Bits and cutting structures

Abstract

A cutting element for a downhole cutting tool including a support element, a shearing element disposed on said support, wherein the shearing element is disposed proximal to a leading edge of the downhole cutting tool, and a retaining element overlaying at least a portion of said shearing element is disclosed.

1 . A cutting element for a downhole cutting tool, comprising: 
 a support element;    a shearing element disposed on said support, wherein the shearing element is disposed proximal to a leading edge of the downhole cutting tool; and    a retaining element overlaying at least a portion of said shearing element.    
     
     
         2 . The cutting element of  claim 1 , wherein said support element comprises thermally stable polycrystalline diamond.  
     
     
         3 . The cutting element of  claim 1 , wherein said retaining element is integral to the support element.  
     
     
         4 . The cutting element of  claim 1 , wherein said shearing element comprises at least one selected from the group of polycrystalline diamond, thermally stable polycrystalline diamond, and boron nitride.  
     
     
         5 . The cutting element of  claim 4 , wherein the shearing element is thermally stable polycrystalline diamond.  
     
     
         6 . The cutting element of  claim 5 , wherein said shearing element further comprises a coating.  
     
     
         7 . The cutting element of  claim 4 , wherein said coating comprises at least one selected from a titanium based coating, a tungsten based coating, and a nickel based coating.  
     
     
         8 . The cutting element of  claim 1 , wherein the support element comprises coated natural diamond.  
     
     
         9 . The cutting element of  claim 1 , wherein the cutting element is disposed on a reamer, stabilizer, or hole opener.  
     
     
         10 . The cutting element of  claim 1 , wherein the cutting element is disposed on a drill bit.  
     
     
         11 . A cutting element for a downhole cutting tool, comprising: 
 a support element;    a thermally stable polycrystalline diamond shearing element disposed on said support, wherein the thermally stable polycrystalline diamond shearing element is disposed proximal to a leading edge of the downhole cutting tool to provide substantially continuous thermally stable polycrystalline diamond exposure during drilling.    
     
     
         12 . The cutting element of  claim 10 , wherein the support element comprises diamond impregnated material.  
     
     
         13 . The cutting element of  claim 10 , further comprising a retaining element overlaying at least a portion of said shearing element.  
     
     
         14 . A hole opener comprising: 
 a tool body comprising upper and lower ends adapted to be coupled to adjacent drilling tools or pipe;    at least two blades formed on the tool body; and    a plurality of cutting elements, wherein the cutting elements comprise: 
 a support element;  
 a shearing element disposed on said support; and  
 a retaining element overlayed on at least a portion of said shearing element,  
   wherein the plurality of cutting elements are configured to increase a diameter of a previously drilled wellbore.    
     
     
         15 . The hole opener of  claim 13 , wherein said support element comprises thermally stable polycrystalline diamond.  
     
     
         16 . The hole opener of  claim 13 , wherein said shearing element comprises at least one selected from the group of polycrystalline diamond, thermally stable polycrystalline diamond, and boron nitride.  
     
     
         17 . The cutting element of  claim 13 , wherein said retaining element is integral to the support element.  
     
     
         18 . The hole opener of  claim 13 , wherein said shearing element further comprises a coating.  
     
     
         19 . The hole opener of  claim 18 , wherein said coating comprises at least one selected from a titanium based coating, a tungsten based coating, and a nickel based coating.  
     
     
         20 . A hole opener comprising: 
 a tool body comprising upper and lower ends adapted to be coupled to adjacent drilling tools;    at least two blades formed on the tool body; and    a plurality of cutting elements, wherein the cutting elements comprise: 
 a support element;  
 a thermally stable polycrystalline diamond shearing element disposed on said support, wherein the thermally stable polycrystalline diamond shearing element is disposed proximal to a leading edge of the downhole cutting tool to provide substantially continuous thermally stable polycrystalline diamond exposure during drilling,  
   
     
     
         21 . The hole opener of  claim 20 , wherein the support element comprises diamond impregnated material.  
     
     
         22 . The hole opener of  claim 20 , further comprising a retaining element overlaying at least a portion of said shearing element.  
     
     
         23 . A drill bit comprising: 
 a bit body having at least one support element;    a shearing element disposed on said support; and    a retaining element overlaying at least a portion of said shearing element.    
     
     
         24 . A drill bit comprising: 
 a bit body having at least one support element; and    a thermally stable polycrystalline diamond shearing element disposed on said support, wherein the thermally stable polycrystalline diamond shearing element is disposed proximal to a leading edge of the downhole cutting tool to provide substantially continuous thermally stable polycrystalline diamond exposure during drilling.    
     
     
         25 . A drill bit comprising: 
 a bit body having at least one support formed from a diamond impregnated material;    a thermally stable polycrystalline diamond shearing element disposed on said support; and    a retaining element overlaying at least a portion of said shearing element.    
     
     
         26 . A drill bit comprising: 
 a bit body having at least one blade thereon, wherein at least one insert is disposed on the at least one blade, wherein the insert comprises 
 a substrate; and  
 a diamond table disposed on said substrate; and  
   a shearing element disposed on the at least one blade, wherein the shearing element has a retaining element overlaying at least a portion of said shearing element.    
     
     
         27 . The drill bit of  claim 26 , wherein said support element comprises thermally stable polycrystalline diamond.  
     
     
         28 . The drill bit of  claim 26 , wherein said retaining element is integral to the diamond impregnated support.  
     
     
         29 . The drill bit of  claim 26 , wherein the at least one insert on the first blade is arranged to contact a formation prior to the shearing element on the second blade.  
     
     
         30 . A drill bit comprising: 
 a bit body having at least one blade thereon, wherein at least one insert is disposed on the at least one blade blade, wherein the insert comprises 
 a substrate; and  
 a diamond table disposed on said substrate; and  
   a thermally stable polycrystalline diamond shearing element disposed on the at least one blade, wherein the thermally stable polycrystalline diamond shearing element is disposed proximal to a leading edge of the downhole cutting tool to provide substantially continuous thermally stable polycrystalline diamond exposure during drilling.    
     
     
         31 . The drill bit of  claim 30 , wherein the at least one insert on the first blade is arranged to contact a formation prior to the shearing element on the second blade.  
     
     
         32 . A method of forming a cutting element, comprising: 
 forming a support element;    bonding a shearing element to the support element; and    providing a retaining element that overlays a portion of the shearing element.    
     
     
         33 . A cutting element for downhole applications, comprising: 
 a diamond impregnated support;    a thermally stable polycrystalline diamond shearing element disposed on said support, wherein the shearing element is arranged so that the thermally stable polycrystalline diamond is substantially the only material cutting the formation.