Fracture and wear resistant rock bits
AssigneeSmith International, Inc.
InventorsDah-Ben Liang, Gary Portwood, Paul E. Cox, John L. Williams
Life of this patent
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Abstract
A fracture and wear resistant rock bit is disclosed, which includes a bit body, and at least one roller cone disposed on the bit body adapted such that at least one row of cutting elements disposed on the at least one roller cone defines a gage row. At least one cutting element disposed on the gage row has a fracture toughness of at least 20 ksi (in)0.5 and a wear number of at least 1.5.
Claims19
A rock bit comprising:
- a bit body;
- at least one roller cone rotatably coupled to the bit body;
- and
- a plurality of cutting elements disposed on the at least one roller cone, wherein at least one row of the plurality of cutting elements defines a gage row, wherein at least one cutting element disposed on the gage row has a fracture toughness of at least 20 ski (in)0.5 and a wear number of at least 1.5.
An insert for a rock bit, the insert having a fracture toughness of at least about 20 ski (in)0.5 and a wear number of at least about 1.5.
An insert for a rock bit, comprising:
- tungsten carbide particles;
- and
- a cobalt binder disposed around the particles, wherein a grain size of the tungsten carbide and a cobalt content of the binder are selected to provide a fracture toughness of at least about 20 ski (in)0.5 and a wear number of at least about 1.5.
A rock bit comprising:
- a bit body;
- at least one roller cone rotatably coupled to the bit body;
- and
- a plurality of cutting elements disposed on the at least one roller cone, wherein at least one row of the plurality of cutting elements defines an interior row, wherein at least one cutting element disposed on the interior row has a fracture toughness of at least 20 ski (in)0.5 and a wear number of at least 1.5.
A rock bit comprising:
- a bit body;
- at least one roller cone rotatably coupled to the bit body;
- and
- a first plurality of tungsten carbide gage row cutting elements disposed on the at least one roller cone,
- a second plurality of tungsten carbide interior row cutting elements disposed on said roller cone,
- wherein at least one cutting element in the gage row has a lower toughness than the cutting elements in the interior row.
A rock bit comprising:
- a bit body;
- at least one roller cone rotatably coupled to the bit body;
- and
- a first plurality of tungsten carbide gage row cutting elements disposed on the at least one roller cone,
- a second plurality of tungsten carbide interior row cutting elements disposed on said roller cone,
- wherein at least one cutting element in the gage row has a lower wear number than the cutting elements in the interior row.
Dependencies are inferred from the claim text.