Fixed cutter drill bit having spherical cutter orienting system

Abstract

A bit for drilling a wellbore includes: 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. The cutting face includes: a blade protruding from the body; a cutter including: a substrate mounted in a pocket formed in the blade; and a cutting table made from a superhard material, mounted to the substrate, and having a non-planar working face with a cutting feature; and a cutter orienting system (COS). The COS includes a knob mounted to or formed on a back face of the substrate; and a dimple formed in a back wall of the pocket and engaged with the knob. The dimple and the knob are positioned relative to the cutting feature to orient the cutting feature to an operative position.

1 . 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 cutter comprising:
 a substrate mounted in a pocket formed in the blade; and 
 a cutting table made from a superhard material, mounted to the substrate, and having a non-planar working face with a cutting feature; and 
 
 a cutter orienting system, comprising:
 a knob mounted to or formed on a back face of the substrate; and 
 a dimple formed in a back wall of the pocket and engaged with the knob, 
 wherein the dimple and the knob are positioned relative to the cutting feature to orient the cutting feature to an operative position. 
 
   
     
     
         2 . The bit of  claim 1 , wherein:
 the cutting feature is a protruding ridge,   the working face has a plurality of protruding ridges spaced therearound,   the cutter orienting system comprises a knob and a dimple for each ridge,   the knobs are spaced around the back face of the substrate, and   each knob is angularly located opposite from the respective ridge.   
     
     
         3 . The bit of  claim 1 , wherein:
 the working face is concave, and   the cutting feature is an axis of the cutting table.   
     
     
         4 . The bit of  claim 1 , wherein the cutting feature is an operative portion of a protruding ridge. 
     
     
         5 . The bit of  claim 1 , wherein the knob is hemi-spherical. 
     
     
         6 . The bit of  claim 5 , wherein a diameter of the knob ranges between 25 percent and 75 percent of a diameter of the back face of the substrate. 
     
     
         7 . The bit of  claim 5 , wherein the dimple is hemi-spherical. 
     
     
         8 . The bit of  claim 1 , wherein:
 the knob is mounted to the back face of the substrate by a first braze material,   the cutter is mounted in the pocket by a second braze material, and   a liquidus temperature of the first braze material is greater than a liquidus temperature of the second braze material.   
     
     
         9 . The bit of  claim 8 , wherein the knob is made from a different material than the substrate. 
     
     
         10 . The bit of  claim 1 , wherein:
 the pocket is formed in a leading edge of the blade, and   the operative position is such that the cutting feature is perpendicular to a projection of the leading edge through the pocket.   
     
     
         11 . The bit of  claim 1 , wherein:
 the bit further comprises a gage section forming an outer portion of the bit, and   the blade extends from a center of the cutting face to the gage section.