Abstract:
An additional string is run through an existing string using a running string. With the strings overlapping an upper inflatable secures them together leaving gaps. The upper inflatable creates an upper expanded zone where the swage assembly is then built. The swage assembly has a seal and upon pressure being applied between the upper inflatable and the seal the swage assembly releases the running string and is pushed to expand the additional string until tagging a cement shoe. The running string is rejoined to the swage assembly and after cementing a lower inflatable is deployed to make a bell and to set an external packer if used. If there is an external packer the shoe releases and on the way out of the hole the upper inflatable sets a seal in the lap.

Description:
FIELD OF THE INVENTION 
     The field of the invention is a method to produce a monobore and more particularly running in a string with a cement shoe and supporting it to an existing string by liner top expansion which makes room to build a swage and drive the swage with applied pressure to the cement shoe. A bell is formed at the lower end of the liner and the liner top is sealed as the inner assembly is pulled after cementing is concluded 
     BACKGROUND OF THE INVENTION 
     Monobore wells have a constant diameter for a given interval that is made up of multiple strings. Typically the existing string has an enlarged segment or bell into which the next string will be supported and then sealed after cementing, in the case of cemented wellbores. The newly added string has to be expanded and in some applications cemented and there needs to be a bell at the lower end of the added string so as to accommodate the next string and retain the monobore nature of the wellbore. The liner is first supported in the bell of the existing string leaving gaps to allow fluid displacement during cementing and those gaps are closed after cementing is completed. 
     The general description of the above procedure is optimized by finding ways to perform the needed steps to deliver, support, expand, cement and seal the liner to an existing tubular in as few trips as possible and ideally in a single trip. 
     One attempt at such a method is described in US Publication 2010/0032167. In one technique in this reference the swage assembly is pumped in a downhole direction for part of the expansion until a cement shoe is tagged. The running string is rejoined to the swage assembly for cementing. Subsequently the swage assembly is driven uphole to support and seal the newly added liner that had previously been supported from the hole bottom. After that the shoe has to be drilled out. There is no discussion of how the lower end of the recently cemented liner is to be belled out because the method described there is not for making a monobore but rather reduces the well diameter with each successive string. In an alternative embodiment the swage assembly is built just above the cement shoe and driven uphole to expand the liner. After cementing with the running string and swage assembly latched to the shoe, the swage assembly is released from the shoe and propelled with pressure from below while retained to the running string to finish the expansion at the liner top to secure and seal the liner to the existing tubular. 
     Various techniques have been developed to expand liners and attach them to existing casing already in the wellbore. Some of these techniques involve running a liner with a wide bell at the bottom where the expansion equipment is located and then driving the swage up the liner and out the top and along the way setting external seals to the surrounding casing as the swage makes an exit. One such process is shown in U.S. Pat. No. 6,470,966. The extensive list of prior art included in that patent is representative of the state of the art in downhole tubular expansion techniques that include attachment to an existing tubular. Other patents show the use of swages that include a series of retractable rollers that can be radially extended downhole to initiate a tubular expansion such as of a casing patch as for example is illustrated in U.S. Pat. No. 6,668,930. Some devices swage in a top to bottom direction as illustrated in U.S. Pat. No. 6,705,395. 
     Another approach is illustrated in an application entitled Pump Down Swage Expansion Method (by some of the inventors of this application) filed Oct. 8, 2010 and having a Ser. No. 12/901,122. That application uses a running string and liner peripheral seals to move a swage assembly for gaining liner support. It continues in that mode with building another swage after support of the liner in the existing tubular. In the same trip the shoe is secured and the liner cemented followed by engaging the seal of the liner hanger with manipulation of the running string. The swage assembly remains connected to the running string during expansion. 
