摘要 |
<p>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. In the prospecting stage, the probability level for points over unknown areas is determined by substituting the factors computed in the instruction stage into the same discriminant functions.</p> |