Dr.
MohammadReza
Jalali
Lecturer
&
Researcher
Swiss
Federal
Institute
of
Technology
(ETH)
ABSTRACT
The Swiss government has decided to phase out nuclear power production by 2034 and transition to electricity production by alternatives such as hydro-power plants and enhanced geothermal systems (EGS). In this context, the newly-founded Swiss Competence Center for Energy Research – Supply of Electricity (SCCER-SoE) is conducting various types of research and development. As a part of the ongoing research, a hydraulic stimulation experiment, called In-situ Stimulation and Circulation (ISC), has been initiated at the Grimsel Test Site (GTS). The main objectives of this experiment are to study and explore
• Fundamental process involved during large volume fluid injection at high pressure to create an efficient and sustainable heat exchanger in hot reservoirs at depth below 3 km.
• Spatio-temporal characterization of induced seismicity such as relative size distribution, stress drop, the relevance of static and dynamic stress transfer as fault reactivation mechanisms, and the decay rate of seismic activity.
• Various injection protocols with the potential to mitigate seismicity through maintaining event magnitude below an acceptable threshold.
• Novel monitoring and imaging techniques for pressure, temperature, stress, strain and displacement as well as geophysical methods such as ground penetration radar (GPR), passive and active seismic.
The ISC experiment is split into four phases, pre-stimulation, stimulation, post-stimulation and circulation phases; each phase includes planning and performing of intense field investigation followed by data analysis that guides design of the subsequent phase.
The
ISC
experiment
is
designed
such
that
stimulation
processes,
i.e.
shear
dilatancy,
seismic
and
aseismic
slip
front
propagation,
and
the
resulting
enhancement
of
the
fracture
conductivity,
are
recorded
in
a
unique
interdisciplinary
dataset.
The
data
will
include
information
on
THM
coupled
processes
and
induced
seismicity
that
could
not
be
obtained
from
stimulation
experiments
in
deep
reservoirs
typically
targeted
for
EGS.
This
dataset
also
allows
us
to
address
the
objectives
as
well
as
validation
and
verification
of
the
existing
THM
and
induced
seismicity
models.