HR: 1330h
AN: H42B-1076    [PDF]
TI: Investigation of effects of fractured porous media on pneumatic tests: An experimental study on mesoscale
AU: Leven, C
EM: carsten.leven@uni-tuebingen.de
AF: Center for Applied Geosciences, Applied Geology, University of Tuebingen, Sigwartstr. 10, Tuebingen, 72076 Germany
AU: * Sauter, M
EM: martin.sauter@geo.uni-goettingen.de
AF: Applied Geology, University of Goettingen, Goldschmidtstr. 3, Goettingen, 37077 Germany
AU: Teutsch, G
EM: georg.teutsch@uni-tuebingen.de
AF: Center for Applied Geosciences, Applied Geology, University of Tuebingen, Sigwartstr. 10, Tuebingen, 72076 Germany
AU: Dietrich, P
EM: peter.dietrich@uni-tuebingen.de
AF: Center for Applied Geosciences, Applied Geology, University of Tuebingen, Sigwartstr. 10, Tuebingen, 72076 Germany
AB: The understanding of the response of an investigated system to particular hydraulic measurements is an essential prerequisite especially for the characterization of highly heterogeneous or anisotropic systems, such as fractured porous aquifers. This understanding is fundamental for the identification of the governing flow and transport processes as well as for the calculation and prediction of flow and transport in such systems. However, most investigation techniques have limitations with respect to the spatial resolution needed to characterize such systems. In this presentation a study of high-resolution pneumatic tests is introduced that are conducted on a fully unsaturated fractured sandstone block (about 1 m$^{3}$ volume) based on the aquifer analogue approach. The principle of an aquifer-analogue is to obtain hydrogeological information on a generally inaccessible confined aquifer system based on direct information from outcrops. For the introduced pneumatic tests a constant pressure was injected over a vertical borehole in the center of the sandstone block and the transient pressure buildup was recorded at the sealed block surface. The analysis of the temporal and spatial evolution of the pressure buildup during the pneumatic tests shows that the direction and contribution of the pressure buildup is highly dependent on the spatial distribution and the characteristics of the fracture network as well as the position of the observation points with respect to highly conductive structures. In addition, the introduced test methods are suitable tools for the characterization of the heterogeneous nature of fractured porous media and for the interpretation of the effects of such highly heterogeneous systems on pneumatic tests.
DE: 1894 Instruments and techniques
DE: 1899 General or miscellaneous
SC: Hydrology [H]
MN: 2003 Fall Meeting