BACKGROUND

[0001] The present disclosure relates generally to an apparatus for expanding tubular members. More particularly, the present disclosure relates to a recoverable shoe assembly for a liner expansion system.

[0002] To form a wellbore using some conventional systems and methods, a drill string initially forms a borehole, and a casing is then installed at the top portion of the borehole. Next, the drill string extends the length of the borehole below the casing. An expandable tubular member, or liner, is then suspended by an expansion assembly within the casing. The expansion assembly includes a tubular member supporting an expansion cone. The expandable liner is then radially expanded by the expansion cone into engagement with the casing to extend the lining of the borehole.

[0003] The expandable liner includes a shoe at its lower end and a launcher assembly disposed therebetween. The shoe has a valveable passage extending therethrough. The launcher assembly has a lower portion connected to the shoe, an upper portion connected to the expandable liner, and a tapered portion extending therebetween. The inner diameter of the lower portion is greater than that of the upper portion, enabling the launcher assembly to receive the expansion cone therein. The expansion cone sealingly engages the lower portion of the launcher assembly. Thus, a chamber is formed within the launcher assembly between the expansion cone and the shoe. The shoe passage, when open or closed, enables or prevents, respectively, fluid communication between the launcher assembly chamber and the annulus between the borehole and expandable liner. The expandable liner is supported by the tubular support member via engagement between the tapered portion of the launcher assembly and the expansion cone.

[0004] Prior to expansion of the expandable liner, a ball, or dart, is delivered via pressurized fluid injected from the surface through the tubular support member, expansion cone, and launcher assembly to seat on the shoe passage, thereby closing the passage and preventing subsequent flow of the pressurized fluid therethrough. Continued injection of pressurized fluid causes pressurized fluid to fill the launcher assembly chamber. When the pressure of fluid contained within the launcher assembly chamber reaches a sufficient level, the fluid pressure causes the expansion cone disposed within the launcher assembly to displace upward within the launcher assembly into the expandable liner. As the expansion cone travels upward within the liner, engagement between the cone and the liner causes radial expansion of the liner. [0005] After the liner has been expanded into engagement with the casing, the expansion cone is removed from the borehole. To again extend the length of the borehole below the now-expanded liner, the shoe coupled to the lower end of the expanded liner must first be removed. The drill string is inserted within the liner, and the shoe is drilled out. Once removed, successive expandable tubulars may be installed and the borehole extended in the same manner until the wellbore reaches the desired depth.

[0006] As the shoe is drilled out, pieces of it fall into the borehole. Occasionally, these pieces block the borehole, thereby preventing further extension of the borehole. Consequently, it becomes necessary to divert the borehole around the blockage, or abandon the wellbore and form another. Given the significant cost associated with both, there is a need for a recoverable shoe that enables installation of an expandable liner.

SUMMARY OF THE DISCLOSURE

[0007] A system including a recoverable shoe assembly for expanding a tubular member, or liner, is disclosed. In some embodiments, the expansion system includes an expansion assembly disposed in sealingly engagement within the tubular member, a shoe assembly releasably coupled within the tubular member, and a chamber disposed therebetween. The expansion assembly has a flowbore and a openable port. The shoe assembly includes a flowbore extending therethrough, the flowbore in fluid communication with the flowbore of the expansion assembly and having a valveable passage. When the valveable passage is closed, the port is adapted to open, whereby the chamber is fluidicly coupled to the flowbore of the expansion assembly. When the valveable passage is open, the port remains closed, whereby the chamber is fluidicly isolated from the flowbore of the expansion assembly.

[0008] In other embodiments, the expansion system includes a tubular launcher having a plurality of circumferentially-spaced slots extending therethrough and a shoe assembly sealingly disposed therein. The shoe assembly has a flowbore extending therethrough, the flowbore having a valveable passage, and a plurality of members, each member radially moveable between an extended position and a retracted position. When in the extended position, each member engages one of the slots, whereby rotation of the shoe assembly relative to the tubular launcher is prevented and whereby axial translation of the shoe assembly relative to the tubular member is prevented in at least a first direction. When in the retracted position, each member is disengaged from the slots.

