FIELD: physics; measurement.
SUBSTANCE: invention relates to geophysics. The method involves emission of an electromagnetic signal from a spot near the sea floor or land surface using an electromagnetic wave transmitter. The electromagnetic wave transmitter contains an antenna, which emits an electromagnetic signal to the top end of an electroconductive casing column or shank. The top end is located near the sea floor. The electromagnetic signal is channelled along the electroconductive casing column to a layer with high resistivity and is then propagated as an electromagnetic signal of a guided wave with relatively higher speed inside the layer with high resistivity compared to propagation speed in less resistive layers. The electromagnetic signal of the guided wave gives rise to an upward directed refracted electromagnetic signal, which has relatively low propagation speed in less resistive layers and has angle of emergence closer to the normal at the boundary surface between the layer with high resistivity and the layer with low resistivity. The front of the refracted electromagnetic wave is detected along a group of pick-up antennae along the sea floor. The group is aligned with the transmitter.
EFFECT: possibility of injecting electromagnetic waves into a collector using a metallic casing column.
13 cl, 14 dwg
