| 摘要 |
An improved drill bit comprises a bit body, a plurality of blades disposed on the bit body, a first plurality of cutting elements disposed on the blades, such that the first plurality of cutting elements define a first cutter profile, and a second plurality of cutting elements disposed on the blades, such that the second plurality of cutting elements define a second cutter profile offset from the first cutter profile. The first plurality of cutting elements may, or may not, be greater in number than the second plurality of cutting elements. The cutting elements of the first plurality may, or may not, be greater in size than the cutting elements of the second plurality. The second cutter profile may be offset inwardly or outwardly from the first cutter profile. The second cutter profile may run along a cone section, a nose section, and/or a shoulder section of the bit.
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