A mobile time-domain sounding system for shallow water

We discuss a new method of marine electromagnetic sounding in shallow water using a horizontal electric dipole as a source of current and a vertical electric dipole as a receiver. The measurements are performed in the time domain at short transmitter-receiver offsets. The locality, sensitivity, resolution and detection depth of the proposed method were studied using a number of simple three-dimensional model examples. A new approach to determining the electrical characteristics of a hydrocarbon reservoir based on seismic ‘skeleton’ fixing the boundaries of the geological formations was demonstrated on the Luva Discovery electrical model. The new method enables surveying in depths of water in the range of 25 to 100 m using a towed source and a vertical four-electrode gradient receiver.