Connectivity in shallow, unconsolidated porous aquifers

• Applicants: Professor Dr. Frank Börner; Professor Dr. Peter Dietrich
• Subject Area: Hydrogeology, Hydrology, Limnology, Urban Water Management, Water Chemistry, Integrated Water Resources Management ; Palaeontology ; Geophysics
• Term: from 2015 to 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 282295196

• Final Report Year: 2024

Final Report Abstract

The spatial variability of hydraulic conductivity in porous aquifers has been widely studied, while only little work has been carried out to record, measure and quantify hydraulic connectivity. Knowledge of the heterogeneity of aquifers caused by sedimentation processes is essential for estimating preferential flow paths and flow times for the dispersion of contaminants and for groundwater protection. It is well known that there is a close correlation between the geophysical measurement method of spectrally induced polarization (SIP) and the hydraulic properties of rocks. The project therefore experimentally investigated whether information on hydraulic connectivity and heterogeneity can also be derived from SIP measurements. Heterogeneous sand samples were analyzed on a decimeter scale with the aim of gaining a better understanding of the relationship between connectivity, heterogeneity and complex electrical parameters derived from SIP measurements. For the laboratory experiments, a measuring cell was constructed to perform hydraulic flow experiments and SIP measurements with 4 electrodes on decimeter-scale samples. The samples consisted of two different sands with different hydraulic properties. The two sands were combined in different volume fractions and geometries as well as in parallel and serial orientation for hydraulic and electric current flow. The test results show that the SIP measured values and the average hydraulic conductivity are clearly dependent on the volume fraction of the sand components. With regard to the preferred flow paths and thus the connectivity, the known correlations to the hydraulic conductivity could be reproduced. However, the mean complex electrical parameters, which are relatively easy to determine, showed no dependence on the orientation of the hydraulic heterogeneities and the associated preferential flow paths within the scope of the measurement accuracy. The reason for this is seen in the fact that both sands differed significantly only in grain surface and hydraulic conductivity, but not in porosity. However, there were indications that further information on connectivity could be extracted from the spectra.

Publications

• Effect of Porosity Changes on Complex Electrical Conductivity in Shaly Sands. International Symposium of the Society of Core Analysts held in Snow Mass, Colorado, USA, 21-26 August 2016
  Frank Boerner & Edith Müller-Huber
  
• The effect of compaction on complex electrical resistivity of shaly sands. Near Surface Geophysics, 15(6), 633-643.
  Börner, Frank; Müller-Huber, Edith; Branka, Daniel & Rücker, Carsten
  
• Combined interpretation of NMR, MICP, and SIP measurements on mud-dominated and grain-dominated carbonate rocks. Journal of Applied Geophysics, 159, 228-240.
  Müller-Huber, Edith; Börner, Frank; Börner, Jana H. & Kulke, Dennis
  
• Faktorisieren hydraulischer Konnektivität mittels SIP. Tagungsband der 79. Jahrestagung der Deutschen Geophysikalischen Gesellschaft, Braunschweig, 2019, GE-P.10
  F. Dinsel; F. Börner & C. Rücker
  
• Porenraumcharakterisierung von Lockergestein bei sukzessiver Verdichtung mittels spektraler induzierter Polarisation und elastischer Wellengeschwindigkeiten. Tagungsband der 81. Jahrestagung der Deutschen Geophysikalischen Gesellschaft, Kiel, 2021, UI-P2.04
  Branka, D.; Börner, F. & Rücker, C.
  
• Untersuchung der hydraulischen Konnektivität in heterogenen Lockergesteinsaquiferen mittels SIP. Tagungsband der 81. Jahrestagung der Deutschen Geophysikalischen Gesellschaft, Kiel, 2021, UI/ZP-06
  Herold, Robert; Rücker, Carsten & Börner, Frank
  
• Untersuchung der hydraulischen Konnektivität in Lockergesteinsaquiferen. Tagungsband der 82. Jahrestagung der Deutschen Geophysikalischen Gesellschaft, München, 2022, PS-A-32
  R. Herold; P. Dietrich & F. Börner
  
• Effekt der Heterogenität und Anisotropie auf die Spektrale Induzierte Polarisation poröser Gesteine. Tagungsband der 83. Jahrestagung der Deutschen Geophysikalischen Gesellschaft, Bremen, 2023, UIP.14
  G. Beisembina; R. Herold; P. Dietrich & F. Börner
  
• Untersuchung der hydraulischen Konnektivität in heterogenen Lockergesteinsaquiferen mittels SIP. Tagungsband der 83. Jahrestagung der Deutschen Geophysikalischen Gesellschaft, Bremen, UIP.09
  R. Herold; P. Dietrich & F. Börner
  
• Experimental investigations on laboratory samples regarding the connection of spectral induced polarization to heterogeneity of hydraulic conductivity. Environmental Earth Sciences, 83(13).
  Herold, Robert; Beisembina, Gulmira; Dietrich, Peter & Börner, Frank
  
• Experimentelle Untersuchung der Wirkung von Heterogenität und Anisotropie auf die Spektrale Induzierte Polarisation poröser Gesteine. Tagungsband der 84. Jahrestagung der Deutschen Geophysikalischen Gesellschaft, Jena, 2024, OG-P-11
  G. Beisembina; R. Herold; P. Dietrich & F. Börner
  
• Untersuchung der hydraulischen Konnektivität in heterogenen Lockergesteinsaquiferen mittels SIP Proceedings der 84. Jahrestagung der Deutschen Geophysikalischen Gesellschaft, Jena, 2024, OG- P-10
  R. Herold; G. Beisembina; P. Dietrich & F. Börner