GFZ German Research Centre for Geosciences

Erik Rybacki is senior research scientist at GFZ Potsdam, section 4.2 ‘Geomechanics and Scientific Drilling’ since 1996. He holds a diploma in Geophysics and achieved his PhD at the University of Bochum, Germany. His scientific interest focuses on rock physics, in particular experimental rheology and fracture mechanics. Current research topics involve high-temperature rheology of crustal rocks and iron oxides, the initiation and evolution of ductile shear zones, the interplay between stress and reaction kinetics, the mechanical behavior of gas and oil shales in unconventional reservoirs, the mechanical characterization of clay rocks for potential nuclear waste disposal sites, and fluid-rock interaction processes and fracture healing in geothermal deposits. Erik Rybacki is responsible for the high-temperature deformation laboratories, the facilities for pore and fracture space characterization, and optical microscopy.

Harald Milsch (born 1968) studied Physical Engineering at the Technical University Berlin and Physics at the University of Göttingen. During and after his Diploma in Physics (1994) he spent two years at the Laboratoire de Glaciologie et Géophysique de l’Environnement (LGGE-CNRS) in Grenoble, France. He continued with a doctoral thesis at the GFZ German Research Centre for Geosciences and received his PhD (2000) in Geology from the University of Potsdam. In 2002, after having worked as a research scientist at the German Federal Institute for Materials Research and Testing, he was granted a research fellowship from the German Science Foundation (DFG) to perform three years of postdoctoral research at the Lamont-Doherty Earth Observatory of Columbia University in New York, USA. Since 2005 and to this date he has been working as a senior research scientist at the GFZ in Potsdam. His research is focused on experimental rock physics and thermophysics of fluids as well as fluid-rock interactions in the context of geothermal technology development.

Johannes Herrmann (born in 1990) did his studies on Petroleum Engineering at the Technical University Freiberg (Germany). In 2019 he finished his PhD in Geomechanics at the University Potsdam (Germany) in collaboration with the GFZ. During this time, he was involved in the European initiative ‘SXT’ within the frame of Horizon 2020, in which he investigated the mechanical behavior of shale rocks subjected to in situ pressure, temperature and stress conditions. Within the MEET project, he is responsible for the preparation, performance and evaluation of experiments dealing with the influence of several factors such as pressure, temperature, fracture surface roughness etc. on the permeability of fractures in Variscan reservoir rocks.

Chaojie Cheng (born in 1991) received a Bachelor’s degree in Geological Engineering in 2014 and a Master’s degree in the major of Geotechnical Engineering in 2016 from China University of Geosciences. From October 2016, he started his PhD study in Hydrogeology at GFZ Potsdam, section 4.8 ‘Geoenergy’, and registered at the University of Potsdam. His doctoral research mainly focused on the long-term evolution of fluid transport properties in fractured porous media in the scope of the geothermal reservoir utilization. Within the MEET project, his main task lies in investigating the long-term variation of fluid transport through rock fractures. Emphasis is on laboratory experiments dealing with how fluid-rock interactions (e.g., dissolution, precipitation, and reactive mass transfer) induce permeability changes of fractures in Variscan reservoir rocks under hydrothermal conditions.