Landsvirkjun, the National Power Company of Iceland is the founder of the Icelandic Deep Drilling Project. The project, which marks a milestone in energy research, involves drilling deeper boreholes than have been attempted before. These boreholes will be 4-5 km in depth and it is estimated that they could give between 5-10 times more energy than standard boreholes. The first borehole (IDDP-1) was drilled in the Krafla area in 2008-2009. The drilling of the well came to an abrupt end at 2.1 km depth where the drill-bit intersected magma.
Flow test of the well in 2010-2012 gave of steam at 430-450°C making it by far the hottest geothermal well in the world
It is estimated that the potential energy production of the borehole could be between 25-35 MWe. Despite the earlier setbacks, the project has provided valuable knowledge and experience for future endeavours.
The IDDP-1 well in Krafla is the first well to be drilled in the Iceland Deep Drilling project (IDDP). IDDP is a collaborative project of Landsvirkjun, Reykjavik Energy (OR) and HS Orka, in addition to Statoil (Norway), and Alcoa (US), and domestic and foreign research groups, the National Power Authority (Iceland), National Science Foundation (US) and the International Continental Scientific Drilling Program (ICSDP). The objective of IDDP-1 was to drill a vertical well to a depth of 4500m. However, magma was encountered at a depth of 2100m and after two setbacks; the well was completed at 2100m, in 2009. The well is therefore a magma well, rather than an actual deep well.
The well has been flow tested intermittently since the spring of 2010. In the initial flow tests, steam well head temperature reached 380°C at 20 bar for a mass flow of 40 kg/s. This corresponds to approx. 25 MWe in electrical production. However, the fluid proved to be both corrosive and abrasive and the wellhead and flow line were redesigned to better handle the difficult fluid and to allow for experiments to be conducted on the steam. The aim of the
experiments is to validate methods to clean the steam and make it suitable for direct use in steam turbines. The well has now been operated continuously at a restricted flow rate of 12 kg/s for over 6 months. Wellhead temperature is 450°C at 140 bar, which is the highest wellhead temperature on record for a geothermal well.
Experiments to scrub the superheated steam from the well were carried out during the year. Initial results are promising, especially with the wet scrubbing method. In this method brine is injected into the steam flow, in effect washing impurities and acid from the steam. The brine is then separated from the steam which can be used on the power plant steam gathering system. Plans are for full scale production of the well in 2012-2013 based on this method. Other methods under investigation are the dry scrubbing method and indirect utilization with a heat exchanger. Additionally, several experiments have been conducted on corrosion and wear resistance.