CALIBRATOR Russian patent published in 2011 - IPC E21B17/10 E21B10/30 

FIELD: oil and gas production.

SUBSTANCE: blade calibrator consists of hollow case with blades, external surface of which is reinforced with rock-destroying elements, and of flush slots made between blades. The distinguished feature of the device is rotating guiding blades secured in the flush slots. Relative to axis of the case external surface of the blades is positioned at radius less, than radius of external surface of the blades. Side walls of the guiding blades are of a drop-like shape, while the flush slots have concave walls in form of portion of Archimedean spiral. External surface of the guiding blades has lengthwise slots, outlet parts of which are arranged at angles diverging one towards another.

EFFECT: increased efficiency of operation of blade calibrator due to more qualitative bottomhole cleaning from slime and due to prevention of seals formation above upper end of blades.

5 cl, 4 dwg