Crown block shifting apparatus and method

Abstract

A drilling rig derrick is adapted to direct the hoist lines reeved between the crown block and the traveling block such that they enter both in a vertical direction if the traveling block is moved laterally to clear the work area over the rotary table. Arrangements are provided to move the crown block laterally, and to move it back over the rotary table. Alternate provisions displace the reeved lines with idler sheaves to move the traveling block only and direct the reeved lines such that they enter both crown block and traveling block sheaves in a near vertical direction. Methods for both options are provided.

The invention having been described, we claim:  
     
         1 . Apparatus for moving a crown block of a drilling rig laterally relative to the vertical centerline of the rotary table to move the suspended position of the traveling block to one side of the work area over the rotary table, the apparatus comprising: 
 a) a distortable derrick capable of responding to an applied distorting force to move the crown block a preselected distance between a first position placing a suspended traveling block over the vertical centerline of the rotary table and a second position placing the traveling block some horizontal distance from said vertical centerline of the rotary table;    b) forcing means operatively associated with said derrick to apply said distorting force.    
     
     
         2 . The apparatus of  claim 1  wherein said derrick has one portion hinged relative to the rest of the derrick, said forcing means arranged to bend the derrick at a selected hinge line.  
     
     
         3 . The apparatus of  claim 1  wherein said derrick consists of two portions, a first portion having a generally parallelogram structure, viewed from either of two opposite sides, with four hinge centerlines defining flexure points, said forcing means arranged to move the upper of the parallelogram structure relative it's lower end.  
     
     
         4 . The apparatus of  claim 1  wherein said crown block is moved laterally, relative to the rest of the derrick, between said two positions.  
     
     
         5 . The apparatus of  claim 1  wherein idler sheaves engage the reeved suspension lines between crown block and traveling block, said idler sheaves arranged to move laterally in response to said applied distorting force to move the lines such that the suspended traveling block moves laterally between the work area over the rotary table and a location some transverse distance from the vertical centerline of the rotary table.  
     
     
         6 . Apparatus for moving the crown block of a drilling rig between a first position, generally over the centerline of the rotary table, and a second position some distance to laterally displace the suspended traveling block, the apparatus comprising: 
 a) a shuttle carriage to support the crown block;    b) a support track mounted on the rig to support said shuttle carriage and accept movement between said two positions; and    c) force means arranged to apply force to said carriage relative to said track to move said carriage between said two positions.    
     
     
         7 . The apparatus of  claim 6  wherein said shuttle carriage has wheels arranged to roll on said support track.  
     
     
         8 . The apparatus of  claim 6  wherein said shuttle carriage has skid pads arranged to slide on said track.  
     
     
         9 . The apparatus of  claim 6  wherein said force means is a hydraulic cylinder.  
     
     
         10 . The apparatus of  claim 6  wherein said force means is a jack screw and nut arrangement.  
     
     
         11 . The apparatus of  claim 6  wherein said force means is a pinion and rack arrangement.  
     
     
         12 . The apparatus of  claim 6  wherein said support track is sloped upward in the direction of displacement from the first position such that the carriage, when displaced, will move back to the first position in the absence of a restraining force.  
     
     
         13 . The apparatus of  claim 6  wherein said movement of said crown block responds to control means near the rig floor.  
     
     
         14 . The apparatus of  claim 6  wherein said shuttle carriage is incorporated into the embodiment of said crown block.  
     
     
         15 . Apparatus for moving the crown block of a drilling rig between a first position, generally over the centerline of the rotary table, and a second position some lateral distance to align sheaves of the crown block with the sheaves of a laterally displaced traveling block, the apparatus comprising: 
 a) a shuttle carriage to support the crown block;    b) a support track mounted on the rig to support said shuttle carriage and accept movement between said two positions; and    c) force means arranged to apply force to said carriage relative to said track to move said carriage between said two positions.    
     
     
         16 . The apparatus of  claim 15  wherein said shuttle carriage has wheels arranged to roll on said support track.  
     
