Cutting Elements with Reduced Variable Back Rake Angle

Patent metadata

Field	Value
Publication number	US-2021370419-A1
Application number	US-202117331358-A
Country	US
Kind code	A1
Filing date	May 26, 2021
Priority date	May 27, 2020
Publication date	Dec 2, 2021
Grant date	—

Abstract

A drill bit for cutting formation comprises a bit body, a plurality of cutters, and a plurality of blades with pockets to accommodate the cutters, respectively. In an embodiment, the plurality of cutters comprise a substrate, an ultra-hard layer, a concave surface on the top of the ultra-hard layer, wherein the concave surface comprises a plurality of planar and curved surfaces.

First claim

What is claimed is:

1 . A cutter comprising
a substrate; an ultra-hard layer; and a concave surface on top of the ultra-hard layer; and wherein the concave surface comprises a plurality of planar and curved surfaces.

2 . The cutter of claim 1 , further comprising a chamfer extending from a periphery of the concave surface to a cutting edge at a side wall of the ultra-hard layer.

3 . The cutter of claim 1 , wherein the concave surface comprises a first flat surface, a second flat surface, a curved surface and a third flat surface arranged radially in order from a cutting point to an opposite edge of the cutting point around a periphery of the concave surface.

4 . The cutter of claim 3 , wherein the first flat surface has a tilted angle α, the second flat surface has a tilted angle β, and angle β is larger than angle α.

5 . The cutter of claim 4 , wherein the third flat surface is parallel to a bottom surface of the cutter or has a tilted angle γ.

6 . The cutter of claim 1 , wherein the concave surface comprises a cutting ridge extending from a cutting point to an opposite edge of a cutting point around a periphery of the concave surface.

7 . The cutter of claim 6 , wherein the concave surface comprises a first slanted surface, a curved surface, and a second slanted surface arranged in order along the cutting ridge.

8 . The cutter of claim 7 , wherein the first slanted surface, the curved surface, and the second slanted surface are slanted downward from the cutting ridge to the periphery of the curved surface along a perpendicular direction with respect to the cutting ridge.

9 . The cutter of claim 1 , wherein the concave surface comprises a first flat surface, a first curved surface, a second curved surface, and a second flat surface arranged in order from a cutting point to an opposite edge of the cutting point around a periphery of the concave surface.

10 . The cutter of claim 1 , wherein the concave surface comprises a first flat surface, a spline surface, and a second flat surface arranged in order from a cutting point to an opposite edge of the cutting point around a periphery of the concave surface.

11 . The cutter of claim 1 , wherein the concave surface comprises a spline surface, a curved surface, and a flat surface arranged in order from a cutting point to an opposite edge of the cutting point around a periphery of the concave surface.

12 . The cutter of claim 1 , wherein the concave surface comprises a slant surface, a curved surface, and a spline surface in order from a cutting point to an opposite edge of the cutting point around a periphery of the concave surface.

13 . The cutter of claim 12 , wherein the slant surface, the curved surface, and the spline surface are slanted downward from a cutting ridge to the periphery of the curved surface along a perpendicular direction with respect to the cutting ridge.

14 . The cutter of claim 1 , wherein the ultra-hard layer comprises two cutting points on opposite sides around a periphery of the concave surface, where the concave surface comprises a first flat surface and a second flat surface on two sides of the cutting points, a third flat surface at the center of the concave surface, and a curved surface between the first flat surface and the second flat surface and the flat surface at the center of the concave surface.

15 . The cutter of claim 14 , wherein the first flat surface and the second flat surface are slanted downwards to the periphery of the concave surface.

16 . The cutter of claim 1 , wherein the ultra-hard layer comprises two cutting points on opposite sides around a periphery of the concave surface, where the concave surface comprises a first undulating surface, a second undulating surface, and a third undulating surface arranged along a cutting ridge connecting the first cutting point and the second cutting point.

17 . The cutter of claim 16 , wherein the first undulating surface, the second undulating surface, and the third undulating surface are propagating downward from the cutting ridge to the periphery of the curved surface along perpendicular directions with respect to the cutting ridge.

18 . The cutter of claim 1 , wherein the ultra-hard layer is formed of polycrystalline diamond, cubic boron nitride, or other ultra-hard materials.

19 . The cutter of claim 1 , wherein the concave surface is machined by electrical discharge machining methods, machined by laser processing, machined by grinding, machined by other material reduction methods, or net shaped from a sintering process.

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

Assignees

• Cnpc Usa Corp
• Beijing Huamei Inc

Inventors

• Yu Jiaqing
• Cheng Chris
• Li Ning
• He David
• Waddell Kevin
• Wang Xu
• Ma Chi
• Yang Xiongwen

Classifications

• B23C5/202 Primary

  Plate-like cutting inserts with special form (special form related to securing of the insert B23C5/22) · CPC title

• E21B10/60

  characterised by conduits or nozzles for drilling fluids (for roller bits E21B10/18; for percussion drill bits E21B10/38) · CPC title

• E21B10/54

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

• E21B10/43 Primary

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

• E21B10/5673

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