Adjustable Hydraulic Coupling For Drilling Tools And Related Methods

Abstract

An adjustable hydraulic coupling device allows simultaneously mounting of different parts of a downhole drilling tool to the drill string near its upper and lower extremities. This top- and bottom-mounting is made to points on the drill string separated by an indeterminate length. The coupling device allows a mechanical and sealed fluid connection between two portions of the tool, and allows assembling of both portions of the drilling tool into one functional unit, and allows both axial translation and rotational motion therebetween. A cylindrical protruding tube is attached to the portion of the drilling tool mounted at its upper extremity while a mating cylindrical tube is attached to the part of the drilling tool mounted near the bottom. During assembly, the smaller tube enters the larger tube and provides a sealed fluid path and also allows for the engagement length of the assembly to vary as required.

1 . A variable length hydraulic coupling for creating a flowpath for drilling fluid in a downhole tool, comprising:
 two hydraulic fitting ends;   a male coupling shaft; and   a female receiving tube;   said shaft and tube hydraulically coupling said ends creating a drilling fluid flowpath therebetween; and   said shaft and tube permitting rotation between said fitting ends during assembly of said downhole tool.   
     
     
         2 . The hydraulic coupling of  claim 1 , further comprising:
 said shaft and tube permitting axial translation between said fitting ends.   
     
     
         3 . The hydraulic coupling of  claim 1 , further comprising:
 said coupling having a longitudinal axis;   said shaft extending along said axis from a first of said hydraulic fitting ends; and   said tube extending along said axis from a second of said hydraulic fitting ends; and   said tube defining a receiver void aligned with said axis.   
     
     
         4 . The hydraulic coupling of  claim 3 , further comprising:
 said tube having a receiver end exposing said receiver void;   said coupling shaft and receiver void hydraulically coupling said fitting ends.   
     
     
         5 . The hydraulic coupling of  claim 3 , further comprising:
 a first portion of said receiver void having a substantially cylindrical shape in the longitudinal axis;   a second portion of said receiver void being chamfered to be larger away from said second hydraulic fitting.   
     
     
         6 . The hydraulic coupling of  claim 1 , further comprising:
 said shaft comprising an exterior shaft coupler;
 said exterior shaft coupler comprising one or more hydraulic seals and one or more radial bearings; 
   said shaft being slidably engageable with said tube along said exterior shaft coupler.   
     
     
         7 . A downhole tool, comprising:
 a variable length hydraulic coupling comprising
 two hydraulic fitting ends; 
 a male coupling shaft; and 
 a female receiving tube; 
 said shaft and tube hydraulically coupling said ends creating a drilling fluid flowpath therebetween; and 
 said shaft and tube permitting rotation between said fitting ends during assembly of said downhole tool; and 
   a first downhole telemetry device;
 said first telemetry device mechanically coupled to a first of said fitting ends. 
   
     
     
         8 . The downhole tool of  claim 7 , further comprising:
 said shaft and tube permitting axial translation between said fitting ends.   
     
     
         9 . The downhole tool of  claim 7 , further comprising:
 a second downhole telemetry device;   said second downhole telemetry device mechanically coupled to a second of said fitting ends.   
     
     
         10 . The downhole tool of  claim 9 , further comprising:
 said variable length hydraulic coupling hydraulically coupling said downhole telemetry devices.   
     
     
         11 . The downhole tool of  claim 9 , further comprising:
 said variable length hydraulic coupling permitting axial translation and rotation between said downhole telemetry devices during assembly of said drilling tool.   
     
     
         12 . The downhole tool of  claim 7 , further comprising:
 said first downhole telemetry device mounted to a first sub;   a second downhole telemetry device;
 said second downhole telemetry device mounted to a second sub; and 
   said variable length hydraulic coupling forming a hydraulic connection between said first downhole telemetry device and said second downhole telemetry device;   wherein the length of said variable length hydraulic coupling adjusts while said subs are translate axially relative to one another.   
     
     
         13 . The downhole tool of  claim 12 , further comprising:
 a non-magnetic drill collar;   wherein each of said subs is connected to an opposite end of said drill collar; and   said first downhole telemetry device comprises a main pulser valve.   
     
     
         14 . The downhole tool of  claim 12 , further comprising:
 a downhole tubular component connected at opposite ends thereof to said first and second subs.   
     
     
         15 . The downhole tool of  claim 7 , further comprising:
 a first hydraulic flowpath between a second of said fitting ends and said first downhole telemetry device; and   a downhole component containing said variable length hydraulic coupling;
 said downhole component and said variable length hydraulic coupling forming an annular space therebetween; and 
   said annular space forming a second hydraulic flowpath.   
     
     
         16 . The downhole tool of  claim 15 , further comprising:
 a second downhole telemetry device;   said second hydraulic flowpath extending between said downhole telemetry devices.   
     
     
         17 . The downhole tool of  claim 15 , further comprising:
 said first hydraulic flowpath comprising said drilling fluid flowpath.   
     
     
         18 . A method of assembling a downhole tool having a longitudinal axis, comprising:
 hydraulically coupling a variable length hydraulic coupling to a first telemetry device;
 said variable length hydraulic coupling comprising
 two hydraulic fitting ends; 
 a male coupling shaft; and 
 a female receiving tube; 
 said shaft and tube hydraulically coupling said ends creating a drilling fluid flowpath therebetween; and 
 said shaft and tube permitting rotation between said fitting ends during assembly of said downhole tool; and 
 
   said hydraulically coupling step comprising mechanically coupling said first telemetry device to a first of said fitting ends.   
     
     
         19 . The method of assembling of  claim 18 , further comprising:
 coupling said first telemetry device to a first sub in a position axially and rotationally fixed thereto about said longitudinal axis.   
     
     
         20 . The method of assembling of  claim 18 , further comprising:
 coupling a second downhole telemetry device to a second sub in a position axially and rotationally fixed thereto about said longitudinal axis;   said second telemetry device mechanically coupled to a second of said fitting ends.   
     
     
         21 . The method of assembling of  claim 18 :
 said hydraulically coupling step further comprising
 engaging said shaft within said tube; 
 creating axial translation between said fitting ends along said longitudinal axis; and 
 creating relative rotation between said fitting ends about said longitudinal axis. 
   
     
     
         22 . The method of assembling of  claim 18 , further comprising:
 said first telemetry device in a position axially and rotationally fixed to a first sub about said longitudinal axis; and   a second of said fitting ends in a position axially and rotationally fixed to a second sub about said longitudinal axis.   
     
     
         24 . The method of assembling of  claim 22 :
 said hydraulically coupling step further comprising
 engaging said shaft within said tube; 
 advancing said second sub along said longitudinal axis toward said first sub; and 
 rotating said second sub about said longitudinal axis. 
   
     
     
         25 . The method of assembling of  claim 22 , further comprising:
 connecting each of said subs to an opposite end of a downhole tubular component.   
     
     
         26 . The method of assembling of  claim 25 , further comprising:
 connecting each of said subs to an opposite end of a non-magnetic drill collar.   
     
     
         27 . The method of assembling of  claim 25 :
 said downhole tubular component comprising a plurality of downhole tubular elements.   
     
     
         28 . The method of assembling of  claim 22 , wherein:
 one of said first and second subs is a drill collar; and   comprising connecting the other of said first and second subs to the drill collar.   
     
     
         29 . The method of assembling of  claim 22 , further comprising:
 threadingly connecting the first and second subs to one another.   
     
     
         30 . The method of assembling of  claim 18 , further comprising:
 said hydraulically coupling step further comprising directly mechanically coupling
 said first telemetry device to a first of said fitting ends.