This study was performed in order to select a proper fiber for the application of a distributed temperature sensing system
within a hot geothermal well in Iceland. Therefore, commercially available high temperature fibers have been tested
under in-situ temperature conditions. Experiments have been performed with four different polyimide coated fibers, a
fiber with an aluminum coating and one with a gold coating. To select a fiber, the relationship between attenuation,
temperature, and time has been analyzed together with SEM micrographs. On the basis of these experiments, polyimide
fibers have been chosen for deployment. Further tests in ambient and inert atmosphere have been conducted with two
polyimide coated fibers to choose a supplier and to set an operating temperature limit. SEM micrographs have been used
to characterize the high temperature performance of the fibers.
A novel cable design has been developed, a deployment strategy has been worked out and a suitable well for deployment
has been selected.