Superhard cutter with spikes

Abstract

A cutter for use with a drill bit includes: a substrate for mounting in a pocket of the drill bit and made from a cermet material; and a cutting table made from a polycrystalline superhard material, mounted to the substrate, and including a set of spikes formed along at least a portion of a side of the cutting table. Each spike has an apical edge extending above a working face of the cutting table and converging toward the working face as the spike extends from the side of the cutting table across at least a portion of the working face. Each spike has a pair of base edges converging toward the apical edge as the spike extends from the side of the cutting table thereacross, thereby forming a progressively wider gap between adjacent spikes.

1 . A cutter for use with a drill bit, comprising:
 a substrate for mounting in a pocket of the drill bit and made from a cermet material; and   a cutting table made from a polycrystalline superhard material, mounted to the substrate, and comprising a set of spikes formed along at least a portion of a side of the cutting table,   wherein:
 each spike has an apical edge extending above a working face of the cutting table and converging toward the working face as the spike extends from the side of the cutting table across at least a portion of the working face, and 
 each spike has a pair of base edges converging toward the apical edge as the spike extends from the side of the cutting table thereacross, thereby forming a progressively wider gap between adjacent spikes. 
   
     
     
         2 . The cutter of  claim 1 , wherein:
 the set further comprises a plurality of channels formed in the side of the cutting table,   each channel is formed between adjacent spikes, and   a width of each channel is sized to induce capillary action of leaching acid.   
     
     
         3 . The cutter of  claim 2 , wherein a floor of each channel converges toward the working face as the channel extends from the side of the cutting table thereacross. 
     
     
         4 . The cutter of  claim 3 , wherein a maximum depth of the channels varies along the set. 
     
     
         5 . The cutter of  claim 4 , wherein a deepest one or more of the channels is located at a center of the set and shallowest ones of the channels are located at the periphery of the set. 
     
     
         6 . The cutter of  claim 1 , wherein each apical edge is parallel with the rest of the apical edges of the set. 
     
     
         7 . The cutter of  claim 1 , wherein the set extends across the working face by a distance ranging between one-eighth and one-half of a diameter of the working face. 
     
     
         8 . The cutter of  claim 1 , wherein a maximum height of the spikes varies along the set. 
     
     
         9 . The cutter of  claim 8 , wherein a tallest one or more of the spikes is located at a center of the set and shortest ones of the spikes are located at the periphery of the set. 
     
     
         10 . The cutter of  claim 8 , wherein a tallest one or more of the spikes has a height ranging between one-half and three millimeters. 
     
     
         11 . The cutter of  claim 1 , wherein the set of spikes extends along the side for a distance ranging between one-quarter to one-half of a circumference of the side. 
     
     
         12 . The cutter of  claim 11 , wherein the substrate has a keyway formed in an edge thereof for orienting the set of spikes. 
     
     
         13 . The cutter of  claim 11 , wherein the substrate has a bump formed in or mounted to a back face thereof for orienting the set of spikes. 
     
     
         14 . The cutter of  claim 11 , wherein the cutting table further comprises a second set of spikes formed along a second portion of the side of the cutting table. 
     
     
         15 . The cutter of  claim 1 , wherein:
 the set further comprises a plurality of leaching passages, and   each leaching passage extends underneath a respective spike.   
     
     
         16 . The cutter of  claim 15 , wherein each leaching passage has a front port at the working face of the cutting table and a side port at the side of the cutting table. 
     
     
         17 . The method of  claim 16 , wherein a depth of each side port corresponds to a height of one of the spikes. 
     
     
         18 . The cutter of  claim 15 , wherein a diameter of each leaching passage ranges between 0.01 mm and 1 mm. 
     
     
         19 . The method of  claim 15 , wherein an inclination angle of each leaching passage relative to the working surface of the cutting table ranges between 5 degrees and 45 degrees. 
     
     
         20 . A bit for drilling a wellbore, comprising:
 a shank having a coupling formed at an upper end thereof;   a body mounted to a lower end of the shank; and   a cutting face forming a lower end of the bit and comprising:
 a blade protruding from the body; and 
 the cutter of  claim 1 , 
   wherein:
 the substrate is mounted in the pocket formed in the blade at a back rake angle, and 
 an inclination angle of each apical edge corresponds to the back rake angle such that the interface is perpendicular or substantially perpendicular to a rock formation engaged by the spikes during drilling.