Expansion and collapse device and method of use thereof

Abstract

An expansion and collapse device and methods of use thereof are provided. The device includes a plurality of elements (52) assembled together to form a ring structure (54) about a longitudinal axis. The ring structure is operable to move between an expanded state and a collapsed state by moving the plurality of elements. At least one set of structural elements (56) each having a first end and a second end is operable to move between the expanded state and the collapsed state by moving the first end in an axial direction and by moving the second end in a radial dimension. The at least one set of elements is operable to move by sliding relative to one another in a direction tangent to a circle concentric with the ring structure. In another aspect, the plurality of elements (82) includes at least one set of structural elements (86) extending longitudinally on the device and operable to slide relative to one another, wherein the sliding movement in a selected plane perpendicular to the longitudinal axis is tangent to a circle lying in the selected plane and concentric with the longitudinal axis. Applications of the invention include oilfield devices, including crush resistant rings, plugs, packers, locks, repair tools, connection systems, and variable diameter tools run into a wellbore.

Description

[0001] The present invention relates to an expansion and collapse device and methods of use thereof, and in particular to an expansion device in the form of a ring operable to move between a collapsed state and an expanded state. The invention also relates to tools and apparatus incorporating the expansion device and methods of use thereof. Preferred embodiments of the invention relate to oilfield equipment (including downhole equipment and wellhead equipment) incorporating the device and methods of use thereof. BACKGROUND

[0003] In many fields of mechanical engineering, and in particular in the field of oil and gas exploration and production, it is well known to provide expansion mechanisms for physical interaction with tubular components. Expansion mechanisms can expand outwards to engage an outer surface, or can collapse inwards to engage an inner surface.

[0004] Its range of applications is broad, but in oil and gas exploration and production it includes actuating and setting fluid barrier and sealing elements such as plugs and packers, anchoring and positioning tools such as wellbore anchors, casing and liner hangers, and locking mechanisms for setting equipment downhole. Other applications include providing crush resistance, mechanical support or bracing for elements such as elastomers or inflatable bladders.

[0005] Typical crush resistance rings are positioned between a packer or sealing element and its actuating sliding member, and are formed from split or segmented metal rings. During deployment of the packer or sealing element, the segments move to a radially expanded state. In the expanded state and during expansion, spaces are formed between the segments as they are required to occupy a larger annular volume. These spaces create crush gaps, which can cause the packer or seal to fail in service.

[0006] Various constructions have been proposed to minimise the effect of the spaces between the crush resistance segments, including providing a multi-layered ring such that the crush gaps are blocked by the offset arrangement of the segments. For example, US 6,598,672 describes a crush resistance ring for a packer assembly having first and second ring portions that are circumferentially offset to create a gap at the circumferentially offset location.

[0007] US 2,701,615 discloses a well packer comprising an arrangement of crown-shaped spring metal elements that expand by relative movement.

[0008] Other proposals such as those disclosed in US 3,572,627, US 7,921,921, US 2013 / 0319654, US 7,290,603 and US 8,167,033 include arrangements of circumferentially overlapping segments. US 3,915,424 describes a similar arrangement in a drilling blowout preventer (BOP) configuration in which overlapping crush resistant members are actuated by radial forces to move radially and circumferentially to a collapsed position supporting an annular seal element. This arrangement avoids introducing a crush gap during expansion, but results in an annulus with uneven or stepped or faceted faces. These configurations fail to provide an uninterrupted support wall for the seal element, are space inefficient, and can be difficult to reliably move back to its collapsed configuration.

[0009] US 8,083,001 proposes an alternative structure in which two sets of wedge-shaped segments are joined together by axial sliding relative to each other to form an expanded gauge.

[0010] The application of existing expansion and collapse devices is limited by the expansion ratio that can be achieved.

[0011] In anchoring, positioning, setting, locking and connecting applications, the radially expanding and collapsing structures are typically circumferentially distributed at discrete locations when in the increased outer diameter state. This reduces the surface area available to contact the auxiliary engagement surface and therefore limits the maximum force and pressure ratings of a given size device. SUMMARY

[0012] It is one of the objects and purposes of the present invention to provide an expanding and collapsing device and method of use thereof which eliminates or mitigates the disadvantages of previously proposed expanding and collapsing devices.

[0013] It is one of the objects and purposes of the present invention to provide an oilfield device, including but not limited to a downhole device, a wellhead device or a drilling device, incorporating an expanding and collapsing device which eliminates or mitigates the disadvantages of prior art oilfield devices.

[0014] Other objects and purposes of the present invention will become apparent to the reader upon reading the following description.

[0015] In the context of the present specification, the terms "ring" and "ring structure" are used to designate an arrangement of one or more components or elements joined to themselves to surround an axis, but are not limited to arrangements that are rotationally symmetric or symmetric about a plane perpendicular to the axis.

[0016] According to a first aspect of the present invention, there is provided a device comprising:

[0017] a plurality of elements assembled together to form a ring structure around a longitudinal axis;

[0018] wherein the ring structure is operable to move between the expanded state and the collapsed state by moving the plurality of elements;

[0019] wherein the plurality of elements comprises at least one set of structural elements each having a first end portion and a second end portion, wherein the structural elements are operable to move between the expanded state and the collapsed state by moving the first end portions along the axial direction and by moving the second end portions along the at least radial dimension;

[0020] and wherein the plurality of elements comprises at least one set of elements operable to move between the expanded state and the collapsed state by sliding relative to each other along a direction tangential to a circle concentric with the ring structure.

[0021] The second end portions are operable to move along the radial direction and the axial direction of the device. The structural elements are operable to move along the circumferential direction of the device.

[0022] Preferably, the structural elements extend longitudinally on the device. The outermost dimension of the second end portions of the structural elements can be arranged at a radial distance from the longitudinal axis which is greater than the radial distance of the outermost dimension of the first end portions when the device is in the expanded state and / or in a partially expanded state. Alternatively or in addition, the outermost dimension of the second end portions of the structural elements can be arranged at a radial distance from the longitudinal axis which is greater than the radial distance of the outermost dimension of the first end portions when the device is in the collapsed state.

[0023] The device can comprise a retaining ring connected to the first end portions of the structural elements. The retaining ring is preferably axially movable on the device and is operable to axially move the first end portions of the structural elements on the device.

[0024] The set of structural elements can together form a substantially conical structure in the expanded state, including a partially, fully or substantially fully expanded state. Alternatively or in addition, the set of structural elements can together form a substantially conical structure in the collapsed state and / or in a partially expanded state. The substantially conical structure can be a truncated conical structure and / or can define a partially convex outer profile at least in its collapsed state.

[0025] In one embodiment, the plurality of elements comprises at least one set of ring elements different from the set of structural elements, the at least one set of ring elements being operable to move between the expanded state and the collapsed state by sliding relative to each other along a direction tangential to a circle concentric with the ring structure. The set of structural elements can be directly or indirectly connected to the set of ring elements and they can together be operable to move between the expanded state and the collapsed state.

[0026] In an alternative embodiment, the structural elements can comprise structural ring elements operable to move between an expanded state and a collapsed state by sliding relative to one another in a direction tangential to a circle concentric with the ring structure.

[0027] The ring elements and / or structural ring elements can subtend an angle (θι) of 45 degrees or less at the outer surface of the ring structure. Such a configuration corresponds to 8 or more ring elements assembled together to form the ring structure.

