DEVICE FOR LOCAL EXPANSION OF THE WELLBORE SECTION Russian patent published in 2023 - IPC E21B7/28 E21B10/26 

FIELD: drilling equipment.

SUBSTANCE: device for local expansion of the wellbore section is designed as a pantograph spatial mechanism. The pantograph spatial mechanism is attached to the sliding and fixed couplings on the shaft and is armed with rock cutting elements. Retractable knives are installed as rock-cutting elements, consisting of releasably connected hinged levers and cutting elements. A cylindrical soil collector is installed at the base of the shaft. The soil collector is designed for rotation on the shaft, thus including a removable housing and a base with a through axial hole. The shaft of the device is additionally equipped with a knife limit straightening limiter. The knife limiter straightening is designed as a washer welded to the upper edge of the shaft.

EFFECT: increased efficiency of local expansion of the wellbore section.

1 cl, 4 dwg