DRILLING BIT WITH FIXED EQUIPMENT, HAVING CORE RECEPTACLE WITH CONCAVE COREBREAKER Russian patent published in 2020 - IPC E21B10/02 E21B10/42 E21B10/54 

FIELD: drilling of wells.

SUBSTANCE: group of inventions relates to a drill bit and a method of drilling a borehole using it. Drill bit comprises shank having threaded connecting part made at its upper end, bit body fixed at lower end of shank and having pressure chamber, calibrating part forming external section of drilling bit, and cutting surface forming lower end of drilling bit. Cutting part comprises core receptacle made at the center of cutting surface with functional capability of receiving rock core, a plurality of blades protruding from the bit body bottom part and extending from the core receptacle periphery to the calibrating portion, and a plurality of front cutting elements arranged along each blade. Core-receiving seat comprises a concave-shaped corebreaker, attached to a lower part of the body of the bit, and a core washing window extending from the pressure chamber through the bottom of the bit housing and configured to discharge the drilling fluid to the core and the concave core. Concave corebreaker is installed in the corebreaker socket, which is formed in the lower part of the bit housing. Edge of the core of the corebreaker crosses the center of the cutting surface.

EFFECT: technical result consists in increase of cutting efficiency in the bit center, using both shear forces and side forces for breakup of core on the part and its crushing.

15 cl, 6 dwg