[0009] Some methods for expanding a tubular member, or liner, in a wellbore include releasably coupling a shoe assembly within the tubular member, delivering pressurized fluid through a flowbore of the shoe assembly, the flowbore having a valveable passage, closing the valveable passage, whereby the pressurized fluid is diverted into a chamber disposed between the shoe assembly and an expansion cone, translating the expansion cone relative to the tubular member under hydraulic pressure, whereby the expansion cone radially expands the tubular member, disengaging the shoe assembly from the tubular member, and retrieving the shoe assembly from the wellbore.

[0010] Thus, embodiments described herein comprise a combination of features and characteristics intended to address various shortcomings associated with certain prior devices. The various characteristics described above, as well as other features, will be readily apparent to those skilled in the art upon reading the following detailed description of the preferred embodiments, and by referring to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0011] For a detailed description of the disclosed embodiments, reference will now be made to the accompanying drawings in which:

[0012] Figure 1 is a cross-sectional view of a liner expansion system including a recoverable shoe assembly in accordance with the principles disclosed herein;

[0013] Figure 2 is a cross-sectional view of the expansion cone of Figure 1;

[0014] Figure 3 is a cross-sectional view of the launcher assembly of Figure 1 ;

[0015] Figure 4 is a schematic, side view of the collet assembly of Figure 1;

[0016] Figure 5 is a schematic side view of the collet assembly assembled between the expansion cone and the lower launcher of Figure 1 ;

[0017] Figure 6 is a schematic, side view of the guide mandrel of Figure 1; and

[0018] Figures 7A and 7B are cross-sectional views of a liner expansion system including another embodiment of a recoverable shoe assembly coupled to and released from, respectively, an expandable liner.

DETAILED DESCRIPTION OF THE DISCLOSED EMBODIMENTS

[0019] The following description is directed to exemplary embodiments of a liner expansion system including a recoverable shoe assembly. The embodiments disclosed should not be interpreted, or otherwise used, as limiting the scope of the disclosure, including the claims. One skilled in the art will understand that the following description has broad application, and that the discussion is meant only to be exemplary of the described embodiments, and not intended to suggest that the scope of the disclosure, including the claims, is limited to those embodiments. [0020] Certain terms are used throughout the following description and the claims to refer to particular features or components. As one skilled in the art will appreciate, different persons may refer to the same feature or component by different names. This document does not intend to distinguish between components or features that differ in name but not function. Moreover, the drawing figures are not necessarily to scale. Certain features and components described herein may be shown exaggerated in scale or in somewhat schematic form, and some details of conventional elements may not be shown in interest of clarity and conciseness.

[0021] In the following discussion and in the claims, the terms "including" and "comprising" are used in an open-ended fashion, and thus should be interpreted to mean "including, but not limited to... ." Also, the term "couple" or "couples" is intended to mean either an indirect or direct connection. Thus, if a first device couples to a second device, that connection may be through a direct connection, or through an indirect connection via other devices and connections. Further, the terms "axial" and "axially" generally mean along or parallel to a central or longitudinal axis. The terms "radial" and "radially" generally mean perpendicular to the central or longitudinal axis, while the terms "azimuth" and "azimuthally" generally mean perpendicular to both the central or longitudinal axis and a radial axis normal to the central longitudinal axis. As used herein, these terms are consistent with their commonly understood meanings with regard to a cylindrical coordinate system.

[0022] Referring now to Figure 1 , there is shown a liner expansion system including a recoverable shoe assembly in accordance with the principles disclosed herein. Liner expansion system 100 includes an expansion assembly 105 coupled to a recoverable shoe assembly 110 installed within an expandable tubular member, or liner, 115. Expansion assembly 105 is hydraulically actuatable to displace upward within expandable liner 115 relative to shoe assembly 110 to radially expand liner 115. Shoe assembly 110 enables coupling of a pressurized fluid source (not shown) to expansion assembly 105, whereby pressurized fluid is delivered through expansion assembly 105 to a chamber 120 within expandable liner 115. The pressurized fluid within chamber 120 causes upward displacement of expansion assembly 105 within expandable liner 115, whereby engagement between expansion assembly 105 and liner 115 causes radial expansion of liner 115. Shoe assembly 110 also sealingly engages the lower end 125 of expandable liner 115 to enable pressurization of chamber 120.

