Background
Supercritical geothermal systems are geothermal systems with very high temperature (≥ 400°C) and enthalpy, which are located at depths near or below the brittle-ductile transition zone in the earth's crust. Near the critical point (critical point for pure water: T = 374 °C; p = 22.1 MPa), the physical properties of water, such as viscosity, density and also dielectric permittivity, change considerably. Such systems have attracted attention in recent years as potential geothermal resources, as a much higher energy yield could be achieved due to the very high enthalpy of their fluids. However, the technologies for the economic exploration and utilization of these types of deposits have not yet been developed. As a contribution to the development of the necessary technologies, the working group is developing the experimental, methodological and technical prerequisites for the systematic investigation of the physical rock and fluid properties as a function of pressure, temperature and chemical or mineralogical composition. These investigations are carried out on typical reservoir rocks and formation fluids under p-T conditions, which are well above the critical point for water. A further focus of the experimental work is on the detection and quantification of fluid-mineral interactions.
Key scientific questions
- Which physical properties in which combination are best suited for the detection and delineation of supercritical reservoirs? Provision of the necessary petrophysical reference data to support geophysical exploration/monitoring
- Which rock alteration processes and dynamics can be expected under supercritical conditions for typical reservoir rocks and fluids? Which elements are mobilized?
- How do changes in p-T conditions due to production affect fluid transport properties in high-temperature systems?
- Which time scales can be derived for which processes?
Related projects
- IMAGE | Integrated Methods for Advanced Geothermal Exploration
- GEMex: Potential analysis of geothermal utilization in Mexico
- REFLECT: Redefining geothermal fluid properties at extreme conditions to optimize future geothermal energy extraction
- Reinhart-Koselleck project of the DFG: “Deciphering the duration of fluid-rock interaction in mid-crustal geological settings”
