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Geothermische
Exploration
MeProRisk
II -
Proof of Concept
A three year research initiative
Geophysica Beratungsgesellschaft mbH (Aachen) joined
together with five university institutes of RWTH
Aachen University, TU Freiberg, Free University
Berlin, Kiel University and Friedrich-Schiller
University Jena within MeProRisk II. Cooperation
agreements were concluded with geothermal reservoir
operators and/or exploration project leaders. This is University
of Western Australia, Perth,
ENEL Green Energy (Pisa, Italy) and
the VIGOR group of the CNR-Institute of Geoscience and
Earth Resources (Pisa, Italy). The MeProRisk II
research project has been funded by the German Federal
Ministry for the Environment, Nature Conservation and
Nuclear Safety (BMU).
The research project MeProRisk-II was targeted to
transfer methods, once developed within the precursor
project MeProRisk to other locations of ongoing
geothermal explorations, designed as a „Proof of
Concept“. The studies concentrate on the three
following locations: a)
Perth Metropolotian Area (sedimentary basin
Western Australia), b)
southern Tuskany (high-enthalpie field of
carbonates and metamorphic basement) und c) Guardia
Lombardi (medium-enthalpie field of carbonates) in
Italy.
The main tasks of Geophysica focused on methods of
thermo-hydraulic characterization of the subsurface by
the means of borehole geophysical logging data and
laboratory investigations on rock samples. It was
demonstrated that methods could successfully be
transferred to new locations, which required adaptions
and future developments on local conditions. This
extended the application fields to new geological
settings. Here, a special focus was given on
geothermal reservoirs in carbonates and basement
rocks, a field which has yet been experienced
extensively.
Beside the thermal and hydraulically characterization
of the subsurface, a second task was to develop model
approaches for the reproduction of geological
heterogeneities within a geothermal reservoir. The
work was targeted to find a method which allows for a
transformation of complex natural geological
structures into a numerical model in a most simplified,
but still representative way. The work started with
testing several model approaches and focused than on
the reproduction of fault and fissure systems, which
mainly control the hydraulic behaviour at the
investigated sites. We developed a „fissure
generator“, which provides an automatic allocation
of numerical model units with hydraulic properties of
orthogonal fissure systems in three dimensions. This
allows for a relative fast and robust simulation of
fault and fissure based fluid transport processes.
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