Отправлено: 14.03.12 07:20. Заголовок: Frequency-dependent Streaming Potential of Reservoir Rocks

Frequency-dependent Streaming Potential of Reservoir Rocks
E. Tardif, E. Walker*, P.W.J. Glover and J. Ruel
Universitй Laval, Quйbec, Quйbec, Canada
paglover@ggl.ulaval.ca, emilie.walker.1@ulaval.ca
Summary
The scientific literature is almost devoid of frequency-dependent electro-kinetic measurements on
geological materials. We have designed, constructed and tested an apparatus that allows the measurement of
the streaming potential coupling coefficient and zeta potential of unconsolidated reservoir materials. The
apparatus uses an electro-magnetic drive and operates in the range 1 Hz to 1 kHz. The sample diameter is
25.4 mm and samples can be up to 150 mm long.
We have made streaming potential coupling coefficient measurements on samples of Ottawa sand as a
function of frequency. The results have been analyzed using critically and variably damped second order
vibrational mechanics models as well as the theoretical models of Packard (1953) for capillary tubes and
Pride (1994) for porous media. Such modelling allows a transition frequency to be calculated, which can in
turn be used to calculate the pore radius of the samples. The permeability of the samples can then be
obtained using the work of Walker and Glover (2010). In all cases the transition frequencies were in good
agreement with those expected from independent measurements of effective pore radius that were derived
from laser diffraction and MICP measurements. This indicates that the transition frequency measurements
can be used to calculate the effective pore radius of the reservoir material. Fluid permeability predicted from
the transition frequency were also in good agreement with those measured on the sand samples.

http://www.cspg.org/documents/Conventions/Archives/Annual/2011/132-Frequency-dependent_Streaming_Potential_of_Reservoir_Rocks.pdf