Patent ID: 6640913
Filing Date: 2003-11-04
Classification: E21B

Abstract:
An earth-boring drill bit for drilling a borehole with a bottom and a borehole corner of a predetermined gage, the bit comprising:(a) a bit body having a bit axis; (b) a plurality of rolling cone cutters, each rotatably mounted on the bit body about a respective cone axis and having a plurality of circumferential rows of cutting inserts thereon; (c) at least one of the plurality of rolling cone cutters comprising a gage row with gage inserts located such that the gage row is first from the bit axis that cuts substantially to the predetermined gage and cuts the bottom of the borehole corner substantially unassisted, the gage inserts having a generally cylindrical base portion secured in the cutter and defining an insert axis that is at an acute angle with respect to the cone axis, and a cutting portion extending from the base portion, the cutting portion comprising a generally convex gage cutting surface with a center axis, at least a portion of the gage cutting surface enhanced with a super abrasive material, such that a relatively thickest portion of the super abrasive material is between the insert axis and a point of contact at a gage.