Tri-jack hydraulic workover unit

Abstract

A hydraulic workover unit includes a work platform and a jacking table assembly disposed adjacent to the work platform. The jacking table assembly includes a jacking table and multiple adjustable legs, and each adjustable leg of the multiple adjustable legs includes multiple telescopic cylinders that provide variable jacking capacity to adjust a position of the jacking table relative to the work platform.

1 . A hydraulic workover unit, comprising:
 a work platform; and   a jacking table assembly disposed adjacent to the work platform, wherein the jacking table assembly comprises a jacking table and a plurality of adjustable legs, and each adjustable leg of the plurality of adjustable legs comprises a plurality of telescopic cylinders that provide variable jacking capacity to adjust a position of the jacking table relative to the work platform.   
     
     
         2 . The hydraulic workover unit of  claim 1 , wherein each adjustable leg of the plurality of adjustable legs comprises a first telescopic cylinder and a second telescopic cylinder as at least a portion of the plurality of telescopic cylinders, the first telescopic cylinder is configured to provide a first jacking capacity to move the jacking table over a first distance, and the second telescopic cylinder is configured to provide a second jacking capacity to move the jacking table over a second distance. 
     
     
         3 . The hydraulic workover unit of  claim 2 , wherein each adjustable leg of the plurality of adjustable legs comprises a third telescopic cylinder configured to move the jacking table over a third distance. 
     
     
         4 . The hydraulic workover unit of  claim 1 , wherein the jacking table comprises an opening configured to support a slip configured to selectively grip and hold a tubular during tripping operations. 
     
     
         5 . The hydraulic workover unit of  claim 1 , comprising a pair of side towers that are supported on the jacking table and extend above the jacking table relative to a vertical axis. 
     
     
         6 . The hydraulic workover unit of  claim 5 , wherein the jacking table assembly is configured to adjust the position of the jacking table relative to the work platform and the pair of side towers. 
     
     
         7 . The hydraulic workover unit of  claim 1 , wherein the work platform comprises an interface configured to support a tool. 
     
     
         8 . The hydraulic workover unit of  claim 7 , wherein the tool comprises an iron roughneck. 
     
     
         9 . The hydraulic workover unit of  claim 7 , comprising a tool crane configured to move the tool between the work platform and the jacking table. 
     
     
         10 . The hydraulic workover unit of  claim 1 , comprising a controller configured to provide control signals to:
 instruct a slip supported on the jacking table to engage a tubular;   while the slip is engaged with the tubular, instruct the plurality of telescopic cylinders of the plurality of adjustable legs to extend to move the jacking table from an initial position to an end position;   in response to reaching the end position, instruct the slip to release the tubular; and   while the slip is released from the tubular, instruct the plurality of telescopic cylinders of the plurality of adjustable legs to retract to return the jacking table from the end position to the initial position.   
     
     
         11 . The hydraulic workover unit of  claim 10 , wherein the controller is configured to provide additional control signals to:
 in response to returning to the initial position, instruct the slip to engage the tubular; and   while the slip is engaged with the tubular, instruct the plurality of telescopic cylinders of the plurality of adjustable legs to extend to move the jacking table from the initial position to an intermediate position to place a joint of the tubular above the jacking table along a vertical axis.   
     
     
         12 . The hydraulic workover unit of  claim 11 , wherein the controller is configured to provide further additional control signals to:
 instruct a tool crane to move an iron roughneck toward the tubular; and   instruct the iron roughneck to break out the joint.   
     
     
         13 . A drilling system, comprising:
 a drilling rig configured to drill a wellbore; and   a hydraulic workover unit configured to be installed on the drilling rig, wherein the hydraulic workover unit comprises:
 a base skid; 
 a jacking table; and 
 a plurality of adjustable legs, wherein each adjustable leg of the plurality of adjustable legs comprises a plurality of telescopic cylinders that provide variable jacking capacity to adjust a position of the jacking table relative to the base skid to facilitate tripping a tubular into the wellbore, out of the wellbore, or both. 
   
     
     
         14 . The drilling system of  claim 13 , wherein the hydraulic workover unit comprises a work platform positioned adjacent to the base skid and comprising an interface configured to support an iron roughneck. 
     
     
         15 . The drilling system of  claim 13 , wherein the plurality of telescopic cylinders provide a first jacking capacity via extension of a first cylinder of the plurality of telescopic cylinders and a second jacking capacity via extension of the first cylinder and a second cylinder of the plurality of telescopic cylinders to thereby provide the variable jacking capacity. 
     
     
         16 . A method of operating a hydraulic workover unit, the method comprising:
 extending a first cylinder of a plurality of telescopic cylinders to provide a first jacking capacity that moves a jacking table over a first distance; and   extending the first cylinder and a second cylinder of the plurality of telescopic cylinders to provide a second jacking capacity that moves the jacking table over a second distance.   
     
     
         17 . The method of  claim 16 , comprising extending the first cylinder, the second cylinder, and a third cylinder of the plurality of telescopic cylinders to provide a third jacking capacity that moves the jacking table over a third distance. 
     
     
         18 . The method of  claim 16 , comprising engaging a tubular with a slip supported on the jacking table of the hydraulic workover unit as the jacking table moves over the first distance and the second distance to facilitate tripping operations. 
     
     
         19 . The method of  claim 16 , comprising using the hydraulic workover unit to carry out tripping operations, milling operations, or both. 
     
     
         20 . The method of  claim 16 , comprising:
 engaging an installation frame with one or more rails disposed on a drill floor of a drilling rig;   positioning a work platform on the installation frame;   positioning a base skid that supports a jacking table assembly with the jacking table and the plurality of telescopic cylinders on the installation frame; and   sliding the installation frame with the work platform and the base skid along the one or more rails to position the base skid vertically above a rotary table relative to a wellbore.