Producing Drill Bits Using Catalyst-free PDC Cutters

Abstract

Cutters for a downhole drill bit can be formed by providing a catalyst-free synthesized polycrystalline diamond (PCD) having a cross-sectional dimension of at least 8 millimeters; providing a substrate comprising tungsten carbide; and attaching the synthesized PCD to the substrate comprising tungsten carbide to form a PDC cutter.

What is claimed is: 
     
         1 . A method of forming a drill bit, the method comprising:
 forming a plurality of cutters, each cutter comprising a catalyst-free synthesized polycrystalline diamond attached to a carbide substrate; and   attaching the plurality of cutters to a body of the drill bit.   
     
     
         2 . The method of  claim 1 , wherein attaching the plurality of cutters to the body of the drill bit comprises brazing the plurality of cutters to the body of the drill bit at more than 750° C. 
     
     
         3 . The method of  claim 1 , wherein forming the catalyst-free synthesized polycrystalline diamond comprises applying a pressure of at least 14 GPa during processing of the catalyst-free synthesized polycrystalline diamond. 
     
     
         4 . The method of  claim 3 , wherein the catalyst-free synthesized polycrystalline diamond is processed to a temperature of at least 1900° C. during processing of the catalyst-free synthesized polycrystalline diamond. 
     
     
         5 . The method of  claim 4 , wherein the catalyst-free synthesized polycrystalline diamond has a diameter of at least 8 mm. 
     
     
         6 . The method of  claim 5 , wherein the catalyst-free synthesized polycrystalline diamond has a diamond table thickness of at least 1 mm. 
     
     
         7 . The method of  claim 6 , wherein the catalyst-free synthesized polycrystalline diamond has a planar end surface. 
     
     
         8 . The method of  claim 6 , wherein the catalyst-free synthesized polycrystalline diamond has a non-planar end surface. 
     
     
         9 . The method of  claim 8 , wherein the catalyst-free synthesized polycrystalline diamond has a conical end surface. 
     
     
         10 . The method of  claim 1 , wherein forming a plurality of cutters comprises:
 providing a substrate comprising tungsten carbide; and   attaching the catalyst-free synthesized PCD to the substrate comprising tungsten carbide to form a PDC cutter.   
     
     
         11 . A drill bit comprising:
 a plurality of cutters attached to a body of the drill bit, each cutter comprising a catalyst-free synthesized polycrystalline diamond attached to a carbide substrate.   
     
     
         12 . The drill bit of  claim 11 , wherein the plurality of cutters are attached to the body of the drill bit through a process comprising brazing the plurality of cutters to the body of the drill bit at more than 750° C. 
     
     
         13 . The drill bit of  claim 11 , wherein the catalyst-free synthesized polycrystalline diamond has a pressure of at least 14 GPa applied during processing of the catalyst-free synthesized polycrystalline diamond. 
     
     
         14 . The drill bit of  claim 13 , wherein the catalyst-free synthesized polycrystalline diamond has a temperature of at least 1900° C. applied during processing of the catalyst-free synthesized polycrystalline diamond. 
     
     
         15 . The drill bit of  claim 14 , wherein the catalyst-free synthesized polycrystalline diamond has a diameter of at least 8 mm. 
     
     
         16 . The drill bit of  claim 15 , wherein the catalyst-free synthesized polycrystalline diamond has a diamond table thickness of at least 1 mm. 
     
     
         17 . The drill bit of  claim 16 , wherein the catalyst-free synthesized polycrystalline diamond has a planar end surface. 
     
     
         18 . The drill bit of  claim 16 , wherein the catalyst-free synthesized polycrystalline diamond has a non-planar end surface. 
     
     
         19 . The drill bit of  claim 18 , wherein the catalyst-free synthesized polycrystalline diamond has a conical end surface. 
     
     
         20 . The drill bit of  claim 11 , wherein the carbide substrate comprises tungsten carbide.