Abstract:
A string to be expanded is run in with a running string that supports a swage assembly. The running string is secured to the existing tubular and the top of the string to be expanded is sealed around the supported running string. The pressure applied to the annular space above the seal drives the liner over the swage. A cement shoe is affixed to the lower end of the string that is expanded after becoming detached from the running string assembly. When the expanded liner bottoms on a support, generally the hole bottom, the cement is delivered through the shoe and the expansion of the top of the string into a recess of the string above continues. The swage assembly with the seal and the anchor are then recovered as the running string is removed during the process of expanding the top of the expanded string into the lower end recess of the existing string already in the wellbore.

Description:
FIELD OF THE INVENTION 
       [0001]    The field of the invention is a method of expansion of tubulars downhole and more particularly expanding one tubular into contact with an open hole section where the added tubular is expanded into a supporting position by advancing the new tubular by moving it over an expansion device 
       BACKGROUND OF THE INVENTION 
       [0002]    Monobore applications using expansion have integrated cementing through a shoe while covering a recess at the end of an existing string with a removable cover that comes off after cementing. A string with a swage is placed in position and the swage is energized to grow in diameter before being advanced through the newly added tubular until the swage exits the top of the added tubular to fixate it into the recess at the lower end of the existing tubular. The result is a monobore well. These designs have also disclosed a deployable shoe that can be delivered with the string prior to expansion and then tagged and retained as a swage moves through the string only to be reintroduced into the expanded string and sealingly fixated to it for the cementing operation. Examples of one or more of these method steps are illustrated in U.S. Pat. Nos. 7,730,955; 7,708,060; 7,552,772; 7,458,422; 7,380,604; 7,370,699; 7,255,176 and 7,240,731. 
         [0003]    Methods that advance a swage through a tubular require the rig equipment to not only support the weight of the string to be expanded but also to be able to handle the applied force to the swage to advance it through the tubular to enlarge the diameter. The present invention reduces the surface equipment capacities needed to perform an expansion to create, for example, a monobore. It entails bracing the workstring to an existing tubular with the string to be expanded inside the existing tubular. The annulus around the work string is sealed and the swage is retained as annulus pressure around the running string advances the string to be expanded with respect to the stationary swage. Subsequently the expanded string is cemented and the expansion is completed by swage movement to exit the tubular that is now expanded, cemented and joined to the existing tubular. The bottom hole assembly that was used to deliver and expand the tubular into a supporting position is then retrieved to the surface. More details of the method will become readily apparent to those skilled in the art from a review of the detailed description of the preferred embodiment and the associated drawings while understanding that the full scope of the invention is to be determined from the literal and equivalent scope of the appended claims. 
       SUMMARY OF THE INVENTION 
       [0004]    A string to be expanded is run in with a running string that supports a swage assembly. The running string is secured to the existing tubular and the top of the string to be expanded is sealed around the supported running string. The pressure applied to the annular space above the seal drives the liner over the swage. A cement shoe is affixed to the lower end of the string that is expanded after becoming detached from the running string assembly. When the expanded liner bottoms on a support, generally the hole bottom, the cement is delivered through the shoe and the expansion of the top of the string into a recess of the string above continues. The swage assembly with the seal and the anchor are then recovered as the running string is removed during the process of supporting the top of the expanded string to the lower end recess of the existing string already in the wellbore. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0005]      FIG. 1  is a simplified diagram of the method showing the string to be expanded delivered to within the string that exists in the wellbore; 
           [0006]      FIG. 2  is the view of  FIG. 1  showing the string advanced over the swage assembly for expansion of the tubular string; 
           [0007]      FIG. 3  is the view of  FIG. 2  showing the cementing process; 
           [0008]      FIG. 4  is the view of  FIG. 3  showing the swage assembly raised to a location where expansion of the top of the string into a recess of the existing tubular can take place; 
           [0009]      FIG. 5  is the view of  FIG. 4  and shows the expansion assembly coming through the string at the close of expansion with the two strings joined and the expanded string cemented; 
