Reykjavík, Iceland c N´ ysköpunarmiðstöð Íslands, Keldnaholti 112 Reykjavík, Iceland d Ásbjörn Einarsson verkfræðiþjónusta, Hörðukór 1, 203 Kópavogi, Iceland e Verkís, Suðurlandsbraut 4, 108 Reykjavík, Iceland f Mannvit, Grensásvegi 1, 108 Reykjavík, Iceland article info Article history: Received 16 March 2012 Received in revised form 28 June 2013 Accepted 1 July 2013 Available online 6 August 2013 Keywords: Steam scrubbing Acid Sulfur Silica dust abstract Material tests and scrubbing experiments were carried out at the IDDP-1 well in the Krafla geothermal field in Iceland. The 450 ◦ C superheated steam contained acid gas (approx. 90 mg/kg HCl and 7 mg/kg HF) and was highly corrosive when it condensed making it unsuitable for utilization without scrubbing. The acid gas could effectively be scrubbed from the steam with water. The steam contained gasous sulfur compond (80–100 mg/kg S), which could only be scrubbed from the steam with alkaline water. The steam contained both silica dust and dissolved silica which was effectively washed from the steam with wet scrubbing. Experiments on corrosion and erosion resistance of metals and alloys were problematic to run because of equipment clogging by silica dust. © 2013 Elsevier Ltd. All rights reserved. 1. Introduction Well IDDP-1 in the Krafla geothermal field in Iceland was drilled as the first well in the Icelandic deep Deep drilling Drilling project Project (IDDP). The drilling operation started in 2008 but in 2009 at around 2100 meters the drill intersected magma and further drilling was abandoned. The well is cased down to 1950 meters with slotted liner from 1950 to 2100. This report deals only with the flow testing that was carried out from March 23rd 2010 until the end of July 2102. During that time, the well was flow-tested several times and it soon became clear that the well was very pow- erful and by far the hottest producing geothermal well in the world. The superheated steam produced by the well was acidic when con- densed. Unfortunately in July 2012 the well had to be shut in and it was found that, as the master valves had failed, the well had to be quenched. This issue will be treated in subsequent publications. For over thirty years the presence of acidic fluid in the roots of the Krafla system has been restricting further utilization of the deeper part of the geothermal system. Below 1800 m depth the ∗ Corresponding author. Tel.: +354 588 9495; fax: +354 588 9487. E-mail address: th@kemia.is (T. Hauksson). reservoir temperature and pressure are high enough to produce superheated dry steam rich in HCl and HF that produces acid by condensation. The presence of the acid component is commonly regarded as input of magmatic gases into the geothermal system (Ármannsson, 2010) but formation of volatile halogens in the deep fluid due to boiling at high temperature has not been ruled out. To enable direct power production from the produced steam from the IDDP-1 and future deep wells in Krafla, several issues of steam quality have to be resolved. Removal of the acid compo- nents is essential for direct use with turbine, and equipment such as pipelines and the wellhead have to be made from materials that can withstand the harsh acidic conditions for long time. Four dif- ferent methods for utilization of acid wells have been suggested (Einarsson et al., 2010), (1) down hole treatment by natural mixing of superheated steam with liquid water, (2) downhole injection of caustic soda (NaOH), (3) surface treatment where the fluid is scrubbed by wet scrubbing, or (4) surface treatment by dry scrub- bing. Both these down hole and surface methods rely on the fact that the dry superheated steam causes no or limited corrosion in the well. This article reports on the experiments carried out on the fluids flowed from IDDP-1, focusing on both production characteristics of IDDP-1 and tests of the usability of the superheated steam by 0375-6505/$ – see front matter © 2013 Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.geothermics.2013.07.003