[0028] Preferably, the angle is 30 degrees or less, corresponding to 12 or more ring elements assembled together to form the ring. More preferably, the subtended angle is in the range of 10 to 20 degrees, corresponding to 18 to 36 elements assembled together to form the ring. In a particularly preferred embodiment, the subtended angle is 15 degrees, corresponding to 24 ring elements assembled together to form the ring structure.

[0029] The ring elements can comprise first and second contact surfaces, which can be oriented in first and second planes. The first and second orientation planes can intersect or meet (i.e. be tangential to) the inner surface of the ring structure formed by the segments at the first and second straight lines. The orientation planes can be tangential to the inner surface of the ring structure in its expanded state. Alternatively, the inner surface of the ring structure can have a truncated (increased) inner diameter, and the orientation planes can be tangential to a circle having a diameter less than the inner surface of the ring structure. Thus, the orientation planes can intersect the inner surface of the ring structure in its expanded state at an angle, which can be defined as θ2 between a radial plane from the centre of the ring structure and the point of intersection or tangency.

[0030] In the case where the structural elements extend longitudinally on the device, they are operable to slide relative to one another with the sliding movement in a selected plane perpendicular to the longitudinal axis being tangential to a circle lying in the selected plane and concentric with the longitudinal axis. In one embodiment, the structural elements extend longitudinally on the device and are operable to slide relative to one another with the sliding movement in any selected plane along the length of the structural elements and perpendicular to the longitudinal axis being tangential to a circle lying in the selected plane and concentric with the longitudinal axis.

[0031] In another alternative embodiment, the device can comprise one or more sets of structural ring elements operable to move between an expanded state and a collapsed state by sliding relative to one another in a direction tangential to a circle concentric with the ring structure and one or more sets of ring elements different from the one or more sets of structural ring elements.

[0032] The structural elements can be pivotally connected at their second end to the ring element. Preferably, the structural elements are connected to the ring element by a connection configured to be able to transmit tension between the structural element and the ring element. This enables tension to be pulled between the structural element and the ring element (or vice versa), which can facilitate retraction of the device from an expanded or partially expanded state. The structural elements can be connected to the ring element, for example, by a ball and socket or a hinged connection. In the case where the device comprises a retaining ring, the structural elements can be connected at their first end to the retaining ring by a connection, for example, by a ball and socket or a hinged connection, which is able to transmit tension between the structural element and the retaining ring. Thus, tension can be pulled between the structural element and the retaining ring (or vice versa), which can facilitate retraction of the device from an expanded or partially expanded state.

[0033] In the case where the set of structural elements together form a substantially conical structure, the substantially conical structure can comprise openings between the structural elements in the conical surface. In such embodiments, the structural elements can comprise struts or spokes, and / or the device can comprise a plurality of struts or spokes distributed circumferentially around the longitudinal axis.

[0034] In an embodiment of the application, the substantially conical structure can comprise a substantially continuous conical surface in the expanded state or in a partially expanded or substantially expanded state. The substantially conical structure can comprise a hollow cone. The substantially conical structure can comprise a substantially or completely uniform wall thickness. Alternatively or additionally, the substantially conical structure can comprise a tapering wall thickness. The substantially conical structure can comprise a cylindrical portion extending from its flared end.

[0035] The hollow cone can be formed from the set of structural ring elements in the expanded or substantially expanded state. Each structural ring element can be a segment of the cone. The structural ring elements can extend longitudinally on the device and can be operable to slide relative to one another, wherein the sliding movement in any selected plane along the length of the structural elements and perpendicular to the longitudinal axis is tangential to a circle lying in the selected plane and concentric with the longitudinal axis.

[0036] The structural elements can be pivotally connected at their second end to the ring element. The structural elements can be pivotally connected to the ring element by a ball and socket or a hinged connection. In the case where the device comprises a retaining ring, the structural elements can be pivotally connected at their first end to the retaining ring by a connection, for example, by a ball and socket or a hinged connection, which is able to transmit tension between the structural element and the retaining ring. Thus, tension can be pulled between the structural element and the retaining ring (or vice versa), which can facilitate retraction of the device from an expanded or partially expanded state.

[0037] The device can include a first set of structural elements, a second set of structural elements, and a set of ring elements distinct from the structural elements. The first set of structural elements can be connected to the set of ring elements at a first axial side of the set of ring elements, and the second set of structural elements can be connected to the set of ring elements at a second axial side of the set of ring elements. The first and / or second set of structural elements can include structural ring elements, which can be segments of a cone.

[0038] In the case where the structural ring elements are segments of a cone, they can describe an angle (θ1) of 45 degrees or less at the outer surface of the cone. Such a configuration corresponds to 8 or more ring elements assembled together to form a ring structure. Preferably, the angle is 15 degrees or less, corresponding to 12 or more structural ring elements assembled together to form a structural ring. More preferably, the described angle is in the range of 10 to 20 degrees, corresponding to 18 to 36 structural elements assembled together to form a structural ring. In a particularly preferred embodiment, the described angle is 15 degrees, corresponding to 24 ring elements assembled together to form a structural ring.

[0039] The ring elements can include first and second contact surfaces, which can be oriented on first and second planes. The first and second orientation planes can intersect or meet (i.e. be tangent to) the inner surface of the ring structure formed by the segments at the first and second straight lines. The orientation planes can be tangent to the inner surface of the ring structure in its expanded state. The orientation planes of the first and second contact surfaces can intersect on a radial plane P that bisects (i.e. is angled θ1 / 2 with respect to both) the radial plane at the point of tangency. This intersection plane P can define the expansion and collapse path of the cone segments.

[0040] The collapsed state can be a first state of the device, and the expanded state can be a second state of the device. Thus, the device can normally be collapsed, and can be actuated to expand. Alternatively, the expanded state can be a first state of the device, and the collapsed state can be a second state of the device. Thus, the device can normally be expanded, and can be actuated to collapse.

[0041] The ring structure can include one or more ring surfaces that can present to a secondary surface, such as the surface of a pipe, when actuated to the expanded state or the collapsed state. The one or more ring surfaces can include a ring surface that is parallel to the longitudinal axis of the device. The ring surface can be an outer ring surface, and can be a substantially cylindrical surface. The ring surface can be arranged to contact or otherwise interact with the inner surface of a pipe or bore.

[0042] Alternatively, the ring surface can be an inner surface of the ring structure, and can be a substantially cylindrical surface. The ring surface can be arranged to contact or otherwise interact with the outer surface of a pipe or cylinder.

[0043] The ring surface can be substantially smooth. Alternatively, the ring surface can be contoured and / or can be provided with one or more functional structures thereon for interacting with the auxiliary surface.

[0044] In the collapsed state, the ring elements can be arranged at a collapsed radial position and can define a collapsed outer diameter and an inner diameter of the ring structure.

[0045] In the expanded state, the ring elements can be arranged at an expanded radial position and can define an expanded outer diameter and an inner diameter of the ring structure. The ring surface can be located at or on the expanded outer diameter of the ring structure or can be located at or on the collapsed inner diameter of the ring structure.

