STABILISING CORE BIT Russian patent published in 2016 - IPC E21B10/48 E21B10/60 

FIELD: oil and gas industry.

SUBSTANCE: invention relates to rock cutting tools for drilling wells for various purposes with coring and can be used in selection of a core in reservoirs of oil and gas wells. Stabilising annular drill bit includes a body with a threaded connection, divided by main flushing channels into sectors with an end surface provided with diamond-carbide inserts having negative rake angles in respect to lateral inner and outer surfaces of cutting and negative rake angles to end surface of downhole wherein main flushing channels are oppositely angled. In crown housing in oppositely angled sectors there are additional flushing channels, primary and secondary flushing channels are formed along entire height of crown housing helical line to right along rotation of crown, height of crown housing depends on pitch of helix of main and additional flushing channel, additional flushing channel has two or more of diamond-carbide calibrating plates, each of which represents a separate helix element and secured to housing by soldering or by mechanical means at a negative angle of minus 5˚ to minus 15˚ relative to cutting surface.

EFFECT: technical result consists in reduction of borehole deviation, increasing mechanical drilling speed, resource or crown.

1 cl, 3 dwg