DRILL BIT FOR REACTIVE TURBODRILLING Russian patent published in 1997 - IPC

FIELD: drilling of large-diameter wells by reactive turbodrilling in hard rocks. SUBSTANCE: teeth rows of roller cutters are made with same taper angle and located by steps. loading are the teeth rows of nose cone. Peripheral teeth row is armored with hard-alloy teeth with wedge-shaped working head. Their side faces are oriented parallel to gaging surface of roller cutter and generator of cone of its teeth rows. Value of displacement of teeth of nose teeth row relative to teeth of peripheral teeth row does not exceed height of teeth protrusion. EFFECT: higher efficiency. 2 dwg