[0023] Expansion assembly 105 includes an expansion cone 130, an expansion mandrel 135 inserted therethrough, and a tubular support member 140 coupled to the upper end 145 of expansion mandrel 135. Tubular support member 140 has a flowbore 150 extending therethrough, and, in this embodiment, is coupled to upper end 145 of expansion mandrel 135 via mating threads 155 formed on the inner and outer surfaces of tubular support member 140 and expansion mandrel 135, respectively. Flowbore 150 of tubular support member 140 is in fluid communication with, or is fluidicly coupled to, the pressurized fluid source.

[0024] Expansion mandrel 135 has a flowbore 160 extending therethrough. When expansion mandrel 135 is coupled to tubular support member 140, as shown in Figure 1, flowbore 160 is in fluid communication with flowbore 150 of tubular support member 140. Expansion mandrel 135 further includes one or more ports 165 extending therethrough. A rupture or burst disc 170 is seated within each port 165. Each rupture disc 170 is configured to prevent fluid flow through port 165 when the pressure of fluid passing through flowbore 160 is less than a preselected level and to burst or rupture when the fluid pressure exceeds the preselected level to allow fluid flow through port 165.

[0025] Referring next to Figure 2, expansion mandrel 135 further includes generally radially extending upper and lower surfaces 137, 139, respectively. When expansion assembly 105 is installed within expandable liner 115, as shown in Figure 1, expansion cone 130 is supported by upper surface 137 of expansion mandrel 135. Referring still to Figure 2, expansion mandrel 135 further includes a plurality of circumferentially-spaced splines 230 extending from lower surface 139. Each spline 230 has a length 235 extending substantially parallel to a longitudinal centerline 228 of expansion mandrel 135 and a width 240 that extends substantially circumferentially or azimuthally relative to centerline 225. Thus, splines 230 may be referred to as longitudinally or axially disposed splines. A recess 245 is formed between each pair of adjacent splines 230. Splines 230 are configured to matingly engage and interlock with another set of splines extending from recoverable shoe assembly 110, as will be described.

[0026] Expansion cone 130 has a throughbore 175 configured to receive expansion mandrel 135 therethrough. Expansion cone 130 further includes an upper portion or neck 180, a lower portion or base 185, and a tapered portion 190 extending therebetween. Neck 180 of expansion cone 130 has an outer surface 195 defined by a diameter that enables insertion of neck 180 into an unexpanded portion 200 (Fig. 1) of liner 115 when expansion assembly 105 is installed within expandable liner 115, as shown in Figure 1. Base 185 has an outer surface 205 defined by a diameter that enables radial expansion of liner 115 to the desired inner diameter and/or wall thickness. Tapered portion 190 of expansion cone 130 has an outer surface 210 configured to engage an inner surface 215 (Fig. 1) of liner 115 to enable expansion cone 130 to radially expand liner 115. In this embodiment, outer surface 210 is substantially linear and offset relative to a longitudinal centerline 225 of expansion cone 130 by an angle 220. [0027] Referring again to Figure 1, expandable liner 115 includes a launcher assembly 250 at its lower end 125. In this embodiment, launcher assembly 250 includes two separate components 260, 265 joined end-to-end by a weld 270. In other embodiments, however, launcher assembly 250 may be a single-piece component.

[0028] Turning to Figure 3, launcher assembly 250 includes an upper launcher 260 and a lower launcher 265. Upper launcher 260 is tubular, having a lower portion 275, an upper portion 280, and a tapered portion 285 extending therebetween. Upper portion 280 has an inner surface 290 defined by a diameter corresponding to the inner diameter of expandable liner 115 prior to radial expansion. Lower portion 275 has an inner surface 295 defined by a diameter that enables expansion cone 130 and shoe assembly 110 to be inserted therein, as shown in Figure 1. As previously described, inner surface 215 of tapered portion 285 engages outer surface 210 of tapered portion 190 of expansion cone 130 during expansion of liner 115.

