ELECTROMAGNETIC ISOPARAMETRIC LOGGING METHOD Russian patent published in 2014 - IPC G01V3/28 

FIELD: physics; geophysics.

SUBSTANCE: invention relates to geophysical investigation of electrical properties of rocks based on isoparametric probing and can be used to determine electrophysical parameters of reservoir beds when drilling oil and gas wells. The method includes using a set of probes with successive increase in the length L_N thereof and reducing the frequency f_N according to an electrodynamic isoparameter equal to the product $$L_N\sqrt{f_N}=const,$$ where N is the serial number of a probe 1; 2; …N-1; N, and measuring the phase of the modulus of the amplitude of the harmonic oscillation of emf in a receiving coil relative to the synchronous oscillation of emf in the radiating coil of the probe. Said operations are performed in each probe according to the successive increase in length thereof.

EFFECT: high sensitivity and resolving radial capability based on data on changes in electrophysical properties of reservoirs and detecting electrophysical inhomogeneities occurring at early stages of drilling, when there is shallow penetration of water from the well with signs of a low-resistivity zone.

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