| US 7,497,281 B2 | ||
| Roller cone drill bits with enhanced cutting elements and cutting structures | ||
| Shilin Chen, The Woodlands, Tex. (US); and James S. Dahlem, Midlothian, Tex. (US) | ||
| Assigned to Halliburton Energy Services, Inc., Houston, Tex. (US) | ||
| Filed on Feb. 06, 2007, as Appl. No. 11/671,649. | ||
| Application 11/671649 is a division of application No. 11/054395, filed on Feb. 09, 2005, granted, now 7,334,652. | ||
| Application 11/054395 is a continuation in part of application No. 10/189305, filed on Jul. 02, 2002, abandoned. | ||
| Application 10/189305 is a continuation of application No. 09/629344, filed on Aug. 01, 2000, granted, now 6,412,577. | ||
| Application 09/629344 is a continuation of application No. 09/387304, filed on Aug. 31, 1999, granted, now 6,095,262. | ||
| Claims priority of provisional application 60/549354, filed on Mar. 02, 2004. | ||
| Claims priority of provisional application 60/098442, filed on Aug. 31, 1998. | ||
| Prior Publication US 2007/0125579 A1, Jun. 07, 2007 | ||
| Int. Cl. E21B 10/16 (2006.01) | ||
| U.S. Cl. 175—374 [175/376; 175/378] | 14 Claims |
| 1. A roller cone drill bit comprising:
a bit body having at least one support arm extending therefrom;
a respective cone assembly rotatably mounted on each support arm for engagement with a subterranean formation to form a wellbore;
each cone assembly having at least one row of cutting elements;
each cutting element having a crest extending from the respective cone assembly;
each cutting element having a first portion and a second portion with the associated crest disposed therebetween;
the first portion of the at least one cutting element having a relatively greater concentration of hard material;
the second portion of the at least one cutting element having a reduced concentration of hard material as compared with the
first portion of the at least one cutting element; and
at least one cone assembly wherein,
at least one row of cutting elements is oriented such that the crest of each cutting element is generally perpendicular to
an associated scraping direction; and
at least another row of cutting elements is oriented such that the crest of each cutting element is generally parallel to
the associated scraping direction.
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