[0029] Lower launcher 265 is also tubular, having an outer surface 315 and an inner surface 305 defined by a diameter that enables expansion cone 130 and shoe assembly 110 to be inserted therethrough. In this embodiment, the diameter of inner surface 305 is substantially constant along the length of lower launcher 265. Moreover, in some embodiments, the diameter of inner surface 305 is slightly less than the inner diameter of lower portion 275 of upper launcher 260 to promote sealing between lower launcher 265 and shoe assembly 110.

[0030] Lower launcher 265 further includes a plurality of circumferentially-spaced slots 310 extending therethrough. Each slot 310 has a height 335 and a width 340. Further, each slot 310 is bounded by a lower surface 320 and an upper surface 325. In this embodiment, lower surface 320 is generally planar and extends normally relative to a longitudinal centerline 345 of launcher assembly 250. Upper surface 325 is generally planar as well but offset relative to centerline 345 by an angle 330. The angular orientation of upper surface 325 is such that height 335 of slot 310 increases through the wall of lower launcher 265 from outer surface 315 toward inner surface 305.

[0031] Returning to Figure 1, recoverable shoe assembly 110 includes a collet assembly 350 and a guide mandrel 355 inserted therein. When shoe assembly 110 is installed within launcher assembly 250 as shown, collet assembly 350 is coupled between expansion mandrel 135 of expansion assembly 105 and lower launcher 265 of launcher assembly 250. Turning to Figure 4, collet assembly 350 has a longitudinal centerline 400. The right half of this figure, defined by centerline 400, is shown in cross-section while the left half of this figure is not. Collet assembly 350 further includes a seal mandrel 360 having a generally cylindrical body 362 with an upper end 365 and a lower end 370. Seal mandrel 360 further includes an outer surface 375 and an inner surface 377 extending between upper and lower ends 365, 370. A groove 380 is formed in outer surface 375 to receive a sealing element 385, such as but not limited to an O-ring. When collet assembly 350 is installed within launcher assembly 250 of liner expansion system 100, as shown in Figure 1, sealing element 385 prevents the leakage of pressurized fluid from chamber 120 between launcher assembly 250 and collet assembly 350 during radial expansion of liner 115.

[0032] Referring still to Figure 4, collet assembly 350 further includes a plurality of circumferentially-spaced splines 390 extending from upper end 365 of seal mandrel 360. Each spline 390 has a length 395 extending substantially parallel to longitudinal centerline 400 of collet assembly 350 and a width 405 that extends substantially circumferentially or azimuthally about centerline 400. Thus, splines 390 may also be referred to as longitudinally or axially disposed splines. A recess 410 is formed between each pair of adjacent splines 390.

[0033] Splines 390 are configured to matingly engage and interlock with splines 230 of expansion mandrel 135, as illustrated by Figure 5. To enable such engagement, length 395 and width 405 of each spline 390 is selected to enable spline 390 to be received within a recess 245 between adjacent splines 230 of expansion mandrel 135. Similarly, length 235 and width 240 of each spline 230 of expansion mandrel 135 is selected to enable each spline 230 to be received in a recess 410 between adjacent splines 390 of collet assembly 350. When the interlocking splines 230, 390 are so engaged, they form an interlocking mechanism between expansion assembly 105 and shoe assembly 110 to prevent relative rotation therebetween.

[0034] Referring again to Figure 4, collet assembly 350 further includes a plurality of circumferentially-spaced collets 415 extending from lower end 370 of seal mandrel 360. Collets 415 are configured to enable releasable coupling of collet assembly 350 within launcher assembly 250. Each collet 415 is flexible to enable limited bending relative to seal mandrel 360. Each collet 415 has an inner surface 530 defined by a diameter greater than a diameter of inner surface 377 of seal mandrel 360. Hence, a shoulder 534 is formed in collet assembly 350 at the transition between seal mandrel 360 and collets 415. Each collet 415 also has a foot 420 that is insertable within and releasable from a slot 310 (Fig. 3) of lower launcher 265. Thus, when collet assembly 350 is inserted within lower launcher 265, each collet 415 can bend radially inward to enable translation of collet assembly 350 within lower launcher 265 until foot 420 engages, or snaps into, a slot 310, as illustrated by Figure 5. Subsequently, each collet 415 can again bend radially inward to enable disengagement of foot 420 from slot 310.

