Seismoelectric Signals Produced by Mesoscopic Heterogeneities: Spectroscopic Analysis of Fractured Media
Abstract
In fluid-saturated porous rocks, the presence of mesoscopic heterogeneities such as, for example, fractures, can produce measurable seismoelectric signals. The conversion of mechanical energy into electromagnetic energy is related to wave-induced fluid flow (WIFF) between the heterogeneities and the embedding background. This physical mechanism is a well-known cause of seismic attenuation, which exhibits a strong frequency dependence related to rock physical and structural properties. Consequently, seismoelectric signals arising from WIFF are also expected to depend on various material properties, such as the background permeability and fracture characteristics. We present analytical and numerical approaches to study the effects of mesoscopic heterogeneities on seismoelectric signals. We develop an energy-based approach to quantify the total energy converted to seismoelectric signals at the sample scale. In particular, we apply our theoretical framework to synthetic models of fractured rock samples and study the spectral signature of the resulting seismoelectric signals. This study highlights the influence of the mechanical and hydraulic properties, as well as the geometrical characteristics, such as degree of fracture connectivity, of the probed medium on the resulting seismoelectric signal.
Domains
Environmental Sciences
Origin : Files produced by the author(s)