METHOD OF HIGH-PRECISE ELECTROMAGNETIC SENSINGS AND DEVICE FOR ITS IMPLEMENTATION Russian patent published in 2017 - IPC G01V3/16 

FIELD: physics.

SUBSTANCE: excitation of the electromagnetic field is carried out by a sequence of pulses, the switching-off front of which is accompanied by a damped oscillatory process. Simultaneously, continuous registration of the current pulse in the generator circuit is performed by measuring its derivative using an inductive sensor located in the immediate vicinity of the current-carrying wire of the generator circuit so that the induced signal from the eddy currents induced in the medium of eddy currents is negligibly small compared to the signal due to the current in the generator circuit. The damped oscillatory process in the generator circuit, which occurs when the current is disconnected, is a natural oscillatory process of the generator circuit, and mainly has its own oscillation frequency of 100 kHz to 5000 kHz, and the attenuation coefficient is predominantly of 25 kHz to 5000 kHz. The device comprises a compensation circuit connected in series with the generator circuit, located inside the receiving circuit, and an inductive current sensor located close to the said generator circuit. The compensation circuit is connected to the generator circuit in series so that the currents flowing in them are in the opposite direction.

EFFECT: taking into account the effect of the current probe pulse on the measurements of the fields induced in the geological medium, obtaining additional information at early times of field formation due to the formation of a special current-off edge in the generator circuit.

12 cl, 2 tbl, 11 dwg