Technischer Bericht NTB 85-10

Sondierbohrungen Böttstein, Weiach, Riniken, Schafisheim, Kaisten, Leuggern Fluid-LoggingTemperatur-, Leitfähigkeits- und Spinnerflowmeter-Messung

As part of the hydrogeological investigations in the six exploratory boreholes drilled by Nagra in northern Switzerland until 1986, a comprehensive data collection programme aimed at the localisation and characterization of zones of increased rock permeability was carried out. Within this programme the "Fluid Logging" campaign investigated temperature, conductivity and flow conditions of the borehole fluid column.

The present report is a comprehensive collection of the most important Fluid-logging runs from all six boreholes (Böttstein, Weiach, Riniken, Schafisheim, Kaisten and Leuggern).

The first part of the report presents the methodology followed and describes the operating principles of the temperature, salinometer and spinner-flowmeter tools used, the range of their application and their performance.

The second part of the report details the individual logging runs for each borehole. It describes the borehole history, which is important for the interpretation of results and states the boundary conditions, e.g. water level in well, pump rate, difficulties encountered etc.

Results are presented as composite logs. The fluid logs are compared with the relevant geological data indicating high permeability zones and the provisional results from the numerous hydraulic tests.