PDC drill bit having cutting structure adapted to improve high speed drilling performance
AssigneeSmith International, Inc.
InventorGraham Mensa-Wilmot
Life of this patent
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Abstract
A drill bit is disclosed which includes a bit body having a plurality of blades thereon. The blades have a plurality of cutting elements affixed thereon at selected positions. The cutting elements are disposed into at least two groups. A first one of the groups has at least 60 percent of the cutting elements therein disposed at a first mean backrake angle. A second group has at least 60 percent of the cutting elements therein disposed at a second mean backrake angle. The second backrake angle is at least about fifteen degrees more than the first backrake angle. A bottom hole coverage of the cutting elements in the second group is at least about eighty percent.
Claims28
A drill bit comprising:
- a bit body having a plurality of blades thereon;
- the blades having a plurality of cutting elements affixed thereon at selected positions;
- the cutting elements being disposed into at least two groups,
- a first one of the at least two groups having at least sixty percent of the cutting elements therein disposed at a first mean backrake angle,
- a second one of the at least two groups having at least sixty percent of the cutting elements therein disposed at a second mean backrake angle, the second mean backrake angle being at least about fifteen degrees more than the first mean backrake angle, a bottom hole coverage of the cutting elements in the second group being at least about eighty percent.
Dependencies are inferred from the claim text.