Abstract
An expansion tool includes a housing and a hydraulic power section for stroking a first expander on a pulling mandrel through a bore of an expandable outer clad, the expansion tool including a ratcheting reaction assembly, having a ratchet rack and a ratcheting component thereon, that engages a proximal end of the outer clad to prevent axial movement of the outer clad as the first expander is drawn through a portion of the bore of the outer clad to expand the outer clad. The ratcheting reaction assembly remains engaged with the proximal end of the outer clad as the housing is repositioned uphole to permit staged expansion of the outer clad using the first expander. The expansion tool improves sealing and structure integrity of the expanded outer clad within the casing by maintaining the outer clad in a position throughout the staged expansion process.
Claims
1. A method, comprising: providing an expansion tool having a housing with a bore, a proximal end with a threaded connection for coupling to a tubular string, a distal end, and a plurality of annular cylinders disposed about the bore and intermediate a plurality of radially inwardly disposed annular stops connected to the bore of the housing, the expansion tool further comprising a pulling mandrel reciprocatably received within the bore of the housing for movement within a limited range relative to the housing defined by the range of movement of a plurality of radially outwardly disposed annular pistons cooperating with the plurality of annular cylinders of the housing, an aperture in the pulling mandrel immediately distal to each of the plurality of annular pistons, a first expander connected to a distal end of the pulling mandrel, the expansion tool further comprising a pulling mandrel extension having a proximal end coupled to the first expander connected to the distal end of the pulling mandrel, a distal end connected to a second expander that is smaller in diameter than the first expander, a bore of the pulling mandrel extension intermediate the proximal end and the distal end and aligned with the bore of the pulling mandrel, and a ball seat in one of the bore of the pulling mandrel and the bore of the pulling mandrel extension, the expansion tool further comprising an elongate ratchet rack having a proximal end coupled to a rack retainer and a threaded exterior, an elastically expandable ratchet ring having a longitudinal slot and an internally threaded bore for uni-directional movement along the ratchet rack in the distal direction, a ring housing surrounding the ratchet ring, an expandable outer clad having a proximal end, a distal end and a bore, the outer clad being axially captured about the elongate ratchet rack and secured with the proximal end of the outer clad coupled to the ring housing and the distal end engaged with the first expander upon connection of the first expander to the distal end of the pulling mandrel, and an expandable inner clad having a proximal end, a distal end, a pre-expanded portion at the distal end and a bore that is aligned with the bore of the outer clad, the inner clad being axially captured intermediate the second expander and the first expander, and the bore being disposed about the pulling mandrel extension, the inner clad being smaller in diameter than the outer clad; connecting the proximal end of the expansion tool to a distal end of a tubular tubular string; running the expansion tool into a targeted section of a well casing; introducing a ball into the tubular string; pumping the ball to engage it with the ball seat; hydraulically pressurizing the bore of the pulling mandrel to communicate fluid pressure, through the plurality of apertures, to the plurality of annular cylinders to displace the plurality of annular cylinders, the pulling mandrel and the pulling mandrel extension towards the proximal end of the housing and to displace the first expander releasably connected to the distal end of the pulling mandrel against the distal end of the expandable outer liner to place the liner in axial compression and to impart a load against the ratchet ring that engages the proximal end of the outer clad; displacing the ring housing, the ratchet ring therein, the ratchet rack on which the ratchet ring is uni-directionally movable, and a rack retainer to which a proximal end of the ratchet rack is coupled in a proximal direction to displace one or more slips, linked to the rack retainer, relative to a slip actuator to deploy the one or more slips radially outwardly to engage and grip the casing; displacing the ratchet ring, the ratchet rack, and the rack retainer further to disengage one of a ridge and a groove on a collet from the other of the ridge and the groove on the pulling mandrel to release the pulling mandrel from the deployed slips and to enable movement of the pulling mandrel in a proximal direction within the housing as the slips remain stationary relative to the housing to force the first expander into the bore of the distal end of the outer clad to radially outwardly expand the diameter of the outer clad to engage the casing while a proximal end of the inner clad disposed axially between the first expander and the second expander moves one of proximal to or into the expanded distal portion of the outer clad; continuing to pressurize the bore of the pulling mandrel to complete the stroke of the plurality of annular pistons of the pulling mandrel within the annular cylinders of the housing and to complete a stage of the expansion of the bore of the outer clad; depressurizing the bore of the pulling mandrel; pulling on the tubular string to pull the housing and the slip actuator from the engaged position within the one or more slips to release the grip of the one or more slips on the casing; continue pulling on the tubular string to re-cock the expansion tool by moving the housing in a proximal direction relative to the stationary pulling mandrel with the first expander at the distal end of the pulling mandrel remaining in an interference fit with the partially expanded portion of the outer clad lodged within the bore of the casing; pressurizing the bore of the pulling mandrel for at least a second time to again set the one or more slips and to thereafter again stroke the pulling mandrel within the housing of the expansion tool to lengthen the expanded portion of the outer clad and to further move the inner clad one of proximal to or into the expanded portion of the outer clad; repeating the stroking and re-cocking of the expansion tool until one of the full length of the expandable outer clad is radially outwardly expanded by the first expander to engage the casing with the expandable inner clad disposed within the bore of the expanded outer clad, and the remaining unexpanded portion of the outer clad is expandable by pulling the tubular string, the housing, the pulling mandrel, the first expander, the pulling mandrel extension and the second expander to expand the remaining unexpanded portion of the outer clad without shifting the expanded portion of the outer clad within the casing; engaging an exterior of the pre-expanded portion at the distal end of the inner clad with the expanded distal end of the outer clad to secure the inner clad against further movement relative to the outer clad; and one of pressurizing the bore of the pulling mandrel to communicate fluid pressure, through the plurality of apertures, to the plurality of annular cylinders to displace the pulling mandrel and the pulling mandrel extension connected thereto towards the proximal end of the housing and to displace the second expander releasably connected to the distal end of the pulling mandrel extension against an interior of the pre-expanded portion at the distal end of the inner clad to expand the inner clad, and pulling the tubular string, the housing, the pulling mandrel, the pulling mandrel extension and the second expander releasably connected thereto to impart a load against the pre-expanded portion at the distal end of the inner clad to expand the inner clad; one of repeating the stroking and re-cocking of the expansion tool until the full length of the inner clad is stepwise radially outwardly expanded to engage the expanded inner clad with the expanded outer clad disposed within and against the bore of the casing, and pulling the tubular string, the housing, the pulling mandrel, the first expander, the pulling mandrel extension and the second expander to move the second expander through the inner clad to expand the inner clad radially outwardly and into engagement with the expanded outer clad without shifting the expanded portion of the inner clad within the outer clad.
2. The method of claim 1, wherein the internally threaded bore of the ratchet ring includes a plurality of buttress threads; and wherein the threaded exterior surface of the ratchet rack includes buttress threads that cooperate with the buttress threads of the ratchet ring.
3. The method of claim 2, wherein the buttress threads of the ratchet ring and the buttress threads of the ratchet rack are buttress threads.
4. The method of claim 1, wherein providing the expansion tool further includes: providing a collet having at least one of a ridge and a groove on at least one collet finger; providing the other of a ridge and a groove on the pulling mandrel to engage the at least one of a ridge and a groove on the at least one collet finger; surrounding the collet with a collet cage; stroking the pulling mandrel to engage the rack retainer against the collet cage to displace the slips from a retracted position to a deployed position engaged with the casing; and continuing the stroke the pulling mandrel to dislodge the ridge from the groove and to thereby permit movement of the pulling mandrel relative to the collet and the collet cage.
5. The method of claim 4, further including: re-engaging the ridge on one of the at least one collet finger and the pulling mandrel with the groove on the other of the at least one collet finger and the pulling mandrel during the re-cocking of the expansion tool.
