US Patent 8021721 - Superabrasive nanoparticles

http://www.freepatentsonline.com/8021721.html

This patent from Smith International teaches a form of diamond nanoparticles can be used to improve the life expectancy of drill bits used in oil drilling. Claim 1 reads:

1. A method of modifying a bottomhole assembly, comprising:

coating at least a portion of a bottomhole assembly with a metal plating;

wherein the metal plating comprises a base metal and clusters of superabrasive nanoparticles;

wherein the superabrasive nanoparticles have a particle size ranging from 0.1 to 100 nanometers; and

wherein the superabrasive nanoparticles comprise a diamond core and a non-diamond carbon-based coating on the diamond core;

wherein the carbon-based coating comprises an inner coating of graphite and an outer coating of amorphous carbon.