[0035] Further, each foot 420 of collets 415 has a width 427 that is slightly less than width 340 (Fig. 3) of the slot 310. Each foot 420 is bounded by a lower surface 425 configured to engage lower surface 320 (Fig. 3) of slot 310 and an upper surface 430 configured to slidingly engage upper surface 325 (Fig. 3) of slot 310. In this embodiment, lower surface 425, like lower surface 320, is generally planar and extends normally relative to longitudinal centerline 400 of collet assembly 350. Upper surface 430, like upper surface 325 of slot 310, is generally planar as well but offset relative to centerline 400 by an angle 435 that is substantially equal to angle 330 of upper surface 325.

[0036] When installed within lower launcher 265, as shown in Figure 5, collet assembly 350 is prevented from rotating relative to lower launcher 265 due to engagement between feet 420 of collets 415 with bounding surfaces of slots 310 of lower launcher 265. Further, collet assembly 350 is prevented from downward axial translation, or translation away from expansion mandrel 135, relative to lower launcher 265 due to engagement between lower surfaces 425 of feet 420 and lower surfaces 320 of slots 310. However, collet assembly 350 may translate in the opposite direction, or axially upward, relative to lower launcher 265 when sufficient upward tension is applied to collet assembly 350. This relative movement is enabled by the sliding engagement between tapered, upper surfaces 430 of feet 420 and similarly tapered, upper surfaces 325 of slots 310. Thus, under sufficient upward tension, collet assembly 350 disengages lower launcher 265.

[0037] Referring next to Figure 6, guide mandrel 355 is tubular in nature, having a flowbore 440 extending therethrough between an inlet 445 and an outlet 450. Flowbore 440 includes an upper portion 455, a lower portion 460, and a tapered portion 465 extending therebetween. Lower portion 460 is bounded by an inner surface 470 of guide mandrel 355 defined by a diameter that is smaller than a diameter of an inner surface 475 of guide mandrel 355 bounding upper portion 455. As such, tapered portion 465 forms a ball seat 480.

[0038] Guide mandrel 355 further includes a generally cylindrical body 485 extending between a fishing neck 490 and a guide nose 495. Fishing neck 490 is configured to be insertable within flowbore 160 of expansion mandrel 135 of expansion assembly 105 when shoe assembly 110 is installed within expandable liner 115 in engagement with expansion assembly 105, as shown in Figure 1. When so inserted, flowbore 440 of guide mandrel 355 is in fluid communication with, or fluidicly coupled to, flowbore 160 of expansion mandrel 135, and fishing neck 490 sealingly engages the inner surface of expansion mandrel 135 and collet assembly 350 via sealing elements 492 (Fig. 1). Consequently, pressurized fluid injected from the surface passes from flowbore 160 of expansion mandrel 135 through flowbore 440 of guide mandrel 355, exiting guide mandrel 355 through outlet 450. To disrupt or prevent fluid flow through guide mandrel 355, a ball (not shown) may be introduced to the pressurized fluid at the surface and delivered through upper portion 455 of flowbore 440 to ball seat 480, whereby fluid flow through guide mandrel 355 is prevented.

[0039] Guide nose 495 has an upper end 510 connected to body 485, a lower end 515 wherein outlet 450 of flowbore 440 is disposed, and an outer surface 520 extending therebetween. The diameter of guide nose 495 at upper end 510 is greater than that of guide nose 495 at lower end 515. As such, the diameter of outer surface 520 increases from lower end 515 of guide nose 495 to upper end 510. Tapering of outer surface 520 in this manner enables run-in of liner expansion system 100 into a wellbore containing fluid. In particular, tapered surface 520 is less resistive to fluid flow than some surfaces having other shapes or orientations.

