Electroseismic and seismoelectric measurements of rock samples in a water tank

Abstract

An electromagnetic wave or a seismic wave can induce seismic or electric waves due to the electrokinetic conversion based on the electric double layer in a fluidsaturated porous medium. In this paper, we observe the acoustic fields generated around the electrodes excited by an electric pulse in a water tank. The electroseismic or seismoelectric waves are measured in the water tank system to confirm that the recorded seismic or electric signals are induced in porous samples due to the electrokinetic conversions. The electroseismic and seismoelectric frequency-responses in Berea sandstone and Westerly granite samples are measured at frequency range of 15 kHz to 150 kHz. The experimental measurements show that the effects of the electric source, background noises, and electroseismic or seismoelectric conversions are separated very clearly. We calculate the electroseismic and seismoelectric normalized coupling coefficients in the rock samples and compare them with the theoretical calculation. The variation trends of the normalized coupling coefficients are in agreement with the theoretical predictions. The measurement method in this paper could be used to investigate other electroseismic and seismoelectric properties for petroleum exploration applications.

Seismoelectric reflection and transmission at a fluid/porous-medium interface

“…The inverse electroseismic conversion was also measured ͑Thompson et Zhu et al, 2008͒. So-called electroseismograms in layered media were presented by several authors ͑e.g., Haartsen and Pride, 1997;Han and Wang, 2001;White and Zhou, 2006;Haines and Pride, 2006͒.…”

Seismoelectric effects due to mesoscopic heterogeneities

“…Arguably, the most important work on this topic is by Haartsen and Pride [1997], who modeled the seismoelectric response from a single sand layer having a thickness much smaller than the predominant seismic wavelengths. More recently, Zhu et al [2008] performed seismoelectric laboratory experiments demonstrating that electromagnetic waves are generated at horizontal fractures intersecting boreholes.…”

Frequency-Dependent Streaming Potentials: A Review

“…Laboratory experiments have also been investigated for a better understanding of the seismoelectric conversions [45][46][47][48][49][50][51][52][53][54][55][56]. These papers describe the laboratory studies performed to investigate this dynamic coupling.…”

“…Recently Tardif et al [64] used an electromagnetic shaker operating in the range 1 Hz to 1 kHz and provided measurements up to 200 Hz. Higher frequencies have been investigated [49,50,52,54,55] for the detection of the interfacial conversions.…”