6. The method of claim 5, wherein the expander is threadably connected to the distal end of the pulling mandrel.
7. An expansion tool for installing a tandem clad liner within a well casing, comprising: an elongate pulling mandrel having a proximal end, a distal end connected to a first expander, a bore, a plurality of annular pistons radially outwardly extending from an exterior wall of the pulling mandrel intermediate the proximal end and the distal end, a ball seat within the bore of the pulling mandrel intermediate the distal end and the plurality of annular pistons, and a plurality of apertures through a wall of the pulling mandrel, each aperture disposed distal to one of the plurality of annular pistons; an elongate pulling mandrel extension having a proximal end coupled to the first expander, a distal end connected to a second expander, and a bore aligned with and in fluid communication with the bore of the pulling mandrel; an elongate housing having a proximal end, a distal end, a bore to receive the pulling mandrel, a plurality of radially inwardly extending stops intermediate the proximal end and the distal end to form a plurality of annular cylinders in which the plurality of annular pistons of the pulling mandrel are reciprocatable, the proximal end of the housing having a threaded connection for sealably securing the expansion tool to a distal end of a tubular string supported at a proximal end by a rig, the rig having a draw works for use in stepwise extending the tubular string to position the expansion tool within the casing of the well and for providing pressurized fluid through the tubular string to the expansion tool; a rack retainer having a bore to receive the pulling mandrel and a proximal end to engage one or more slips angularly distributed about the pulling mandrel, the one or more slips being radially movable by engagement of the rack retainer between a radially retracted position and a radially outwardly deployed position to grip the interior bore of a casing in which the expansion tool is disposed; an elongate ratchet rack having a proximal end coupled to the rack retainer, a distal end, a bore through which a lower portion of the pulling mandrel extends, the ratchet rack having an exterior with a plurality of buttress threads; a ratchet ring having a bore with buttress threads for cooperating with the threaded exterior of the ratchet rack, the ratchet ring expandably disposed within a ring housing, the ratchet ring further including a longitudinal slot to enable the ratchet ring to elastically circumferentially expand and contract as the buttress threads of the interior bore of the ratchet ring slidably engage the buttress threads along the exterior of the ratchet rack and as the cooperating threads on the exterior of the ratchet rack and the interior bore of the ratchet ring interact as the ratchet ring is moved in a distal direction relative to the ratchet rack, the ratchet ring and ratchet rack being buttress threaded to resist movement of the ratchet ring relative to the ratchet rack in a proximal direction; an expandable outer clad having a proximal end engaged with the ring housing, a distal end that is one of engaged with and proximal to the first expander, and a bore therebetween, the expandable outer clad being receivable onto the expansion tool by insertion of the elongate ratchet rack into the bore of the expandable outer clad until the proximal end of the outer clad engages the ring housing that surrounds the ratchet ring movable on the exterior of the ratchet rack, the outer clad being securable on the expansion tool by connection of the first expander to the distal end of the pulling mandrel to capture the outer clad axially intermediate the first expander and the ring housing; an expandable inner clad having a proximal end, a distal end, a pre-expanded portion at the distal end, and a bore therebetween, the expandable inner clad being receivable onto the expansion tool by insertion of the elongate pulling mandrel extension into the bore of the expandable inner clad and securing of the inner clad onto the expansion tool by connection of the second expander to the distal end of the pulling mandrel extension to axially capture the inner clad intermediate the second expander and the first expander; an annular slip actuator having a proximal end engaged with the housing and having a plurality of sloped slip lobes on a radially outer surface; and one or more slips disposed radially outwardly of the annular slip actuator and radially movable by the slip actuator from a retracted position to a radially outwardly deployed position to grip a bore of the well casing in which the expansion tool is disposed to secure the housing of the expansion tool in position within the well casing.
8. The apparatus of claim 7, wherein the threads within the bore of the ratchet ring and the threads on the exterior of the ratchet rack are buttress threads having a steep load-bearing face on a first side of each thread and a ramped face on a second and opposite side of each thread to provide for elastic spreading of the slot of the ratchet ring to enable thread-skipping movement of the ratchet ring in a distal direction relative to the ratchet rack.
9. The expansion tool of claim 7, wherein the introduction of a sufficient hydraulic pressure into the bore of the pulling mandrel is communicated through the apertures in the pulling mandrel to the plurality of annular cylinders and axially intermediate the one or more annular pistons formed on the pulling mandrel and an adjacent annular stop formed in the housing displaces the plurality of annular pistons, the pulling mandrel and the expander connected thereto in a proximal direction relative to the housing; and wherein displacement of the first expander in the proximal direction moves the expandable outer clad, the ratchet ring, the ratchet rack and the rack retainer to engage and displace the slips radially outwardly against the slip actuator to grip the casing, after which further movement of the first expander in the proximal direction pulls the first expander into the bore of the distal end of the outer clad to radially expand a portion of the outer clad to an expanded diameter as the outer clad is retained in position against the force applied by the first expander by the ratchet ring and the ratchet rack threadably engaged with the ratchet ring; wherein the expansion tool is re-cocked by relieving the fluid pressure applied to the bore of the pulling mandrel, using the draw works on the rig to pull on the housing to unseat the slips from the casing, and using the draw works on the rig to reposition the housing uphole as the pulling mandrel, the first expander connected thereto and the annular pistons extending radially therefrom remain in a lodged position with an expanded portion of the outer clad disposed circumferentially around the first expander and between the first expander and the casing; and wherein the ratchet ring remains engaged with the bore of the proximal end of the outer clad as the housing is repositioned uphole with the ratchet rack, the ratchet ring then threadably engaging the ratchet rack at a new position distal to the original position of the ratchet ring on the ratchet rack to provide resistance to axial movement of the outer clad in response to a subsequent expansion stroke of the first expander.
10. The apparatus of claim 7, wherein the first expander is threadably connected to the distal end of the pulling mandrel.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0035] FIG. 1 is a sectional elevation view of a proximal end of an embodiment of the expansion tool of the present invention in a run-in configuration. The distal end of the tubular string used to run and position the expansion tool in the well is not shown in FIG. 1.
[0036] FIG. 2 is the view of FIG. 1 after the proximal end of the pulling mandrel is hydraulically displaced by an expansion stroke to a position that is closer to the proximal end of the housing of the expansion tool.
[0037] FIG. 3 is a sectional elevation view of a portion of the hydraulic section of the expansion tool of FIG. 1 illustrating an annular piston on the pulling mandrel disposed adjacent to an annular stop of the housing forming an end of an annular chamber in which an annular piston is movable. FIG. 3, like FIG. 1, illustrates the run-in configuration of the expansion tool.
[0038] FIG. 4 is a sectional view of a gripping portion of an embodiment of the expansion tool that includes a plurality of slip actuators coupled to the housing and a plurality of slips coupled to a ratchet retainer and displaced by initial movement of the pulling mandrel relative to the housing at the onset of an expansion stroke. A reaction assembly of the expansion tool (including a rack retainer, a ratchet rack and a ratcheting component) is illustrated as being disposed below the slips to react against the outer clad at the onset of expansion of the outer clad.
[0039] FIG. 4A is an enlarged view of a radially inwardly disposed protrusion of the collet at the location of interaction with a radially outwardly disposed notch of the pulling mandrel.
[0040] FIG. 5 is an enlarged view of a portion of a ratcheting component threadedly engaged with the exterior surface of a ratchet rack to enable relative movement of the ratchet rack only in a proximal direction relative to the ratcheting component.
[0041] FIG. 5A is a sectional view of the ratcheting component of the expansion tool illustrated in FIG. 5 with the ratchet ring in the radially inwardly collapsed or contracted mode to prevent movement of the ratchet rack in a distal direction relative to the ratcheting component.
[0042] FIG. 5B is the sectional view of the portion of the expansion tool of FIG. 5A with the ratchet ring in the circumferentially expanded mode to permit movement of the ratchet rack in a proximal direction relative the ratcheting component.
[0043] FIG. 6 is a sectional elevation view of a portion of the embodiment of the expansion tool of the present invention including slip actuators positioned for being moved under or radially within the adjacent slips to secure the housing within the casing in which the expandable outer clad is to be expanded.
[0044] FIG. 7 is a sectional elevation view of the distal end of an embodiment of an expansion tool of the present invention illustrating the distal portion of the expandable outer clad, a ball seat within the bore of the pulling mandrel, the first expander coupled to the pulling mandrel. The bore of the pulling mandrel can be isolated for pressurization using a ball to engage the ball seat.
[0045] FIG. 8 is the lower portion of the view of FIG. 7 illustrating a ball being received in the ball seat to isolate the bore of the pulling mandrel to enable the expansion tool to be hydraulically stroked, causing the first expander to enter and expand the bore of the expandable outer clad.
[0046] FIG. 9 is a sectional elevation view of a portion of the hydraulic section of the expansion tool of the present invention illustrating the initial separation of an annular piston on the pulling mandrel from an adjacent annular stop of the housing that occurs at the onset of a hydraulic stroke the expansion tool.
