DOWNHOLE DEVICE OF ELECTRICAL LOGGING OF CASED WELLS Russian patent published in 2017 - IPC G01V3/20 

FIELD: mining.

SUBSTANCE: downhole tool consists of a ground power source, a logging cable, a housing, an actuator, a probe containing electronic components and electrodes with sharp hard alloy inserts. Each electrode with the sharp hard alloy insert is mounted on one end of the spring rod, with the possibility of displacement in the plane perpendicular to the borehole axis. A roller with grooves for the working line is installed at the other end of the rod, which is cinematically connected to the actuator. The drilling cable passes over guide rollers. It has been designed as an endless belt or a segment with one end anchored. The electrode is designed as a conical tip or a rotating roller with a pointed solid or serrated edge made of hard alloy material. Each electrode is located in a separate module, which are assembled in one- and two-electrode units, while the well deck probe is assembled of various modules and blocks, including power modules. Intermittent power pulses can be applied to electrodes for better contact with the casing.

EFFECT: increased reliability, simplified structure, improved contact between the electrode and the casing, modularity.

4 cl, 17 dwg