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 
covered. 
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.

Grensasvegur 9
Reykjavik,
Iceland