Experimental studies of seismoelectric effects in fluid-saturated porous media

In order to study seismoelectric field characteristics, which may possess great potential in oil exploration and production, we have made a number of experimental measurements of seismoelectric effects in fluid-saturated porous media, and successfully observed two kinds of electromagnetic field excited by the acoustic wave propagating in such media. The first kind of electromagnetic field, which only exists within the area disturbed by the acoustic wave propagation, is produced inside the media. The other kind is produced at the interface between two different media and can be received anywhere within the range of detection. Through quantitative analysis of the experimental results, we have found relationships between the strength of the seismoelectric signal and the concentration of the saturated solution and source-receiver offset. On the basis of experiments on several different contrasts, we have also found that the seismoelectric conversion is sensitive to the oil-saltwater interface.