DOWNHOLE ELECTROMAGNETIC LOGGING TOOL Russian patent published in 2025 - IPC E21B47/85 E21B47/13 G01V11/00 

FIELD: measuring.

SUBSTANCE: invention relates to logging equipment in oil and gas field machine building. Disclosed is a downhole electromagnetic logging tool comprising a transmitting system for generating a magnetic field, an array of magnetic field sensors for receiving a secondary magnetic field and a control module connected to the transmitting system and the array of magnetic field sensors. Transmitting system comprises an upper transmitting coil and a lower transmitting coil located above and below the array of magnetic field sensors, respectively, to create magnetic fields with opposite polarities and opposite directions. Magnetic fields with different directions, created by the upper and lower transmitting coils, are concentrated, according to the principle of unipolar repulsion, in the place where the array of magnetic field sensors is located. Array of magnetic field sensors receives the secondary magnetic field to complete the detection of defects on the casing. Array of magnetic field sensors is a rotary array of magnetic field sensors, and the downhole electromagnetic logging tool further comprises a drive device for driving the array of magnetic field sensors. Driving device is connected to a control module which controls rotation of the rotary matrix of the magnetic field sensors using the driving device to reduce the blind zone for detecting defects.

EFFECT: high accuracy of measurements with an electromagnetic logging tool.

9 cl, 7 dwg