Abstract:
An adjustable swage features an ability to enhance a radial collapse force when an obstruction in a tubular is encountered to allow radial contraction so that the obstruction can be cleared. The movable segments are configured to elastically bend on high loading so as to create additional radial component force to aid the adjustable swage in reducing its size to clear the obstruction.

Description:
FIELD OF THE INVENTION 
       [0001]    The field of the invention is swages that adjust in diameter for expanding tubulars and more particularly that have the ability to collapse if an obstruction is encountered to clear past it. 
       BACKGROUND OF THE INVENTION 
       [0002]    Swages are used to expand downhole diameter of tubulars. They can be fixed conical shapes or they can be adjusted to change diameter downhole. The swages that can change diameter can be more versatile in that they can do expansion of a given tubular in stages to avoid overstressing. They can be collapsed after the expansion is complete to facilitate removal. 
         [0003]    There are concerns when using adjustable swages that involve a plurality of segments that do the expansion. Gaps between the segments can cause lines of stress concentration that can ultimately create a fracture longitudinally. An adjustable swage design is disclosed in US Publication Number 2003/01558118 A1 that involves wedge shaped segments that translate with respect to each other. Alternating wedges are held fixed while the movable segments are powered by a hydraulic piston. Applied pressure moves the movable segments into alignment with the stationary segments so that their high spots align to create the swaging diameter. The segments are dovetailed on an incline so that as they move relatively into alignment they also move radially into a larger radius. A ratchet system is incorporated to hold the position of the segments attained in response to applied hydraulic pressure to the piston. The discussion below of the basic components of this adjustable swage gives the general starting point for the present invention. 
         [0004]    Additional flexibility can be achieved by using flexible swage  138 .  FIG. 1  shows it in perspective and  FIGS. 2   a - 2   c  show how it is installed above a fixed swage  134 . The adjustable swage  138  comprises a series of alternating upper segments  140  and lower segments  142 . The segments  140  and  142  are mounted for relative, preferably slidable, movement. Each segment,  140  for example, is dovetailed into an adjacent segment  142  on both sides. The dovetailing can have a variety of shapes in cross-section; however an L shape is preferred with one side having a protruding L shape and the opposite side of that segment having a recessed L shape so that all the segments  140  and  142  can form the requisite swage structure for 360 degrees around mandrel  144 . The opening  148  made by the segments  140  and  142  (see  FIG. 1 ) fits around mandrel  144 . 
         [0005]    Segments  140  have a wide top  150  tapering down to a narrow bottom  152  with a high area  154 , in between. Similarly, the oppositely oriented segments  142  have a wide bottom  156  tapering up to a narrow top  158  with a high area  160 , in between. The high areas  154  and  160  are preferably identical so that they can be placed in alignment, as shown in  FIG. 3   a . The high areas  154  and  160  can also be lines instead of bands. If band areas are used they can be aligned or askew from the longitudinal axis. The band area surfaces can be flat, rounded, elliptical or other shapes when viewed in section. The preferred embodiment uses band areas aligned with the longitudinal axis and slightly curved. The surfaces leading to and away from the high area, such as  162  and  164  for example can be in a single or multiple inclined planes with respect to the longitudinal axis. 
         [0006]    Segments  140  have a preferably T shaped member  166  engaged to ring  168 . Ring  168  is connected to mandrel  144  at thread  170 . During run in a shear pin  172  holds ring  168  to mandrel  144 . Lower segments  142  are retained by T shaped members  174  to ring  176 . Ring  176  is biased upwardly by piston  178 . The biasing can be done in a variety of ways with a stack of Belleville washers  180  illustrated as one example. Piston  178  has seals  182  and  184  to allow pressure through opening  186  in the mandrel  144  to move up the piston  178  and pre-compress the washers  180 . A lock ring  188  has teeth  190  to engage teeth  192  on the fixed swage  134 , when the piston  178  is driven up. Thread  194  connects fixed swage  134  to mandrel  144 . Opening  186  leads to cavity  196  for driving up piston  178 . Preferably, high areas  154  and  160  do not extend out as far as the high area  198  of fixed swage  134  during the run in position shown in  FIG. 2 . The fixed swage  134  can have the variation in outer surface configuration previously described for the segments  140  and  142 . 
