DRILL BIT (VERSIONS) Russian patent published in 2013 - IPC E21B10/02 

FIELD: oil and gas industry.

SUBSTANCE: bit contains bit shank, which butt end is divided by grooves for washing into sectors reinforced by well- and core-forming cutters. Feature of the bit is rectangular-trapezium shape of well- and core-forming cutters and orientation of their base of less size towards the side of the bit rotation. At that inclined sides of trapezium are oriented towards each other, have concave shape or shape of a straight line and create an auxiliary channel for washing liquid between themselves and groves for washing.

EFFECT: increased efficiency of bit operation.

4 cl, 3 dwg