           [0010]      FIG. 6  is the view of  FIG. 5  with the running string and expansion assembly fully removed; 
           [0011]      FIG. 7   a  is a view of the assembly at the bottom of the string to be expanded and the components that interact with those components that are located at the lower end of the running string; 
           [0012]      FIG. 7   b  shows the various configuration of the dual swage assembly in the various steps of the method; 
           [0013]      FIG. 8  shows running in a coiled tubing version of the string to be expanded; 
           [0014]      FIG. 9  shows the top of the string to be expanded being cut in an injector assembly; 
           [0015]      FIG. 10  shows the running string run into the injector assembly; 
           [0016]      FIG. 11  shows the running string tagged into the swage assembly; 
           [0017]      FIG. 12  shows the string to be expanded positioned so that the swage assembly is below the lower end of the existing string; 
           [0018]      FIG. 13  shows the installation of a top seal that will later permit pressurizing the annulus; 
           [0019]      FIG. 14  shows pressure applied in the annulus above a seal to drive the string to be expanded over the swage assembly while the running string is anchored to an existing string; 
           [0020]      FIG. 15  shows engaging the cementing shoe to the already expanded lower end of the string being expanded; 
           [0021]      FIG. 16  shows continuation of expansion and the movement of displaced fluid during such expansion; 
           [0022]      FIG. 17  shows release of the running string anchor and stabbing the expansion assembly into the cement shoe; 
           [0023]      FIG. 18  shows pumping cement and the movement of displaced fluid from cementing; 
           [0024]      FIG. 19  shows the cementing job finished; 
           [0025]      FIG. 20  shows circulating out the excess cement; 
           [0026]      FIG. 21  shows releasing the expansion assembly from the shoe and raising the expansion assembly to a position where expansion can continue; 
           [0027]      FIG. 22  shows contacting the recess in the existing string with the top of the string being expanded; 
           [0028]      FIG. 23  shows lowering the expansion assembly so that the larger swage can be collapsed; 
           [0029]      FIG. 24  shows concluding the expansion with the smaller swage while the larger swage is collapsed. 
           [0030]      FIG. 25  shows a bypass opened in the cup seal as the balance of the expansion concludes with the swage assembly engaging into the cup seal assembly; 
           [0031]      FIG. 26  shows the cup seal assembly released from the liner top being expanded; 
           [0032]      FIG. 27  shows the swage assembly coming out of the liner top; 
           [0033]      FIG. 28  shows a set down force to collapse the smaller of the swages; 
           [0034]      FIG. 29  shows movement down through the expanded string to confirm that it has the required drift dimension that allows the swage assembly to exit in a collapsed state; 
           [0035]      FIG. 30  shows the assembly removed and the resulting extension of the well as a monobore. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0036]    A very simplified version of the method is illustrated in  FIGS. 1-6  to show in general terms how it operates. A borehole  10  extends past an existing tubular  12  that has a recess  14  near its lower end. The recess  14  could have been placed there with an expansion tool that expanded the string  12  after it was originally placed in position in the wellbore  10 . A running string  16  delivers a string to be expanded  18  and has a top end seal  20  to close off the annulus  22 . Near the lower end of the running string  16  is a smaller swage  24  and a larger swage  26  shown in the collapsed condition. Preferably the swages are made of wedge segments that slide axially relative to each other to change between a collapsed dimension and an expansion dimension. The strings  18  and  16  can be coiled or jointed tubing. The string  18  can also have either a round or folded cross-section. 
         [0037]    In  FIG. 2  the pressure has been applied as indicated by arrow  28  to move the string  18  in a downward direction. Such movement acts to enlarge the swages to their desired diameters for expansion. The upper end  30  is not yet expanded leaving a gap  32  for fluid displacement when cementing begins as depicted in  FIG. 3 . 
         [0038]    In  FIG. 3  the string  16  is tagged into a cement shoe that is not shown and cement is delivered into the annulus  34 . At the conclusion of cementing in  FIG. 4 , the string  16  is released from the shoe (not shown) and the swages  24  and  26  are raised in a manner that only swage  24  is deployed. The cement in the unexpanded annulus  32  will remain in place until squeezed out of the liner top during liner lap expansion. The swage  24  is either pulled by string  16  or is driven up by pressure delivered through string  16  to below swage  26  to drive the swages  24  and  26  out through the string  18  to close the gap  32  as shown in  FIG. 5 .  FIG. 6  shows the expansion assembly removed and the resulting wellbore completed as a monobore with the drift diameter at  36  at least as large as the diameter at  38 . 