     
         17 . The apparatus of  claim 15  wherein said shuttle carriage has skid pads arranged to slide on said track.  
     
     
         18 . The apparatus of  claim 15  wherein said force means is a hydraulic cylinder.  
     
     
         19 . The apparatus of  claim 15  wherein said force means is a jack screw and nut arrangement.  
     
     
         20 . The apparatus of  claim 15  wherein said force means is a pinion and rack arrangement.  
     
     
         21 . The apparatus of  claim 15  wherein said support track is sloped upward in the direction of displacement from the first position such that the carriage, when displaced, will move back to the first position in the absence of a restraining force.  
     
     
         22 . The apparatus of  claim 15  wherein said movement of said crown block responds to control means near the rig floor.  
     
     
         23 . The apparatus of  claim 15  wherein said shuttle carriage is incorporated into the embodiment of said crown block.  
     
     
         24 . Apparatus for moving the crown block of a drilling rig between a first position, generally over the centerline of the rotary table, and a second position some lateral distance to reduce the angle, off vertical, of cables reeved between sheaves of the crown block and the sheaves of a laterally displaced traveling block, the apparatus comprising: 
 a) a shuttle carriage arranged to support the crown block;    b) a support track mounted on the rig to support said shuttle carriage and accept movement between said two positions; and    c) force means to apply force between said track and said carriage to move said carriage between said two positions.    
     
     
         25 . The apparatus of  claim 24  wherein said shuttle carriage has wheels arranged to roll on said support track.  
     
     
         26 . The apparatus of  claim 24  wherein said shuttle carriage has skid pads arranged to slide on said track.  
     
     
         27 . The apparatus of  claim 24  wherein said force means is a hydraulic cylinder.  
     
     
         28 . The apparatus of  claim 24  wherein said force means is a jack screw and nut arrangement.  
     
     
         29 . The apparatus of  claim 24  wherein said force means is a pinion and rack arrangement.  
     
     
         30 . The apparatus of  claim 24  wherein said support track is sloped upward in the direction of displacement from the first position such that the carriage, when displaced, will move back to the first position in the absence of a restraining force.  
     
     
         31 . The apparatus of  claim 24  wherein said movement of said crown block responds to control means near the rig floor.  
     
     
         32 . The apparatus of  claim 24  wherein said shuttle carriage is incorporated into the embodiment of said crown block.  
     
     
         33 . A method for conducting pipe string assembly management operations on a drilling rig having a crown block, a traveling block, and cables reeved between crown block sheaves and traveling block sheaves, and a work area over a rotary table, the method comprising the steps: 
 a) displacing the traveling block laterally from the work area over the rotary table;    b) moving the crown block laterally to a location generally over the displaced traveling block;    c) conducting pipe assembly management work over the rotary table and moving the traveling block to make an upward excursion;    d) moving the crown block back over the rotary table to suspend the traveling block over the rotary table; and    e) suspending the pipe string upper end from the traveling block and moving the pipe string axially through the opening of the rotary table.    
     
     
         34 . A method for conducting pipe string assembly management operations on a drilling rig having a crown block, a traveling block, and cables reeved between crown block sheaves and traveling block sheaves, and a work area over a rotary table, the method comprising the steps: 
 a) displacing the crown block laterally from the work area over the rotary table to displace the traveling block laterally from the work area over the rotary table;    b) conducting pipe assembly management work over the rotary table and moving the traveling block to make an upward excursion;    c) moving the crown block back over the rotary table; and    d) suspending the pipe string upper end from the traveling block and moving the pipe string axially through the opening of the rotary table.    
     
     
         35 . The method of  claim 34  wherein said pipe assembly management is related to tripping the pipe string out of the hole.  
     
     
         36 . The method of  claim 34  wherein said pipe assembly management is related to tripping the pipe string into the hole.  
     
     
         37 . The method of  claim 34  wherein said pipe assembly management is related to tripping the pipe string out of the hole.  
     
     
         38 . The method of  claim 34  wherein said pipe assembly management is related to tripping the pipe string into the hole.