Cutter support element

Patent metadata

Field	Value
Publication number	US-10352103-B2
Application number	US-201414338404-A
Country	US
Kind code	B2
Filing date	Jul 23, 2014
Priority date	Jul 25, 2013
Publication date	Jul 16, 2019
Grant date	Jul 16, 2019

Abstract

Cutters mounted on bits for advancing boreholes are subject to extreme forces that can separate the cutter from the bit. A cutter backing element with a rearward extending lug and forward face can provide support to the cutter. The backing element is attached to the back face of the cutter and the lug of the backing element is received in a recess of the bit. The backing element can be brazed to the bit and the cutter. The lug is offset from a longitudinal axis of the backing element. Forces applied to the front of the cutter during drilling operations are transferred through the cutter to the backing element and to the bit through the offset lug.

First claim

The invention claimed is:

1. A backing element for a PDC cutter having a diamond table mounted to a substrate to be installed to a drill bit with a blade including:
a body with a forward face and a first longitudinal axis normal to the forward face adapted for supporting a rear end of a separate cutter element comprising a PDC cutting portion affixed to a substrate portion; and
a lug offset from the first longitudinal axis extending rearward from the body for acceptance in a recess of the blade, the lug having a second longitudinal axis extending downwardly from the first longitudinal axis, but not perpendicular to it;
where force applied to a front end of the cutter element is transferred through the forward face of the backing element rearward through the offset lug into the blade of the bit;
wherein at least a portion of an exterior surface of the body is convex along the first longitudinal axis.

2. The backing element of claim 1 wherein the second longitudinal axis is inclined to the first longitudinal axis at an inclusive angle between 45 to 75 degrees.

3. The backing element of claim 1 where the offset lug is brazed in the blade of the bit.

4. The backing element of claim 1 where the forward face of the body is brazed to the back face of the cutter element.

5. The backing element of claim 1 where the lug is round in cross section.

6. The backing element of claim 1 where the backing element is steel.

7. The backing element of claim 1 where the backing element is metal carbide.

8. A method of supporting a cutter on a drill bit comprising:
receiving a backing element including an offset lug in a first recess in the bit, wherein the offset lug is a portion of the backing element and wherein the backing element is also at least partially received in a second recess of the bit;
receiving the cutter in the second recess of the bit adjacent the backing element;
bonding a front face of the backing element to a back face of the received cutter; and
bonding the backing element to the first and second recesses of the bit;
where the cutter has a longitudinal axis and the lug has a longitudinal axis and the cutter axis is offset from the lug axis at an inclusive angle between 45 to 75 degrees.

9. The method of claim 8 comprising brazing the backing element in the first recess.

10. The method of claim 8 comprising brazing the cutter in the second recess.

11. The method of claim 8 comprising brazing the front face of the backing element to the back face of the cutter.

12. A drill bit comprising:
a drill bit body with blades;
a cutter with a rear face;
a cutter support with a front face and an offset lug extending rearward spaced from the front face, wherein the offset lug is a portion of the cutter support;
a recess in the bit for receiving the lug; and
a seat in the bit for receiving the cutter;
where the front face of the cutter support abuts the rear face of the cutter substrate with the lug received in the recess, the cutter support at least partially received in the seat in the bit, and the cutter received in the seat.

13. The drill bit of claim 12 where the cutter support front face is brazed to the cutter rear face.

14. The drill bit of claim 12 where the cutter support lug is brazed in the recess of the bit.

15. The drill bit of claim 12 where the cutter is brazed to the seat of the bit.

16. The drill bit of claim 12 where the lug is offset 45 to 75 degrees from a longitudinal axis of the cutter support normal to the front face.

17. A drill bit comprising:
a drill bit body with blades;
a cutter with a rear face;
a cutter support with a front face and an offset lug extending rearward spaced from the front face;
a recess in the bit for receiving the lug; and
a seat in the bit for receiving the cutter;
where the front face of the cutter support abuts the rear face of the cutter substrate with the lug received in the recess and the cutter received in the seat; and
where the cutter support extends above the cutter rear face to engage the rock face and limit the depth of engagement by the cutter.

18. The drill bit of claim 12 where the cutter rear face conforms to the surface of the cutter support front face.

19. A drill bit comprising:
a bit body with blades;
a cutter secured to the bit body, the cutter having a front face and a rear face;
a cutter support in contact with the cutter with a rearward extending lug offset from the rear face towards the bit body and secured to the bit body;
wherein the cutter support extends outward of the rear face of the cutter to limit depth or penetration of the cutter.

20. A drill bit tooth comprising:
a backing element; and
a cutter element;
wherein the backing element has
a body with a forward face and a first longitudinal axis normal to the forward face adapted for supporting the rear end of the cutter element, and
a lug offset from the first longitudinal axis extending reward from the body for acceptance in a recess of a blade, the lug having a second longitudinal axis extending downwardly from the first longitudinal axis, but not perpendicular to it;

wherein the cutter element comprises a cutter portion affixed to a substrate portion formed of a different material from the cutter, the cutter portion being the forward face of the cutter element and the substrate portion being the rear end of the cutter element;
wherein the body includes an enlarged cross-sectional area as compared to a cross-sectional area of the lug; and
wherein the backing element and the cutter element are preformed separately.

21. The tooth of claim 20 wherein the second longitudinal axis is inclined to the first longitudinal axis at an inclusive angle between 45 to 75 degrees.

22. The tooth of claim 20 wherein the offset lug is brazed in the blade of the bit.

23. The tooth of claim 20 wherein the forward face of the body is brazed to the back face of the cutter element.

24. The tooth of claim 20 wherein the lug is round in cross section.

25. The tooth of claim 20 wherein the backing element is steel.

26. The tooth of claim 20 wherein the backing element is metal carbide.

Assignees

• Ulterra Drilling Tech Lp

Inventors

• Maw Jason

Classifications

• E21B10/43 Primary

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

• B23K35/0211

  for use in cutting (B23K35/0205 takes precedence) · CPC title

• B22F7/062

  involving the connection or repairing of preformed parts · CPC title

• B23K35/00

  Rods, electrodes, materials, or media, for use in soldering, welding, or cutting · CPC title

• B23K35/0222

  for use in soldering or brazing (B23K35/0205 takes precedence) · CPC title