Systems and Methods For Rotating a Casing String In a Wellbore

Abstract

An offline casing string rotation system can include a ring gear configured to be coupled to a rotatable mandrel casing hanger, where the rotatable mandrel casing hanger is part of a wellhead assembly and is coupled to a top end of a casing string. The offline casing string rotation system can also include a gear driving assembly moveably coupled to the ring gear, wherein the gear driving assembly, when enabled, causes the gear to rotate the rotatable mandrel casing hanger.

What is claimed is: 
     
         1 . An offline casing string rotation system comprising:
 a ring gear configured to be coupled to a rotatable mandrel casing hanger, wherein the rotatable mandrel casing hanger is part of a wellhead assembly and is coupled to a top end of a casing string; and   a gear driving assembly moveably coupled to the ring gear, wherein the gear driving assembly, when enabled, causes the gear to rotate the rotatable mandrel casing hanger.   
     
     
         2 . The offline casing string rotation system of  claim 1 , wherein the gear driving assembly comprises a drive unit and a gear driving mechanism coupled to the drive unit. 
     
     
         3 . The offline casing string rotation system of  claim 2 , wherein the gear driving mechanism of the gear driving assembly further comprises a pinion, and wherein the gear comprises a ring. 
     
     
         4 . The offline casing string rotation system of  claim 2 , wherein the gear driving mechanism of the gear driving assembly further comprises a worm, and wherein the gear comprises a worm wheel. 
     
     
         5 . The offline casing string rotation system of  claim 2 , wherein the drive unit operates hydraulically. 
     
     
         6 . The offline casing string rotation system of  claim 2 , wherein the drive unit is motorized. 
     
     
         7 . The offline casing string rotation system of  claim 1 , wherein the gear has a spiral bevel configuration. 
     
     
         8 . The offline casing string rotation system of  claim 1 , further comprising a sensor that measures a rate of rotation of the rotatable mandrel casing hanger has driven the gear driving assembly. 
     
     
         9 . The offline casing string rotation system of  claim 8 , wherein the rate of rotation is at least 5 rotations per minute. 
     
     
         10 . The offline casing string rotation system of  claim 1 , further comprising a cement head support system coupled to a top end of the wellhead assembly, wherein the cement head support system remains stationary as the rotatable mandrel casing hanger rotates. 
     
     
         11 . The offline casing string rotation system of  claim 1 , wherein cement is pumped through a cavity formed by the rotatable mandrel casing hanger and the casing string as the rotatable mandrel casing hanger is rotated. 
     
     
         12 . The offline casing string rotation system of  claim 1 , wherein the ring gear is coupled to the rotatable mandrel casing hanger using a plurality of fastening devices. 
     
     
         13 . A method for rotating a casing string, the method comprising:
 coupling a ring gear to a rotatable mandrel casing hanger, wherein the rotatable mandrel casing hanger is part of a wellhead assembly and is coupled to a top end of a casing string;   engaging a gear driving mechanism with the ring gear, wherein the gear driving mechanism is part of a gear driving assembly; and   operating a drive unit coupled to the gear driving mechanism, wherein the drive unit, when operating and using the gear driving mechanism and the ring gear, rotates the rotatable mandrel casing hanger.   
     
     
         14 . The method of  claim 13 , further comprising:
 pumping cement through a cavity in the rotating mandrel casing hanger and the casing string as rotatable mandrel casing hanger is rotated.   
     
     
         15 . The method of  claim 13 , wherein the gear driving mechanism comprises a pinion and a shaft coupled to the pinion, wherein the pinion engages the ring gear, and wherein the shaft is further coupled to the drive unit. 
     
     
         16 . The method of  claim 15 , wherein the pinion has a first size that is smaller than a second size of the ring gear. 
     
     
         17 . The method of  claim 13 , wherein the drive unit operates hydraulically. 
     
     
         18 . A system for cementing a casing string in a wellbore, the system comprising:
 a wellhead assembly disposed at an entry point of the wellbore, wherein the wellhead assembly comprises a rotatable mandrel casing hanger coupled to a top end of the casing string;   a cement head coupled to a top end of the wellhead assembly; and   an offline casing string rotation system coupled to the rotatable mandrel casing hanger, wherein the offline casing string rotation system comprises:
 a ring gear coupled to the rotatable mandrel casing hanger; and 
 a gear driving assembly moveably coupled to the ring gear, wherein the gear driving assembly, when enabled, causes the gear to rotate the rotatable mandrel casing hanger. 
   
     
     
         19 . The system of  claim 18 , wherein the gear driving assembly comprises a drive unit and a gear driving mechanism coupled to the drive unit. 
     
     
         20 . The system of  claim 19 , wherein the gear driving mechanism comprises a pinion gear and a shaft.