Analysis of the pico-seismic response of a fractured rock volume to fluid injections in the Bedretto Underground Laboratory, Switzerland
- 1ETHZ, Swiss Seismological Service (SED) , ZURICH, Switzerland (virginie.durand@sed.ethz.ch)
- 2Institute of Geophysics, ETH Zürich, Switzerland
- *A full list of authors appears at the end of the abstract
The Bedretto Underground Laboratory for Geoenergies and Geosciences (BULGG) is a multidisciplinary laboratory on the hundred meter scale run by ETH Zurich. It is located in the Swiss Alps, in the middle of a 5.2km long horizontal tunnel, 1.0km below the surface.
Seven 250-300m long boreholes have been equipped with different instruments: Acoustic Emission Sensors, Accelerometers, Fiber Optics (allowing simultaneous DTS, DSS and DAS measurements), Strainmeters and Pore Pressure Sensors. The variety of the instrumentation allows a multidisciplinary analysis of the response of the rock volume to fluid injections. The fluid injections are realized through a 400m injection borehole located in the center of the instrument network. It is divided into 14 intervals, allowing us to make injections at different depths.
We will first present the methods used to generate a pico-seismic catalog with precise locations and a magnitude of completeness as low as -5, and the associated challenges. Then, we show a preliminary analysis of the spatio-temporal evolution of the pico-seismicity generated by different injection protocols. We interpret the evolution of the seismicity in comparison with the injection parameters (i.e., injection pressure and rate) and the stimulated intervals.
The team involves more than 30 people, from ETHZ and 10 research institutes and companies involved in the Bedretto Laboratory
How to cite: Durand, V., Rosskopf, M., Plenkers, K., Obermann, A., Schwarz, M., Villiger, L., Meier, M.-A., Maurer, H., Giardini, D., and Wiemer, S. and the Bedretto Team: Analysis of the pico-seismic response of a fractured rock volume to fluid injections in the Bedretto Underground Laboratory, Switzerland, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-9233, https://doi.org/10.5194/egusphere-egu22-9233, 2022.
