In order to decide about the overall feasibility of EGS projects some key
parameters have to be investigated: downhole temperature, downhole
pressure, brine chemistry and the potential maximum flow rate which can be
achieved. Wireline logging operations are performed in EGS wells in order to
help answering these key questions.
We look into the characteristics of these wireline logging programs performed
in various classes of EGS projects in typical and representative geological
settings: deep sedimentary structures, deep granites, shallow volcanics and
shallow metamorphics. Chraracteristics of these EGS classes regarding the
wireline tools applied and typical evaluation procedures used are going to be
We ask the question where adjustments to typical wireline logging programs
can contribute to a further increase in drilling cost effectiveness of EGS wells
and search for the potential of further standardisation and “streamlining” of
wireline logging programs within EGS projects. Finally we look into the need for
further research and development.