Patent ID: 9016407
Filing Date: 2015-04-28
Classification: E21B

Abstract:
1. A drill bit for drilling a borehole in earthen formations, the bit comprising: a bit body having a bit axis and a bit face including a cone region, a shoulder region, and a gage region; a first primary blade extending radially along the bit face from the cone region to the gage region; a plurality of primary cutter elements mounted to the first primary blade, each primary cutter element on the first primary blade being mounted in a different radial position; a second primary blade extending radially along the bit face from the cone region to the gage region; a plurality of primary cutter elements mounted to the second primary blade, each primary cutter element on the second primary blade being mounted in a different radial position; wherein a first primary cutter element of the plurality of primary cutter elements on the first primary blade and a first primary cutter element of the plurality of primary cutter elements on the second primary blade are each positioned in the cone region; wherein the first primary cutter element on the first primary blade is redundant with the first primary cutter element on the second primary blade; wherein the cone region has a total cutter redundancy percentage; and wherein the shoulder region has a total cutter redundancy percentage that is less than the total cutter redundancy percentage in the cone region.