[0046] In the collapsed state, the elements can occupy a collapsed annular volume and, in the expanded state, the elements can occupy an expanded annular volume. The collapsed annular volume and the expanded annular volume can be discrete and separate volumes or the volumes can partially overlap.

[0047] The ring elements can be configured to move between their expanded and collapsed radial positions along a path that is tangential to a circle described around and concentric with the longitudinal axis.

[0048] Preferably, each ring element of the ring structure comprises a first contact surface and a second contact surface that abut with first and second adjacent elements, respectively. The ring elements can be configured to slide relative to each other along their respective contact surfaces.

[0049] The first and / or second contact surfaces can be oriented tangentially to a circle described around and concentric with the longitudinal axis. The first and second contact surfaces are preferably non-parallel. The first and second contact surfaces can converge with each other in a direction towards the inner surface of the ring structure (and can therefore diverge with each other in a direction away from the inner surface of the ring structure).

[0050] At least some of the ring elements are preferably provided with an interlocking profile for interlocking with an adjacent element. Preferably, the interlocking profile is formed in the first and / or second contact surface. Preferably, the ring elements are configured to interlock with the contact surfaces of adjacent elements. Such interlocking can prevent or limit separation of assembled adjacent elements along the circumferential and / or radial direction of the ring structure while enabling relative sliding movement of the adjacent elements.

[0051] Preferably, at least some of the ring elements that assemble to form the ring, and more preferably all of the ring elements, are identical to each other, and each ring element comprises an interlocking profile configured to interlock with a corresponding interlocking profile on another ring element. The interlocking profile can comprise at least one recess, such as a groove, and at least one protrusion, such as a tongue or pin, configured to be received in the groove. The interlocking profile can comprise at least one dovetail recess and dovetail protrusion.

[0052] The first and second contact surfaces of the ring elements can be oriented on first and second planes that can intersect the inner surface of the ring at first and second intersection lines, such that a segment of an imaginary cylinder is defined between the longitudinal axis and the intersection lines. The central angle of the segment can be 45 degrees or less. Such a configuration corresponds to 8 or more ring elements assembled together to form the ring structure.

[0053] Preferably, the central angle of the segment is 30 degrees or less, corresponding to 12 or more ring elements assembled together to form the ring. More preferably, the central angle of the segment is in the range of 10 to 20 degrees, corresponding to 18 to 36 ring elements assembled together to form the ring. In a particularly preferred embodiment, the central angle of the segment is 15 degrees, corresponding to 24 ring elements assembled together to form the ring structure.

[0054] Each ring element can comprise one, preferably two, structural elements connected to the ring structure. The structural elements can comprise structural ring elements, and can be defined by the same central angle as the ring elements.

[0055] Preferably, the angle described between the first contact surface and the second contact surface corresponds to the central angle of the segment. Thus, preferably, the angle described between the first contact surface and the second contact surface is in the range of 10 to 20 degrees, and in a particularly preferred embodiment, the angle described between the first contact surface and the second contact surface is 15 degrees, corresponding to 24 elements assembled together to form the ring structure.

[0056] In a preferred embodiment, the device comprises a support surface for the ring structure. The support surface can be an outer surface of a mandrel or tube. The support surface can support the ring structure in a collapsed state of the device.

[0057] The support surface can be an inner surface of a mandrel or tube. The support surface can support the ring structure in an expanded state of the device.

[0058] In some embodiments, the device operates in its expanded state, and in other embodiments, the device operates in its collapsed state. Preferably, at least some of the elements forming the ring structure support each other in the operational state of the device. Where the operational state of the device is its expanded state (i.e. when the device is operated in its expanded state), the device can comprise a substantially solid cylindrical ring structure in its expanded state, and the ring elements can fully support each other.

[0059] In one embodiment, the substantially solid cylindrical ring structure of the device can be supported by one or more substantially conical structures formed from structural elements. The structural elements can fully support each other.

[0060] In one embodiment, the device can comprise one or more substantially conical structures in its expanded state, and the structural elements can fully support each other.

[0061] Where the operational state of the device is its collapsed state (i.e. when the device is operated in its collapsed state), the ring structure is preferably a substantially solid ring structure in its collapsed state, and the ring elements can fully support each other.

[0062] The device can comprise a structure configured to apply a radial expansion or collapse force component to the structural elements of the ring structure from an axial actuation force. The device can comprise a pair of structures configured to apply a radial expansion or collapse force component to the structural elements of the ring structure from an axial actuation force. The one or more structures can comprise a wedge or wedge profile, and can comprise a tapered wedge or wedge profile.

[0063] The device can comprise a biasing means which can be configured to bias the ring structure to one of its expanded or collapsed states. The biasing means can comprise a circumferential spring, a snap spring or a helical retaining ring. The biasing means can be arranged around an outer surface of the ring structure to bias it towards the collapsed state, or can be arranged around an inner surface of the ring structure to bias it towards the expanded state. One or more of the elements can comprise a structure such as a groove for receiving the biasing means. Preferably, the grooves in the elements combine to form a circumferential groove in the ring structure. A plurality of biasing means can be provided on the ring structure.

[0064] According to a second aspect of the application, there is provided a device comprising:

[0065] a plurality of elements assembled together to form a ring structure about a longitudinal axis;

[0066] wherein the ring structure is operable to move between an expanded state and a collapsed state by moving the plurality of elements;

[0067] wherein the plurality of elements comprises at least one set of structural elements which extend longitudinally on the device and are operable to slide relative to one another, wherein the sliding movement in a selected plane perpendicular to the longitudinal axis is tangential to a circle lying in the selected plane and concentric with the longitudinal axis.

[0068] In one embodiment, the structural elements extend longitudinally on the device and are operable to slide relative to one another, wherein the sliding movement in any selected plane along the length of the structural elements and perpendicular to the longitudinal axis is tangential to a circle lying in the selected plane and concentric with the longitudinal axis.

[0069] The structural elements can each have a first end and a second end, wherein the structural elements are operable to move between an expanded state and a collapsed state by moving the first end along an axial direction and by moving the second end along at least a radial dimension;

[0070] and wherein the plurality of elements comprises at least one set of elements which are operable to move between an expanded state and a collapsed state by sliding relative to one another in a direction tangential to a circle concentric with the ring structure.

[0071] Embodiments of the second aspect of the application can include one or more features of the first aspect of the application or embodiments thereof, or vice versa.

[0072] According to a third aspect of the application, there is provided an expandable and collapsible ring device comprising:

[0073] a plurality of elements assembled together to form a ring structure around a longitudinal axis;

[0074] wherein the ring structure is operable to move between an expanded state and a collapsed state;

[0075] wherein in the expanded state, the plurality of elements combine to form a conical structure having a substantially smooth conical outer surface.

[0076] The substantially smooth conical outer surface can be substantially uninterrupted. Preferably, the ring structure comprises a pair of conical structures having a substantially smooth conical outer surface. Thus, one or more sides or faces of the ring structure (i.e. surfaces presented in the longitudinal direction) can have a smooth surface.

[0077] The device can further comprise a solid ring structure having a substantially smooth circular profile in a plane perpendicular to the longitudinal axis.

[0078] The plurality of elements can comprise at least one set of structural elements.

[0079] The plurality of elements can comprise at least one set of elements operable to move between the expanded state and the collapsed state by sliding relative to one another in a direction tangential to a circle concentric with the ring structure.

