Recessed extended nozzles for drill bits and drill bits so equipped

Abstract

A nozzle includes a nozzle body having an extended, tubular nozzle protrusion terminating at a nozzle exit, the nozzle body having an annular shoulder surrounding a base of the nozzle protrusion. A passage extends through the nozzle body, necking down in cross-sectional area before entering the nozzle protrusion and distally terminating at a nozzle exit, where drilling mud is discharged. A nozzle configured as described is disposed in a nozzle recess of a bit body of a rotary drag bit, the nozzle recess being of sufficient depth to receive the nozzle and recess the annular shoulder of the nozzle body a substantial distance from the bit face. A snap-ring is received in an annular groove in the wall of the nozzle recess and extends inwardly over the annular shoulder of the nozzle body. The nozzle protrusion exit extends to a location proximate the bit face.

1 . A nozzle for a drill bit for drilling subterranean formations, the nozzle comprising:
 a substantially cylindrical nozzle body comprising a tubular protrusion extending from one end thereof, the tubular protrusion surrounded at a base thereof by an annular shoulder; and   a passage extending longitudinally through the nozzle body from an end thereof opposite the one end to a nozzle exit at a distal end of the protrusion.   
   
   
       2 . The nozzle of  claim 1 , wherein the passage extends from an entry bore at an end of the nozzle body opposite the one end and reduces in cross-sectional area to an exit bore extending through the tubular protrusion to the nozzle exit. 
   
   
       3 . The nozzle of  claim 1 , wherein the nozzle body comprises tungsten carbide. 
   
   
       4 . A rotary drill bit for drilling subterranean formations, comprising:
 a bit body having a face and including at least one nozzle recess opening onto the face, the nozzle recess having an annular groove in a wall thereof;   a nozzle disposed in the at least one nozzle recess, the nozzle comprising:
 a substantially cylindrical nozzle body comprising a tubular protrusion extending from one end thereof, the tubular protrusion surrounded at a base thereof by an annular shoulder; and 
 a passage extending longitudinally through the nozzle body from an end thereof opposite the one end to a nozzle exit at a distal end of the protrusion; and 
   a retention element disposed partially within the annular groove and extending over at least a portion of the annular shoulder.   
   
   
       5 . The rotary drill bit of  claim 4 , wherein the retention element comprises a snap-ring. 
   
   
       6 . The rotary drill bit of  claim 4 , further including:
 another annular groove in the wall of the nozzle recess located inwardly of the annular groove; and   a resilient annular seal disposed substantially within the another annular groove and compressed against an outer surface of the nozzle body.   
   
   
       7 . The rotary drill bit of  claim 4 , wherein the passage extends from an entry bore at an end of the nozzle body opposite the one end and reduces in cross-sectional area to an exit bore extending through the tubular protrusion to the nozzle exit. 
   
   
       8 . The rotary drill bit of  claim 4 , wherein the nozzle exit is located proximate the bit body face. 
   
   
       9 . The rotary drill bit of  claim 4 , wherein the nozzle body comprises tungsten carbide. 
   
   
       10 . The rotary drill bit of  claim 4 , wherein the rotary drill bit is configured as a drag bit. 
   
   
       11 . The rotary drill bit of  claim 4 , wherein the annular groove is located at least about one-half inch from the bit body face. 
   
   
       12 . The rotary drill bit of  claim 14 , wherein the nozzle recess comprises an annular seat at an inner end thereof, and the nozzle body is secured between the annular seat and the retention element. 
   
   
       13 . A rotary drag bit for drilling subterranean formations, comprising:
 a bit body having a face and including at least one nozzle recess opening onto the face;   a nozzle disposed in the at least one nozzle recess, the nozzle comprising:
 a substantially cylindrical nozzle body comprising a tubular protrusion extending from one end thereof and terminating distally at a nozzle exit, the tubular protrusion surrounded at a base thereof by an annular shoulder; 
   wherein the annular shoulder is located within the nozzle recess at least about one-half inch from a surface of the bit face surrounding the nozzle recess; and   wherein the nozzle exit is located immediately proximate the surface.   
   
   
       14 . The rotary drag bit of  claim 13 , wherein the nozzle recess includes an annular groove therein proximate the annular shoulder, and further comprising a retention element disposed partially within the annular groove and extending over at least a portion of the annular shoulder. 
   
   
       15 . The rotary drill bit of  claim 14 , wherein the nozzle recess comprises an annular seat at an inner end thereof, and the nozzle body is secured between the annular seat and the retention element.