Tubing rotator

Abstract

A tubing rotator 10 rotatably suspending a tubing string TS in a well having a wellhead W includes a tubing hanger 12 for supporting the tubing string, and a mandrel 14 having a bore therein and connected to the tubing string. A coupling sleeve 30 rotatably connects the mandrel to the rotator drive shaft 16, and transfers rotational energy from the drive shaft to the mandrel while allowing for the disengagement of the coupling sleeve from the mandrel in a direction substantially parallel to a longitudinal axis of the mandrel. The coupling sleeve has interior surfaces 70 for mating with an exterior surfaces 72 on the mandrel, with each surface having a substantially curvilinear configuration about its circumference defining a plurality of curved radially outward extending peaks and curved radially inward extending valleys.

1 . A tubing rotator for rotatably suspending a tubing string in a well having a wellhead, the tubing rotator comprising: 
 a tubing hanger for engagement with the wellhead and supporting the tubing string;    a mandrel having a bore therein and connected to the tubing string;    a coupling sleeve rotatably connecting the mandrel to a rotator drive shaft, the coupling sleeve transferring rotational energy from the drive shaft to the mandrel while allowing for the disengagement of the coupling sleeve from the mandrel in a direction substantially parallel to a longitudinal axis of the mandrel; and    the coupling sleeve having an interior surface for mating with an exterior surface on the mandrel, each surface having a substantially curvilinear configuration about its circumference and defining a plurality of curved radially outward extending peaks and curved radially inward extending valleys.    
   
   
       2 . A tubing rotator as defined in  claim 1 , wherein each of the curvilinear surfaces on the mandrel and on the coupling sleeve have a substantially sinusoidal configuration with respect to the axis of the mandrel.  
   
   
       3 . A tubing rotator as defined in  claim 1 , further comprising: 
 a bearing between the tubing hanger and the mandrel to facilitate rotation of the mandrel within the tubing hanger.    
   
   
       4 . A tubing rotator as defined in  claim 1 , further comprising: 
 a first seal between the tubing hanger and the wellhead, and a second seal between the tubing hanger and the mandrel.    
   
   
       5 . A tubing rotator as defined in  claim 1 , further comprising: 
 an upper portion of said mandrel including internal tubing string pickup threads.    
   
   
       6 . A tubing rotator as defined in  claim 1 , further comprising: 
 a tubing rotator housing mounted on the wellhead; and    a portion of the mandrel is positioned within a wellhead and a portion of the mandrel is positioned within the tubing rotator housing.    
   
   
       7 . A tubing hanger as defined in  claim 1 , wherein the interior surface on the coupling sleeve and the exterior surface on the mandrel extend axially in a direction substantially parallel to the longitudinal axis of the mandrel.  
   
   
       8 . A tubing rotator as defined in  claim 1 , wherein the drive gear is a worm gear having worm gear teeth for engagement with the coupling sleeve.  
   
   
       9 . A tubing rotator is defined in  claim 1 , wherein the tubing hanger has a tapered exterior surface for engaging a tapered interior surface on the wellhead for supporting the tubing hanger.  
   
   
       10 . A tubing rotator as defined in  claim 1 , wherein a lower end of said mandrel includes threads for threaded engagement with the tubing string.  
   
   
       11 . A tubing rotator for rotatably suspending a tubing string in a well having a wellhead, the tubing rotator comprising: 
 a tubing hanger for engagement with the wellhead and supporting the tubing string;    a mandrel having a bore therein and connected to the tubing string and supported on the tubing hanger;    a coupling sleeve rotatably connecting the mandrel to a rotator drive shaft, the coupling sleeve transferring rotational energy from the drive shaft to the mandrel while allowing for the disengagement of the coupling sleeve from the mandrel in a direction parallel to a longitudinal axis of the mandrel;    the coupling sleeve having an interior surface for mating with an exterior surface on the mandrel, each surface having a substantially curvilinear configuration about its circumference and defining a plurality of curved radially outward extending peaks and curved radially inward extending valleys;    each of the curvilinear surfaces on the mandrel and on the coupling sleeve have a substantially sinusoidal configuration with respect to the axis of the mandrel; and    a bearing between the tubing hanger and the mandrel to facilitate rotation of the mandrel within the tubing hanger.    
   
   
       12 . A tubing rotator as defined in  claim 11 , further comprising: 
 a first seal between the tubing hanger and the wellhead, and a second seal between the tubing hanger and the mandrel.    
   
   
       13 . A tubing hanger as defined in  claim 11 , wherein the exterior surface on the coupling sleeve and the interior surface on the mandrel extend axially in a direction substantially parallel to the longitudinal axis of the mandrel.  
   
   
       14 . A tubing rotator as defined in  claim 11 , further comprising: 
 a tubing rotator housing mounted on the wellhead; and    a portion of the mandrel is positioned within a wellhead and a portion of the mandrel is positioned within the tubing rotator housing.    
   
   
       15 . A tubing rotator as defined in  claim 11 , wherein the drive gear is a worm gear having worm gear teeth for engagement with the mandrel.  
   
   
       16 . A method of rotatably suspending a tubing string in a well having a wellhead, the method comprising: 
 engaging a tubing hanger with the wellhead for supporting the tubing string;    connecting a mandrel having a bore therein with the tubing string;    rotatably connecting a coupling sleeve between the mandrel and a rotator drive shaft, the coupling sleeve transferring rotational energy from the drive shaft to the mandrel while allowing for the disengagement of the coupling sleeve from the mandrel in a direction substantially parallel to a longitudinal axis of the mandrel; and    providing the coupling sleeve with an interior surface for mating with an exterior surface on the mandrel, each surface having a substantially curvilinear configuration about its circumference and defining a plurality of curved radially outward extending peaks and curved radially inward extending valleys.    
   
   
       17 . A method as defined in  claim 16 , wherein each of the curvilinear surfaces on the mandrel and on the coupling sleeve have a substantially sinusoidal configuration with respect to the axis of the mandrel.  
   
   
       18 . A method as defined in  claim 16 , further comprising: 
 providing an upper portion of said mandrel with internal tubing string pickup threads; and    lifting the tubular string from the pickup threads.    
   
   
       19 . A method as defined in  claim 16 , further comprising: 
 providing a first seal between the tubing hanger and the wellhead; and    providing a second seal between the tubing hanger and the mandrel.    
   
   
       20 . A method as defined in  claim 16 , further comprising: 
 providing a bearing between the tubing hanger and the mandrel to facilitate rotation of the mandrel within the tubing hanger.