[0080] In the case where the structural elements extend longitudinally on the apparatus, they are operable to slide relative to one another with the sliding movement in a selected plane perpendicular to the longitudinal axis being tangential to a circle lying in the selected plane and concentric with the longitudinal axis. In one embodiment, the structural elements extend longitudinally on the apparatus and are operable to slide relative to one another with the sliding movement in any selected plane along the length of the structural elements and perpendicular to the longitudinal axis being tangential to a circle lying in the selected plane and concentric with the longitudinal axis.

[0081] The structural elements can each have a first end and a second end, wherein the structural elements are operable to move between the expanded state and the collapsed state by moving the first end in an axial direction and by moving the second end in at least a radial dimension;

[0082] and wherein the plurality of elements comprises at least one set of elements operable to move between the expanded state and the collapsed state by sliding relative to one another in a direction tangential to a circle concentric with the ring structure.

[0083] Embodiments of the third aspect of the application can include one or more features of the first or second aspects of the application or embodiments thereof, or vice versa.

[0084] According to a fourth aspect of the application, there is provided an oilfield apparatus comprising:

[0085] a plurality of elements assembled together to form a first ring structure around a longitudinal axis;

[0086] a plurality of elements assembled together to form a second ring structure around a longitudinal axis;

[0087] wherein the first and second ring structures are operable to move between an expanded state and a collapsed state;

[0088] wherein in its expanded state, the plurality of elements of the first and second ring structures combine to form first and second conical structures;

[0089] and wherein in its expanded state, at least one of the first and second ring structures provides mechanical support for the other of the first and second ring structures.

[0090] Embodiments of the fourth aspect of the application can include one or more features of the first to third aspects of the application or embodiments thereof, or vice versa.

[0091] According to a fifth aspect of the application, there is provided a fluid barrier apparatus for a borehole or conduit, the fluid barrier apparatus comprising an expansion and collapse apparatus according to any of the preceding aspects of the application.

[0092] The fluid barrier apparatus can comprise a sealing apparatus for a borehole or conduit, and can be configured to maintain a pressure differential across the sealing apparatus.

[0093] Embodiments of the fifth aspect of the application can include one or more features of the first to fourth aspects of the application, or vice versa.

[0094] According to a sixth aspect of the application, there is provided a sealing assembly for a borehole or conduit, the sealing assembly comprising:

[0095] at least one expansion and collapse apparatus and a sealing element according to any of the preceding aspects of the application;

[0096] wherein the at least one expansion and collapse apparatus is arranged to provide mechanical support for the sealing element in its expanded state.

[0097] The sealing apparatus can comprise a first expansion and collapse apparatus according to any of the preceding aspects of the application and a second expansion and collapse apparatus according to any of the preceding aspects of the application. The sealing element can be disposed between the first and second expansion and collapse apparatuses, and can be mechanically supported by the first and second expansion and collapse apparatuses in their expanded states.

[0098] Embodiments of the sixth aspect of the application can include one or more features of the first to fifth aspects of the application, or vice versa.

[0099] According to a further aspect of the application, there is provided an oilfield tool comprising an apparatus according to any of the preceding aspects of the application.

[0100] The oilfield tool can be a downhole tool. Alternatively, the oilfield tool can comprise a wellhead tool.

[0101] The downhole tool can comprise a downhole tool selected from the group comprising a plug, a packer, an anchor, a tubing hanger or a downhole locking tool.

[0102] The plug can be a bridge plug, and can be a retrievable bridge plug. Alternatively, the plug can be a permanent plug.

[0103] According to a further aspect of the application, there is provided a variable diameter downhole tool, the tool comprising an apparatus according to the preceding aspects of the application.

[0104] The downhole tool can be selected from the group comprising a wellbore centralizer, a wellbore reaming tool and a wellbore drift tool.

[0105] According to another aspect of the application, there is provided a connector system comprising a first connector and a second connector, wherein one of the first and second connectors comprises the apparatus of any preceding aspect of the application.

[0106] According to another aspect of the application, there is provided a patching apparatus for a fluid conduit or tubular, the patching apparatus comprising the apparatus of any preceding aspect of the application.

[0107] According to another aspect of the application, there is provided a method of expanding or collapsing an expanding and collapsing apparatus, the method comprising:

[0108] providing a plurality of elements assembled together to form a ring structure about a longitudinal axis, wherein the plurality of elements comprises at least one set of structural elements each having a first end and a second end,

[0109] moving the first end of the structural segment in an axial direction and moving the second end of the structural segment along at least a radial dimension;

[0110] and moving the at least one set of elements between an expanded state and a collapsed state by sliding relative to one another along a direction tangential to a circle concentric with the ring structure.

[0111] According to another aspect of the application, there is provided a method of expanding or collapsing an expanding and collapsing apparatus, the method comprising:

[0112] providing a plurality of elements assembled together to form a first ring structure about a longitudinal axis; and providing a plurality of elements assembled together to form a second ring structure about a longitudinal axis;

[0113] moving the first and second ring structures between an expanded state and a collapsed state;

[0114] wherein in its expanded state the plurality of elements of the first and second ring structures combine to form first and second conical structures;

[0115] and wherein in its expanded state at least one of the first and second ring structures provides mechanical support to the other of the first and second ring structures.

[0116] According to another aspect of the application, there is provided a method of forming a fluid barrier or seal in a bore, the method comprising the method or apparatus of any preceding aspect of the application. The bore can be a wellbore, and can be a cased or lined wellbore.

[0117] Embodiments of other aspects of the application can include one or more features of any of the preceding aspects of the application or embodiments thereof, or vice versa. BRIEF DESCRIPTION OF DRAWINGS

[0118] Various embodiments of the application will now be described, by way of example only, with reference to the accompanying drawings in which:

[0119] Figures 1A-1D are a perspective view, a first end view, a partial section view and a second end view of the device for understanding the application, respectively, shown in the collapsed condition;

[0120] Figures 2A-2D are a perspective view, a first side view, a partial section view and a second side view of the device of Figures 1A-1D , respectively, shown in the expanded condition;

[0121] Figure 3 is a geometric representation of the elements of the device of Figures 1A-1D , shown from one side;

[0122] Figures 4A-4F are a first perspective view, a second perspective view, a plan view, a first end view, a bottom view and a second end view of the elements of the device of Figures 1A-1D , respectively;

[0123] Figures 5A-5C are an isometric view, a side view and an end view of the device according to an embodiment of the application, respectively, in the collapsed condition;

[0124] Figures 6A-6C are an isometric view, a side view and an end view of the device of Figures 5A-5C , respectively, in the partially expanded condition;

[0125] Figures 7A-7C are an isometric view, a side view and an end view of the device of Figures 5A-5C , respectively, in the fully expanded condition;

[0126] Figure 8 is a geometric representation of the elements of the device of Figures 5A-5C , shown from one side;

[0127] Figures 9A-9F are a first perspective view, a second perspective view, a plan view, a first end view, a bottom view and a second end view of the elements of the device of Figures 5A-5C , respectively;

[0128] Figure 10A and Figure 10B are an isometric view and a longitudinal section view of the device according to another embodiment of the application, respectively, in the collapsed position;

[0129] Figure 10C and Figure 10D are cross-sectional views of the device of Figure 10A and Figure 10B , taken along lines C-C and D-D, respectively;

