hide
Free keywords:
-
Abstract:
The main concern in the development of Enhanced
Geothermal Systems (EGSs) through hydraulic
stimulation treatments is the potential risk of injection-
induced seismicity. Especially for the safe development
of EGS near urban areas, e.g., for heating purposes, a
better understanding and confidence in seismic risk
assessment and mitigation measures is therefore a
prerequisite for unlocking the enormous geothermal
potential of such systems. In the Helmholtz Young
Investigator Group ARES (Advanced reservoir
engineering concepts for a controlled utilization of deep
geothermal energy in urban areas) we investigated the
influence of the injection protocol on induced
seismicity with experiments and models at different
scales. In particular, we were interested in the question
how a stimulation should be started, how to inject
during stimulation and how it should be stopped. We
find that slow pressurization at the start of the
stimulation, stepwise injection during the stimulation
and flowback instead of shut-in at the end of the
stimulation result in the lowest seismic risk. However,
the influence of the injection protocol strongly depends
on the site-specific geological conditions.