[0047] FIG. 10 is a sectional elevation view of the gripping section of the expansion tool of the present invention with the slip actuator coupled to the housing and the slips in a deployed configuration to engage and grip the casing. FIG. 10 corresponds to the position of the annular piston and adjacent annular stop of FIG. 9.
[0048] FIG. 11 is a sectional elevation view of a portion of the gripping section of the expansion tool in the gripping configuration of FIG. 10 and illustrates the coupling between the expandable outer clad, the ratcheting component, the ratchet rack, the rack retainer and the slips are intercoupled to deploy the gripping section of the expansion tool at the onset of an expansion stroke of the expansion tool.
[0049] FIG. 12 is a sectional view of a distal portion 80 of the expansion tool 10 of the present invention, shown in the lower portion of FIG. 12, and the intermediate portion 73 of FIG. 7 shown in the upper portion of FIG. 12 to illustrate the interaction between the expandable inner clad 260, the second expander 187 and the pulling mandrel extension 144 of the expansion tool 10, on the one hand, and the expanded portion 25 of the outer clad 62, the first expander 87 and the pulling mandrel 40, on the other hand.
[0050] FIG. 13 is the view of the expansion tool of FIG. 12 after the first expander is pulled further through the outer clad to lengthen the expanded portion of the outer clad and to move a substantial portion, including the proximal end, of the unexpanded inner clad into the bore of the expanded portion of the outer clad.
[0051] FIG. 14 is the view of the expansion tool of FIG. 13 after the first expander is pulled further through the outer clad to lengthen the expanded portion of the outer clad and to move all of the inner clad except the pre-expanded portion into the bore of the expanded portion of the outer clad.
[0052] FIG. 15 is the view of FIG. 14 after the second expander is pulled by movement of the pulling mandrel, the first expander and the pulling mandrel extension through an expanded portion of the inner clad having a length.
[0053] FIG. 16 is a high-level flowchart illustrating the steps of a method of expanding a liner within a targeted interval of a casing using an embodiment of a liner expansion tool.
DETAILED DESCRIPTION
[0054] FIG. 1 is a sectional view of a proximal end 12 of an embodiment of the expansion tool 10 of the present invention disposed within a casing 99. FIG. 1 illustrates a threaded connector 15 that used to secure the housing 11 of the liner expansion tool 10 to a correspondingly threaded distal end of a tubular string (not shown) extended stepwise from a rig (not shown) into a casing 99 of a well. The proximal end of the tubular string is conventionally coupled to a draw works on the rig to enable positioning of the liner expansion tool 10 in the casing 99.
[0055] FIG. 1 illustrates the position of a proximal end 42 of a pulling mandrel 40 that is reciprocatably and slidably disposed within the bore 14 of the housing 11 of the expansion tool 10. In FIG. 1, the proximal end 42 of the pulling mandrel 40 is at a distance 16 from the proximal end 12 of the housing 11. FIG. 1 further illustrates a bore 44 of the pulling mandrel 40 and a seal 19 between an annular stop 18 extending radially inwardly from the bore 14 of the housing 11 and the exterior surface 41 of the pulling mandrel 40. The seal 19 prevents fluid pressure introduced into the proximal end 12 of the housing 11 from being communicated to the bore 14 of the housing 11 below the seal 19, and the seal 19 re-directs fluid pressure that is introduced through the tubular string (not shown) and into the proximal end 12 of the housing 11 into the bore 44 of the pulling mandrel 40. It will be noted that, in the embodiment of the apparatus of the present invention shown in FIG. 1, the bore 14 of the housing 11 is substantially larger below the seal 19 than it is above the seal 19. Hydraulic stroking of the pulling mandrel 40 within the bore 14 of the housing 11 from the position illustrated in FIG. 1 to the position illustrated in FIG. 2 results in movement of the pulling mandrel 40 within the bore 14 of the housing 11 in the direction of arrow 39 to the position illustrated in FIG. 2.
[0056] FIG. 2 is the sectional view of the proximal end of the embodiment of the expansion tool 10 of FIG. 1 after the pulling mandrel 40 has been hydraulically displaced within the bore 14 of the housing 11 towards the proximal end 12 of the housing 11 by hydraulically stroking of the expansion tool 10. FIG. 2 illustrates the upwardly repositioned proximal end 42 of the pulling mandrel 40 within the bore 14 of the housing 11 from the distance 16 from the threaded connector 15 illustrated on FIG. 1 to lesser distance 26 illustrated on FIG. 2. As will be explained in detail below, the distance of the displacement of the pulling mandrel 40 during a stroke is illustrated by the distance 16 of FIG. 1 less the distance 26 in FIG. 2, and that difference is related to the interval of an expandable outer clad 62 (not shown) that can be expanded by a single hydraulic stroke of the expansion tool 10, after which the expansion tool 10 must be re-cocked in order to subsequently further expand additional intervals of the expandable outer clad 62. It will be understood, however, that at some point during the stepwise outer clad expansion process, the remaining portion of the expandable outer clad 62, or some portions of the expandable outer clad 62, can be expanded by merely pulling the expansion tool 10 using the draw works on the rig. The inner clad 260, which is expanded after the expansion of the outer clad 62 is completed, may be expanded in its entirety by use of the draw works on the rig to pull the expansion tool 10 to draw the second expander 187 through the bore 123 of the inner clad 260, but the hydraulic section of the expansion tool 10 remains available for being set in the casing 99 and stroked to pull the second expander 187 should a tight spot be encountered, as will be discussed in more detail below.
[0057] Stroking of the expansion tool 10 from the run-in configuration or cocked configuration, illustrated in FIG. 1, to the stroked configuration or un-cocked configuration, illustrated in FIG. 2, is enabled by hydraulic pressurization of the tubular string (not shown) and the bore 44 of the pulling mandrel 40. FIG. 2 illustrates a first annular piston 48 extending radially outwardly from an exterior surface 41 of the pulling mandrel 40 to slidably and sealably engage the bore 14 of the housing 11. A seal 49 on the first annular piston 48 engages the bore 14 of the housing 11. FIG. 2 further illustrates a first annular stop 18 extending radially inwardly from the bore 14 of the housing 11 to sealably and slidably engage the exterior surface 41 of the pulling mandrel 40 at the seal 19. The first annular piston 48 on the pulling mandrel 40 appears in FIG. 2, and not in FIG. 1, because FIG. 2 illustrates the position of the pulling mandrel 40 after upward displacement of the pulling mandrel 40 in the proximal direction (in the direction of arrow 39 on FIG. 1) within the bore 14 of the housing 11 to bring the first annular piston 48 proximal to the first annular stop 18 and into the same view as the proximal end 12 of the housing 11. Fluid pressure introduced into the tubular string (not shown) and into the proximal end 12 of the housing 11 is isolated by the seal 19 on the first annular stop 18 and thereby redirected into the bore 44 of the pulling mandrel 40. The pressure is communicated from the bore 44 of the pulling mandrel 40 through aperture 77 in the pulling mandrel 40 to a first annular chamber 78 formed radially between the exterior surface 41 of the pulling mandrel 40 and the bore 14 of the housing 11 and formed axially between the first annular stop 18 of the housing 11 and a second annular stop 118 (not shown in FIG. 2—see FIG. 3) of the housing 11 that is below and spaced apart from the first annular stop 18. More specifically, it will be noted that the aperture 77 is disposed distal to the first annular piston 48 so that fluid pressure introduced into the first annular chamber 78 bears against the first annular piston 48 to displace the first annular piston 48 in the proximal direction (of arrow 39 in FIG. 1) during a hydraulic stroke of the expansion tool 10.
