f Cross-borehole electromagnetic induction for reservoir characterization and process monitoring

The radius of investigation of single borehole electrical logs used in reservoir description is currently limited to several meters around the borehole. The object of crossborehole EM is to extend the knowledge of the resistivity distribution to the region between boreholes. Crosshole EM signals at audio frequencies may be propagated through sand/shale reservoirs and detected at distances of several hundreds of meters. Crosshole EM data has a high sensitivity to the interwell resistivity distribution and complements other types of geological and geophysical data.