Expansion assembly for a tubular expander tool, and method of tubular expansion

Abstract

An improved expansion assembly for an expander tool is provided, and a method for expanding a surrounding tubular body within a wellbore. The expansion assembly first comprises a piston disposed within a recess of the expander tool. The top surface of the piston closely receives a body. The bearing body includes one or more races which house at least one bearing. In one arrangement, at least one bearing is provided which rotationally resides within a single race. In another arrangement, a plurality of bearings are provided that recirculate within one or more races. In this arrangement, the bearing body is preferably a tapered, cylindrical roller actuated into contact with the surrounding tubular by hydraulic pressure applied from within the bore of the expander tool. These arrangements reduce the geometric size of the expansion assembly, affording a larger inner diameter for the hollow bore of the expander tool itself.

1 . An expansion assembly for an expander tool for expanding a surrounding tubular body, the expansion assembly being disposed within a recess in the body of the expander tool, and the expander tool having a bore therethrough, the expansion assembly comprising: 
 a piston disposed within the recess of the expander tool, the piston having a bottom surface and a top surface, the bottom surface being exposed to a radially outward force within the bore of the expander tool, and the piston being outwardly extendable from the body of the expander tool within the recess in response to the radially outward force; and    a bearing body residing in close proximity to the top surface of the piston, the bearing body having at least one race for receiving at least one bearing for engaging the surrounding tubular body when the piston is extended away from the body of the expander tool.    
     
     
         2 . The expansion assembly of  claim 1 , wherein the at least one bearing defines a plurality of recirculating bearings.  
     
     
         3 . The expansion assembly of  claim 2 , wherein the bearing body defines a tapered, non-circular body.  
     
     
         4 . The expansion assembly of  claim 3 , wherein the bearing body comprises: 
 a first substantially flat surface residing upon the top surface of the piston; and    a second arcuate surface above the first substantially flat surface.    
     
     
         5 . The expansion assembly of  claim 3 , wherein the at least one race defines at least two elongated, non-parallel races.  
     
     
         6 . The expansion assembly of  claim 3 , wherein the at least one race defines an elongated, non-linear race.  
     
     
         7 . The expansion assembly of  claim 3 , wherein the at least one race defines at least two substantially linear, substantially parallel races.  
     
     
         8 . The expansion assembly of  claim 6 , wherein the bearing body is substantially rotationally fixed relative to the top surface of the piston.  
     
     
         9 . The expansion assembly of  claim 3 , further comprising a mounting arrangement for supporting the bearing body upon the top surface of the piston.  
     
     
         10 . The expansion assembly of  claim 9 , wherein the mounting arrangement comprises: 
 a first bracket affixed to the top surface of the piston for supporting the bearing body at a first end; and    a second bracket affixed to the top surface of the piston for supporting the bearing body at a second opposite end.    
     
     
         11 . The expansion assembly of  claim 10 , wherein each of the first and second brackets receives a connector for connecting the first and second brackets to the respective first and second opposite ends of the body.  
     
     
         12 . The expansion assembly of  claim 11 , wherein the connector comprises: 
 a plate secured to the bracket; and    a tongue extending from the bracket and received within the bearing body at an end.    
     
     
         13 . The expansion assembly of  claim 12 , wherein each of the first and second brackets receives a connector for connecting the first and second brackets to the respective first and second opposite ends of the body.  
     
     
         14 . The expansion assembly of  claim 13 , wherein the connector comprises: 
 a plate secured to the bracket; and    a tongue extending from the bracket and received within the bearing body at an end.    
     
     
         15 . The expansion assembly of  claim 5 , wherein the top surface of the piston comprises a plurality of scallops, each scallop sized and configured to receive the plurality of bearings as they recirculate within the at least two races.  
     
     
         16 . The expansion assembly of  claim 3 , wherein the orientation of the bearing body is skewed relative to the longitudinal center axis of the bore of the expander tool.  
     
     
         17 . The expansion assembly of  claim 3 , wherein the radially outward forces are hydraulic forces from within the bore of the expander tool.  
     
     
         18 . The expansion assembly of  claim 17 , wherein the piston sealingly resides within the recess of the body of the expander.  
     
     
         19 . The expansion assembly of  claim 1 , wherein: 
 the at least one race comprises a first race and a second adjacent race; and    the at least one bearing comprises first and second bearings received within the first and second adjacent races, respectively.    
     
     
         20 . The expansion assembly of  claim 19 , wherein the first bearing is larger than the second bearing.  
     
     
         21 . The expansion assembly of  claim 1 , wherein the bearing body comprises one race, and one bearing received within the race.  
     
     
         22 . The expansion assembly of  claim 21 , wherein the radially outward forces are hydraulic forces from within the bore of the expander tool.  
     
     
         23 . The expansion assembly of  claim 22 , wherein the bearing body is integral to the piston.  
     
     
         24 . An expansion assembly for a hydraulic expander tool for expanding a surrounding tubular body, the expansion assembly being sealingly disposed within a recess in the body of the expander tool, and the expander tool having a bore therethrough, the expansion assembly comprising: 
 a piston residing within the recess of the expander tool, and being outwardly extendable from the body of the expander tool within the recess in response to hydraulic pressure within the bore of the expander tool, the piston comprising a bottom surface exposed to fluid pressure within the expander tool, and a top surface;    a bearing body residing upon the top surface of the piston, the roller having at least one race for receiving at least one bearing that engages a surrounding tubular body when the piston is extended away from the body at the expander tool; and    a mounting arrangement for supporting the bearing body upon the top surface of the piston such that the roller is substantially rotationally fixed relative to the top surface of the piston.    
     
