Superhard gouging cutter or shock stud for fixed cutter drill bit

Abstract

A gouging cutter or shock stud for mounting in a drill bit includes: a substrate being cylindrical for at least a portion thereof; and a cap or head made from a superhard material, mounted to the substrate at an interface, having a working face formed in an end thereof opposite to the interface, and having a round periphery connecting the interface and the substrate. The working face has a central tip elevated at a height above a maximum height of the periphery. The working face has a plurality of plows and a plurality of ribs arranged therearound in an alternating fashion. The plows and the ribs each extend from the periphery of the cap inward and upward to the tip. The plows and ribs each have a pair of sides and an apical edge. The plows have a different shape than a shape of the ribs.

1 . A gouging cutter or shock stud for mounting in a drill bit, comprising:
 a substrate being cylindrical for at least a portion thereof; and   a cap or head made from a superhard material, mounted to the substrate at an interface, having a working face formed in an end thereof opposite to the interface, and having a round periphery connecting the interface and the substrate,   wherein:
 the working face has a central tip elevated at a height above a maximum height of the periphery, 
 the working face has a plurality of plows and a plurality of ribs arranged therearound in an alternating fashion, 
 the plows and the ribs each extend from the periphery of the cap inward and upward to the tip, 
 the plows and ribs each have a pair of sides and an apical edge, and 
 the plows have a different shape than a shape of the ribs. 
   
     
     
         2 . The gouging cutter or shock stud of  claim 1 , wherein, at the periphery, a height of each rib apical edge is greater than a height of each plow apical edge and a circumferential width of each rib is greater than a circumferential width of each plow. 
     
     
         3 . The gouging cutter or shock stud of  claim 1 , wherein the rib sides converge from the periphery toward the rib apical edge at a junction located between the periphery and the tip. 
     
     
         4 . The gouging cutter or shock stud of  claim 2 , wherein:
 the rib apical edges extend from the periphery to the junction with a constant shape and a constant slope, and   the rib apical edges radially converge and extend with an exponential slope from the junction to the tip.   
     
     
         5 . The gouging cutter or shock stud of  claim 1 , wherein the plows have a sinusoidal shape and the ribs have a triangular shape. 
     
     
         6 . The gouging cutter or shock stud of  claim 1 , wherein:
 the tip is flat and has a round-rectangular shape,   the plow apical edges terminate at round corners of the tip,   the plow sides and the rib apical edges terminate at sides of the tip.   
     
     
         7 . The gouging cutter or shock stud of  claim 1 , wherein the cap or head is a cap made from a polycrystalline superhard material and the interface is non-planar. 
     
     
         8 . The gouging cutter or shock stud of  claim 1 , wherein the cap or head is a head made from a cermet impregnated with superhard material and the interface is planar. 
     
     
         9 . 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; 
 a leading cutter comprising:
 a substrate mounted in a pocket formed in a leading edge of the blade; and 
 a cutting table made from a superhard material and mounted to the substrate; and 
 
 the gouging cutter or shock stud of  claim 1  mounted in a pocket formed in the bearing face of the blade. 
   
     
     
         10 . The bit of  claim 9 , wherein an orientation guide is formed in the bearing face adjacent to the pocket. 
     
     
         11 . The bit of  claim 9 , wherein the gouging cutter or shock stud is back raked or forward raked at an angle ranging between 1 degree and 10 degrees. 
     
     
         12 . The bit of  claim 9 , wherein the gouging cutter or shock stud has an exposure equal to or less than an exposure of the leading cutter. 
     
     
         13 . The bit of  claim 9 , wherein the gouging cutter or shock stud is aligned with the leading cutter. 
     
     
         14 . The bit of  claim 9 , wherein:
 the cutting face has a plurality of leading cutters mounted in respective pockets formed along the leading edge of the blade, and   the gouging cutter or shock stud is located at an interruptive position between a pair of the leading cutters.   
     
     
         15 . The bit of  claim 9 , wherein:
 the cutting face has an inner cone section, an outer shoulder section, and an intermediate nose section, and   the cutting face has a plurality of gouging cutter or shock studs mounted in respective pockets formed in the bearing face of the blade along the nose and shoulder sections.   
     
     
         16 . The bit of  claim 9 , wherein:
 the cutting face has an inner cone section, an outer shoulder section, and an intermediate nose section, and   the cutting face has a plurality of gouging cutter or shock studs mounted in respective pockets formed in the bearing face of the blade along the cone, nose, and shoulder sections.   
     
     
         17 . The bit of  claim 9 , wherein:
 the cutting face has an inner cone section, an outer shoulder section, and an intermediate nose section, and   the cutting face has a plurality of gouging cutter or shock studs mounted in respective pockets formed in the bearing face of the blade along the nose section.   
     
     
         18 . 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 gouging cutter or shock stud of  claim 1  mounted in a pocket formed in a leading edge of the blade. 
   
     
     
         19 . A gouging cutter or shock stud for mounting in a drill bit, comprising:
 a cylindrical substrate; and   a head made from a superhard material, mounted to the substrate at an interface, and having a working face formed in an end thereof opposite to the interface,   wherein:
 the working face has a central tip having a maximum height of the working face above the substrate, 
 a plurality of pads and a plurality of slots are arranged around the head in an alternating fashion, 
 the pads each extend from a periphery of the substrate inward and upward to the tip, 
 the working face has protruding borders formed between the pads, 
 the slots each extend from the periphery inward, and 
 each border extends from an inner end of the respective slot to the central tip. 
   
     
     
         20 . The gouging cutter or shock stud of  claim 19 , wherein the slots each expose an upper face of the substrate.