Master‘s Thesis topic
4D Geo-positron-emission-tomography (GeoPET) on granite drill core of Soultz-sous-Forêts (France) geothermal research plant.
Originally used for clinical purposes, in the last decade the research group around Dr. Johannes Kulenkampff managed to work out a method making it possible to use Positron-Emission-Tomography (PET) for geoscientific applications. The so-called “GeoPET” thereby uses the same principals as its clinical counterpart, although a higher rate of radioactivity is necessary due to the high density of geo-materials such as stone, sand or gypsum. In theory, a radioactive labeled fluid (radio-tracer) is flushed through the granitic sample at low velocity rates, which makes it possible to trace its track inside the sample, without destroying the drill core. Therefore, it is possible to study its hydraulic properties (for e.g. its flow-rate) in situ. Meanwhile the PET can assign the emitted β+-radiation from the tracer to a certain coordinate of the sample/model.
Fig. 1: Illuminated streamlines (white) within the natural fracture (greyish)
indicate the flow path of the labeled fluid from the inlet (bottom left) to the outlet (top left).
Within the scope of this Master’s Thesis, we especially try to study the flow properties/behavior inside a granitic drill core, particularly within a natural fracture (see Fig. 1). The sample comes from the geothermal research plant of Soultz-sous-Forêts (France) and was allocated in collaboration with the Friedrich-Schiller University of Jena.