     
         25 . The expansion assembly of  claim 24 , wherein: 
 the bearing body is integral to the piston;    the at least one race defines a single race; and    the at least one bearing defines a single bearing that rotationally resides within the single race.    
     
     
         26 . The expansion assembly of  claim 24 , wherein the bearing body defines a tapered eccentric body comprising: 
 a first substantially flat surface residing upon the top surface of the piston; and    a second arcuate surface above the first substantially flat surface.    
     
     
         27 . The expansion assembly of  claim 26 , wherein: 
 the at least one race defines at least two substantially linear, substantially parallel races;    the at least one bearing defines a plurality of bearings that recirculate within the races; and    the top surface of the piston comprises a plurality of scallops, each scallop sized and configured to receive the plurality of bearings as they recirculate within the at least two races.    
     
     
         28 . The expansion assembly of  claim 27 , wherein the mounting arrangement comprises: 
 a first bracket affixed to the top surface of the piston for supporting the bearing body at a first end; and    a second bracket affixed to the top surface of the piston for supporting the bearing body at a second opposite end.    
     
     
         29 . The expansion assembly of  claim 28 , wherein the orientation of the bearing body is skewed relative to the longitudinal center axis of the bore of the expander tool.  
     
     
         30 . The expansion assembly of  claim 29 , wherein each of the first and second brackets receives a connector for connecting the first and second brackets to the respective first and second opposite ends of the roller, the connector comprising: 
 a plate secured to the bracket; and    a tongue extending from the bracket and received within the roller at an end.    
     
     
         31 . A method for expanding a tubular body within a hydrocarbon wellbore, comprising the steps of: 
 attaching an expander tool to the lower end of a working string, the expander tool having a body and a plurality of recesses within the body, each recess receiving an expansion assembly, each expansion assembly comprising: 
 a piston disposed within the recess of the expander tool, the piston having a bottom surface and a top surface, the bottom surface being exposed to a radially outward force within the bore of the expander tool, and the piston being outwardly extendable from the body of the expander tool within the recess in response to the radially outward force;  
 a bearing body residing in close proximity to the top surface of the piston, the bearing body having at least one race for receiving at least one bearing that engages the surrounding tubular body when the piston is extended away from the body of the expander tool; and  
 a mounting arrangement for supporting the bearing body upon the top surface of the piston such that the bearing body is substantially rotationally fixed relative to the top surface of the piston;  
   running the working string with the expander tool into a wellbore; and    rotating the working string in order to radially expand a section of the surrounding tubular body within the wellbore.    
     
     
         32 . The method for expanding a tubular body within a wellbore of  claim 31 , wherein the at least one bearing defines a plurality of bearings that recirculate within the races.  
     
     
         33 . The method for expanding a tubular body within a wellbore of  claim 32 , wherein the bearing body comprises: 
 a first substantially flat surface residing upon the top surface of the piston; and    a second arcuate surface above the first substantially flat surface.    
     
     
         34 . The method for expanding a tubular body within a wellbore of  claim 33 , wherein the mounting arrangement comprises: 
 a first bracket affixed to the top surface of the piston for supporting the roller at a first end; and    a second bracket affixed to the top surface of the piston for supporting the roller at a second opposite end.    
     
     
         35 . The method for expanding a tubular body within a wellbore of  claim 33 , wherein the at least one race defines at least two substantially linear, substantially parallel races.  
     
     
         36 . The method for expanding a tubular body within a wellbore of  claim 35 , wherein the top surface of the piston comprises a plurality of scallops, each scallop sized and configured to receive the plurality of bearings as they recirculate within the at least two races.  
     
     
         37 . The method for expanding a tubular body within a wellbore of  claim 35 , wherein the orientation of the roller is skewed relative to the longitudinal center axis of the bore of the expander tool.  
     
     
         38 . The method for expanding a tubular body within a wellbore of  claim 35 , wherein the radially outward forces are hydraulic forces from within the bore of the expander tool.  
     
     
         39 . The method for expanding a tubular body within a wellbore of  claim 31 , wherein: 
 the at least one race defines a single race;    the at least one bearing defines a single bearing rotationally residing within the single race; and    the bearing body is integral to the piston.    
     
     
         40 . The method for expanding a tubular body within a wellbore of  claim 31 , wherein: 
 the at least one race defines two separate but adjacent races;    the at least one bearing defines a single bearing rotationally residing within each of the two respective races; and    the bearing body is integral to the piston.    
     
     
         41 . An expander tool for expanding a surrounding tubular body in a wellbore, comprising: 
 a body;    at least one radially expandable member; and    at least one rotatable member disposed on an outer surface of the expandable member for engaging the surrounding tubular body when the radially extendable member is extended away from the body of the expander tool.    
     
     
         42 . A method of expanding a tubular in a wellbore comprising: 
 running an expander tool into the wellbore to a predetermined location adjacent the tubular to the expander, the expander tool comprising: 
 a body;  
 at least one radially expandable member disposed along the body; and  
 at least one rotatable member disposed on an outer surface of the expandable member; and  
   actuating the expander tool, thereby urging the at least one rotatable member into contact with the surrounding tubular member, thereby expanding the tubular member past its elastic limits.