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Permeability Dependence of Streaming Potential Coupling Coefficients in Porous Media
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, 76th EAGE Conference and Exhibition 2014, Jun 2014, Volume 2014, p.1 - 5
Abstract
Seismoelectric effects and streaming potential play an important role in geophysical applications. For example, seismoelectric effects are used to investigate oil and gas reservoirs and downhole seismoelectric imaging. Streaming potential is used for mapping subsurface flow in oil reservoirs, the study of hydrothermal activity in geothermal areas. The permeability of reservoir rocks is an important parameter influencing the coupling between fluid flow and electrical current. Permeability dependence of streaming potential coupling coefficients was already studied without consideration of the variation of zeta potential from sample to sample and the variation of the surface conductance versus electrolyte concentrations. The authors presumed that the zeta potential to be the same for the same kind of materials. However, the mineral compositions are somehow different from sample to sample even though they are taken from the same block and therefore, the zeta potential may vary. To study permeability dependence of streaming potential including the effects of the variation of the zeta potential and surface conductance, we performed streaming potential measurements on consolidated samples. The results have shown that the coupling coefficients strongly depend on permeability for low fluid conductivity. This behavior was quantitatively explained by surface conductivity effect in combination with a theoretical model.