Patent ID: 7026819

Claim:
A method for recovering a volume of hydrocarbon from a submarine or subterranean reservoir comprising: conducting an electromagnetic survey to determine a content of the submarine or subterranean reservoir having an electromagnetic characteristic and having an approximate geometry and location that are known, comprising: applying a time varying electromagnetic field in the form of a wave to the strata containing the reservoir; detecting the electromagnetic wave field response; and analyzing the effects on the characteristics of the detected field that have been caused by the reservoir, thereby determining the content of the reservoir, based on the analysis, wherein the analysis comprises comparing the electromagnetic characteristic theoretically predicted for the reservoir based on the approximate geometry of the reservoir and based on the reservoir being a water-bearing or hydrocarbon-bearing reservoir to the electromagnetic characteristic for the reservoir that is determined from the detected electromagnetic wave field response of the reservoir, wherein a distance between a transmitter and a receiver is given by the formula 0.5λ≦L≦10λ; where λ is the wavelength of the transmission through an overburden and L is the distance between the transmitter and the receiver; inferring from the electromagnetic survey that the volume of hydrocarbon is present in the reservoir; and producing the volume of hydrocarbon from a well that penetrates the reservoir.