| 摘要 |
A drill bit for drilling a borehole in earthen formations. In an embodiment, the bit comprises a bit body having a bit face comprising a cone region, a shoulder region, and a gage region. In addition, the bit comprises at least one primary blade disposed o n the bit face, wherein the at least one primary blade extends into the cone region. Further, the bi t comprises a plurality of primary cutter elements mounted on the at least one primary blade in the con e region. Still further, the bit comprises a plurality of backup cutter elements mounted on the at least one primary blade in the cone region, wherein the at least one primary blade has a cone backup cutter density and a shoulder backup cutter density, and wherein the cone backup cutter density o f the at least one primary blade is greater than the shoulder backup cutter density of the at least one primary blade.
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