Calibration and Reliability in Groundwater Modelling: From Uncertainty to Decision Making (Proceedings of ModelCARE’2005, The Hague, The Netherlands, June 2005). IAHS Publ. 304, 2006. pp.17–24.

Reducing ambiguity in fractured-porous media characterization using single-well tracer tests

I. Ghergut1, C. McDermott2, M. Sauter1, M. Herfort3 & O. Kolditz2

1 Applied Geology Group, Geosciences Centre (GZG), University of Göttingen, Goldschmidtstrasse 3,
D-37077 Göttingen, Germany

iulia.ghergut@geo.uni-goettingen.de

2 Geo-Hydro-Informatics Group, Applied Geosciences Centre (ZAG), University of Tübingen, Sigwartstrasse 10,
D-72076 Tübingen, Germany

3 Engineering Geology Group, ETH Zurich, Hoenggerberg, CH-8093 Zurich, Switzerland

Abstract The specific area of the contact surface between fractures and rock matrix, that has an important role in solute and heat transport in fractured-porous reservoirs, is not properly captured by hydraulic and geophysical tests, nor by flow-path tracings in highly dispersive flow fields. A single-well tracing method that increases the sensitivity of tracer breakthrough curves with regard to the contact-surface area parameter is described, with its first application in deep (geothermal) reservoirs in Germany.

Keywords dual-tracer; fractured-porous contact surface; matrix diffusion; push-pull