Abstract
In order to make the world’s energy consumption sustainable there is a need for reducing emissions of CO2 and to shift towards renewable energy sources. Geothermal energy has a large potential in certain parts of the world. One example is Iceland, where the reservoir in IDDP-2 is around 427°C and 340 bar at a final well depth of 4650 m. This makes it attractive as a geothermal reservoir of high enthalpy supercritical water with the potential for conversion of large amounts of high temperature deep geothermal energy.
Production from the IDDP-2 is scheduled to start in 2019, and hence the fluid composition is not known. Using available data for nearby wells, and in particular IDDP-1, an estimate can still be made. A combination of high temperature and pressure, the presence of corrosive agents (such as HCl and H2S), a low pH and reducing conditions gives rise to challenges related to material selections.
This paper summarizes part of a desktop case study that addresses corrosion and scaling issues for conditions relevant for the IDDP-2 geothermal well. The reservoir and well data are based on temperature measurements inside the well and assumptions on a hydrostatic reservoir. The total depth of the well is 4650 meters. Based on this a model is set up for temperature and pressure profile along the well. Knowledge gaps, such as lacking solubility data and corrosion rates at supercritical conditions are pointed out.