     Methods that mechanically 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. This reference, identified in the previous paragraph, reduces the surface equipment capacities needed to perform an expansion to complete a well. The method features a top down expansion using a plurality of adjustable swages that get built at different times and that are driven from applied annulus pressure delivered around a workstring. The tubular to be expanded is placed in an overlapping position with an existing tubular. The swage assembly is pushed on a guide extending from the running string by virtue of a cup seal around the running string and another peripheral seal on the top of the liner to be expanded to prevent pressure bypassing as the swage assembly is run into the liner string to support the liner without sealing it. A further swage is built in the liner at a location below the support point to the existing liner and the balance of the liner is expanded to bottom while engaging the cement shoe as the swage assembly leaves the lower end of the now expanded liner. The shoe is repositioned and set at the lower end of the expanded liner and a cement job follows with a subsequent reversing out of excess cement. The swage assembly is pulled through the liner and another swage is built before it is pushed down through the liner top to set the seal of the liner hanger or optionally to go though past the slips of the liner hanger to create a constant drift though the expanded liner top. The assembly is removed. 
     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. Other patents relating to expansion by moving a cone uphole from within a bell at a lower end of a liner to be supported to a recess in existing tubing and creating a monobore as well as expansion of tubulars downhole are as follows: 6,712,154; 7,185,710; 7,410,000; 7,350,564; 7,100,684; 7,195,064; 7,258,168; 7,416,027; 7,290,616; 7,121,352; 7,234,531; 7,740,076; 7,100,685; 7,556,092; 7,516,790; 7,546,881; 6,328,113; 7,086,475; 6,745,845; 6,575,240; 6,725,919; 6,758,278; 6,739,392; 7,201,223; 7,204,007; 7,172,019; 7,325,602; 7,363,691; 7,146,702; 7,172,024; 7,308,755; 6,568,471; 6,966,370; 7,419,009; 7,040,396; 6,684,947; 6,631,769; 6,631,759; 7,063,142; 6,705,395; 7,044,221; 6,857,473; 7,077,213; 7,036,582; 7,603,758; 7,108,061; 6,631,760; 6,561,227; 7,159,665; 7,021,390; 6,892,819; 7,246,667; 7,174,964; 6,823,937; 7,147,053; 7,299,881; 7,231,985; 7,168,499; 7,270,188; 7,357,190; 7,044,218; 7,357,188; 7,665,532; 7,121,337; 7,434,618; 7,240,729; 7,077,211; 7,195,061; 7,198,100; 6,640,903; 7,438,132; 7,055,608; 7,240,728; 7,216,701; 6,604,763; 6,968,618; 7,172,021; 7,048,067; 6,976,541; 7,159,667; 7,108,072 and 6,55,7640. 
     What is needed and provided by the method of the present invention is a way to introduce a string with a cementing shoe into a wellbore with an existing tubular with a lower end bell and add strings in a monobore completion where each string can be supported, expanded, optionally cemented and sealed to the bell of the existing tubular while leaving a lower end bell on the recently added tubular so that the process can be repeated for the particular zone or interval. Those skilled in the art will more readily appreciate additional aspects of the invention from 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 
     A liner string is run into position on a running string. The assembly features a cement shoe retained at a lower end and an external isolation device. At the upper end is a hanger and seal on the outside of the liner and internally is an inflatable which has supported below it a buildable swage assembly that can selectively be detached from the upper inflatable and an associated packer cup to allow driving the swage with pressure applied in a downhole direction after release from the upper inflatable. The upper inflatable sets the hanger at the liner top and expands a portion near the liner top. The swage assembly is built in the recently expanded liner top and then released from the running string to tag into the shoe. The running string is reconnected to allow cementing through the swage assembly and the shoe. A lower inflatable around the shoe and within the liner is expanded to set the external seal before the cement sets. This allows the lower inflatable to be deflated with the running string attached to the shoe and no cement flow back because the external seal has been set. Setting the external seal is coincident with creating a lower end bell in the liner. The running string can then pull out the swage assembly and shoe with the lower inflatable out of the liner. On the way out of the liner the upper inflatable sets a seal adjacent to the already set slips and the bottom hole assembly is pulled leaving a monobore down to the lower end of the liner that now has a bell for the next string to be attached to extend the monobore. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  illustrates running in the liner to overlap with the lower end of the existing tubular in an embodiment with an external lower end packer where the shoe will be retrieved; 
