Abstract: A method for direct airborne electromagnetic prospecting of hydrocarbons by transmitting many primary electromagnetic fields and detecting any deviation of the primary electromagnetic fields due to secondary electromagnetic fields. The transmitting and detecting operations are carried out first over a known area comprising a known petroleum deposit and known barren locations (a stage of system instruction) and then over an unknown area to be explored (a stage of actual prospecting). The enormous volume of data obtained in both stages is processed electronically, using pattern recognition theory, into a probability level of the hydrocarbon presence or absence for all measuring points over the unknown area. In the stage of system instruction, the detected signal deviations are converted into factors of discriminant functions by substituting the high absolute probability levels for known hydrocarbon deposit and barren locations (above +0.8 and below -0.8, respectively) into these functions.

Abstract: An electrical geophysical method and system for direct and diagnostic prospecting of hydrocarbon deposits. Numerous combinations of connections of the transmitting array and numerous combinations of frequencies are employed in sequence to create many unique electromagnetic fields in the earth, first over a number of locations known to contain hydrocarbons and known to be barren, then over prospecting locations. Numerous electric and magnetic components of each electromagnetic field are measured with a receiving array located in the near field of the transmitting array. The huge amounts of measured data are processed using Pattern Recognition techniques in a processor to yield directly a probability measure of hydrocarbon occurrence at each prospecting location.

Abstract: An apparatus for direct airborne electromagnetic prospecting of hydrocarbons by transmitting many primary electromagnetic fields and detecting any deviation of the primary electromagnetic fields due to secondary electromagnetic fields. The transmitting and detecting operations are carried out first over a known area, as a stage of system instruction, and then over an unknown area, as a stage of actual prospecting. A transmitting system, suspended vertically from a helicopter, is adapted to radiate electromagnetic fields of many different frequencies and many different orientations controlled automatically. A receiving system, suspended vertically from the transmitting system, is adapted to detect signals of three orthogonal components of electromagnetic deviations as a function of helicopter altitude, frequency, transmitter loop orientation and receiver antenna orientation.