[0058] FIG. 3 is a sectional view of a lower portion of the expansion tool 10 of FIG. 1 illustrating a first annular piston 48 on the pulling mandrel 40 adjacent and proximal to a second annular stop 118 of the housing 11. Fluid pressure introduced into the bore 44 of the pulling mandrel 40 is communicated from the bore 44 of the pulling mandrel 40 through the aperture 77 to a distal portion 81 of the annular cylinder 78, distal to the first annular piston 48 and between the first annular piston 48 and the second annular stop 118. The distal portion 81 of the annular cylinder 78 appears very small in FIG. 3 because the expansion tool 10 is in the run-in configuration or the cocked configuration, meaning that the expansion tool 10 in the configuration in FIG. 3 is cocked and ready for being hydraulically stroked. The fluid pressure introduced into the distal portion 81 of the annular cylinder 78 will displace the first annular piston 48 and the pulling mandrel 40 in an upward or proximal direction (in the direction of the arrow 39). Fluid residing in the remaining or proximal portion of the first annular cylinder 78, that is, between the first annular piston 48 and the first annular stop 18 (see FIG. 2), is displaced from the expansion tool 10 through exhaust aperture 79 (not shown in FIG. 3—see FIGS. 1 and 2) in the housing 11 as the first annular piston 48 and pulling mandrel 40 are moved within the housing 11. It will be understood that the distal end of the first annular piston 48 is exposed to the elevated fluid pressure provided through the bore 44 of the pulling mandrel 40 and through the aperture 77 in the pulling mandrel 40 during a hydraulic stroking of the expansion tool 10.
[0059] The second annular stop 118 shown in FIG. 3 forms a distal end of a first annular cylinder 78 in which the annular piston 48 on the pulling mandrel 40 is movable. The portion of the expansion tool 10 illustrated in FIG. 3 is distal to the portion of the expansion tool 10 illustrated in FIGS. 1 and 2. FIG. 3 illustrates the first annular cylinder 78 axially intermediate a first annular stop 18 (not shown in FIG. 3—see FIGS. 1 and 2) extending radially inwardly from the interior surface 34 of the housing 11 and a second annular stop 118 also extending radially inwardly from the interior surface 34 of the housing 11. The first annular stop 18 of FIG. 1 and the second annular stop 118 of FIG. 2 are spaced apart one from the other within the housing 11 to define the first annular cylinder 78 axially therebetween, and both of the first annular stop 18 and the second annular stop 118 sealably engage the exterior surface 41 of the pulling mandrel 40 at seals 19 and 35, respectively. A first annular piston 48 moves within the first annular cylinder 78 and is depicted in FIG. 3 immediately adjacent to the second annular stop 118 of the housing 11, thereby indicating that the expansion tool 10 is in the cocked configuration in FIG. 3. The seal 35 on the second annular stop 118 and the seal 19 on the first annular stop 18 (see FIG. 1) engage the exterior surface 41 of the pulling mandrel 40 to isolate the first annular cylinder 78 so that fluid pressure introduced into the distal portion 81 of the first annular cylinder 78 through the aperture 77 will exert a displacing force against the first annular piston 48 to move it within the first annular cylinder 78 as fluid is displaced from the first annular cylinder 78 through exhaust apertures 79 shown on FIGS. 1-3.
[0060] FIG. 3 illustrates the aperture 77 in the pulling mandrel 40 positioned to axially coincide with the distal portion 81 of the first annular cylinder 78 shown in FIG. 3 intermediate the first annular piston 48 of the pulling mandrel 40 and the second annular stop 118 of the housing 11. Pressurization of fluid within the tubular string (not shown in FIG. 3) is communicated through the proximal end 12 of the housing 11 (see FIG. 1), into the bore 44 of the pulling mandrel 40 and through the aperture 77 in the pulling mandrel 40 to the portion of the annular chamber 78 at the distal end 81 to hydraulically urge the first annular piston 48 and the pulling mandrel 40 to move in the proximal direction as indicated by arrow 39. It will be understood that hydraulic displacement of the first annular piston 48 of FIG. 3 in a proximal direction and away from the second annular stop 118 of the housing 11 and towards the first annular stop 18 of the housing 11 (shown on FIG. 1) to increase the distal portion 81 will move the pulling mandrel 40 to the “stroked” or un-cocked position corresponding to FIG. 2.
[0061] FIG. 3 also illustrates a second annular piston 148 on the pulling mandrel 40 that is spaced apart on the pulling mandrel 40 from the first annular piston 48. The second annular piston 148 is movable within a second annular chamber 178 formed axially between the second annular stop 118 of the housing 11 and a third annular piston 218 (not shown in FIG. 3) and radially between the exterior surface 41 of the pulling mandrel 40 and the interior surface 34 of the housing 11. The alternating arrangement of annular stops and annular pistons illustrated in FIGS. 1 and 3 can be extended to provide an aligned series of stacked annular cylinders, each reciprocatably receiving annular pistons to thereby multiply the amount of force that can be hydraulically applied to the pulling mandrel 40 to displace the pulling mandrel 40 within the bore 14 of the housing 11 during a stroke of the expansion tool 10. As stated above, and reiterated below, the hydraulic section of the expansion tool 10 can be used to hydraulically displace the pulling mandrel 40, the first expander 87 coupled thereto, the pulling mandrel extension 140 and the second expander 187 coupled thereto.
[0062] FIG. 4 is a sectional view of a portion of the embodiment of the expansion tool 10 of FIGS. 1-3 that is below the hydraulic section of the expansion tool 10 illustrated in FIGS. 1-3. The portion of the expansion tool 10 illustrated in FIG. 4 includes a plurality of slips 47 linked to a rack retainer 52 that is secured to a collet cage 20 that, in turn, surrounds a collet 21. Turning to FIG. 4A, the collet 21 is releasably coupled to the pulling mandrel 40 using one or more radially outwardly disposed notches 28 on the pulling mandrel 40 that releasably receive one or more radially inwardly protruding ridges 27 on the collet 21. The collet cage 20 includes an interior channel 22 that surrounds the collet 21 and allows a limited amount of movement of the collet 21 within the collet cage 20. Returning to FIG. 4, the collet cage 20 is coupled to the ratchet rack 55. The ratchet rack 55 is a tubular member having a bore 54 and a buttress-threaded exterior 56 to cooperate with a ratcheting component 150 that is movable in the direction of arrow 69 along the ratchet rack 55. It will be understood that the ratcheting component 150 may move in the direction of arrow 69 along a stationary ratchet rack 55 or the ratchet rack 55 is movable in the direction of arrow 39 within a stationary ratcheting component 150, which is the same relative direction of movement of one component relative to the other. This unidirectional movement is permitted by the buttress-threaded exterior 56 of the ratchet rack 55 and the corresponding buttress-threaded interior bore of the ratchet ring 57. The ratcheting component 150 includes the ratchet ring 57 captured within a shaped chamber 159 (see FIGS. 5 and 5A) of a ring housing 50. The ratchet ring 57 is illustrated in FIG. 5 in the collapsed or contracted position to lock the ratcheting component 150 in position relative to the ratchet rack 55 and to thereby prevent movement of the proximal end 61 of the expandable outer clad 62 relative to the ratchet rack 55. It will be understood that this condition may leave a small amount of space within the chamber 159 radially outwardly of the ratchet ring 57. The ratchet ring 57 may include radially outwardly extending exterior threads 59 for engaging the correspondingly shaped chamber 159 of the ring housing 50 upon expansion of the ratchet ring 57. The ratchet ring 57 of FIG. 5 further includes radially inwardly extending interior buttress threads 58 that cooperate with correspondingly shaped buttress threads along the threaded exterior 56 of the ratchet rack 55. In FIG. 5, these interior buttress threads 58 of the ratchet ring 57 are shown engaged with the correspondingly shaped threaded exterior 56 of the ratchet rack 55 of the expansion tool 10.
[0063] Returning to FIG. 4, the reaction assembly of the expansion tool 10 of the embodiment of the present invention illustrated in the appended drawings includes the rack retainer 52, the collet cage 20, the collet 21, the ratchet rack 55 and the ratcheting component 150 which includes a ratchet ring 57 and a ratchet housing 50. The ratchet ring 57 includes a longitudinal slot to allow expansion and contraction of the ratchet ring 57 within the ratchet housing 50 as one of the ratcheting component 150 and the ratchet rack 50 moves relative to the other of the ratcheting component 150 and the ratchet rack 50. Turning again to FIG. 5, the ratchet ring 57 is specially threaded to enable uni-directional movement along the ratchet rack 55 relative to the ratcheting component 150 by circumferentially expanding, along the slot of the ratchet ring 57, within the chamber 159 of the ring housing 50 to a size large enough to allow the radially inwardly disposed buttress threads 58 of the ratchet ring 57 to index or to skip over the corresponding radially outwardly extending buttress threads 56 on the exterior of the ratchet rack 55 for relative movement of the ratchet ring 57 and ring housing 50 in the direction of arrow 157 or, conversely, for relative movement of the ratchet rack 55 relative to the ratchet ring 57, and relative to the ring housing 50 in which the ratchet ring 57 is expandably captured, in the direction of arrow 155. It will be understood that each buttress thread of the various buttress-threaded surfaces each include a ramped side and a steep side, and that the inwardly extending buttress-threads 58 on the ratchet ring 57 and the outwardly extending buttress-threads on the ratchet rack 55, respectively, are together arranged for movement in the direction of the ramped side of the buttress threads. The reaction assembly is adapted to accommodate both axial outer clad 62 shrinkage due to radial expansion and re-cocking of the expansion tool 10 for repeated and sequential strokes, as will be discussed below.