         FIG. 2  is the view of  FIG. 1  showing the upper inflatable securing the hanger at the upper end of the liner being run; 
         FIG. 3  is the view of  FIG. 2  showing the upper inflatable deflated and shifted lower for sequential inflation and deflation with movement to create an expanded zone below the set hanger; 
         FIG. 4  is the view of  FIG. 3  showing the sequential movement and inflation and deflation used to create the upper expanded zone in the liner; 
         FIG. 5  is the view of  FIG. 4  showing the swage assembly raised into the recently expanded zone so that the swage assembly can be built; 
         FIG. 6  is the view of  FIG. 5  showing the swage assembly built and released from the running string so that pressure from above onto the associated packer cup will drive the swage assembly; 
         FIG. 7  is the view of  FIG. 6  showing the swage assembly bottoming out in the zone expanded with the upper inflatable; 
         FIG. 8  is the view of  FIG. 7  showing the swage assembly continuing the liner expansion to a point just short of tagging into the cement shoe; 
         FIG. 9  is the view of  FIG. 8  showing the swage assembly tagged into the shoe at the lower end of the liner; 
         FIG. 10  is the view of  FIG. 9  showing the upper inflatable released to allow the running string to be lowered; 
         FIG. 11  is the view of  FIG. 10  showing the running string tagged into the swage assembly so that cementing can begin; 
         FIG. 12  is the view of  FIG. 11  shown after the cement has been delivered through the show and into the surrounding annular space about the liner; 
         FIG. 13  is the view of  FIG. 12  showing the lower inflatable expanded to set the external packer and to create a bell at the lower end of the liner; 
         FIG. 14  is the view of  FIG. 13  showing the lower inflatable deflated to allow the running string to be pulled out of the hole; 
         FIG. 15  is the view of  FIG. 14  showing the upper inflatable aligned with the hanger and ready to set the external seal; 
         FIG. 16  is the view of  FIG. 15  showing the upper inflatable setting the seal to the existing tubular by expansion of the upper end of the liner; 
         FIG. 17  is the view of  FIG. 16  showing the removal of the upper and lower inflatable seals and the swage assembly from the wellbore; 
         FIG. 18  is the view of  FIG. 17  showing the wellbore after the removal of the upper and lower inflatable seals and the swage assembly; 
         FIG. 19  is an alternative embodiment to that of  FIG. 1  shown being run into the wellbore with the difference being the absence of an external seal at the lower end of the liner being run in that is not needed if the cement shoe is left in place after cementing; 
         FIG. 20  is the view of  FIG. 19  with the upper inflatable actuated to hang the liner to the existing tubular; 
         FIG. 21  shows the upper inflatable deflated and repositioned to start expanding the upper end of the liner; 
         FIG. 22  is the view of  FIG. 21  showing expansion of the upper portion of the liner with the upper inflatable using a sequence of inflation/deflation/relocation steps; 
         FIG. 23  is the view of  FIG. 22  showing the swage assembly repositioned into the recently expanded portion of the liner; 
         FIG. 24  is the view of  FIG. 23  showing the swage assembly released from the running string and moving to the lower end of the already expanded portion of the liner; 
         FIG. 25  is the view of  FIG. 24  with the swage assembly reaching the lower end of the already expanded portion of the liner; 
         FIG. 26  is the view of  FIG. 25  showing the swage assembly driven by pressure delivered through the running string with the upper inflatable set; 
         FIG. 27  is the view of  FIG. 26  showing the swage assembly tagged into the cement shoe; 
         FIG. 28  is the view of  FIG. 27  showing the upper inflatable deflated; 
         FIG. 29  is the view of  FIG. 28  showing the running string reconnected to the swage assembly so that cementing can begin; 
         FIG. 30  is the view of  FIG. 29  showing the cement delivered through the shoe and going up the outer annulus around the expanded liner; 
         FIG. 31  is the view of  FIG. 30  showing the lower inflatable set to make a lower end bell in the liner; 
         FIG. 32  is the view of  FIG. 31  showing the running string being pulled leaving the shoe and lower inflatable as the cement sets; 
