Cutting elements with increased curvature cutting edges

Patent metadata

Field	Value
Publication number	US-11591858-B2
Application number	US-202017247478-A
Country	US
Kind code	B2
Filing date	Dec 11, 2020
Priority date	Dec 12, 2019
Publication date	Feb 28, 2023
Grant date	Feb 28, 2023

Abstract

A drill bit for cutting formation comprises a bit body, a plurality of cutters, a plurality of blades with pockets to accommodate the cutters respectively. Each of the plurality of cutters has an ultra-hard layer, two side facets extending obliquely inward from the substrate to a top surface of the ultra-hard layer, a convex portion between the two side facets. The convex portion comprises a transition surface and the transitional surface is convex as it extends between adjacent the two side facets. The curvature of the transitional surface varies along the cutter axis with the curvature at the cutting edge larger than the curvature of the cutter circumferential surface.

First claim

What is claimed is:

1. A cutter comprising
a substrate;
an ultra-hard layer;
two side facets extending obliquely inward from the substrate to a top surface of the ultra-hard layer; and
a convex portion between the two side facets,
wherein the top surface of the ultra-hard layer forms at least two intersecting planes of equal area;
wherein the convex portion comprises a transitional surface, wherein the transitional surface is convex as the transitional surface extends between the two side facets; and
wherein a radius of curvature of the transitional surface varies along a central axis of the substrate.

2. The cutter of claim 1 , wherein the radius of curvature of the transitional surface decreases along the central axis from bottom of the transitional surface to top of the transitional surface.

3. The cutter of claim 2 , wherein the radius of curvature at the top of the transitional surface is smaller than the radius of curvature of the cutter circumferential surface.

4. The cutter of claim 1 , wherein variation of the radius of curvature of the transitional surface is continuous.

5. The cutter of claim 1 , wherein the transitional surface is a partial conical surface.

6. The cutter of claim 1 , wherein the two side facets are planar.

7. The cutter of claim 1 , wherein the two side facets are convex.

8. The cutter of claim 1 , wherein the top surface of the ultra-hard layer comprises a slanted flat top surface.

9. The cutter of claim 1 , wherein the ultra-hard layer is formed of PCD.

10. The cutter of claim 1 , wherein the transition surface is machined by Electrical Discharge Machining, Laser Processing, Grinding or other material reduction methods.

11. The cutter of claim 1 , where the cutter is net shaped from sintering process.

12. The cutter of claim 1 , wherein the transitional surface is a partial lateral surface of an oblique cone.

13. A drill bit comprising at least one cutter of claim 1 .

14. The drill bit of claim 13 , wherein the ultra-hard layer comprises multiple flat top surfaces.

Assignees

• Cnpc Usa Corp
• Beijing Huamei Inc
• China Nat Petroleum Corp

Inventors

• Yu Jiaqing
• Cheng Chris X
• Guo Jianhua
• Zhou Bo
• Qiao Shijun
• Zhang Chuang
• Wang Xu
• Ma Chi
• Yang Xiongwen

Classifications

• E21B10/5673 Primary

  having a non planar or non circular cutting face · CPC title

• E21B10/43

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

• E21B10/58 Primary

  Chisel-type inserts ({E21B10/485,} E21B10/52 take precedence) · CPC title

• E21B10/54 Primary

  the bit being of the rotary drag type, e.g. fork-type bits · CPC title

• E21B10/56

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