Coated diamonds for use in impregnated diamond bits

Abstract

An insert for an impreg bit that includes coated diamond particles disposed in a matrix material, wherein the coated diamond particles include a boride, a nitride, and a carbide of a group IVA, VA, VI transition metal or silicon disposed on synthetic, natural, TSP diamonds, or combinations thereof is disclosed. A method of forming a diamond-impregnated insert, including coating a plurality of diamond particles with a coating formed from a boride, a nitride, and a carbide of a group IVA, VA, VI transition metal or silicon or mixtures thereof, and forming a diamond impregnated insert body is also disclosed.

1 . An insert for a impreg drill bit comprising: 
 coated diamond particles disposed in a matrix material, wherein the coated diamond particles comprise at least one compound selected from a boride, a nitride, and a carbide of a group IVA, VA, VI transition metal or silicon disposed on synthetic, natural, TSP diamonds, or combinations thereof.    
     
     
         2 . The insert of  claim 1 , wherein the coated diamond particles are coated prior to formation of the insert.  
     
     
         3 . The insert of  claim 1 , wherein the matrix material comprises at least one material selected from tungsten carbide, tungsten alloy, tungsten carbide in combination with elemental tungsten, tungsten alloy in combination with elemental tungsten, titanium-based compounds, and nitrides.  
     
     
         4 . The insert of  claim 1 , wherein the diamonds are coated with at least one of titanium carbide and silicon carbide.  
     
     
         5 . An impreg drill bit comprising: 
 a bit body; and    a plurality of ribs formed in the bit body and at least in part from a matrix material infiltrated with a binder alloy, the ribs being infiltrated with a plurality of abrasive particles, at least a portion of the abrasive particles being coated diamond particles, wherein the coated diamond particles comprise at least one compound selected from a boride, a nitride, and a carbide of a group IVA, VA, VI transition metal or silicon disposed on synthetic, natural, TSP diamonds, or combinations thereof.    
     
     
         6 . The drill bit of  claim 5 , wherein the bit body comprises said coated diamond particles.  
     
     
         7 . An impreg drill bit, comprising: 
 a bit body; and    a plurality of inserts affixed to said bit body, at least one of said plurality of inserts comprising coated diamond particles disposed in a matrix material, wherein the coated diamond particles comprise at least one compound selected from a boride, a nitride, and a carbide of a group IVA, VA, VI transition metal or silicon disposed on synthetic, natural, TSP diamonds, or combinations thereof.    
     
     
         8 . The drill bit of  claim 7 , wherein the bit body comprises said coated diamond particles.  
     
     
         9 . A method of forming a diamond-impregnated insert, comprising: 
 coating a plurality of diamond particles with a coating comprising at least one compound selected from a boride, a nitride, and a carbide of a group IVA, VA, VI transition metal or silicon; and    forming a diamond impregnated insert body using the coated diamond particles and a matrix material.    
     
     
         10 . The method of  claim 9 , wherein the forming the diamond impregnated insert body uses a mold having at least one hole, and at least one upper plunger.  
     
     
         11 . The method of  claim 10 , wherein the matrix material is selected from tungsten carbide, tungsten alloy, tungsten carbide in combination with elemental tungsten, tungsten alloy in combination with elemental tungsten, titanium-based compounds, and nitrides.  
     
     
         12 . The method of  claim 11 , wherein the forming the diamond impregnated insert body is performed at a temperature of at least 1500° F. and at greatest 2200° F.  
     
     
         13 . The method of  claim 12 , wherein the forming the diamond impregnated insert body is performed at a temperature of at least 1800° F. and at greatest 2100° F.  
     
     
         14 . The method of  claim 9 , wherein the diamond impregnated insert body is formed using a high pressure, high temperature process.  
     
     
         15 . The method of  claim 9 , wherein the diamond impregnated insert body is formed using hot isostatic pressing.  
     
     
         16 . A method of forming a diamond-impregnated bit, comprising: 
 coating a plurality of diamond particles with a coating comprising at least one compound selected from a boride, a nitride, and a carbide of a group IVA, VA, VI transition metal or silicon; and    forming a diamond impregnated bit using the coated diamond particles and a matrix material.    
     
     
         17 . The method of  claim 16 , wherein at least one diamond-impregnated insert is affixed to a bit body.  
     
     
         18 . The method of  claim 16 , wherein the forming the diamond impregnated insert uses a mold having at least one hole, and at least one upper plunger.  
     
     
         19 . The method of  claim 16 , wherein the matrix material is selected from tungsten carbide, tungsten alloy, tungsten carbide in combination with elemental tungsten, tungsten alloy in combination with an elemental tungsten, titanium-based compounds, and nitrides.  
     
     
         20 . The method of  claim 16 , wherein the forming the diamond impregnated insert bit is performed at a temperature of at least 1500° F. and at greatest 2200° F.  
     
     
         21 . The method of  claim 16 , wherein the forming the diamond impregnated insert bit is performed at a temperature of at least 1800° F. and at greatest 2100° F.  
     
     
         22 . A method of drilling a formation comprising: 
 contacting an impreg bit with the formation, wherein the impreg bit comprises a bit body; and    a plurality of inserts affixed to said bit body, at least one of said plurality of inserts comprising coated diamond particles disposed in a matrix material, wherein the coated diamond particles comprise at least one selected from a boride, a nitride, and a carbide of a group IVA, VA, VI transition metal or silicon disposed on synthetic, natural, TSP diamonds, or combinations thereof.