[0064] FIG. 5A is a sectioned view of the portion of the expansion tool 10 illustrated in FIG. 5 with the section line taken through the ratchet ring 57 and the ring housing 50 in which the ratchet ring 57 is expandably captured. FIG. 5A shows the pulling mandrel 40, which is movably received within the bore 54 of the ratchet rack 55, which is movably received within the ratchet ring 57 which is expandably captured within the ring housing 50. The sectional view of FIG. 5A illustrates the contracted or locked position of the ratchet ring 57 and only a small amount of the inwardly extending buttress threads 58 of the ratchet ring 57 can be seen in FIG. 5A because they are locked and engaged with the corresponding buttress threads 56 of the ratchet rack 55. The outwardly extending threads 59 of the ratchet ring 57 are visible in FIG. 5A between the ratchet ring 57 and the ring housing 50. This position corresponds to the condition of the reaction assembly that resists movement of the ratchet ring 57 and ring housing 50 along the ratchet rack 55, such as when the expandable outer clad 62 is first being expanded within the well casing 99 and requires that the reaction assembly hold it in position within the well casing 99. It will be noted that in FIG. 5A, which corresponds to the contracted position of the ratchet ring 57, there is either no gap or a small gap 57A formed at the slot of the ratchet ring 57 which is in its circumferentially contracted configuration. It will be further noted that the expandable outer clad 62 is not in the sectioned view of FIG. 5A, which is above the expandable outer clad 62.
[0065] FIG. 5B is another sectioned view of the portion of the expansion tool 10 illustrated in FIG. 5 with the section line taken through the ratchet ring 57 and the ring housing 50 in which it is expandably captured. FIG. 5B also shows the pulling mandrel 40, the ratchet rack 55, the ratchet ring 57 and the ring housing 50, but the sectional view of FIG. 5B illustrates the expanded position of the ratchet ring 57. It should be noted that the inwardly extending buttress threads 58 of the ratchet ring 57 can be seen in FIG. 5B because they are expanded and disengaged from the buttress threads 56 of the ratchet rack 55. The outwardly extending threads 59 of the ratchet ring 57 are not visible in FIG. 5B between the ratchet ring 57 and the ring housing 50 because they are recessed within the shaped chamber 159 of the ring housing 50. This position corresponds to the condition of the reaction assembly that permits movement of the ratchet ring 57 and ring housing 50 along the ratchet rack 55, such as when the expandable outer clad 62 axially contracts while being expanded within the well casing 99. It will be noted that in FIG. 5B, which corresponds to the expanded position of the ratchet ring 57, there is a larger gap 57B formed in the ratchet ring 57 which is in its circumferentially expanded configuration.
[0066] Returning to FIG. 5, a proximal end 61 of an expandable outer clad 62 is received concentrically onto the elongate ratchet rack 55 prior to connection of the expander 87 (see FIG. 7) to axially capture the expandable outer clad 62 between the expander 87 and the ratcheting component 150 and to concentrically surround the ratchet rack 55 with the expandable outer clad 62. The expandable outer clad 62 is also axially captured intermediate the ring housing 50 of the ratcheting component 150, which is engaged with the proximal end 61 of the expandable outer clad 62, and the expander 87 (not shown in FIG. 5—see FIGS. 7 and 8) connected to a distal end of the pulling mandrel 40 that is reciprocatably received through the bore 54 of the ratchet rack 55. The proximal end 61 of the expandable outer clad 62 is illustrated in FIG. 5 as being disposed around at least a portion of the ring housing 50 and secured to the ring housing 50 by threaded fasteners 71. The expandable outer clad 62 is illustrated in FIG. 5 and in FIGS. 7 and 8 in position for being radially outwardly expanded by stroking of the pulling mandrel 40 to pull the first expander 87 to expand an interval the expandable outer clad 62 and to engage the expanded interval of the outer clad 62 with the interior wall 98 of the targeted interval of the well casing 99.
[0067] FIG. 6 illustrates how the expansion tool 10 of the present invention is securable in the well casing 99 in which the expandable outer clad 62 is to be expanded and installed, as opposed to being securable in the expandable outer clad 62 itself, as are some other downhole casing liner expansion tools. The slips 47 of the expansion tool 10 are radially outwardly deployable to engage the interior wall 98 of the well casing 99 by initial movement of the pulling mandrel 40 and the first expander 87 attached thereto in the direction of the arrow 39 relative to the housing 11 of the expansion tool 10. Movement of the pulling mandrel 40 (and the first expander 87 connected thereto and shown in FIGS. 7 and 8) in the direction of the arrow 39 places the expandable outer clad 62 in axial compression and transfers the axial component of the force applied by the first expander 87 to the distal end 64 (not shown in FIG. 6—see FIG. 8) of the expandable outer clad 62 to the ring housing 50 and to the ratchet ring 57 within the ring housing 50 engaged with the proximal end 61 of the expandable outer clad 62. The ratchet ring 57 transfers the axial component of the force applied by the first expander 87 through the expandable outer clad 62 to the ring housing 50 that is uni-directionally disposed on the ratchet rack 55. The ring housing 50 transfers the force, through the ratchet ring 57, to the ratchet rack 55 and to the collet cage 20 that surrounds the collet 21. The collet cage 20 transfers the force to the rack retainer 52 that is connected through the collet cage 20 to the ratchet rack 55, and the rack retainer 52 transfers the force to the slips 47 and urges the slips 47 in a proximal direction relative to the slip actuator 46. The slips 47 include sloped interior portions 67 that slide against and cooperate with similarly sloped exterior portions 43 of the slip actuator 46. As the slips 47 are displaced upwardly in the direction of arrow 39 relative to the slip actuators 46 by the force applied to the slips 47 by the rack retainer 52 during an expansion stroke as described above, the slips 47 are radially outwardly deployed away from the axis 88 of the expansion tool 10 to engage and grip the interior wall 98 of the casing 99. It should be noted that the slips 47 are radially outwardly deployed by a small amount of axial movement of the slips 47 relative to the cooperating slip actuators 46 to engage and grip the casing 99. It will be understood that the slips 47 may be disposed within a slip cage portion or extension of the tubular housing 11 having openings or “windows” adjacent to the slips 47 to permit the slips 47 to grippingly engage the interior wall 98 of the casing 99 upon deployment to secure the expansion tool 10 in position within the casing 99. In one embodiment, the slips 47 may be biased towards the retracted configuration by springs 51.
[0068] FIG. 5 is an enlarged view of the specially threaded interface between the ratchet rack 55 and the ratchet ring 57 of the expansion tool 10. The ratchet ring 57 includes a threaded interior bore 58 having threads such as, for example, buttress threads. Optionally, the ratchet ring 57 may also include exterior surface features such as, for example, exterior threads 59 for grippingly engaging the interior bore 53 of the proximal end 61 of the expandable outer clad 62. The ratchet ring 57 illustrated in FIG. 5 is secured to the proximal end 61 of the expandable outer clad 62 using threaded fasteners 71. The ratchet rack 55, on which the ratchet ring 57 is uni-directionally movable, also includes a bore 54 through which the pulling mandrel 40 is received. It will be understood that only small portions of the pulling mandrel 40, the ratchet rack 55 and the ratchet ring 57 are shown in the enlarged view of FIG. 5. The threaded exterior surface 56 of the ratchet rack 55 also includes buttress threads 56 such as, for example, buttress threads, that cooperate with the buttress threads on the threaded interior bore 58 of the ratchet ring 57 to provide for movement of the ratchet ring 57 only in the distal direction along the ratchet rack 55, as indicated by arrow 157 in FIG. 5 or, stated another way, to provide for movement of the ratchet rack 55 in a proximal direction relative to the ratchet ring 57, as indicated by arrow 155. The threads 58 of the ratchet ring 57 and the engaging threads 56 of the ratchet rack 55 cooperate to prevent movement of the ratchet ring 57 in the proximal direction along the ratchet rack 55. It will be understood that the axially compressing force applied by the first expander 87 (see FIG. 7) to the distal end 64 of the outer clad 62 is transferred to the retainer ring 57 urging it to move along the ratchet rack 55, and that the threading of the ratchet rack 55 and ratchet ring 57 (see FIG. 5) prevent movement of the ratchet ring 57 in response to the force applied by the first expander 87 to the outer clad 62. This interaction between the ratchet rack 55 and the ratchet ring 57 enables the transfer of the force to the rack retainer 52 and to the slips 47 at the onset of an expansion stroke.
