VIBRATION DAMPER - CALIBRATING DEVICE Russian patent published in 2014 - IPC E21B17/07 E21B17/10 

FIELD: oil and gas industry.

SUBSTANCE: vibration damper - calibrating device comprises a body and a gage plug. The body is perforated in longitudinal and circumferential directions with formation of grooves at exterior surface. The gage plug has joggles at inner surface, and at outer surface between joggles there are soldered hard-alloyed fins. The body and bushing are perforated through and shaped as prismatic grooves thus forming frames with installed steel balls. Diameter of the balls is increasing while distance to the next ball is reducing in longitudinal direction of the vibration damper - calibrating device bottom-up.

EFFECT: improved efficiency in dampening of longitudinal direction that impact the bottom assembly of the drill stem and in calibrating of the well bore.

3 cl, 2 dwg