Fabrication of downhole drilling tools

Patent metadata

Field	Value
Publication number	US-12024470-B2
Application number	US-202117170006-A
Country	US
Kind code	B2
Filing date	Feb 8, 2021
Priority date	Feb 8, 2021
Publication date	Jul 2, 2024
Grant date	Jul 2, 2024

Abstract

A method of forming a composite cutter for a downhole drilling tool is described. The method includes: mixing a polycrystalline diamond powder and a cubic boron nitride powder with a molar ratio between 0.1 and 0.9 to form a catalyst-free composite mixture; placing the catalyst-free composite mixture into a mold configured in a shape of a cutter; exposing the catalyst-free composite mixture to an ultra-high-pressure, high-temperature treatment including a pressure between 11 Gigapascals (GPa) and 20 GPa, and a temperature between 1300 Kelvins (K) and 2600 K to form a solid composite body; and cooling the solid composite body to form the composite cutter.

First claim

What is claimed is:

1. A method of forming a composite cutter for a downhole drilling tool, the method comprising:
mixing a polycrystalline diamond powder and a cubic boron nitride powder with a molar ratio between 0.1 and 0.9 to form a catalyst-free composite mixture;
placing the catalyst-free composite mixture into a mold configured in a shape of a cutter;
exposing the catalyst-free composite mixture to an ultra-high-pressure, high-temperature treatment comprising a pressure between 11 Gigapascals (GPa) and 20 GPa, and a temperature between 1300 Kelvins (K) and 2600 K to form a solid composite body; and
cooling the solid composite body to form the composite cutter having a hardness greater than 70 GPa, wherein cooling the solid composite body includes between 2 and 10 hours of decompression.

2. The method of claim 1 , wherein providing the catalyst-free synthesized composite mixture comprises the polycrystalline diamond powder and the cubic boron nitride powder with a characteristic grain size between 0.1 and 50 μm.

3. The method of claim 1 , further comprising drying the catalyst-free synthesized composite mixture in a vacuum furnace at a temperature between 1100 K and 1350 K for a duration between 1 hour and 2 hours.

4. The method of claim 1 , wherein the ultra-high-pressure, high-temperature treatment comprises between 1 minute and 10 minutes.

5. The method of claim 1 , wherein sintering comprises forming a strong covalent bonding using the cubic boron nitride powder.

6. The method of claim 5 , wherein the cubic boron nitride powder acts as a binder.

7. The method of claim 1 , further comprises forming new chemical bonds at or near the diamond and cBN grain boundaries of the diamond-cBN composite.

8. The method of claim 7 , wherein forming the new chemical bonds include B—C and C—N.

9. The method of claim 1 , wherein the drilling tool comprises a PDC drill bit, a reamer, a hole opener, a milling tool, or a stabilizer.

10. The method of claim 1 , wherein the composite cutter has an onset oxidation temperature greater than 1070 K.

Assignees

• Saudi Arabian Oil Co
• Chengdu Dongwei Tech Co Ltd

Inventors

• Zhan Guodong
• Xu Jianhui
• He Duanwei
• Alshaikh Abrar

Classifications

• C04B2235/386

  Boron nitrides · CPC title

• C04B2235/786

  Micrometer sized grains, i.e. from 1 to 100 micron · CPC title

• C04B2235/785

  Submicron sized grains, i.e. from 0,1 to 1 micron · CPC title

• C04B2235/6567

  Treatment time · CPC title

• C04B2235/604

  Pressing at temperatures other than sintering temperatures · CPC title