         [0039]    From the detail offered thus far it can be seen that the string  18  is advanced over a stationary swage assembly  24  and  26  that is initially located below the existing tubular  12  that has a lower end recess  14 . After cementing, the balance of the expansion can take place by advancing the swages  24  in the expanded position and  26  in the collapsed position by literally pulling on the running string  16  or by delivering pressure though the running string  16  to then drive up the swage  24  by pressurizing space  40  that is below and within the string  18 . 
         [0040]    In order to understand the details of the method, a more specific explanation of some of the introduced components will follow that also adds some new components. The detailed functioning of all the components will then be developed as the step by step description that then follows. Repeated in  FIG. 7   a  from  FIGS. 1-6  are the liner  18  that is to be expanded with the swages  24  and  26 . The seal  20  seals around the running string  16 . The remaining components will now be introduced and discussed in greater detail. A selectively deployed anchor  42  is attached to the running string  16  and can be selectively deployed to the existing string  12  as will be explained below. The seal  20  has a central passage  44  and a stack of chevron seals  46  or some equivalent seal so that a seal can be maintained in annuls  22  as pressure represented by arrow  28  is applied and the seal  20  moves with the string  18  relatively to the stationary pipe  16 . It is preferred that the length of the running string  16  over which the seals  46  will travel should be polished to enhance sealing for at least the travel length of movement of seals  46  on the outside surface of the string  16 . The seal assembly  20  is secured to the string  18  by a breakable connection  48 . A connector tool  50  is at the lower end of the string  16  and can selectively engage the receptacle  52  above swage  24 . The connector tool  50  has lateral passages  54  and a through passage  56 . A series of bow springs  58  can serve as a centralizer as well as any equivalent device so that tagging into the receptacle  52  can be facilitated. A cement shoe  60  is schematically illustrated below the swage  26 . As will be explained below, the shoe  60  is designed to separate from the string  16  and sealingly anchor to the expanded portion at the lower end of the string  18  as will be explained in more detail below. 
         [0041]      FIG. 7   b  shows the four positions of the swages  24  and  26  during the practice of the method. In the first view both are collapsed for run in. In the second view both are expanded for initial expansion by the string  18  moving past as pressure is applied above seal  20  as indicated by arrow  28 . In the third view only swage  24  is activated for the finish of the expansion of the string  18  by either pulling with string  16  or pushing from behind swage  24  with pressure delivered through string  16  as swage  24  holds a seal against string  18  for the finish of expansion. In the final view both swages  24  and  26  are again collapsed for removal from the now secured string  18 . 
         [0042]      FIGS. 8-30  detail the method for using coiled tubing for the liner  18  but the method is applicable to jointed tubing as well but different surface equipment will be used. The string  18  can be circular when run in or folded in a general figure eight shape as indicated by  62 . The main difference between using rounded string  18  to a folded version for running in is that the folded version  62  will need dual running strings  16  to reside in the wide portions of the figure eight shape to ensure that the folded shape transitions to round and that the expansion swage is loaded in a symmetrical manner. 
         [0043]    In  FIG. 8  a rig  64  is in position over the borehole  10 . Spool  66  has the string  18  that wraps around it and feeds out through a guide  68  and then through injectors  70  and  72 . It should be noted that typical well control equipment such as blowout preventers are omitted for clarity and added to that the drawings are also somewhat schematic so that details are omitted that are not significant to understanding the operation of the method. A flange  74  will subsequently accept a stuffing box as will be discussed with regard to  FIG. 13 . The existing tubular  12  is already in position with a lower end recess  14 . The swages  24  and  26  and the shoe  60  are connected to the lower end of the string  18  before running into the wellbore  10 . 
         [0044]    In  FIG. 9  the string  18  is cut at  76  when the appropriate length has been fed off the spool  66 . The cut is made between the guides  70  and  72  and the cut end is dressed to sealingly accept the seal assembly  20  as will be discussed with regard to  FIG. 10 . 
