BORE BIT WITH THREE ROLLER CUTTERS Russian patent published in 2009 - IPC E21B10/16 

FIELD: oil and gas production.

SUBSTANCE: invention refers to rock destroying tool, notably, to bore cone bits for boring inclined and horizontal boreholes. Roller cutters of the bore bit are equipped with central and peripheral bits of hard alloyed teeth. One roller cutter has one-row peripheral bit, while another has two-row peripheral bit with teeth arranged in a staggered order in a peripheral and before peripheral rows, the third roller cutter has two-row peripheral bit with group arrangement of teeth in a staggered order and with teeth of the before peripheral row arranged in pairs between the groups. On inverse cones of the roller cutters there are cut through slots of depth not less, than weighing of roller cutters relative to bore bit legs. Width of slots on the first and the second roller cutters and opposite to groups of teeth of the third roller cutter is equal to inner distance between base of heads of teeth of the peripheral row, while opposite to in pairs arranged teeth of before peripheral row of the third roller cutter there are cut two slots; also one of slots is two times narrower, than the other. The slots on all roller cutters are made so, that their lengthwise axes are parallel to planes passing through axes of rotation of the roller cutters and are set off relative to these planes in the direction opposite to the direction of rotation of the roller cutters at value y_n: y_n=(y_k-k)/2, where y_k- is distance in plane view from cross axis of the bore bit parallel to axis of the roller cutter to the point of tangency of circumference of the base of the inverse cone of the roller cutter with circumference radius equal to radius of the bore bit; k is set off of roller cutter axis in plane view relative to cross axis of the bore bit.

EFFECT: increased operational life of three roller cutters bore bit under conditions of boring with control over curvature and decreased stick hazard in inclined and horizontal boreholes.

7 dwg