Reduced length and low cobalt content cutters and drill bit made therewith

Abstract

A cutter for a fixed cutter drill bit includes a substrate and a cutting material surface affixed to one end of the substrate. The substrate comprises tungsten carbide having at least six percent by weight and at most ten percent by weight of cobalt. An overall length of the cutter is at most 10 millimeters. In one embodiment an overall length of the cutter is at most 8 millimeters.

What is claimed is: 
     
         1 . A cutter for a fixed cutter drill bit comprising:
 a substrate; and   a cutting material surface affixed to one end of the substrate, wherein the substrate comprises tungsten carbide having at least six percent by weight and at most ten percent by weight of cobalt, and wherein an overall length of the cutter is at most 10 millimeters.   
     
     
         2 . The cutter of  claim 1  wherein the cutting material surface comprises at least one of polycrystalline diamond and cubic boron nitride. 
     
     
         3 . The cutter of  claim 1  wherein a length of the substrate is about eight millimeters. 
     
     
         4 . The cutter of  claim 1  wherein an overall length of the cutter is at most 8 millimeters. 
     
     
         5 . The cutter of  claim 4  wherein a length of the substrate is about 6 millimeters. 
     
     
         6 . The cutter of  claim 1  wherein the cutter is a primary cutter disposed on a drill bit body radially outside a cone of the bit and radially inside a gage of the bit. 
     
     
         7 . A fixed cutter drill bit comprising:
 a bit body; and   a plurality of cutters affixed to the bit body, each of the cutters comprising a substrate and a cutting material surface affixed to one end of the substrate, wherein the substrate comprises tungsten carbide having at least six percent by weight and at most ten percent by weight of cobalt, and wherein an overall length of each cutter is at most 10 millimeters.   
     
     
         8 . The bit of  claim 7  wherein the bit body comprises a plurality of blades. 
     
     
         9 . The bit of  claim 7  wherein the cutting material surface of each cutter comprises at least one of polycrystalline diamond and cubic boron nitride. 
     
     
         10 . The bit of  claim 7  wherein an overall length of each of the plurality of cutters is at most 10 millimeters. 
     
     
         11 . The bit of  claim 10  wherein a length of the substrate of each of the plurality of cutters is about eight millimeters. 
     
     
         12 . The bit of  claim 7  wherein an overall length of each of the plurality of cutters is at most 8 millimeters. 
     
     
         13 . The bit of  claim 11  wherein a length of the substrate of each cutter is about 6 millimeters. 
     
     
         14 . The bit of  claim 7  wherein each of the plurality of cutters is a primary cutter disposed on a drill bit body radially outside a cone of the bit and radially inside a gage of the bit.