[0130] Figure 11A and Figure 11B They are Figures 10A-10D An isometric view and a longitudinal sectional view of the device in an extended state;

[0131] Figure 11C and Figure 11D These are cuts taken along lines CC and DD respectively. Figure 11A and Figure 11B A cross-sectional view of the equipment;

[0132] Figure 12 yes Figures 10A-10D Isometric views of the structural components of the equipment;

[0133] Figure 13 yes Figures 10A-10D Isometric views of the ring elements of the device;

[0134] Figure 14A and Figure 14B It is a reference virtual cone Figure 12 A view of a structural element that is a segment of a virtual cone;

[0135] Figures 15A-15C It is a geometric reference diagram, which helps to understand how to form the structural elements of the embodiments of the present invention;

[0136] Figures 16A-16C These are, respectively, a first equidistant view, a bottom view, and a second equidistant end view of the ring element of the device according to an alternative embodiment of the present invention;

[0137] Figure 17A and Figure 17B These are first and second isometric views of structural elements of a device according to an alternative embodiment of the present invention;

[0138] Figure 18A and Figure 18B It combines in the collapsed and expanded states respectively. Figures 16A-17B A longitudinal sectional view of the device containing ring elements and structural elements;

[0139] Figures 19A-19C These are, respectively, an isometric view, a longitudinal sectional view, and an end view of the device in a collapsed state according to an alternative embodiment of the present invention;

[0140] Figures 20A-20C They are Figures 19A-19C Isometric view, longitudinal sectional view and end view of the device in an extended state;

[0141] Figures 21A-21C These are, respectively, an isometric view, a longitudinal sectional view, and a cross-sectional view of a device in a collapsed state according to an alternative embodiment of the present invention;

[0142] Figure 22A and Figure 22B are respectively Figures 21A-21C partially sectioned isometric and longitudinal sectional views of the device in an expanded state;

[0143] Figure 22C and Figure 22D are respectively Figure 22A and Figure 22B cross-sectional views of the device;

[0144] Figures 23A-23C are respectively isometric, longitudinal sectional and end views of a sealed device in a collapsed state according to an alternative embodiment of the application;

[0145] Figures 24A-24C are respectively Figures 22A-22C isometric, longitudinal sectional and end views of the device in an expanded state. DETAILED DESCRIPTION

[0146] Exemplary embodiments of the application will be described with reference to Figures 5 to 24. Referring first to Figures 1 to 4, the principles of the application will be described with reference to an expanding device in the form of a simple ring. In this arrangement, an expanding device, generally designated 10, comprises an expanding ring structure configured to expand from a first, collapsed or unexpanded state (as shown in Figure 1) to a second, expanded state (as shown in Figure 2). For convenience, the devices of the arrangements and embodiments of the application can be referred to as “expanding devices” because they are operable to move from a normal, collapsed state to an expanded state. However, the devices can equally be referred to as collapsed devices or expanding or collapsed devices because they are capable of expanding or collapsing depending on the state of operation. Figures 1A-1D Figures 2A-2D The expanding device 10 comprises a plurality of elements 12 assembled together to form a ring structure 11. The elements 12 define an inner ring surface supported by the outer surface of a cylindrical body 14. Each element comprises an inner surface 20, an outer surface 21 and first and second contact surfaces 22 and 23. The first and second contact surfaces are oriented in non-parallel planes that are tangential to a circle centred on the longitudinal axis of the device. The planes converge towards the inner surface of the element. Thus, each element is in the general form of a wedge and the wedges are assembled together in a circumferentially overlapping manner to form the ring structure 11. In use, the first and second contact surfaces of adjacent elements are mutually supportive.

[0147] As

[0148] As Figure 3 ​As most clearly shown, when the ring structure expands to its optimal outer diameter, the orientation planes of the first and second contact surfaces intersect the inner surface of the ring structure and, together with the longitudinal axis of the device and the line of intersection, define a cylindrical segment. In this case, the ring structure is formed by 24 identical elements, and the central angle θ1 is 15 degrees. The angle described between the orientation planes of the first and second contact surfaces is the same as the central angle of the cylindrical segment, such that the elements are arranged rotationally symmetrically within the structure.

[0149] Each element is based on an imaginary wedge-shaped segment of a ring centered on the axis, with each imaginary wedge-shaped segment inclined relative to the radial direction of the ring. The nominal outer diameter of the segment is at the optimal expansion of the ring (radius shown as r1).

[0150] The orientation planes of the first and second contact surfaces of the element are tangent to a circle of radius r3 and concentric with the annulus at points t1 and t2. The angle described between the tangent points is equal to the segment angle θ1. The orientation planes of the first and second contact surfaces of each imaginary wedge segment intersect each other on a radial plane P, which bisects the radial plane located at the tangent point (i.e., at an angle θ1 / 2 relative to both). This intersecting plane P defines the expansion and collapse paths of the segments.

[0151] In the constructions shown in Figures 1 and 2, the hypothetical wedge segment is modified by removing the tip 29 of the wedge to ensure that the ring is in the position of the ring. Figure 2A and Figure 2D The extended state shown provides a curved or arcuate inner surface 20 with a radius of r2. Modification of the wedge element can be considered as an increase of 2 (r2-r3) in the diameter of the inner hole through the ring structure, or a truncation of the inner diameter. This change in the inner diameter from an imaginary inner diameter r3 tangent to the contact surface to a truncated inner diameter r2 has the effect of altering the angle between the contact surface and a radial plane from the center of the ring. Angle θ2 is set as the angle described between the contact surface and the radial plane, defined between the center point of the ring structure and the point where the orientation plane meets or intersects the circle at a radial position on the inner surface; θ2 varies depending on the amount by which the inner diameter of the segment is truncated. For the imaginary wedge segment, the orientation plane of the contact surface is tangent to the circle with an inner diameter of r1 (i.e., angle θ2 is 90 degrees). For the modified element 12, the orientation plane of the contact surface, conversely, intersects the circle with an (increased) inner diameter of r2 and is inclined at a decreasing angle θ2.

[0152] The angle of the segment θ2 is related to the amount of material removed from the imaginary wedge segment, but is independent of the central angle θ1 of the wedge. The angle θ2 is selected to provide element dimensions that are suitable for manufacture, robustness, and fit within the desired annular clearance volume and inner and outer diameters of the collapsed ring. As the angle θ2 approaches 90 degrees, a shallower, more refined wedge profile can be created by the element, which can enable optimization of the collapsed volume of the ring structure. While a shallower, more refined wedge profile can have the effect of reducing the size of the gap created at the inner surface of the ring in the collapsed state and / or achieving a more compact collapsed state, there are some consequences. These include the introduction of flat portions at the inner surface of the element, which appear as space at the inner diameter of the ring when in the expanded or partially expanded state. When θ2 = 90 degrees, the collapsed volume for a given outer and inner diameter is most efficient when the segment is perfectly tangent to the inner diameter, but the inner surface of the ring structure is polygonal, with each segment forming a flat portion. In some constructions, these flat portions can be undesirable. There can also be potential difficulties in manufacture of the element and robustness of the element and assembled ring structure. However, in many applications, where the profile of the inner surface of the expanded ring is not important, for example when the inner diameter of the ring structure is floating, and / or the true inner diameter is defined by the actuating wedge profile rather than the inner surface of the ring, this tradeoff can not be detrimental to the operation of the device, and the reduced collapsed volume can justify a wedge angle θ2 of 90 degrees (or close to it).

