GEOPHYSICAL EXPLORATION METHOD AND DEVICE FOR RECORDING PARAMETERS OF THE NATURAL PULSED ELECTROMAGNETIC FIELD OF THE EARTH

The inventions relate to the field of electromagnetic exploration. The problem of the inventions consists in detecting and mapping structural and lithological irregularities in the Earth's crust (faults, fractures, interfaces between heterogeneous rocks, hydrocarbon traps) on the basis of measurements of the parameters of the natural pulsed electromagnetic field of the Earth. The geophysical exploration method consists in determining the differences in the intensities of the natural pulsed electromagnetic field of the Earth, in the pulse arrival times and in the quantity of pulses between a territorial point of interest and a certain unchanged (reference) point on this territory. Measurements in a very low frequency band are taken using a plurality of route devices which can be moved over the territory and a plurality of stationary devices which are installed at a reference point. Prior to the start of the measurements, the parameters of all of the devices are adjusted, the maximum degree of identicalness thereof is derived, and said devices are sorted into reference devices and route devices. The remaining lack of identicalness is taken into consideration in the processing of the results with the aid of calculated transmission coefficients. The differences in the parameters of the natural pulsed electromagnetic field of the Earth along a profile are determined by means of eliminating those variations in the fields which are recorded at the same time by the reference devices from the readings of the route devices. In order to implement the method, devices for recording the natural pulsed electromagnetic field of the Earth are used which each have a proposed scheme which comprises at least two channels for recording and converting signals in different reception directions. Les inventions se rapportent au domaine de la prospection électromagnétique. L'invention vise à détecter et cartographier les irrégularités structurales et lithologiques de l'écorce terrestres (failles, fractures, limites entre des roches hétérogènes, pièges à hydrocarbures) sur la base de mesures des paramètres du champ électromagnétique naturelle pulsé de la Terre. Le procédé de prospection géophysique consiste à déterminer les différences dans l'intensité du champ électromagnétique naturelle pulsé de la Terre, à des moments d'arrivée des impulsions temps, et leur quantité entre un point du territoire d'intérêt et un certain point inchangé (de référence) sur ce territoire. Les mesures d