ELECTRICAL CASED WELL LOGGING METHOD Russian patent published in 2012 - IPC G01V3/20 

FIELD: physics.

SUBSTANCE: invention relates to well logging and can be used to determine electrical resistance of rock formations surrounding a well cased by a metal column. First and second potential differences are determined using combined measurements of two devices for measuring small quantities which measure voltage drop between neighbouring electrodes of a set of three equidistant measuring electrodes. When determining resistance of a section of a column, non-uniformity of flow of currents transmitted to current electrodes upwards and downwards the column is taken into account.

EFFECT: suppressing the dependency of the measured resistivity of rock formations from systematic multiplicative error of the devices for measuring small quantities, high quality and reliability of measurements.

9 dwg