Hysteresis of the self-potential response associated with harmonic pumping tests

A. Revil (1, 2) , C. Gevaudan (1) , N. Lu (1) , A. Maineult (3)

1 Department of Geophysics [Golden CO]
2 LGIT - Laboratoire de Géophysique Interne et Tectonophysique
3 IPGP (UMR_7154) - Institut de Physique du Globe de Paris

Harmonic pumping tests performed in an unconfined aquifer are responsible for a non-linear and phase shifted behavior of the self-potential response recorded at the ground surface with respect to the change in the pressure heads of the aquifer. The observed non-linearity of the transfer function can be reproduced with a petrophysical model in which the permeability, the capillary pressure curve, and the streaming potential coupling coefficient are modelled inside a unified framework approach based on the van Genuchten parametrization including a hysteretic behaviour with the water saturation. The field equations for the hydraulic heads and the self-potential signals are solved with a finite-element code, which is used to compute the time variation of the self-potential variations over time for two numerical experiments accounting or not for hysteresis. Only the model with hysteresis can reproduce the field observations.

Domaines: Géophysique [physics.geo-ph]

A. Revil, C. Gevaudan, N. Lu, A. Maineult. Hysteresis of the self-potential response associated with harmonic pumping tests. Geophysical Research Letters, 2008, 35 (16), pp.L16402. ⟨10.1029/2008GL035025⟩. ⟨insu-00372083⟩