ABSTRACT
In Germany the exploitation of hydro-geothermal systems becomes more and more important. Especially the (Upper Jurassic) Malm Aquifer beneath the South German Molasse Basin is predominated for a hydro-geothermal utilization. The research project PrognosPermae aims to develop a workflow to decrease the exploration risk of geothermal drillings. Several tests has been executed on analogue samples of Jurassic limestone and dolomite. The results are used to verify the numerical modelling.
The focus of this paper lies on using laboratory tests on increasing specimen volumes as an approach for upscaling the geomechanical properties. The carbonates were characterized by density, porosity, water-permeability, uniaxial compressive and tensile strength, cohesion and friction angle, and ultrasonic wave velocities. All these experiments were executed on both dry and saturated samples. This work aims to identify the influence of specimen size and porosity on strength and ultrasonic velocity. The results show a marginal size effect for the tested diameter range but a significant influence of the total porosity.
