EARTH-BORING TOOLS WITH PRIMARY AND SECONDARY BLADES, METHODS OF FORMING AND DESIGNING SUCH EARTH-BORING TOOLS

• US 20090114453A1
• Filed: 11/05/2008
• Published: 05/07/2009
• Est. Priority Date: 11/05/2007
• Status: Active Grant

• Current Assignee: Baker Hughes Holdings LLC (Baker Hughes Company)
• Original Assignee: Baker Hughes Incorporated (Baker Hughes Company)
• Inventors: Gavia, David
• Granted Patent: US 8,316,967 B2
• Time in Patent Office: Days
• US Class Current: 175/425
• CPC Class Codes: E21B 10/43 characterised by the arrangement of teeth or other cutting elements
• CPC Class Codes: Y10T 29/49826 Assembling or joining

Abstract

Earth-boring tools comprise a body including a face at a leading end thereof and a shank at a trailing end. At least one primary blade may extend radially outward over the face and may comprise a plurality of cutting elements disposed thereon. At least one secondary blade may also extend radially outward over a portion of the face and the at least one secondary blade may comprise a plurality of cutting elements disposed thereon only over at least a portion of an area of greatest work rate per cutting element. Methods of forming earth-boring tools and methods of designing earth-boring tools are also disclosed.

Claims

1. An earth-boring tool, comprising:

a body comprising a face at a leading end thereof and a shank at an opposing trailing end thereof;

at least one primary blade extending radially outward over the face and comprising a plurality of cutting elements disposed thereon; and

at least one secondary blade extending radially outward over a portion of the face and comprising a plurality of cutting elements disposed thereon only over at least a portion of an area of greatest work rate per cutting element.

2. The earth-boring tool of claim 1, wherein the area of greatest work per cutting element comprises an area of the face comprising at least a portion of a cone region and at least a portion of a nose region.

3. The earth-boring tool of claim 1, wherein the area of greatest work per cutting element comprises an area of the face comprising at least one of a portion of the cone region and a portion of a nose region.

4. The earth-boring tool of claim 1, further comprising a plurality of secondary blades extending radially outward over a portion of the face.

5. The earth-boring tool of claim 4, wherein:

at least one secondary blade of the plurality of secondary blades comprises at least one cutting element disposed thereon only over a portion of the area of greatest work rate per cutting element, and

at least one other secondary blade of the plurality of secondary blades comprises at least one cutting element disposed thereon only over another portion of the area of greatest work rate per cutting element.

6. An earth-boring tool, comprising:

a body comprising a face at a leading end thereof, the face comprising a cone region located proximate a longitudinal axis of the body, a nose region located radially outward from and adjacent to the cone region, and a shoulder region located radially outward from and adjacent to the nose region;

at least one primary blade extending radially from the cone region to the shoulder region; and

at least one secondary blade extending radially from at least the cone region to at least the nose region and including a plurality of cutting elements disposed thereon over a portion of the at least one secondary blade only within at least one of the cone region and the nose region.

7. The earth-boring tool of claim 6, wherein the plurality of cutting elements are disposed over a portion of the at least one secondary blade extending from a location in the cone region proximate to the longitudinal axis at least to the nose region.

8. The earth-boring tool of claim 6, wherein the plurality of cutting elements are disposed over a portion of the at least one secondary blade extending from a location within the cone region to a location within the nose region proximate a radially inner portion of the shoulder region.

9. The earth-boring tool of claim 6, comprising a plurality of primary blades extending radially from the cone region to the shoulder region.

10. The earth-boring tool of claim 6, comprising a plurality of secondary blades extending radially from at least the cone region to at least the nose region.

11. The earth-boring tool of claim 10, wherein:

at least one secondary blade of the plurality of secondary blades comprises at least one cutting element disposed over a portion thereof only within the cone region; and

at least one other secondary blade of the plurality of secondary blades comprises at least one cutting element disposed over a portion thereof only within the nose region.

12. The earth-boring tool of claim 6, wherein the body is comprised of a material selected from the group of materials consisting of a metal, a metal alloy, and a particle-matrix composite.

13. A method of forming an earth-boring tool, comprising:

forming a body comprising a face at a leading end thereof and a shank at a trailing end thereof;

forming at least one primary blade extending radially outward over the face and comprising a plurality of cutting elements disposed thereon; and

forming at least one secondary blade extending radially outward over a portion of the face and comprising a plurality of cutting elements disposed thereon positioned substantially over an area of greatest work rate per cutting element.

14. The method of claim 13, wherein forming the body comprises forming a body of a material selected from the group of materials consisting of a metal, a metal alloy, and a particle-matrix composite.

15. The method of claim 14, forming the body comprising a particle-matrix composite material comprises:

providing a powder mixture;

pressing the powder mixture to form a green bit body; and

at least partially sintering the green bit body.

16. The method of claim 13, wherein forming the body comprising the face at a leading end thereof comprises forming the face to comprise a cone region located proximate a longitudinal axis of the body, a nose region located radially outward from and adjacent to the cone region, and a shoulder region located radially outward from and adjacent to the nose region.

17. The method of claim 16, wherein forming the at least one primary blade extending radially outward over the face and comprising a plurality of cutting elements disposed thereon comprises forming the at least one primary blade extending radially outward over the face and comprising a plurality of cutting elements disposed from the cone region to the shoulder region.

18. The method of claim 16, wherein forming the at least one secondary blade extending radially outward over a portion of the face and comprising a plurality of cutting elements disposed thereon positioned substantially over an area of greatest work rate per cutting element comprises disposing the plurality of cutting elements on the face over an area only within at least one of the cone region and the nose region.

19. A method of designing an earth-boring tool, comprising:

providing a body comprising at least one primary blade extending radially outward over a face Thereof;

determining an area of greatest work rate per cutting element on the body;

designing at least one secondary blade positioned on the face and extending over at least the area of greatest work rate per cutting element; and

selecting a position of a plurality of cutting elements on the at least one secondary blade, the position for each cutting element of the plurality of cutting elements being located only within the area of greatest work rate per cutting element.

20. The method of claim 19, wherein providing the body comprising at least one primary blade extending radially outward over a face thereof comprises providing the body as a computer generated model or a physical model.

21. The method of claim 19, wherein determining an area of greatest work rate per cutting element on the body comprises employing a computational analysis.

22. The method of claim 19, wherein determining an area of greatest work rate per cutting element on the body comprises physically testing the body.