[0153] In the device of FIGS. 1-4, the angle θ2 is 75 degrees. Relaxing θ2 to a reduced angle provides a smooth outer and inner diameter profile for the expanded ring, as a portion of the inner circular arc is preserved at the cost of a slightly increased collapsed volume. It should be noted that the angle θ2 is independent of the angle θ1. In cases where it is desirable for the ring structure to have a circular inner surface, a preferred arrangement can have an angle θ2 in the range of (90 degrees - 2θ1) to 90 degrees, inclusive, and a particularly preferred arrangement has an angle θ2 in the range of 70 degrees to 90 degrees (most preferably in the range of 73 degrees to 90 degrees). In general, to provide sufficient inner diameter truncation to preserve a useful portion of the inner arc and provide a smooth inner surface for the ring structure, the maximum useful value of θ2 is (90 degrees - θ1 / 2). In the arrangement, this angle would be 82.5 degrees.

[0154] In other constructions, again in accordance with embodiments of the present invention (and as described below), the geometry of the imaginary wedge segment forming the element can not be modified (other than to provide functional structures such as for interlocking and / or retention of the element) and no material is removed from the tip of the imaginary wedge segment. Such embodiments can be preferred when it is not necessary for the ring structure to have a circular inner surface.

[0155] As Figures 4A-4FAs best shown in Figure 1, the first and second contact surfaces of the elements have corresponding interlocking profiles 24 formed therein, such that adjacent elements can interlock with one another. In this case, the interlocking profiles comprise dovetail grooves 25 and corresponding dovetail tongues 26. The interlocking profiles resist circumferential and / or radial separation of the elements in the ring structure, but allow relative sliding between adjacent elements. The interlocking profiles also facilitate smooth and even expansion and collapse of the elements during use. It will be appreciated that alternative forms of interlocking profiles, for example comprising other shapes and forms of recesses and protrusions, can be used within the scope of the present application.

[0156] The elements are also provided with inclined side wall portions 27, which can facilitate deployment of the device in use. The side wall portions are formed as inverse conic shapes, which correspond to the shape and curvature of the actuation taper wedge profile when the device is in its maximum load state, typically in its optimum expanded state.

[0157] Each element is also provided with a recess 28, and in the assembled ring structure the recesses are aligned to provide a circular recess extending around the ring. The recess accommodates a biasing element (not shown), for example a spiral retaining ring sold by Smalley Steel Ring Company under the Spirolox brand, or is a snap spring. In this case, the biasing means is located around the outer surface of the elements to bias the device towards the Figures 1A-1D collapsed state shown. Although one recess for accommodating the biasing means is provided in this arrangement, a plurality of recesses and biasing means can be provided in embodiments of the present application.

[0158] The device 10 comprises a wedge member 16, which in this case is an annular ring having a conical surface 18 opposite one side of the ring structure 11. The wedge angle corresponds to the angle of the inclined conic side walls 27 of the elements. A corresponding wedge profile (not shown) is optionally provided on the opposite side of the ring structure to facilitate expansion of the ring elements. In alternative arrangements, this optional additional wedge member can be replaced with an abutment shoulder.

[0159] The operation of expanding the device 10 will now be described. In a first, collapsed or unexpanded state, as shown in Figure 1, the elements are assembled in a ring structure 11 extending to a first outer diameter. In this configuration, as shown in Figures 1 and 2, the wedge member 16 defines the maximum outer diameter of the device in the first state. The elements are biased towards the unexpanded state by spiral retaining rings (not shown) and are supported on the inner surface by the outer surface of the cylinder 14. Figure 1C Figure 1B Figure 1C

[0160] ​​​In use, an axial actuation force is applied to the wedge member 16. Any of a variety of suitable devices known in the art can be used to apply the axial actuation force, for example, to apply a force from an external sleeve positioned around the cylinder. The force moves the wedge member 16 axially relative to the cylinder and transmits a component of the axial force to the recessed side walls of the elements. The angle of the wedge transmits a radial force component to the elements 12, which causes them to slide relative to each other along their respective contact surfaces.

[0161] The movement of the expanding elements is tangential to a circle defined about the longitudinal axis of the device. The contact surfaces of the elements support each other before, during, and after expansion. The radial position of the elements increases with continued application of the axial actuation force until the elements are at the desired outer radial position. This radial position can be defined by a controlled and limited axial displacement of the wedge member, or alternatively, can be determined by the inner surface of a hole or pipe in which the device is disposed.

[0162] Figures 2A-2D The device is clearly shown in an expanded state. In the best expanded state, as shown in Figure 2B and Figure 2D the outer surfaces of the individual elements combine to form a complete circle with no gaps between the individual elements. The outer surface of the expanding device can be optimized for a particular diameter to form a perfectly circular expanded ring (within manufacturing tolerances) with no extrusion gaps on the inner or outer surface of the ring structure. The design of the expanding device also has the advantage that a certain degree of under-expansion or over-expansion (e.g., to a slightly different radial position) does not introduce significantly larger gaps.

[0163] The described arrangement features elements that support each other before, throughout, and after expansion, and that do not create gaps between the individual elements during expansion or at the fully expanded position. In addition, the arrangement of the elements in a circumferential ring and their movement in a plane perpendicular to the longitudinal axis facilitates providing a smooth side surface or face on the expanded ring structure. As the elements are deployed in the plane of the ring structure, the overall width of the ring structure does not change. This enables the device to be used in locations that are axially close to other functional elements.

[0164] The device has a range of applications, some of which are shown in the following exemplary embodiments. However, other applications of the device are possible that take advantage of the device’s ability to effectively perform one or more of the following: block or seal an annulus path; contact an auxiliary surface; grip or anchor on an auxiliary surface; position or engage a radially spaced profile; and / or support a radially spaced component.

[0165] Aspects of the invention extend the above principles to an extended device comprising structural elements, ring elements and combinations thereof, which has particular application and advantages for systems in which it is desirable to increase the expansion ratio. The following embodiments of the invention describe examples of such a device.

[0166] Reference is now made to Figures 5A-7C which shows an extended device according to a first embodiment of the invention. Figures 5A-5C are isometric, side and end views respectively of the device, generally designated 50, shown in a collapsed state on a central mandrel 60. Figures 6A-6C are corresponding views of the device 50 in a partially expanded state, and Figures 7A-7C are corresponding views of the device 50 in a fully expanded state.

[0167] The device 50 comprises an expansion assembly 51 formed of a plurality of elements, including a set of ring elements 52 assembled together to form a centrally disposed ring structure 54, and two sets 55a, 55b of structural elements 56. The ring elements 52 are similar to the elements 12, and their form and function will be understood from Figures 1 to 4 and their accompanying description. The ring elements 52 are shown in more detail in Figure 8 and Figures 9A-9F and include inner and outer surfaces, first and second contact surfaces, interlocking profiles and grooves for retaining circumferential springs, which features are equivalent in form and function to those of the elements 12. Biasing means in the form of circumferential springs (not shown) maintain the central ring structure in the collapsed state shown in Figures 5A-5C .

