Discharge Testing of Magma Well IDDP-1

Abstract

Well IDDP-1 in Krafla, Iceland, was the first well drilled in the Icelandic Deep Drilling Project (IDDP). The target depth of 4000-5000m was not achieved as the well was drilled into magma at a depth of 2100m and further drilling was not possible. The well was completed with a cemented 9 5/8” sacrificial casing to 1950 m and a 9 5/8” slotted liner from 1950 m to 2072 m depth. The well was flow tested from March 2010 to July 2012. The well proved to be very powerful with max flow rate of 40-50 kg/s at 40-80 bar wellhead pressure and max temperature of 450°C at 140 bar wellhead pressure which is the highest recorded temperature for a flowing geothermal well. The super-heated steam from the well contained hydrogen chloride and dissolved silica which caused corrosion and erosion to casing and surface equipment. To address the different challenges which emerged during the discharge testing period, several modifications were needed to the wellhead and discharge pipelines. Continuous monitoring of the well was required to ensure the integrity of surface equipment and area and personnel safety and a HSE program was specially adapted to the situation. Lessons learned from the IDDP-1 discharge testing form the basis for well, wellhead and flow line designs for future magma-enhanced geothermal wells.