f Evaluation of Well Casing Effect on Measurements with Surface-to-Borehole Electrode Arrays

Reservoir monitoring and surveillance are very important in reservoir management. Deep-reading electric and electromagnetic measurements that now receive most attention use a cross-borehole configuration and induction coil transmitters and receivers located in a borehole. The objective is to find out the conductivity of layers between boreholes and measure conductivity changes caused by oil-water replacement during production. Obviously, the presence of a steel casing makes the measurements less sensitive because of a sizable attenuation of the signal in a metal pipe.