DEVICE FOR ELECTRICAL LOGGING CASED WELLS Russian patent published in 2009 - IPC G01V3/22 

FIELD: physics; measurement.

SUBSTANCE: invention relates to well log survey and is meant for determining electrical resistivity of rocks in cased wells. Invented is a device for electrical logging cased wells, consisting of a body, actuator, and a probe made in form of a series of five electrodes, equally spaced out along the axis of the well. The electrodes are fitted on opening lever-type centralisers, with top and bottom levers, one end of which is pivotally connected to common axes and joined to the actuator through actuating mechanisms. The actuator is provided with a rotary shaft, which has sections with helical surfaces, the number of which is equal to the number of actuating mechanisms. Electrodes, located on common axes of the levers of the centralisers, are made in form of hard-alloy uniform rollers, freely rotating on common axes. Peripheral parts of the rollers are made in form of sharpened edges. The second ends of the top levers are joined to the body. Each actuating mechanism is a helical bushing joined to the helical part of the shaft, bordered by two clamps, between which a ring is put, resiliently pressed the upper clamp. The ring is pivotally connected to the second ends of the bottom levers of the centralisers.

EFFECT: reduced proneness to accidents and increased technical capabilities, while simplifying the design of the device.

2 cl, 2 dwg