         [0045]    In  FIG. 10  the anchor  42  is affixed to the running string  16  as is the seal assembly  20  with the connector tool  50  then being attached to the string  16 . The string  16  can be a coiled tubing string fed off spool  78 . The packer cup assembly  20  is attached to the already dressed upper end of the string  18  using the breakable connection  48 . Anchor  42  at this point is still loosely fit to the string  16 . 
         [0046]    In  FIG. 11  the string  16  is advanced until the connector tool  50  latches into receptacle  52  so that the string  16  can take on the weight of the liner  18 . The running string  16  is picked up to insure it is supporting the liner  18  and if it is then the anchor  42  is attached to the liner  18 . 
         [0047]    In  FIG. 12  the swages  24  and  26  are lowered with the string  16  to below the lower end of the existing string  12 . In  FIG. 13  a stuffing box  80  is secured at flange  74 . In  FIG. 14  a pump truck  82  is connected with a line  84  to below the stuffing box  80  to result in a downward force represented by arrow  86  against the seal  20 . Before such pressure is applied however, the anchor  42  is set against the parent casing  88  so that the rig  64  is not stressed from the expansion operation that results from pressure advancing string  18  over the now deployed swages  24  and  26  that remain stationary because they are now supported by anchor  42 . The anchor  42  can be made responsive to deploy upon delivery of pressure represented by arrow  86  or alternatively by mechanical tension of running string  16 . Higher pressure than needed to set the anchor  42  then shears the connection between the liner  18  and the swages  24  and  26  as the liner  18  starts moving. The initial liner  18  movement builds the swages  24  and  26  to their full dimension with swage  26  being larger than swage  24 . A bell  90  forms at the lower end of string  18  as pressure on seal  20  advances string  18  over fully built swages  24  and  26 . 
         [0048]    In  FIG. 15  the shoe  60  releases from swages  24  and  26  and deploys sealingly against the now expanded bell  90  at the lower end of the string  18 . A seal and slip assembly is schematically illustrated at  92  to show the shoe  60  secured to the string  18  for subsequent cementing.  FIG. 16  shows the liner  18  continuing to advance and displace fluid as it does so. The displaced fluid is represented by arrows  94 ,  96  and  98  that then enter ports  100  in the seal assembly  20 . From there the flow continues into annulus  102  as indicated by arrows  104  and  106  and into ports  54  of connector  50 . From there the flow can go into space  40  whose volume grows as the liner  18  moves downhole, as illustrated by arrow  110  or uphole through the liner  18  as illustrated by the arrow  108 . As an alternative to the above flow scheme the cement shoe  60  can have its ports  112  held open to take returns into space  40  and when the initial expansion is done the check valves (not shown) in the shoe  60  can be enabled to stop flow into space  40  when the cementing later takes place. 
         [0049]    The expansion stops in  FIG. 17  just short of the recess  14  and the removal of pressure unsets the anchor  42 . The work string  16  is advanced to tag the swage assembly into the cement shoe. The connection to receptacle  52  can be confirmed with a pickup force to run in string  16 . At this time the string  16  is latched through to the cement shoe  60  and cementing can begin. 
         [0050]    In  FIG. 18  a lead plug  114  has been dropped ahead of the cement being added to close off ports  54  that schematically are no longer shown in the connector  50 . The plug  114  has a passage through it temporarily blocked by a rupture disc (not shown) so that the delivered cement goes straight through the connector  50  and out the ports  112  as indicated by arrows  116 . At this time the seal assembly  20  is out of contact with the recess  14  so that fluids displaced by the flowing cement go uphole and past the unset anchor  42  as indicated by arrows  118  and  120 . Arrow  122  represents cement delivery through the string  16 .  FIG. 19  shows the cement delivered to fill the gap  32  and the plug behind the cement (not shown) bumped against the lead plug  114  (not shown in this view). The cement pumps can be turned off at this time.  FIG. 20  shows the shoe  60  released by the swages  24  and  26  which has the effect of closing ports  112  in opposed directions to flow. Circulation flow represented by arrow  124  down the string  16  removes excess cement that then travels through the end of the string  16  represented by arrows  126 ,  128  and  130  through ports  100  and up to the surface as represented by arrows  132 . This circulation can be repeated as expansion is resumed to remove further displaced cement out of gap  32  as gap  32  is closed by continuing expansion. 