[0168] The geometry of the individual ring elements 52 differs from that of the ring elements 12, in that these elements are based on unmodified hypothetical wedge-shaped segments (except for providing functional structures such as for interlocking and / or retention of the elements), and no material has been removed from the tips of the hypothetical wedge-shaped segments. This arrangement can be preferred when it is not required for the ring structure to have a circular inner surface, as is the case for the “floating” ring structure of the device 50.

[0169] Each element includes an outer surface 221 and first and second contact surfaces 222, 223. The first and second contact surfaces are oriented in non-parallel planes that are tangent to a circle of radius r3 centered on the device longitudinal axis. The inner surface of the ring structure is defined at r3 and so the tangent planes are oriented perfectly (and the angle Θ2 is 90 degrees). The planes converge towards the intersection on a radial plane P that bisects the radial plane at the tangent point (i.e. at an angle Θ1 / 2 to both). This intersection plane P defines the segmented expansion and collapse path. Thus, each element is in the general form of a wedge and the wedges are assembled together in a circumferential overlap to form the ring structure 52. In use, the first and second contact surfaces 222, 223 of adjacent elements are mutually supportive.

[0170] In this case, the ring structure 54 is formed from 24 identical elements and the angle described between the first and second contact surfaces is 15 degrees, such that the elements are arranged rotationally symmetrically in the structure.

[0171] As Figures 9A-9F most clearly shown in Figure 2, the first and second contact surfaces of the elements have corresponding interlocking profiles 224 formed therein, such that adjacent elements can interlock with one another. In this case, the interlocking profiles comprise dovetail grooves 225 and corresponding dovetail tongues 226. The interlocking profiles resist circumferential and / or radial separation of the elements in the ring structure, but allow relative sliding between adjacent elements. The interlocking profiles also facilitate smooth and uniform expansion and collapse of the elements during use. The elements 52 differ from the elements 12 in that the tongues and grooves are inverted, with the tongues on the (longer) contact surface 223 on the elements 52. This facilitates increased contact between adjacent elements throughout the expansion and collapse range. It will be appreciated that alternative forms of interlocking profiles, for example comprising other shapes and forms of recesses and protrusions, can be used within the scope of the present application.

[0172] Each element is also provided with a groove 228 and, in the assembled ring structure, the grooves are aligned to provide a circular groove extending around the ring. The groove accommodates a biasing element (not shown), for example a spiral retaining ring sold by Smalley Steel Ring Company under the Spirolox brand, or is a snap spring. In this case, the biasing device is located around the outer surface of the elements to bias the device towards the Figures 5A-5C collapsed state shown. Although one groove for accommodating a biasing device is provided in this arrangement, a plurality of grooves and biasing devices can be provided in embodiments of the present application.

[0173] The structural elements 56 are in the form of spokes or struts. A first end of each spoke 56 is connected to a respective retaining ring 57a, 57b. Each ring element 52 is connected to the second end of a pair of spokes 56, one from each of the respective sets 55a, 55b. The first and second ends are provided with balls or joints 58 which are received in respective sockets 59 (not shown in Figures 1 to 4 for clarity of geometry) in the retaining rings and ring elements to form a pivotal and rotational connection. In the first, collapsed state, the device has a first outer diameter defined by the outer edges of the ring elements 54. Figure 8 or Figure 9) to form a pivotal and rotational connection. In the first, collapsed state, the device has a first outer diameter defined by the outer edges of the ring elements 54.

[0174] Reference will also be made to Figures 6A-7C The operation of an embodiment of the device will be described. The device is actuated by an axial actuation force which acts on one or both of the retaining rings to move the one or both retaining rings relative to the mandrel 60 to radially expand to a second diameter. The retaining rings act as push rings for the device. Any of several suitable means known in the art can be used to apply the axial actuation force, for example, to apply a force from an external sleeve positioned around the cylinder. The axial actuation force acts through the multiple sets of spokes to apply axial and radial force components onto the ring elements. The pivot points between the ring elements and the spokes are arranged radially further from the mandrel than the pivot points between the retaining rings and the spokes. This ensures that any compressive force on the end rings has a radial component to act radially on the ring elements. The radial expansion of the ring structure 54 is initially resisted by the circumferential spring. When the force of the spring is overcome, the ring elements of the central ring structure move radially outwardly from the collapsed position towards the expanded position. Figures 6A-6C The radial outward movement of the ring structure 54 causes the spokes to pivot relative to the retaining rings and the ring elements to form a pair of substantially conical supports for the ring structure 54. As the first ends of the spokes move towards each other, the ring elements 52 slide tangentially relative to each other to expand the central ring structure.

[0175] As the retaining rings and multiple sets of spokes are brought towards Figures 7A-7C the position shown, the ring elements 52 slide relative to each other to a radially expanded state. The radial movement of the elements of the outer ring is the same as the movement of the elements described with reference to Figures 1 to 4: the ring elements slide relative to each other in a tangential direction while maintaining flat contact with each other. The interlocking arrangement of the ring elements enables the device to move uniformly between the collapsed and expanded states.

[0176] The resulting expanded state is shown in Figures 7A-7CThe device forms a solid expanding ring structure with no gaps between its elements and has a smooth circular outer surface in its fully expanded state. The outer diameter of the expanding ring is significantly larger than the outer diameter of the ring structure in its collapsed state, with the expansion increase being caused by the combination of the groups of structural elements supporting the ring structure 54. The open structure of the conical supports makes this embodiment particularly suitable for applications such as lightweight centering, swaging applications, removable support structures and / or adjustable drifting tools.

[0177] Maintaining the axial force on the retaining ring will keep the device in the expanded state, and reducing the axial force to disengage the retaining ring enables the ring structure and the groups of spokes to collapse under the retaining force of the spring elements. Thus, the collapse of the device to the collapsed state is achieved by releasing the axial actuation force. The disengagement of the retaining ring enables the ring structure to collapse back to Figures 5A-5C the collapsed position shown.

[0178] In addition, the connections between the spokes and the ring elements, and between the spokes and the fixed ring, which in this embodiment are ball and socket or hinged connections, are configured to be able to transmit tension. This enables tension to be pulled between the retaining ring, the structural elements and the ring elements (or vice versa). This axial interlocking of the spokes and the ring elements longitudinally connects the components together and enables tension to be pulled between the elements to retract or retract the device towards or to its collapsed state. In combination with the action of the biasing springs, the pulling tension can facilitate the collapse of the device to its original outer diameter, or in an alternative embodiment, the tension can be used to retract the device without the use of biasing springs. Thus, the device can be a passive device, with no default state defined by biasing the device.

[0179] The combination of the structural elements and the ring structure enables the provision of an expanding and collapsing device with the following advantages: the expanding ring structure is solid, with no gaps between its elements, and has a smooth circular outer surface in its fully expanded state, with an increased maximum expansion ratio. This arrangement provides an increased maximum expansion ratio compared to the ring structure of Figures 1 to 4, with little additional moving parts and little increase in complexity.

[0180] Reference is now made to Figures 10A-11D , which shows an expanding and collapsing device according to another embodiment of the application, generally designated 80. Figure 10A and Figure 10B are respectively an isometric view and a longitudinal sectional view of the device in the collapsed position, and Figure 10C and Figure 10D are respectively cross-sectional views taken along lines C-C and D-D of Figure 10B . Figures 11A-11D is a corresponding view of the device in the expanded state.

