| Summary: | Streaming potential across a porous medium is induced by a fluid flow due to an electric
double layer between a solid and a fluid. When an acoustic wave propagates through a
porous medium, the wave pressure generates a relative movement between the solid and
the fluid. The moving charge in the fluid induces an electric field due to the
seismoelectric conversion. In order to investigate the streaming potential and the
seismoelectric conversion in the same rock sample, we conduct quantitative
measurements with cylindrical and plate samples of Berea sandstone 500 saturated by
NaCl solutions with different conductivities. We measure the electric voltage (streaming
potential) across a cylinder sample in solutions with different conductivities and under
different pressures. In a solution container, we measure the seismoelectric signals
induced by acoustic waves at different frequencies and solution conductivities.
We calculate the quantitative coupling coefficients of the seismoelectric conversion at
DC and high frequencies with samples saturated by solutions with different
conductivities. According to the streaming potentials, we calculate the theoretical
coupling coefficients at the DC and high frequency range. The experimental and
theoretical results are compared quantitatively and their differences are discussed.
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