[0040] The outer diameter of guide nose 495 at upper end 510 is greater than that of cylindrical body 485 coupled thereto. Hence, a shoulder 525 is formed in guide mandrel 355 at the transition between guide nose 495 and body 485. The outer diameter of guide nose 495 at shoulder 525 is less than that of inner surfaces 305, 295 of lower and upper launchers 265, 260, respectively. This enables guide mandrel 355 to be pulled from liner 115 via wireline, or similar device, as will be described below. Moreover, the outer diameter of guide nose 495 at shoulder 525 is greater than the diameter of inner surface 377 (Fig. 4) of seal mandrel 360. As such, shoulder 525 enables retrieval of collet assembly 350 with guide mandrel 355 when the latter is pulled from liner 115. When a tension load is applied to guide mandrel 355 via wireline, or similar device, guide mandrel 355 initially displaces axially upward relative to collet assembly 350 until shoulder 525 of guide mandrel 355 engages shoulder 534 of collet assembly 350. Additional tension to guide mandrel 355 causes guide mandrel 355 to displace collet assembly 350 axially upward such that collets 415 disengage slots 310 of lower launcher 265. Once disengaged, collet assembly 350 is supported by guide mandrel 355 as guide mandrel 355 and collet assembly 350 are pulled from the wellbore.

[0041] Body 485 of guide mandrel 355 includes lower portion 535 connected to guide nose 495 and an upper portion 540 extending between lower portion 535 and fishing neck 490. Lower portion 535 has an outer surface 565 defined by a diameter that is smaller than that of inner surface 530 of collets 415 to provide a clearance 570 (Fig. 1) therebetween. Clearance 570 between collets 415 and guide mandrel 355 enables collets 415 to bend radially inward to engage and disengage slots 310 of lower launcher 265, as described above.

[0042] Upper portion 540 of body 485 has an outer surface 545 defined by a diameter that is slightly less that the diameter of an inner surface 550 (Fig. 1) of seal mandrel 360. Upper portion 540 includes a groove 555 formed in outer surface 545 to receive a sealing element 560, such as but not limited to an O-ring. When guide mandrel 355 is installed within collet assembly 350, as shown in Figure 1, sealing element 555 sealing engages inner surface 550 of seal mandrel 360 to prevent leakage of pressurized fluid from chamber 120 between guide mandrel 355 and collet assembly 350 during expansion of liner 115.

[0043] In some embodiments, guide mandrel 355 may include either or both of an external fishing profile 500 and an internal fishing profile 505, each configured to enable retrieval of guide mandrel 355 and other components coupled thereto, such as collet assembly 350, from a wellbore in which liner expansion system 100 is installed. In this embodiment, guide mandrel 355 includes both. External fishing profile 500 is an annular lip formed about the free end of fishing neck 490. Internal fishing profile 505 is a shoulder formed along inner surface 455 bounding flowbore 440 proximate inlet 445. To retrieve guide mandrel 355, a wireline, or similar device, is lowered from the surface into the wellbore to enclose about lip 500 or to engage shoulder 505. Once connected thereto, the wireline may then be used to pull guide mandrel 355 and collet assembly 350 from the wellbore.

[0044] Returning to Figure 1, to assemble liner expansion system 100, expansion assembly 105 is installed within expandable liner 115. Expansion mandrel 135 is inserted through bore 175 of expansion cone 130, and expansion cone 130, with expansion mandrel 135 disposed therein, is inserted through lower launcher 265 into upper launcher 260 of launcher assembly 250. Next, recoverable shoe assembly 110 is then coupled to expansion assembly 105 and expandable liner 115. Guide mandrel 355 is inserted through collet assembly 350 such that fishing neck 490 of guide mandrel 355 extends into flowbore 160 of expansion mandrel 135 and shoulder 525 of guide mandrel 355 abuts shoulder 534 of collet assembly 350. Collet assembly 350, with guide mandrel 355 disposed therein, is inserted into lower launcher 265 to engage collets 415 of collet assembly 350 within slots 310 of lower launcher 265. Guide mandrel 355 is coupled in position within collet assembly 350 with one or more shear pins 357 (Fig. 1) extending between guide mandrel 355 and launcher assembly 250. The assembled components are then run-in to a wellbore to the desired depth.