[0069] FIG. 5A shows an embodiment of the ratchet ring 57 for use in connection with the expansion tool 10 of the present invention that includes a slot 57A to allow for circumferential elastic expansion and contraction (collapse) of the ratchet ring 57 as it and the ring housing 50 ratchets along the exterior surface 56 of the ratchet rack 55 (in one direction only due to the buttress threads). It will be understood that the ramping side 63 of the buttress threads 58 (see FIG. 5) within the bore of the ratchet ring 57 will slide along the ramping side 68 of the exterior buttress threads 56 on the ratchet rack 55 to impart an expanding force to the ratchet ring 57 that will cause the slot 57A (see FIG. 5A) to open and expand the ratchet ring 57 enough to allow movement of the ratchet ring 57 in a distal direction (in the direction of arrow 157 on FIG. 5) relative to the ratchet rack 55. The slotted ratchet ring 57 of FIG. 5A will elastically return to a contracted configuration after the peaks 83 of the threads 56 and 58 of the ratchet rack 55 and ratchet ring 57 each pass the other and return to the collapsed configuration shown in FIG. 5. FIG. 5B shows the peaks 83 of the threads 56 of the ratchet rack 55 and the threads 58 of the ratchet ring 57 engaged just before the ratchet ring 57 collapses or retracts back to the configuration shown in FIG. 5A. It will be noted that in FIG. 5B the slot 57B is at its largest opening.
[0070] Alternately, in other embodiments of the expansion tool of the present invention, the ratcheting function of the ratchet ring 57, as it moves in one (the distal) direction only, can be provided by a conventional spring-biased dog provided on the ratchet ring 57 in lieu of the slot 57A. The spring-biased dog engages and rides along the thread profile 56 of the ratchet rack 55 with the spring biasing the dog to remain engaged with the threads on the ratchet rack 55. Each time a force is applied to move the ratchet ring 57 in the distal direction, the dog will be displaced radially outwardly against the spring element and away from the ratchet rack 55 as the dog clears a thread peak 83. After the dog clears the thread peak 83, the biasing of the spring element restores the dog into a valley between two adjacent thread peaks to re-engage the dog with the steep side of the thread and to prevent movement of the ratchet ring 57 in the proximal direction. It will be understood that a spring-biased dog is the same apparatus used in many conventional ratcheting apparatuses such as, for example, a ratchet tool for use with sockets and a bumper jack used to lift an automotive vehicle. It will be understood that a large variety of elastically deformable components could be included within a ratchet ring 57 to provide the elastic restoring function of the slotted ratchet ring 57 or the spring-biased ratchet ring described above.
[0071] FIG. 6 illustrates the positions of the slips 47, the slip actuator 46, the rack retainer 52, the ratchet ring 57, the ring housing 50 and the ratchet rack 55 on which the ratchet ring 57 is received with the expansion tool 10 in the run-in configuration. It can be seen in FIG. 6 that the pulling mandrel 40 is slidably received through the bore 54 of the ratchet rack 55 and through the slip actuator 46. The slip actuator 46 includes a plurality of radially outwardly extending lobes 43 that axially and slidably engage and radially outwardly displace a corresponding plurality of lobes 67 of the slips 47 when the slips 47 are displaced, relative to the slip actuator 46, by the collet 21, collet cage 20 and the rack retainer 52 engaged thereby. Each of the slips 47 are radially captured between the slip actuator 46 and a retainer spring 51, and each slip 47 is disposed adjacent a window 13 within the housing 11 through which the slip 47 can engage the interior wall 98 of the casing 99. The portion of the housing 11 adjacent to the windows 13 and adjacent to the slips 47 may be referred to as a cage portion of the housing 11 because the windows 13 give that portion a cage-like appearance. The application of force by the first expander 87 (not shown in FIG. 6—see FIG. 7) to the outer clad 62, transferred through the ring housing 50, the ratchet ring 57, the ratchet rack 55 and the rack retainer 52 to the slips 47, displaces the slips 47 axially and in the proximal direction of the arrow 39, onto the slip actuator 46, and radially outwardly against the spring 51 to engage and grip the casing 99. Once the slips 47 engage and grip the casing 99, all further hydraulic displacement of the pulling mandrel 40 relative to the housing 11 results in expansion of a portion of the expandable outer clad 62. The collet 21 and collet cage 20 cooperate with the pulling mandrel 40 (see FIG. 4A) to set the slips 47 to grip the casing 99 prior to the pulling mandrel 40 disengaging the collet 21.
[0072] FIG. 7 is a sectional view of an intermediate portion 73 of the expansion tool 10 including the first expander 87 and a ball seat 75 within the bore 44 of the pulling mandrel 40. The ball seat 75 is sized to receive a ball 72 (shown in FIG. 7 as being en route to the ball seat 75) and to thereby isolate the bore 44 of the pulling mandrel 40. The ball 72 and ball seat 75 enable fluid pressure within the bore 44 to increase to a pressure sufficient to stroke the annular pistons 48 and 148 (not shown in FIG. 7—see FIGS. 2 and 3) within the annular cylinders 78 and 178 of the hydraulic section of the expansion tool 10. The ball 72 is introduced into the tubular string (not shown) at the rig, and pumped through the bore 44 of the pulling mandrel 40 and displaced to the intermediate portion 73 of the expansion tool 10 to sealably engage the ball seat 75. FIG. 7 further illustrates an optional safety joint 29 that allows the expansion tool 10 to be rotated free of the first expander 87 and ball seat 75 in the event of the expansion tool 10 becoming stuck in the casing 99. The safety joint 29 can be rotated free of the expander 87 and ball seat 75 because the keys 74 (see FIG. 6) slidably engage the grooves 76 in the pulling mandrel 40 to rotatably secure the pulling mandrel to the housing 11 while allowing axial movement of the pulling mandrel 40 relative to the keys 74 and the housing 11. This arrangement enables torque applied to the proximal end 12 of the housing 11 to be transferred through the keys 74 and grooves 76 to the safety joint 29.
[0073] FIG. 8 is the lower portion of FIG. 7 illustrating the position of the ball 72 after it has been sealably received onto the ball seat 75 to isolate the bore 44 of the pulling mandrel 40 (see FIG. 7) and to enable the expansion tool 10 to hydraulically stroke the first expander 87 to enter the distal end 64 of the expandable outer clad 62 and to expand the expandable outer clad 62. As the pumping of fluid into the bore 44 of the pulling mandrel 40 continues, the pressure within the bore 44 of the pulling mandrel 40 increases and displaces the annular pistons 48 and 148 and the pulling mandrel 40 to which these annular pistons 48 and 148 are secured in a proximal direction (in the direction of arrow 39 in FIGS. 1, 3 and 4) within the bore 14 of the housing 11. This relative movement causes the slips 47 to be displaced radially outwardly relative to the slip actuators 46 (see FIG. 6) to grip the casing 99 prior to disengagement of the collet 21 from the pulling mandrel 40 (see FIG. 4A) and expansion of the expandable outer clad 62.
