Cutting structures, tools for use in subterranean boreholes including cutting structures and related methods

Patent metadata

Field	Value
Publication number	US-9493991-B2
Application number	US-201313826832-A
Country	US
Kind code	B2
Filing date	Mar 14, 2013
Priority date	Apr 2, 2012
Publication date	Nov 15, 2016
Grant date	Nov 15, 2016

Abstract

Cutting structures for use with downhole tools in subterranean boreholes include a blade, a plurality of primary cutting elements coupled to the blade, and at least one secondary element rotationally leading the plurality of primary cutting elements in a direction of intended rotation of the cutting structure. The at least one secondary element is coupled to the blade proximate a leading surface of the blade and comprises at least one of a rubbing surface and a cutting surface. An exposure of at least one primary cutting element of the plurality of primary cutting elements is greater than an exposure of the at least one secondary element. Downhole tools such as reamers include cutting structures. Methods of enlarging a subterranean borehole include reaming a borehole with cutting structures.

First claim

What is claimed is:

1. A reamer for use in a subterranean borehole comprising:
a body; and
a plurality of blades coupled to the body, each blade of the plurality of blades comprising:
a plurality of primary cutting elements coupled to the respective blade of the plurality of blades, each primary cutting element of the plurality of primary cutting elements comprising a polycrystalline diamond compact having a planar cutting face configured to remove material from the subterranean borehole; and
at least one secondary element rotationally leading the plurality of primary cutting elements in a direction of intended rotation of the body, the at least one secondary element coupled to the respective blade proximate a leading surface of the respective blade, the at least one secondary element positioned and oriented on the respective blade as a rubbing surface primarily configured for wear, the rubbing surface being substantially flush with at least one radially outermost surface of the respective blade, wherein an exposure of at least one primary cutting element of the plurality of primary cutting elements is greater than an exposure of the at least one secondary element, and wherein a back rake angle of the of at least one primary cutting element of the plurality of primary cutting elements is less than a back rake angle of the at least one secondary element.

2. The reamer of claim 1 , wherein the plurality of primary cutting elements extends along the respective blade in a direction substantially parallel to a centerline of the respective blade.

3. The reamer of claim 2 , wherein each of the plurality of primary cutting elements is positioned proximate to the centerline of the respective blade.

4. The reamer of claim 3 , wherein each of the plurality of primary cutting elements is positioned at the centerline of the respective blade.

5. The reamer of claim 3 , wherein each of the plurality of primary cutting elements is positioned between the centerline of the respective blade and a trailing surface of the respective blade.

6. The reamer of claim 1 , wherein the at least one secondary element comprises a plurality of inserts.

7. The reamer of claim 6 , wherein the plurality of inserts is formed from at least one of a diamond-enhanced material and a material comprising tungsten carbide.

8. The reamer of claim 6 , wherein the plurality of inserts comprises at least one of an ovoid shape, a disc shape, or a brick shape.

9. The reamer of claim 1 , wherein the at least one secondary element comprises a hardfacing material formed on a portion of a body of the respective blade.

10. The reamer of claim 1 , wherein an exposure of each primary cutting element of the plurality of primary cutting elements is greater than the exposure of the at least one secondary element.

11. The reamer of claim 1 , wherein the at least one secondary element is laterally offset from each of the plurality of primary cutting elements in a direction transverse to the direction of intended rotation of the cutting structure.

12. The reamer of claim 1 , wherein the at least one secondary element is positioned at the leading surface of the respective blade.

13. The reamer of claim 12 , wherein the at least one secondary element comprises a plurality of secondary elements positioned on the leading surface of the respective blade and a radially outward surface of the respective blade.

14. A reamer for use in a subterranean borehole comprising:
a body; and
a plurality of blades coupled to the body, each blade of the plurality of blades comprising:
a plurality of primary cutting elements coupled to the respective blade of the plurality of blades and extending along the respective blade in direction substantially parallel to a centerline of the respective blade; and
at least one non-cutting rubbing surface configured for wear coupled to the respective blade proximate a leading surface of the respective blade and rotationally leading the plurality of primary cutting elements, wherein an exposure of at least one primary cutting element of the plurality of primary cutting elements is greater than an exposure of the at least one non-cutting rubbing surface configured for wear, and wherein a majority of a radially outermost portion of the non-cutting rubbing surface configured for wear is positioned substantially flush with a radially outermost surface of the respective blade.

15. The reamer of claim 14 , wherein each of the plurality of primary cutting elements of each blade of the plurality of blades is positioned proximate to the centerline of the respective blade of the plurality of blades.

16. The reamer of claim 15 , wherein each of the plurality of primary cutting elements of each blade of the plurality of blades is positioned between the centerline of the respective blade of the plurality of blades and a trailing surface of the respective blade.

17. A method for enlarging a subterranean borehole, the method comprising:
engaging a subterranean borehole with at least one reamer blade coupled to a reamer;
reaming a portion of the subterranean borehole with a plurality of primary cutting structures positioned proximate a centerline of the at least one reamer blade;
pivoting the reamer about the plurality of primary cutting structures on the at least one reamer blade; and
engaging the subterranean borehole with a non-cutting rubbing surface configured for wear of at least one secondary element positioned proximate a leading surface of the at least one reamer blade and positioned substantially flush with at least one radially outermost surface of the at least one reamer blade.

18. The method of claim 17 , further comprising protecting at least a portion of the reamer with the at least one secondary element comprising a material selected for wear-resistance.

Assignees

• Baker Hughes Inc

Inventors

• Lyons Nicholas J

Classifications

• E21B10/322 Primary

  cutter shifted by fluid pressure (E21B10/345 takes precedence) · CPC title

• E21B10/26

  Drill bits with leading portion, i.e. drill bits with a pilot cutter; Drill bits for enlarging the borehole, e.g. reamers (percussion drill bits with leading portion E21B10/40) · CPC title

• E21B10/32 Primary

  with expansible cutting tools · CPC title

• E21B10/43 Primary

  characterised by the arrangement of teeth or other cutting elements · CPC title