         [0007]    The operation of the method using the flexible swage  138  will now be described. The swage  134  makes contact with an obstruction. At first, an attempt to set down weight could be tried to see if swage  134  could go through the damaged portion of the casing. If this fails to work, pressure is applied from the surface. If the fixed swage  134  goes through the obstruction, the flexible swage could then land on the obstruction and then be expanded and driven through it. Pressure from the surface enters opening  186  and forces piston  178  to compress washers  180 , as shown in  FIG. 3   b . Lower segments  142  rise in tandem with piston  178  and ring  176  until no further uphole movement is possible. This can be defined by the contact of the segments  140  and  142  with the casing or tubular  133 . This contact may occur at full extension illustrated in  FIGS. 3   b  or  4 , or it may occur short of attaining that position. The full extension position is defined by alignment of high areas  154  and  160 . Washers  180  apply a bias to the lower segments  142  in an upward direction and that bias is locked in by lock ring  188  as teeth  190  and  192  engage as a result of movement of piston  178 . At this point, downward stroking from the force magnification tool  66  forces the swage downwardly. The friction force acting on lower segments  142  augments the bias of washers  180  as the flexible swage  138  is driven down. This tends to keep the flexible swage at its maximum diameter for  360  degree swaging of the casing or tubular  133 . The upper segments do not affect the load on the washers  180  when moving the flexible swage  138  up or down in the well, in the position shown in  FIG. 3   a.    
         [0008]    What the above description from the original disclosure didn&#39;t go into much detail about is what happens when segments  140  and  142  are in alignment and encounter an obstruction through which the fixed cone  134  has already cleared. Two things can happen. If the adjustable swage is to clear the obstruction, it needs to get smaller in diameter by moving from the  FIG. 3   a  position back to the  FIG. 2   a  position. Since segments  142  are required to move down to do this, there clearly needs to be a radial reaction force to urge the separation of the segments  140  and  142  to go to a smaller diameter through a resulting longitudinal relative movement. However the radial force must be large enough to create a longitudinal component greater than the reaction force resulting from pushing the adjustable swage against the obstruction. In other words, as shown in  FIG. 3   a , the aligned segments  140  and  142  are up against the tubular  10 . Arrow  12  represents the pushing force from the surface that is generally coming from a set anchor and a hydraulic stroker (not shown). Other ways to create the pushing force can be used. Since the angle of surface  14  is very steep the radial component of any reaction force  16  is also very small, compared to the vertical reaction force  18  which is equal to the pushing from the surface  12 , as illustrated in  FIG. 5 . It is the radial force  16  that is necessary to get the diameter of the adjustable swage smaller so that it can pass the obstruction in the tubular  10 . This radial component force is what drives the wedges  140  and  142  from the  FIG. 4  position to the  FIG. 1  position along their sloping tongue and groove edge connections. In essence the segments  142  push the fixed swage  134  downhole for the adjustable swage to reduce in diameter by assuming the  FIG. 2   a  position. If the radial component is not sufficient to overcome the resistance to relative movement of the segments  140  and  142  under the loading imposed from being stuck against the tubular  10  the assembly will simply stall and not get through the obstruction. 
         [0009]    What the present invention attempts to do is to enhance the radial force that urges collapse of the adjustable swage when it gets stuck on an obstruction that the fixed swage  134  has already passed. The invention seeks to redirect the longitudinal loading force to create an additional radial component when the adjustable swage is stuck. One way this is accomplished is to alter the loading angles on the mounts for the segments so as to create additional radial load component when the adjustable swage sticks in the tubular on an obstruction. Those skilled in the art will better appreciate the full scope of the invention from the claims below. The detailed description and drawings illustrate the concept of the invention by showing the preferred embodiment. 
       SUMMARY OF THE INVENTION 
       [0010]    An adjustable swage features an ability to enhance a radial collapse force when an obstruction in a tubular is encountered to allow radial contraction so that the obstruction can be cleared. The movable segments are configured to elastically bend on high loading so as to create additional radial component force to aid the adjustable swage in reducing its size to clear the obstruction. 