         FIG. 33  is the view of  FIG. 32  showing the upper inflatable in position and inflated to seat the upper seal on the liner; 
         FIG. 34  is the view of  FIG. 33  showing the running string removing the upper inflatable and swage assembly from the wellbore; and 
         FIG. 35  is the view of  FIG. 34  showing the wellbore after removal of the running string, the upper inflatable and the swage assembly from the liner. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       FIG. 1  shows a casing  10  which has been cemented at  12 . At the lower end  14  a running string  16  supports a liner or tubular string  18 . Item  20  schematically represents slips and a sealing element that will be set in sequence with the slips being set first to support liner  18  to the casing  10 , as will be explained below. For run in the liner  18  is releasably supported to the running string  16  by a breakable member such as a shear pin that is not shown that can be broken by the actuation of the upper inflatable isolator  22  that is shown deflated for run-in in  FIG. 1 . Alternatively, the release could be controlled directly by pressure such as a piston releasing slips or dogs. A swage assembly  24  is releasably supported from mandrel  26  of the upper inflatable  22  by virtue of connection  28 . Connection  28  can release and re-latch as will be explained below. Between the swage assembly  24  and the connection  28  is a resilient seal such as a packer cup open in an uphole direction denoted as  30 . 
     At the lower end  32  of liner  18  is an external open hole packer  34  and internally is a cement shoe  36  that is temporarily retained to the liner  18  by a breakable member such as one or more shear pins that are not shown. Surrounding the shoe  36  is a lower inflatable isolator  38  shown deflated for run-in in  FIG. 1 . Actuation of the lower inflatable  38  releases the shoe  36  from the liner  18  and creates a lower end bell as shown in  FIG. 13 . Such actuation also sets the open hole packer in the already pumped cement as will be explained later with regard to  FIG. 13 . 
       FIG. 7  shows the swage assembly progressed to transition location  40  with pressure into chamber  42  and to some extend its own weight so that further expansion can then start.  FIG. 8  shows the volume of chamber  42  growing as the expansion with pressure on the swage assembly  24  drives it using the attached seal  30 . At the end of the expansion in this manner the latch  33  will land in receptacle  44  in shoe  36  and automatically collapse the swage assembly  24  to its run in diameter upon connection to receptacle  44 , as shown in  FIG. 9 . The automatic collapse operation can be initiated by geometrical mating such as collet/profile matching or as a hydraulic result of seals from the swage assembly  24  stabbing into a seal profile in receptacle  44 . As the swage assembly  24  lands in the shoe  36  the pressure in the string  16  will spike giving surface personnel the signal that the shoe  36  has been tagged and that the upper inflatable  22  can now be allowed to deflate as shown in  FIG. 10 . The string  16  is lowered to reconnect connection  28  as is shown in  FIG. 11 . At this time as shown in  FIG. 12  the cement  46  is delivered through the string  16  and through the shoe  36  and into the surrounding annulus  48  around the liner  18 . Before the cement  46  sets the lower inflatable  38  is inflated to not only make a bell  50  but to also set the open hole packer  34 . Doing this will allow the shoe  36  to be retrieved and will prevent cement flow back when the lower inflatable  38  is deflated as shown in  FIG. 14 . At this time any excess cement in the string  16  can be circulated out through the shoe  36  although it is not shown in the drawings. The string  16  is lifted as shown in  FIG. 15  until the upper inflatable is aligned with the assembly  20  that up to this time has only had its slips set for support of the liner  18  from the casing  10 . This was done so that during cementing in  FIG. 12  the cement could displace fluid through the assembly  20  to allow the cement to advance in a manner known in the art. Now, as shown in  FIG. 16 , it is time to engage a seal of assembly  20  to the casing  10  to seal the liner  18  to the casing  10 . This sealing action is schematically represented in  FIG. 16  by the elimination of the assembly  22 . All that remains is for the string  16  to be pulled out of the well and take with it the entire bottom hole assembly as shown in  FIG. 17  which then leaves a monobore shown in  FIG. 18  with a lower end bell  50  ready to receive the next liner string that is not shown after the well is drilled deeper. This process repeats to well bottom to produce the monobore. 
