Rolling cone drill bit having cutting elements with improved orientations

A method of orienting cutting elements on a cone cutter of a drill bit for drilling a borehole in earthen formations, the method comprising:

• providing a bit body having a bit axis;
• mounting a rolling cone cutter on the bit body, the rolling cone cutter adapted for rotation about a cone axis in a cutting direction;
• inserting a plurality of inserts into the cone cutter, wherein the plurality of inserts are arranged in a plurality of circumferential rows that are axially spaced relative to the cone axis, wherein each insert has a base portion secured in a mating socket of the cone cutter and a cutting portion extending from the base portion, wherein the base portion has a central axis and the cutting portion has a cutting surface;
• identifying a transition insert on the cone cutter, the transition insert being disposed at a first radial position;
• wherein a first of the plurality of inserts is an asymmetric insert disposed at the first radial position or radially inward of the first radial position relative to the bit axis, and wherein a second of the plurality of inserts is an asymmetric insert disposed radially outward of the first radial position relative to the bit axis;
• orienting the first of the plurality of inserts such that its cutting surface has a leading side relative to the cutting direction with a first geometry;
• orienting the second of the plurality of inserts such that its cutting surface has a leading side relative to the cutting direction with a second geometry that is different than the first geometry, wherein each of said first of the plurality of inserts and each of said second of the plurality of inserts is symmetric about a first plane along the central axis of said insert, and wherein each of said first of the plurality of inserts and each of said second of the plurality of inserts is not symmetric about a second plane along said central axis of said insert, wherein said second plane is perpendicular to said first plane and is parallel to, or coplanar with, a third plane along the cone axis.

A rolling cone drill bit for drilling a borehole in earthen formations, the bit comprising:

• a bit body having a bit axis;
• a rolling cone cutter mounted on the bit body and adapted for rotation about a cone axis in a cutting direction;
• at least one transition insert mounted to the cone cutter at a first radial position relative to the bit axis;
• a first insert having a central axis and being mounted to the cone cutter at the first radial position or radially inward of the first radial position relative to the bit axis;
• wherein the central axis of the first insert defines is along a first insert axis plane that is parallel to the cone axis, wherein the cone axis defines is along a first cone axis plane that is parallel to the first insert axis plane, and wherein the first insert axis plane is offset from the first cone axis plane by a first offset distance measured perpendicularly therebetween;
• a second insert having a central axis and being mounted to the cone cutter radially outward of the first radial position relative to the bit axis;
• wherein the central axis of the second insert defines is along a second insert axis plane that is parallel to the cone axis, wherein the cone axis defines is along a second cone axis plane that is parallel to the second insert axis plane, and wherein the second insert axis plane is offset from the second cone axis plane by a second offset distance measured perpendicularly therebetween;
• wherein the first offset distance is different than the second offset distance.