         [0051]    In  FIG. 21  the string  16  is picked up to engage swage  24  that is now built and close off the ability for flow to bypass the swages  24  and  26 . The swage can seal metal to metal upon expansion contact or there can be a sealing tool independent of the swages above or below the swages that allows for pressure buildup behind the swages  24  and  26  as represented by arrows  134 . While initial overpull helps to obtain the seal, thereafter pressure applied as indicated by arrows  134  helps to maintain the seal so that the swage  24  can be powered up to continue expansion of the liner  18  to close the gap  32  by displacing cement out of it. In  FIG. 22  the smaller swage is in the recess  14  and the larger swage  26  is just below recess  14 . The lap  136  is now anchored and sealed. 
         [0052]    In  FIG. 23  the string  11  is lowered and pressure is applied in the string  16  as indicated by arrow  138  and in the annulus as indicated by arrow  140  at the same time. The net result is that the larger swage  26  is collapsed while swage  24  continues to be in the built condition for further expansion. The annulus pressure represented by arrow  140  goes through ports  100  and into space  40 . There is no flow past seal  20  because of the balanced pressure applied in the string  16 . 
         [0053]    In  FIG. 24  the swage  24  is raised to sealing contact with the liner  18  and pressure is only applied in the string  16  represented by arrow so that the liner lap is made longer as hanger seals and slips on the string  18  (not shown) are brought into contact with the recess  14 . In  FIG. 25  the expansion has continued until the connector  50  bumps the seal  20  so that they attach to each other and that opens the bypass for the seal  20  that is schematically illustrated as  142 . The removal of the string  16  past the recess  14  will not allow for pulling a wet string or swabbing the well because the bypass openings  142  are open. 
         [0054]    Further movement of the string  16  in  FIG. 26  breaks the connection  48  of the seal  20  to the liner  18 . Continued pumping allows the swages  24  and  26  to exit the liner  18  at the top, as shown in  FIG. 27  with the swage  24  still in the recess  14 . A set down force as shown in  FIG. 28  allows the swage  24  to collapse. The force can be from simply setting down weight or applying annulus pressure to create an impact force to collapse the swage  24 . 
         [0055]      FIG. 29  shows an option trip downhole to check drift with the seal assembly  20 . The movement of the seal assembly  20  can be aided with pressure for both uphole and downhole movement of the seal assembly  20 . In the  FIG. 29  position the borehole  10  can be pressured to test the integrity of the connection between the liner  18  and the existing tubular.  FIG. 30  shows the string  16  and the equipment mounted to it removed from the well  10 . 
         [0056]    Those skilled in the art will appreciate that the method allows for completion of a well by adding a string and connecting it to an existing string involving an expansion that features advancing the string to be expanded over a swage assembly using pressure provided above a seal that moves with the string being expanded. The expansion takes place from the bottom up and employs variable swage devices that build to a first size for initial expansion and then to a smaller size inside a recess of the existing tubular so that the seal and swage assemblies can ultimately exit from the tubular being expanded and the existing tubular. In the preferred embodiment a monobore completion is achieved. The expansion is in stages with cementing taking place while a gap exists between the tubular being expanded and a lower end recess in the existing tubular. The seal assembly is bypassed in the recess of the existing tubular during cementing. A bypass opens in the seal assembly for ultimate removal to prevent pulling a wet string or swabbing the formation. The running string is anchored in the well against tension applied from forcing the tubular being expanded over a stationary swage assembly. The swage assembly uses two swages having different diameters that can both be deployed for the initial expansion and where a smaller of the two is deployed for connecting the top of the string being expanded to a lower end recess of an existing tubular. The string to be expanded can be jointed tubing or coiled tubing and its initial shape can be round or folded, such as in a generally figure eight shape, for example. The figure eight shape can use two running strings deployed in the wide portions of the folded string so that the act of driving the string over the swage assembly will not put harmful moments on the tubular that is being unfolded and expanded as it is driven past the swage assembly. 
         [0057]    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.