GUIDING OR CENTERING UNIT FOR DRILLING PIPE (VARIANTS) Russian patent published in 2006 - IPC E21B17/10 

FIELD: well drilling equipment, particularly devices adapted for drilling tool centering and protection from wear.

SUBSTANCE: unit made in accordance with the first embodiment comprises body with super-hard layer connected to outer surface of the unit. The layer is divided into several parts by transversal groove having depth of not less than super-hard layer thickness. Unit in accordance with the second embodiment comprises body with slots in which replaceable blades covered with super-hard layer are arranged. The super-hard layer is divided into several parts by transversal groove having depth of not less than super-hard layer thickness.

EFFECT: possibility of drilling tool lowering in deflected well and simplified unit structure.

6 cl, 5 dwg