Cutting structures for fixed cutter drill bit and other downhole cutting tools

Patent metadata

Field	Value
Publication number	US-9404312-B2
Application number	US-201213370862-A
Country	US
Kind code	B2
Filing date	Feb 10, 2012
Priority date	Feb 10, 2011
Publication date	Aug 2, 2016
Grant date	Aug 2, 2016

Abstract

A downhole cutting tool may include a tool body; a plurality of blades extending azimuthally from the tool body; and a plurality of cutting elements disposed on the plurality of blades, the plurality of cutting elements comprising: at least two conical cutting elements comprising a substrate and a diamond layer having a conical cutting end, wherein at least one of the at least two conical cutting elements has a positive back rake angle, and at least one of the at least two conical cutting elements has a negative back rake angle.

First claim

What is claimed:

1. A downhole cutting tool, comprising:
a tool body;
a plurality of blades extending azimuthally from the tool body; and
a plurality of cutting elements disposed on the plurality of blades, the plurality of cutting elements comprising:
at least two conical cutting elements comprising a substrate and a diamond layer having a conical cutting end,
wherein at least one of the at least two conical cutting elements has a positive back rake angle, and at least one of the at least two conical cutting elements has a negative back rake angle, and
wherein a plurality of conical cutting elements in a cone region of the downhole cutting tool having a positive back rake angle and a plurality of conical cutting elements in a shoulder region of the downhole cutting tool have a negative back rake angle.

2. The downhole cutting tool of claim 1 , wherein the at least one conical cutting elements having a positive back rake angle, and the at least one conical cutting elements having a negative back rake angle are disposed on the downhole cutting tool at the same radial position from a bit centerline.

3. The downhole cutting tool of claim 1 , wherein the plurality of cutting elements further comprises at least one cutter having a substrate and a diamond table with a substantially planar cutting face, wherein in a rotated view of the plurality of cutting elements into a single plane, the at least one cutter is located a radial position from the downhole cutting tool axis that is intermediate the radial positions of the at least one conical cutting element having a positive back rake angle and the at least one conical cutting element having a negative back rake angle.

4. The downhole cutting tool of claim 1 , wherein a plurality of conical cutting elements in a nose region of the downhole cutting tool have a substantially neutral back rake angle.

5. The downhole cutting tool of claim 1 , wherein the plurality of cutting elements further comprises at least one cutter having a substrate and a diamond table with a substantially planar cutting face, wherein the at least one cutter is disposed at the same radial distance from a bit centerline as at least one of the conical cutting elements.

6. The downhole cutting tool of claim 1 , wherein the at least two conical cutting elements are on two separate blades.

7. The downhole cutting tool of claim 1 , wherein the at least two conical cutting elements are on the same blade.

8. The downhole cutting tool of claim 1 , wherein the at least two conical cutting elements are disposed in a nose region and shoulder region of a cutting profile.

9. The downhole cutting tool of claim 1 , further comprising a center coring conical cutting element disposed in a region between at least two blades.

10. The downhole cutting tool of claim 1 , wherein the downhole cutting tool is a drill bit comprising:
a bit body having a bit axis and a bit face; and
a plurality of blades extending radially along the bit face.

11. The downhole cutting tool of claim 1 , wherein the at least two conical cutting elements have a back rake selected from about −10 to 10.

12. A downhole cutting tool, comprising:
a tool body;
a plurality of blades extending azimuthally from the tool body; and
a plurality of cutting elements disposed on the plurality of blades, the plurality of cutting elements comprising:
at least two conical cutting elements comprising a substrate and a diamond layer having a conical cutting end,
wherein at least one of the at least two conical cutting elements has a positive side rake angle, and at least one of the at two least conical cutting elements has a negative side rake angle, wherein the at least two conical cutting elements are primary cutting elements, and wherein the at least two conical cutting elements are disposed in at least one of a nose region or a shoulder region of a cutting profile.

13. The downhole cutting tool of claim 12 , wherein the at least one conical cutting elements having a positive side rake angle, and the at least one conical cutting elements having a negative side rake angle are disposed on the downhole cutting tool at the same radial position from a bit centerline.

14. The downhole cutting tool of claim 12 , wherein the plurality of cutting elements further comprises at least one cutter having a substrate and a diamond table with a substantially planar cutting face, wherein in a rotated view of the plurality of cutting elements into a single plane, the at least one cutter is located a radial position from the downhole cutting tool axis that is intermediate the radial positions of the at least one conical cutting element having a positive side rake angle and the at least one conical cutting element having a negative side rake angle.

15. The downhole cutting tool of claim 12 , wherein the plurality of cutting elements further comprises at least one cutter having a substrate and a diamond table with a substantially planar cutting face, wherein the at least one cutter is disposed at the same radial distance from a bit centerline as at least one of the conical cutting elements.

16. The downhole cutting tool of claim 12 , wherein the at least two conical cutting elements are on two separate blades.

17. The downhole cutting tool of claim 12 , wherein the at least two conical cutting elements are on the same blade.

18. The downhole cutting tool of claim 12 , further comprising a center coring conical cutting element disposed in a region between at least two blades.

19. The downhole cutting tool of claim 12 , wherein the downhole cutting tool is a drill bit comprising:
a bit body having a bit axis and a bit face; and
a plurality of blades extending radially along the bit face.

20. A drill bit for drilling a borehole in earth formations, comprising:
a bit body having a bit axis and a bit face;
a plurality of blades extending radially along the bit face;
a plurality of cutting elements disposed on the plurality of blades; and
a conical coring cutting element disposed in a region between at least two blades,
wherein an apex of the conical coring cutting element is at a height H less than a cutting edge of the most radially interior cutting element, wherein H ranges up to 0.35 times a diameter of the bit.

21. The drill bit of claim 20 , wherein H is up to 0.1 times the bit diameter.

22. The drill bit of claim 20 , wherein a cone angle of the conical coring cutting element ranges from 60 to 120 degrees.

23. The drill bit of claim 20 , wherein a ratio of H to a diameter of the conical coring cutting element ranges from 0.5 to 3.

24. A downhole cutting tool, comprising:
a tool body;
a plurality of blades extending azimuthally from the tool body; and
a plurality of cutting elements disposed on the plurality of blades, the plurality of cutting elements comprising:
at least one conical cutting elements comprising a substrate and a diamond layer having a conical cutting end,

wherein a cutting profile of the plurality of cutting elements in a rotated view comprises at least one non-smooth step therein.

25. The downhole tool of claim 24 , wherein the at least one conical cutting element transitions between adjacent stages and creates a vertex in the cutting profile.

26. The downhole tool of claim 25 , wherein the conical cutting element creates a convex portion of the non-smooth cutting profile.

27. The downhole tool of

Assignees

• Azar Michael G
• Durairajan Bala
• Keshavan Madapusi K
• Smith International

Inventors

• Azar Michael G
• Durairajan Bala
• Keshavan Madapusi K

Classifications

• E21B10/627

  with plural detachable cutting elements · CPC title

• E21B10/633

  independently detachable · CPC title

• E21B10/485

  with inserts in form of chisels, blades or the like · CPC title

• E21B10/46

  characterised by wear resisting parts, e.g. diamond inserts · CPC title

• E21B10/56

  Button-type inserts (E21B10/52 takes precedence) · CPC title