DEVICE FOR EXAMINING CEMENT RING BEHIND CASING STRING IN WELLS AND MAIN PIPELINES Russian patent published in 2007 - IPC G01V5/12 E21B47/00 

FIELD: geophysical well research, possible use for controlling cementing quality of casing strings in wells and main pipelines using dissipated gamma-radiation method.

SUBSTANCE: device contains measuring probe for gamma-gamma logging, including gamma-radiation source, immobile screen with circular collimation window for gamma-radiation source, gamma-radiation detector, positioned in the body inside hollow shaft, immovably held on device axis, screen with sector collimation window for gamma-radiation detector, movably mounted on hollow shaft, system, ensuring even rotation of mobile screen of gamma-radiation detector, registration device and direction and position sensors. Coaxially to movable screen of gamma-radiation, immovable screen with circular collimation window is mounted. Additionally a measuring probe of gamma-gamma logging is mounted in the device, gamma-radiation detector of which is positioned coaxially with first detector of gamma-radiation, in the same body, outside the zone of movable screen.

EFFECT: increased reliability of device and improved operation characteristics of device.

5 cl, 2 dwg