       FIG. 7  shows the swage assembly progressed to transition location  40  with pressure into chamber  42  and to some extend its own weight so that further expansion can then start.  FIG. 8  shows the volume of chamber  42  growing as the expansion with pressure on the swage assembly  24  drives it using the attached seal  30 . At the end of the expansion in this manner the latch  32  will land in receptacle  44  in shoe  36  and automatically collapse the swage assembly  24  to its run in diameter upon connection to receptacle  44 , as shown in  FIG. 9 . The automatic collapse operation can be initiated by geometrical mating such as collet/profile matching or as a hydraulic result of seals from the swage assembly  24  stabbing into a seal profile in receptacle  44 . As the swage assembly  24  lands in the shoe  36  the pressure in the string  16  will spike giving surface personnel the signal that the shoe  36  has been tagged and that the upper inflatable  22  can now be allowed to deflate as shown in  FIG. 10 . The string  16  is lowered to reconnect connection  28  as is shown in  FIG. 11 . At this time as shown in  FIG. 12  the cement  46  is delivered through the string  16  and through the shoe  36  and into the surrounding annulus  48  around the liner  18 . Before the cement  46  sets the lower inflatable  38  is inflated to not only make a bell  50  but to also set the open hole packer  34 . Doing this will allow the shoe  36  to be retrieved and will prevent cement flow back when the lower inflatable  38  is deflated as shown in  FIG. 14 . At this time any excess cement in the string  16  can be circulated out through the shoe  36  although it is not shown in the drawings. The string  16  is lifted as shown in  FIG. 15  until the upper inflatable is aligned with the assembly  20  that up to this time has only had its slips set for support of the liner  18  from the casing  10 . This was done so that during cementing in  FIG. 12  the cement could displace fluid through the assembly  20  to allow the cement to advance in a manner known in the art. Now, as shown in  FIG. 16 , it is time to engage a seal of assembly  20  to the casing  10  to seal the liner  18  to the casing  10 . This sealing action is schematically represented in  FIG. 16  by the elimination of the assembly  22 . All that remains is for the string  16  to be pulled out of the well and take with it the entire bottom hole assembly as shown in  FIG. 17  which then leaves a monobore shown in  FIG. 18  with a lower end bell  50  ready to receive the next liner string that is not shown after the well is drilled deeper. This process repeats to well bottom to produce the monobore. 
       FIGS. 19-35  are similar to  FIGS. 1-18  but differ in that there is no open hole packer  34  used on the liner  18 . Because of that, after the cement is pumped in  FIG. 30  and the lower inflatable  38 ′ is inflated to make bell  50 ′ the connection  32 ′ releases as seen in  FIG. 32  and the lower inflatable  38 ′ stays inflated until the cement  46 ′ sets. Excess cement  46  in the string  16 ′ can be circulated out through connection  32 ′ as the string  16 ′ is pulled as shown in  FIGS. 33 and 34 . After the cement has hardened, the lower inflatable  38 ′ will be drilled up before proceeding into the next zone similar to a common cement retainer. In other respects the sequence in  FIGS. 19-35  is the same as in  FIGS. 1-18 . 
     Although the preferred isolation and expansion devices at the upper and lower ends of the liner  18  are indicated as inflatables  22  and  38 , other devices that can seal and expand against the liner  18  are contemplated such as mechanically or hydraulically set packers or spaced opposed seals forming a straddle tool wherein the gap between the seals can be pressurized for expansion of a tubular between the seals, to mention a few examples. The temporary retaining devices can be shear pins or rings or other frangible retainers. Optionally, one or more isolation and expansion devices can be used. 
     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.