[0074] FIG. 9 is a sectional elevation view of a portion of the hydraulic section of the expansion tool 10 of the present invention illustrating a small amount of initial separation between the first annular piston 48 of the pulling mandrel 40 from a second annular stop 118 of the housing 11. FIG. 9 may be compared to FIG. 3, which reflects the condition of the expansion tool 10 prior to pressurization of the bore 44 of the pulling mandrel 40. The small amount of separation illustrated in FIG. 9 occurs after the ball 72 sealably engages and seats in the ball seat 75 of the pulling mandrel 40 and fluid within the bore 44 of the pulling mandrel 40 is pressurized to stroke the expansion tool 10, and this configuration indicates the initial portion of the stroke of the hydraulic section of the expansion tool 10. The initial separation illustrated in FIG. 9 may be correlated to the setting of the slips 47, illustrated in FIG. 10, that occurs at the onset of the stroking of the hydraulic section of the liner expansion tool 10 to secure the housing 11 of the expansion tool 10 in place within the casing 99. The small amount of separation between the first annular piston 48 and the second annular stop 118 indicates the condition of the expansion tool 10 at the time the slips 47 become engaged to grip the casing 99. Continued pressurization of the fluid in the bore 44 of the pulling mandrel 40 after the separation indicated by FIG. 9 causes further movement of the first annular piston 48 within the first annular cylinder 17 (see also FIG. 3) of the housing 11 to draw the first expander 87 into the distal end 64 of the expandable liner 62 (see FIG. 8), thereby radially expanding the expandable outer clad 62 as the first expander 87 moves through the expandable outer clad 62. After the outer clad 62 is expanded, the inner clad 260 is then expanded as the second expander 187 moves through the inner clad 260, as discussed further below in connection with FIGS. 12-15.
[0075] FIG. 10 is a sectional elevation view of the slips 47 and slip actuator 46 of the expansion tool 10 of the present invention with the slips 47 (also shown in FIG. 6 as being coupled to the ratchet rack 55) displaced from their original position and forced axially onto the slip actuator 46. The slips 47 are illustrated in FIG. 10 in a deployed configuration engaging and gripping the interior wall 98 of the casing 99 in which the expansion tool 10 is disposed. FIG. 10 corresponds to the relative positions of the first annular piston 48 and the adjacent second annular stop 118 illustrated in FIG. 9. FIG. 10 illustrates how the slips 47 of the expansion tool 10 are deployed at the onset of the pressurization of the bore 44 of the pulling mandrel 40 to secure the housing 11 of the expansion tool 10 within the casing 99 before the expander 87 is pulled through a distal portion of the expandable outer clad 62.
[0076] FIG. 11 is a sectional elevation view of the slips 47 and slip actuator 46 of the expansion tool 10 and of the components of the reaction assembly that maintains the position of the expandable outer clad 62 during expansion. FIG. 11 illustrates how the expandable clad 62 and the components of the reaction assembly of the expansion tool 10 are coupled to deploy the slips 47 upon initial pressurization of the bore 44 of the pulling mandrel 40 for an expansion stroke. Optionally, the expandable outer clad 62 of FIG. 11 includes a plurality of elastomeric seals 82 disposed on the expandable outer clad 62 to engage and seal with the bore 98 of the casing 99 upon expansion of the expandable outer clad 62. The expandable outer clad 62, upon engagement at the distal end 64 (not shown—see FIGS. 7 and 8) by the expander 87, is urged against the ring housing 50 that houses the ratchet ring 57. The ratchet ring 57 cannot move along the ratchet rack 55 in the direction of arrow 39 due to the threaded arrangement (see FIG. 5) and the reaction force applied by the ring housing 50 to the axially compressed outer clad 62 as the force applied by the first expander 87 to the outer clad 62 is transferred through the ring housing 50 and the ratchet ring 57 housed therein to the ratchet rack 55. The ratchet rack 55 is coupled to the rack retainer 52 and the force applied by the ratchet ring 57 to the ratchet rack 55 is transferred through the rack retainer 52 to the slips 47, causing them to move in the axial direction of arrow 39 into the deployed and gripping configuration illustrated in FIG. 11.
[0077] Once the slips 47 engage the casing 99, the continued introduction of pressurized fluid into the bore of the pulling mandrel causes the pulling mandrel 40 to be displaced in a proximal direction within the bore of the housing 11 and to pull the first expander 87 into the bore of the distal end 64 of the outer clad 62. The resulting expansion of the expandable outer clad 62 continues until the stroke of the annular pistons 48 and 148 is completed. At this juncture, the first expander 87 is securely lodged within the partially expanded bore of the expandable outer clad 62 and the exterior surface of the expandable outer clad 62, in the portion of the expandable outer clad 62 that has been expanded, is in engagement with the casing 99.
[0078] The remaining unexpanded portion of the expandable outer clad 62 that has not yet been expanded by movement of the first expander 87 through the bore of the distal end 64 of the expandable outer clad 62 can be expanded by subsequent strokes of the expansion tool 10. Subsequent strokes require that the expansion tool 10 be re-cocked to reset the hydraulic section of the expansion tool 10, which means that the pulling mandrel 40 and the annular pistons 48 and 148 thereon must be restored to their original “run-in” positions relative to the housing 11 and the annular chambers defined by the stops 18 and 118 provided within the housing 11 for reciprocal movement of the annular pistons 48 and 148.
[0079] The expansion tool 10 can be re-cocked by first relieving the fluid pressure within the bore 44 of the pulling mandrel 40 to relieve force applied to each of the annular pistons 48 and 148 disposed on the pulling mandrel 40 by the fluid pressure within each of the annular chambers defined by the stops 18 and 118. It will be understood that relieving the pressure within the bore 44 of the pulling mandrel 40 requires control of the pumps that pump fluid into the bore 44 of the pulling mandrel 40 by pumping down the tubular string to the housing 11. With the hydraulic pressure in the bore 44 of the pulling mandrel 40 relieved, and with the first expander 87 securely lodged within the partially expanded expandable outer clad 62, the expanded portion of which engages the casing 99, the expansion tool 10 can be re-cocked by using the draw works on the rig to pull the tubular string (not shown) and the proximal end 12 of the housing 11 of the expansion tool 10 to which it is threadably connected in a proximal direction within the casing 99 to displace the annular pistons 48 and 148 back to their original locations within the annular chambers defined by the annular stops 18 and 118 of the proximally displaced housing 11. It will be understood that the pulling mandrel 40 and the first expander 87 to which it is connected will remain stationary during the re-cocking process, and also that the ball 72 does not disengage the ball seat 75 during this re-cocking step as long as the pressure within the bore 44 of the pulling mandrel 40 does not fall below the pressure within the casing 99. Once the housing 11 of the expansion tool 10 is displaced relative to the pulling mandrel 40 and the first expander 87 by using the draw works to pull the proximal end 12 of the housing 11, the expansion tool 10 is re-cocked and ready for being hydraulically stroked to set the slips 47 and then to expand an additional interval of the expandable outer clad 62.
[0080] Subsequent pressurization of the tubular string and of the bore 44 of the pulling mandrel 40 causes the slips 47 to again be engaged to grip the casing 99, and further pressurization causes the first expander 87 to be drawn in a proximal direction further within the bore of the expandable outer clad 62 to expand another portion of the expandable outer clad 62. It will be understood that with each stroke of the expansion tool 10, the axial length of the expanded portion of the expandable outer clad 62 increases. It will be further understood that since the expanded portion of the expandable outer clad 62 engages the casing 99, each stroke of the expansion tool 10 increases the overall surface area of frictional engagement between the exterior surface of the expanded portion of the expandable outer clad 62 and the casing 99 in which the expandable outer clad 62 is installed. It will be further understood that the expandable outer clad 62 is initially, during the early stages of expansion of the expandable outer clad 62, secured in place by the ratchet ring 57, the ring housing 50 and the ratchet rack 55, and by the arrangement of buttress threads within the bore of the ratchet ring 57 and on the exterior surface of the ratchet rack 55. However, once a sufficient amount of frictional engagement between the expanded portion of the expandable outer clad 62 and the casing 99 exists, the ratchet ring 57 and cooperating ratchet rack 55 will no longer continue to be loaded during strokes of the first expander 87 within the bore of the expandable outer clad 62 since movement of partially expanded expandable outer clad 62 within the casing 99 will be prevented by the steadily increasing frictional engagement between the expanded portion of the expandable outer clad 62 and the casing 99 in which it is expanded. At some point during the expansion of the expandable outer clad 62, the use of the hydraulic components (annular pistons 48 and 148, annular chambers defined by stops 18 and 118, etc.) and the gripping components (slips 47 and slip actuator 46) of the expansion tool 10 can be terminated, and the draw works of the rig from which the tubular string is run can be used to pull the expansion tool 10 and the first expander 87 coupled thereto to expand the remaining unexpanded portion of the partially expanded outer clad 62. If the weight on the draw works were to exceed a safe threshold beyond which the draw works or the tubular string may be damaged, the hydraulic components such as the annular pistons 48 and 148 and the annular stops 18 and 118, and the gripping components of the expansion tool 10 such as the slips 47 and the slip actuator 46 can be again engaged to continue expanding the expandable outer clad 62 one stroke at a time.