[0045] Next, tubular support member 140 is coupled to the installed liner expansion system 100 to provide pressurized fluid to system 100 for expansion of liner 115. Tubular support member 140 is inserted downhole to couple with expansion mandrel 135. In this embodiment, tubular support member 140 threadingly engages expansion mandrel 135 via mating threads 155. As described above, when collet assembly 350 is installed within lower launcher 265, the engagement of feet 420 of collets 415 of collet assembly 350 within slots 310 of lower launcher 265 prevents relative rotation of these components. Further, when collet assembly 350 is coupled to expansion cone 130 of expansion assembly 105 via interlocking splines 230, 390, collet assembly 350 cannot rotate relative to expansion cone 130. Thus, once installed, expansion cone 130 and expansion mandrel 135 disposed therein are prevented from rotating relative to liner 115. This enables rotational coupling of tubular support member 140 to expansion mandrel 135.

[0046] During operation of liner expansion system 100, pressurized fluid is delivered from the pressurized fluid source at the surface through flowbore 150 of tubular support member 140, flowbore 160 of expansion mandrel 135, and flowbore 440 of guide mandrel 355 to exit system 100 via outlet 450. To initiate radial expansion of liner 115, a ball (not shown) is introduced to the pressurized fluid at the surface. The pressurized fluid carries the ball along the same path to seat on ball seat 480, whereby the flow of pressurized fluid from guide mandrel 355 through outlet 450 is interrupted.

[0047] Due to the blockage of fluid flow through flowbore 440 of guide mandrel 355, the pressure of fluid in flowbore 160 of expansion mandrel 135 increases until it reaches the preselected level at which discs 170 rupture. After discs 170 rupture, pressurized fluid passes from flowbore 160 through ports 165 of expansion mandrel 135 into chamber 120. When the pressure of fluid within chamber 120 reaches a sufficient level, pressure acting on expansion cone 130 causes cone 130 to displace axially upward, whereby engagement between inner surface 215 of liner 115 and outer surface 190 of expansion cone 130 causes radial expansion of liner 115. At the same time, collets 415 of collet assembly 350 resist the axial pressure load of the fluid acting on seal mandrel 360 and provide support to seal mandrel 360.

[0048] When radial expansion of liner 115 is complete, the flow of pressurized fluid to system 100 is discontinued, and expansion assembly 105 is pulled from the wellbore. Next, a wireline, or similar device, is lowered into the wellbore to engage either external or internal fishing profiles 500, 505 of guide mandrel 355. A tension load is then applied to guide mandrel 355, causing severance of shear pins 357 coupled between guide mandrel 355 and launcher assembly 250. After pins 357 are sheared, guide mandrel 355 displaces axially upward relative to collet assembly 350 until shoulder 525 of guide mandrel 355 engagesshoulder 534 of collet assembly 350. Continued tension to guide mandrel 355 and therefore collet assembly 350 causes collets 415 to disengage slots 310 of lower launcher 265. Once disengaged, guide mandrel 355 and collet assembly 350 supported thereon are pulled from expanded liner 115. Thus, shoe assembly 110 is recovered, eliminating the need to drill out the shoe, as is typically done in conventional liner expansion systems, and the associated problems.

[0049] In the above-described embodiment, flexible collets 415 enable releasable coupling of recoverable shoe assembly 110 to launcher assembly 250. One of ordinary skill in the art will readily appreciate that releasable coupling of these respective assemblies 250, 110 may be achieved using other types of mechanisms, or devices. For example, in place of collets, the recoverable shoe assembly may include a plurality of lugs that are extendable and retractable to engage and release, respectively, the launcher assembly.

[0050] Figures 7A and 7B depicts a liner expansion system with another recoverable shoe assembly in accordance with the principles disclosed herein installed within a lower launcher. As in the liner expansion system described above, lower launcher 615 is also tubular, having an outer surface 620 and an inner surface 625 defined by a diameter than enables expansion cone 130 and shoe assembly 600 to be inserted therethrough. Lower launcher 615 further includes a plurality of circumferentially-spaced slots 630 extending therethrough.