     
     
       DETAILED DESCRIPTION OF THE DRAWINGS 
         [0011]      FIG. 1  is a perspective view of a prior art adjustable swage in its smaller dimension; 
           [0012]      FIGS. 2   a - 2   c  are a prior art section view of the adjustable swage in the  FIG. 1  position; 
           [0013]      FIGS. 3   a - 3   c  are the view of  FIGS. 2   a - 2   c  but in the maximum dimension for the adjustable swage; 
           [0014]      FIG. 4  shows the prior art adjustable swage in its maximum dimension; 
           [0015]      FIG. 5  is a perspective view of the present invention during normal operation; 
           [0016]      FIG. 6  is the view of  FIG. 5  showing what happens when the adjustable swage reaches an obstruction; 
           [0017]      FIG. 7  shows a single segment of the adjustable swage during normal operation; 
           [0018]      FIG. 8  is the view of  FIG. 7  when an obstruction in the tubular to be expanded is encountered; 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0019]      FIG. 5  shows wedge segments  20  and  22  oriented in the same direction with segment  24  going the other way. The layout of the segments and how they are joined together is identical to the view in  FIG. 1  and the basic operation of the adjustable swage discussed above will not be repeated. What is unique about the arrangement will now be reviewed. 
         [0020]    Segments  20  and  22  and the other similarly situated segments that are not shown preferably have a flexible flange  26  spaced apart from base surface  28 . Retainer  30  has an inner recess  32  that holds a guide flange  34  that is part of the segment  20  or  22  or the other similarly situated segments that are not shown. Retainer  30  has a bearing surface  36  that contacts surface  38  on flexible flange  26 . Surface  38  is part of an inwardly oriented ring  40  that defines circular recess  32 . The connection arrangement for the oppositely oriented segments is substantially the same with ring  42  having a bearing surface  44  to contact surface  46  on flexible flange  48  on segment  24  and the others that are similarly oriented and not shown. 
         [0021]    When the segments that make up the adjustable swage hit an obstruction the contact location is still on steep surface  50  as shown in  FIG. 7 . When the segments hit the obstruction at surface  50  the applied force increases from retainer  30 . This creates a reaction force similar to what was shown in  FIG. 5 . As before, the radial component  52  is quite small when compared to the longitudinal component  54 . As before in  FIG. 5 , it is the radial component that drives the segments in the adjustable swage to go to a smaller diameter by moving them relatively along their inclined dovetail connection to essentially advance the fixed swage  134  that has already cleared the obstruction. Here again, if the generated radial component was sufficiently small the adjustable swage segments would not move relatively to each other because the generated force would not be strong enough to advance the fixed swage  134  to allow the peaks  154  and  160  the ability to separate. The adjustable swage would simply stall at the obstruction. 
         [0022]    The present invention addresses this situation as the loading increases when an obstruction is hit.  FIG. 8  shows that ring  40  has bent elastically toward recess  32  thus placing the loading surface  36  on an incline where the mating surface  38  has the same angle because of the way the surfaces engage each other and the way they are each supported. Now a loading force delivered through ring  40  and represented by arrow  56  results in skewing the contact axis between surfaces  36  and  38  by angle a in  FIG. 6 . As a result of such surface skewing a radial component of force is generated as indicated by arrow  56 . This radial load is over and above the radial load generated by the direct contact of the segments with the obstruction as illustrated in  FIG. 5 . As a result the adjustable swage is now more likely to clear an obstruction rather than stall due to the additional radial collapse force provided. 
         [0023]    Those skilled in the art will appreciate that both ends can have the same treatment to create a radial component force at both ends even though only one end has been described. While the creation of the additional radial force has been accomplished with bending load surfaces other ways to create a radial force when an obstruction is hit are also within the scope of the invention. In the preferred embodiment the additional radial force is not created until an obstruction is hit so that in normal expansion operation the operation of the adjustable swage described is similar to the prior art operation. In that sense a radial collapsing force is not created during normal operations when it is not needed. Rather, it is when an obstruction is encountered and the adjustable swage needs to get smaller in diameter to get past that obstruction that the bending takes place and the collapse force comes into play to get the adjustable swage past the obstruction. 
         [0024]    Additionally, the size of gap  58  adjacent flexible flange  26  is sized such that even when flange  26  closes gap  58 , the bending is still in the elastic range. 
         [0025]    The above description is illustrative of the preferred embodiment and many modifications may be made by those skilled in the art without departing from the invention whose scope is to be determined from the literal and equivalent scope of the claims below.