BIT FOR HARD ROCKS Russian patent published in 2013 - IPC E21B10/42 

FIELD: oil and gas industry.

SUBSTANCE: bit consists of a pilot jumper bit, a housing with screw blades, drill cutters equipped with hard-alloy inserts. The housing with screw blades is made as a single piece with a pitch of screw blades, which is equal to diameter of the bit. Drill cutters are installed on a support plate asymmetrically to each other and at angle α to vertical and at angle β to horizontal. Every next cutter is exceeded by not more than the height of hard-alloy inserts of the cutter.

EFFECT: increasing well boring speed.

3 dwg