[0051] Recoverable shoe assembly 600 includes a seal mandrel 605, guide mandrel 355 disposed therein, and a plurality of circumferentially-spaced lugs 610 that are extendable to engage slots 630 of lower launcher 615, as shown in Figure 7 A, and retractable to disengage slots 630, as shown in Figure 7B. Seal mandrel 605 has a generally cylindrical body 635 with an upper end (not shown) and a lower end 640. Although not shown, seal mandrel 605, like seal mandrel 360 described above, includes a plurality of splines 390 extending from its upper end. Splines 390, as previously described, are configured to matingly engage and interlock with splines 230 of expansion mandrel 135. When the interlocking splines 230, 390 are so engaged, they form an interlocking mechanism between expansion assembly 105 and shoe assembly 600 to prevent relative rotation therebetween. Seal mandrel 605 further includes a plurality of circumferentially-spaced slots 645 extending therethrough. Each slot 645 is configured to receive a lug 610, as shown.

[0052] Lugs 610 are actuatable to extend to engage slots 630 of lower launcher 615, as shown in Figure 7 A, and to retract to disengage slots 630, as shown in Figure 7B. In some embodiments, lugs 610 are spring-loaded and biased toward their retracted orientation. Each lug 610 includes a body 650 and a head 655 coupled thereto. Body 650 is configured to be received within slots 630, 645 of lower launcher and seal mandrel 605, respectively. Head 655 has a cross-section that is larger than that of slot 645, thereby limiting radial extension of lug 610 within slots 630, 645. Head 655 engages guide mandrel 355 when guide mandrel 355 is inserted within seal mandrel 605, as shown. In some embodiments, one or more of the radial extending surfaces 660 of head 655 are angled or cropped to enable guide mandrel 355 to be inserted between lugs 610. The angular nature of surface 660 provides sliding engagement with upper portion 540 of guide mandrel 355 as guide mandrel 355 is inserted within lugs 610 and seal mandrel 605.

[0053] During assembly, lugs 610 are installed within seal mandrel 605, and seal mandrel 605 is inserted within lower launcher 615 such that slots 630, 645 align. Guide mandrel 355 is then installed within seal mandrel 605. As guide mandrel 335 is inserted within seal mandrel 605, contact between upper portion 540 of guide mandrel 355 and angled surfaces 660 of lugs 610 causes lugs 610 to extend into slots 630 of lower launcher 615 and enables guide mandrel 355 to be received between lugs 610. When lugs 610 engage slots 630, seal mandrel 605 is prevented from rotating and from translating axially relative to lower launcher 615. As previously described, this enables coupling of tubular support member 140 (Fig. 1) to expansion mandrel 135 (Fig. 1).

[0054] When it is desired to remove shoe assembly 600 from lower launcher 615, for instance, when expansion of a liner coupled to lower launcher 615 is complete, a wireline, or similar device, is coupled to guide mandrel 355, and guide mandrel 355 is pulled upward relative to lower launcher 615, as described above. When upper portion 540 of guide mandrel 355 translates axially above lugs 610, lugs 610 retract radially inward toward lower portion 535 of guide mandrel 355 and disengage slots 630 in lower launcher 615, as shown in Figure 7B. Once retracted, seal mandrel 605 with lugs 610 supported therein is translatable and rotatable relative to lower launcher 615. Further upward translation of guide mandrel 355 due to tension from the wireline causes engagement between lugs 610 and shoulder 525 of guide mandrel 355. Engagement between shoulder 525 and lugs 610 enables seal mandrel 605 and lugs 610 to be supported by guide mandrel 355 as shoe assembly 600 is pulled from lower launcher 615 and the expanded liner coupled thereto.

[0055] While various embodiments have been shown and described, modifications thereof can be made by one skilled in the art without departing from the spirit and teachings herein. The embodiments herein are exemplary only, and are not limiting. Many variations and modifications of the apparatus disclosed herein are possible and within the scope of the invention. Accordingly, the scope of protection is not limited by the description set out above, but is only limited by the claims which follow, that scope including all equivalents of the subject matter of the claims.