Patent ID: 6900639

Claim:
A method for recovering a volume of hydrocarbon from a location in a submarine or subterranean reservoir comprising: conducting an electromagnetic survey of the reservoir, the survey method comprising (a) deploying an electric dipole transmitter; (b) deploying an electric dipole receiver; (c) applying an electromagnetic (EM) field to the strata using the transmitter; (d) detecting the EM wave field response using the receiver; (e) extracting phase information from the wave response; (f) repeating procedures (a) through (e) with the transmitter and/or receiver in different locations for a plurality of transmissions; and (g) using the phase information from the wave response for the plurality of transmissions, in order to determine the presence and/or nature of the reservoir by analyzing the detected wavefield for the presence of a refracted wave component; wherein the transmitter is operated at a transmission frequency in the range of 0.01 Hz to 1 kHz for the plurality of transmissions; using the electromagnetic survey to determine that a volume of hydrocarbon is present at a location in the reservoir; and producing the volume of hydrocarbon from a well that penetrates the reservoir near the location in the reservoir.