The spatial time-frequency EM survey (FTEM-3D)

摘要

FIELD: physics.;SUBSTANCE: disclosed is a three-dimensional frequency-time electrical prospecting method, which involves passing electric current in form of a series of a continuous sequence of rectangular pulses of different duration in a mounted power supply in form of an earthed line AB. An electromagnetic field is induced and frequency and transient characteristics of the geologic environment are detected using sensors of the horizontal electric component, e.g., earthed receiving electrical lines MN lying on a regular profile network on the area of the investigated section. Current in the supply line is detected synchronously with changes. The frequency-time relationship of spatial distribution of the field, which carries information on geoelectric parameters of the environment, e.g., conductivity, resistance and polarisability, is determined. Mineral deposits are then detected and delineated based on the results of analysing geoelectric parameters.;EFFECT: high accuracy of measurement and efficiency of detecting hydrocarbon deposits.;4 cl, 2 dwg