Patent ID: 6859038

Claim:
A method of determining the nature of a reservoir stratum covered by S meters of overburden and having an approximate geometry and location that are known, comprising: using a source to transmit a transmitted electromagnetic wave from a location that is at least S meters distant from the reservoir stratum, with the transmitted electromagnetic wave having a wavelength of at least 0.1 S and no more than 5 S; using a receiver to receive signals created by the transmitted electromagnetic wave; and, analyzing the received signals for electromagnetic wave refraction signals to detect the presence of oil or water in the reservoir stratum, wherein the source is used to transmit the transmitted electromagnetic wave as a polarized transmitted electromagnetic wave, and the source further includes a dipole antenna and is used to transmit an E-field component of the polarized transmitted electromagnetic wave such that the E-field component is approximately directed along a line between the antenna and the receiver.