Collar swaging of single-piece centralizers

Abstract

A method for manufacturing a centralizer. The method includes selecting a tubular having a first inner diameter, cutting the tubular to form a blank including at least one end collar and ribs integrally-formed therewith, and swaging the at least one end collar such that the first inner diameter is modified to a second inner diameter.

What is claimed is: 
     
         1 . A method for manufacturing a centralizer, comprising:
 selecting a tubular having a first inner diameter;   cutting the tubular to form a blank comprising at least one end collar and ribs integrally-formed therewith; and   swaging the at least one end collar such that the first inner diameter is modified to a second inner diameter.   
     
     
         2 . The method of  claim 1 , wherein swaging the at least one end collar comprises expanding the first inner diameter, the second inner diameter being larger than the first inner diameter. 
     
     
         3 . The method of  claim 2 , wherein expanding the first inner diameter comprises:
 receiving a die into engagement with an inner diameter surface of the at least one end collar; and   expanding the die.   
     
     
         4 . The method of  claim 2 , wherein expanding the first inner diameter comprises moving a die through the at least one end collar, the die having a maximum outer diameter that is greater than the first inner diameter. 
     
     
         5 . The method of  claim 1 , wherein swaging the at least one end collar comprises decreasing the first inner diameter, the second inner diameter being less than the first inner diameter. 
     
     
         6 . The method of  claim 5 , wherein decreasing the first inner diameter comprises:
 positioning a set of crimping dies around an outer diameter surface of the at least one end collar; and   forcing the set of crimping dies radially-inwards.   
     
     
         7 . The method of  claim 5 , wherein decreasing the first inner diameter comprises moving a die having an inner diameter that is less than an outer diameter of the at least one end collar over an outer diameter surface of the at least one end collar. 
     
     
         8 . The method of  claim 1 , further comprising heating at least a portion of the blank before swaging the at least one end collar. 
     
     
         9 . The method of  claim 1 , wherein cutting the tubular comprises defining a window in the at least one end collar, the window being sized and configured to receive a stop-feature. 
     
     
         10 . A centralizer comprising:
 a rolled tubular having a seam;   at least one rib formed in the rolled tubular; and   at least one end collar formed in the rolled tubular, wherein the at least one end collar has a first inner diameter prior to a swaging process and a second inner diameter after the swaging process.   
     
     
         11 . The centralizer of  claim 10 , wherein the second inner diameter is larger than the first inner diameter. 
     
     
         12 . The centralizer of  claim 10 , wherein the second inner diameter is smaller than the first inner diameter. 
     
     
         13 . The centralizer of  claim 10 , wherein a first window is defined radially-through the rolled tubular and circumferentially-offset from the at least one rib, and wherein a second window is defined radially-through the at least one end collar. 
     
     
         14 . A swaging device for a centralizer, comprising:
 a body having a tapered surface; and   a plurality of dies each having:
 a reverse-tapered surface that is reverse tapered with respect to the tapered surface of the body; and 
 an engagement surface that is opposite to the reverse-tapered surface, wherein the body is configured to slide relative to the plurality of dies so as to swage an end collar of the centralizer. 
   
     
     
         15 . The swaging device of  claim 14 , wherein the body and the plurality of dies are configured to be disposed radially-inside of the end collar of the centralizer. 
     
     
         16 . The swaging device of  claim 15 , wherein the tapered surface of the body is an outer surface thereof, and the reverse-tapered surface of the plurality of dies is an inner surface thereof, and wherein, when the body is moved in a first axial direction, the body causes the plurality of dies to expand radially-outward. 
     
     
         17 . The swaging device of  claim 14 , further comprising:
 a driver coupled with the body to move the body with respect to the plurality of dies;   a retaining plate disposed between the driver and the body; and   a shaft connecting the driver and the body,   wherein the shaft is received through the retaining plate, and the retaining plate is configured to maintain a position of the plurality of dies when the body is moved by the driver.   
     
     
         18 . The swaging device of  claim 14 , wherein the body comprises a plurality of rollers. 
     
     
         19 . The swaging device of  claim 18 , wherein the plurality of rollers are cylindrical and disposed in cutouts defined in the tapered surface of the body. 
     
     
         20 . The swaging device of  claim 14 , further comprising:
 a vehicle configured to be moved into proximity of a wellsite; and   a hoisting device coupled with the vehicle and configured to move the centralizer such that the end collar of the centralizer is received around or within the plurality of dies.