DRILLING THREE-ROLLER BIT Russian patent published in 2010 - IPC E21B10/16 

FIELD: oil and gas production.

SUBSTANCE: drilling three-roller bit comprises support brackets with inclined pivot shafts and rolling cutters mounted thereon by a retaining bearing with their hard-alloy cutting structure, and two rolling cutters has a periphery equipped with two rows of hard-alloy teeth, while the third rolling cutter has one line. The tops of the second rows of the hard-alloy teeth of two first rolling cutters are arranged in a teeth row groove of the third triangular rolling cutter provided between peripheral and adjacent teeth row. The angle between a side of the triangular flute formed by a generatrix of the cone and a perpendicular to the axis of the rolling cutter is specified equal to 25-30°, and maximum depth h of the teeth row groove and a curve radius R connecting two sides of the teeth row groove are specified as h=(0.4-0.5)d₃, where: d₃ is a diametre of hard-alloy teeth arranged in the teeth row groove of the third rolling cutter, mm.

EFFECT: lower power consumption of rock cutting ensured by eliminated bottom rack, higher drilling feed range and speed.

2 cl, 2 dwg