[0081] One embodiment of the method of the present invention includes the step of providing elastomeric seals 82 on the exterior surface 65 of the expandable outer clad 62 to engage the casing 99 upon expansion of the expandable outer clad 62. FIG. 11 illustrates a plurality of elastomeric seals 82 disposed on the expandable outer clad 62 near the proximal end 61 of the expandable outer clad 62. It will be understood that these seals 82 can be installed at a plurality of locations along the exterior surface 65 of the expandable outer clad 62 to engage the casing 99 upon expansion of the expandable outer clad 62 and to thereby provide additional sealing integrity.
[0082] FIG. 12 is a sectional view of a distal portion 80 of the expansion tool 10 of the present invention, shown in the lower portion of FIG. 12, and the intermediate portion 73 of FIG. 7 shown in the upper portion of FIG. 12 to illustrate the interaction between the expandable inner clad 260, the second expander 187 and the pulling mandrel extension 144 of the expansion tool 10, on the one hand, and the expanded portion 25 of the outer clad 62, the first expander 87 and the pulling mandrel 40, on the other hand. The inner clad 260 includes a proximal end 261, a distal end 269 and a pre-expanded portion 299 at the distal end 269 of the inner clad 260. The pre-expanded portion 299 of the inner clad 260 shown in the lower portion of FIG. 9 is too large in diameter to enter the expanded portion 25 of the outer clad 62 shown in the upper portion of FIG. 9. That relative sizing between the pre-expanded portion 299 of the inner clad 260 and the expanded portion 25 of the outer clad 62 serves an important purpose, as will be discussed in more detail below. The remaining portion of the inner clad 260, the portion above the pre-expanded portion 299 of the inner clad 260, is advantageously small enough to be received into the bore 23 of the expanded portion 25 of the outer clad 62 as the outer clad 62 is progressively expanded, from distal end 64 to the proximal end 61, by movement of the first expander 87 being drawn through the outer clad 62 by the pulling mandrel 40. The pulling mandrel extension 140 includes a proximal end 141 that is coupled to the first expander 87, a bore 144 that extends the bore 44 of the pulling mandrel 40, and a distal end 149 that is coupled to the second expander 187. The inner clad 260 is axially captured intermediate the second expander 187, which is engaged with and lodged in the pre-expanded portion 299 of the inner clad 260, and the first expander 87, with the pulling mandrel extension 140 disposed within the bore 123 of the inner clad 260. Unlike the outer clad 62, the inner clad 260 is positioned for expansion by engagement of the pre-expanded portion 299 with the expanded distal end 64 of the outer clad 62 (instead of by use of a ratcheting component). While FIG. 12 illustrates the length of the inner clad 260 as being equal to the distance 125 from the retainer 188 (that secures the first expander 87 in place on the pulling mandrel 40) to the second expander 187, it will be understood that the inner clad 260 may be shorter in length than the distance 125. In one embodiment, the length of the unexpanded inner clad 260 is equal to the length of the unexpanded outer clad 62 plus the length 189 of the pre-expanded portion 299 of the distal end 269 of the inner clad 260. This length combination ensures that the expanded outer clad 62 and the expanded portion 25 of the inner clad 260 installed therein, which is the portion of the inner clad 260 above the pre-expanded portion 299, will be about the same length. It will be understood that the lengths of the inner clad 260 and the outer clad 62 may vary in other embodiments.
[0083] FIG. 13 is the view of the expansion tool 10 of FIG. 12 after the first expander 87 is pulled further through the outer clad 62 to lengthen the expanded portion 25 of the outer clad 62 and to move a substantial portion, including the proximal end 261, of the unexpanded inner clad 260 into the bore of the expanded portion 25 of the outer clad 62. It can be seen in the lower portion of FIG. 13 that the distal end 64 of the outer clad 62, which was the first portion of the outer clad 62 to be expanded upon entry of the first expander 87 into the outer clad 62, is adjacent to the second expander 187 but not yet engaged by the pre-expanded portion 299 at the distal end 269 of the inner clad 260. It will be understood that as the second expander 187 and the pre-expanded portion 299 of the inner clad 260 into which the second expander 187 is received will continue to be drawn closer to the expanded distal end 64 of the expanded portion 25 of the outer clad 62 as the pulling mandrel 40, the first expander 87, the pulling mandrel extension 140, the pre-expanded portion 299 of the inner clad 260 and the second expander 187 lodged therein continue to be moved upwardly relative to the outer clad 62 and the casing 99 engaged by the expanded outer clad 62. It will be noted that there remains clearance between the unexpanded inner clad 260 and the expanded outer clad 62 to accommodate expansion of the inner clad 260 by the second expander 187 after the pre-expanded portion 299 of the inner clad engages the distal end 64 of the outer clad 62.
[0084] FIG. 14 is the view of the expansion tool 10 of FIG. 13 after the first expander 87 is pulled further through the outer clad 62 to lengthen the expanded portion 25 of the outer clad 62 and to move all of the inner clad 260 except the pre-expanded portion 299 into the bore of the expanded portion 25 of the outer clad 62. It can be seen in the lower portion of FIG. 14 that the distal end 64 of the outer clad 62, which was the first portion of the outer clad 62 to be expanded upon entry of the first expander 87 into the outer clad 62, is engaged by the pre-expanded portion 299 at the distal end 269 of the inner clad 260, and that the second expander 187 is lodged within the pre-expanded portion 299 of the inner clad 260. The first expander 87 has emerged from the now-expanded proximal end 61 of the outer clad 62. It will be understood that as the second expander 187 continues to be pulled upwardly by continued movement of the pulling mandrel 40, the first expander 87 and the pulling mandrel extension 140, the pre-expanded portion 299 of the inner clad 260 will not enter the bore of the now fully expanded outer clad 62 because there is insufficient annular clearance between the bore of the expanded outer clad 62 and the second expander 187. As a result, the movement of the inner clad 260 will stop at the position illustrated in FIG. 14, and the second expander 187 will be drawn into the bore of the inner clad 260 to expand the inner clad 260 radially outwardly to engage the bore of the outer clad 62 and to close the clearance between the bore of the outer clad 62 and the inner clad 260 that is shown in FIG. 14.
[0085] FIG. 15 is the view of FIG. 14 after the second expander 187 is pulled by movement of the pulling mandrel 40, the first expander 87 and the pulling mandrel extension 140 through an expanded portion 125 of the inner clad 260 having a length 124. It will be understood that further upwardly movement of the pulling mandrel 40, the first expander 87, the pulling mandrel extension 140 and the second expander 187 will result in further expansion of the inner clad 260 until the second expander 187 exits the proximal end 261 (not shown in FIG. 15) of the inner clad 260 to complete the installation of the tandem clad liner comprising the expanded outer clad 62 and the expanded inner clad 260 therein. It will be noted that the pre-expanded portion 299 of the inner clad 260 remains engaged with the distal end 64 of the expanded outer clad 62.
[0086] FIG. 16 is a high level flow chart illustrating the steps of an embodiment of a method 100 of the present invention for installing an expandable liner 62 within a casing 99. These steps are clearly related to the use of the liner expansion tool 10 illustrated in FIGS. 1-15 as well as other embodiments of the liner expansion tool 10 of the present invention.
[0087] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term “outer clad” is used to refer to a tubular liner adapted for being expanded within a bore of an interval of casing targeted for being lined using a tandem liner. As used herein, the term “inner clad” is used to refer to a tubular liner adapted for being expanded within the expanded outer clad, excepting the pre-expanded portion at the end of the inner clad.
[0088] As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, components and/or groups, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.
[0089] The terms “preferably,” “preferred,” “prefer,” “optionally,” “may,” and similar terms are used to indicate that an item, condition or step being referred to is an optional (not required) feature of the invention.
[0090] The corresponding structures, materials, acts, and equivalents of all means or steps plus function elements in the claims below are intended to include any structure, material, or act for performing the function in combination with other claimed elements as specifically claimed. The description of the present invention has been presented for purposes of illustration and description, but it is not intended to be exhaustive or limited to the invention in the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the invention. The embodiment was chosen and described in order to best explain the principles of the invention and the practical application, and to enable others of ordinary skill in the art to understand the invention for various embodiments with various modifications as are suited to the particular use contemplated.