[0181] Device 80 is similar to device 50 and will be understood from Figures 5-9 and the accompanying description. Device 80 includes an expanded assembly 81 formed from a plurality of elements including a set of ring elements 82 assembled to form a centrally disposed ring structure 84. In Figure 13 Ring elements 82, shown most clearly in Figure 8, are similar in form and function to ring elements 52 of the foregoing embodiments of the application. Two sets 85a, 85b of structural elements 86 are in the form of conical segments, shown most clearly in Figure 12 Figure 9. Conical segments 86 have an outer surface 91, an upper planar contact surface 93, and a lower planar contact surface 95. The first end of each conical segment 86 is connected to a respective retaining ring 87a, 87b by a hook 88 for engagement with a notch in the retaining ring. Each ring element 82 is connected to a pair of segments 86 at their second end, each segment from each of the respective sets 85a, 85b. The second end of segments 86 are provided with a ball or joint 83 that is received in a respective recess 89 in the ring element to form a pivotal and rotational connection. In the first collapsed state, the device has a first outer diameter defined by the outer edge of ring elements 84.

[0182] Operation of this embodiment of the device is similar to that of device 50. The device is actuated by an axial actuation force acting on one or both of the retaining rings to move one or both of the retaining rings relative to mandrel 90 to radially expand to a second diameter. The axial actuation force acts through the multiple sets of conical segments to impart axial and radial force components onto the ring elements. The radial expansion of ring structure 84 is initially resisted by the circumferential springs, but when the force of the springs is overcome, the ring elements of central ring structure 84 move radially outward from the collapsed position toward the expanded state shown in Figure 9. As ring structure 84 moves radially outward, the segments pivot relative to the retaining rings and ring elements to form a pair of conical support structures for ring 84. Each ring segment is supported in an A-frame arrangement. As the first end of the conical segments move toward one another, the ring elements 82 slide tangentially relative to one another to expand the central ring structure. Additionally, in any selected plane along the length of the conical segments that is perpendicular to the longitudinal axis (e.g., cross-section C-C of Figures 11A-11D and Figure 10C and Figure 10D the conical segments move tangentially to a circle that lies within the selected plane and is concentric with the longitudinal axis.

[0183] The movement of conical segments 86 relative to one another is determined by their shape, and Figure 14A , Figure 14B and Figures 15A-15C It is useful for understanding the manner in which the shape of the conical segments is formed in embodiments of the application. Figure 14A and Figure 14BA conical segment 86 is shown as a segment of a hollow cone 92, which includes a hook 88 and a joint 83. Figures 15A-15C is a geometric reference figure for understanding how a simplified conical segment 96 of an embodiment of the application is formed.

[0184] Reference is made to Figures 15A-15C , the starting point for forming the conical segment 96 is a hollow cone 102 Figure 15C , which has an inner conical angle, a minimum inner diameter and an outer diameter, and a maximum inner diameter and an outer diameter. The cone can have any inner and outer angles, and need not have a uniform wall thickness (although the exemplary cone 102 has a uniform wall thickness).

[0185] On the small end of the cone, as Figure 15B shown, the cross-sectional profile of the conical segment is based on an imaginary wedge-shaped segment of a ring, as described in the preceding embodiment. The ring is centered on an axis, with the imaginary wedge-shaped segment tilted with respect to the radial direction of the ring. The nominal outer diameter of the segment is at the best expanded state of the ring (radius shown as r1). As with the embodiment of Figures 5-9, the orientation planes of the upper and lower contact surfaces of the segment element are tangent to a circle having a radius of r3 and centered on the longitudinal axis of the device. The inner surface of the ring structure is defined at r3, and thus the orientation planes are fully tangent (and the angle θ2 is 90 degrees). The angle described between the tangent points is equal to the segment angle θ1. The orientation planes of the first and second contact surfaces of each imaginary wedge-shaped segment intersect on a radial plane P that bisects the radial plane at the tangent points (i.e. at an angle θ1 / 2 with respect to both). This intersection plane P defines the expansion and collapse path of the segment.

[0186] In this device, the segment angle θ1 is 15 degrees, and the radial plane P is tilted 7.5 degrees with respect to the radial plane at the tangent points.

[0187] After the profile 104 of one end of the segment is determined, the inner angle of the inner surface of the cone 102 defines the tilt angle of the upper and lower flat surfaces of the formed segment that extend from the end profile 104. The upper flat surface 93 is defined by a cut through the cone body from the upper line of the end profile 104, where the cut remains tangent to the inner surface of the cone throughout the length of the cone. The lower flat surface 95 is defined by a cut through the cone body from the lower line of the end profile 104, where the cut remains tangent to the inner surface of the cone throughout the length of the cone. The outer surface 91 of the segment is simply the outer surface of the cone between the upper and lower flat surfaces.

[0188] The geometry of the cross-section of the cone segment is identical at every position along the length of the segment: in the best expanded state of the ring, the outer surface 91 is at the nominal outer diameter of the segment; the first and second contact surfaces of the cone segment are tangent to a circle of radius r3, and the orientation planes of the first and second contact surfaces intersect in a radial plane P that is tilted by an angle of ¾ / 2 with respect to the radial plane at the point of tangency. The same radial plane P can be described as being tilted by an angle of 90-¾ / 2 degrees with respect to the upper contact surface, and by an angle of 90+¾ / 2 degrees with respect to the lower contact surface.

[0189] This principle is used to determine the basic shape of the cone segment, which can then be detailed with additional features such as grooves and notches to shape the functional cone segment 86.

[0190] In use, when the retaining ring 87 and the plurality of sets of cone segments are brought to the position shown, Figures 11A-11D the ring elements 82 and the structural ring elements 86 slide relative to each other to a radially expanded state. The radial movement of the elements of the outer ring is identical to the movement of the elements described with reference to Figures 1 to 4: the elements 82 and 86 slide relative to each other along the tangential direction while maintaining a flat contact that supports each other. The centrally located ring segments ensure that the outer structural segments remain in a uniform pattern, equally spaced and uniformly deployed. The expansion of the central ring also controls the alignment and order of the outer structural segments.

[0191] The resulting expanded state is as shown in Figures 11A-11D The device preferably expands to a best expanded state, in which the flat surfaces of the cone segments are in full contact, and in which the outer diameter defined by the ring structure 84 is slightly smaller than the inner diameter of the conduit or borehole in which the device is located. Further pushing force on the retaining ring results in over-expansion of the ring structure, without substantially affecting the surface profile of the conical or cylindrical ring structure.

[0192] Maintaining an axial force on the retaining ring will keep the device in the expanded state, and reducing the axial force to disengage the retaining ring enables the ring structure and the plurality of sets of spokes to collapse under the retaining force of the spring elements. The collapse of the device to the collapsed state is thus achieved by releasing the axial actuation force. The disengagement of the retaining ring enables the ring structure 82 to collapse under the retaining force of its biasing spring back to the collapsed position shown in Figures 10A-10C

[0193] ​The combination of structural elements and ring structure enables the provision of an expansion and collapse device with an increased maximum expansion ratio. This arrangement provides an increased maximum expansion ratio compared to the ring structure of Figures 1 to 4, with little additional moving parts and little increase in complexity. The device forms a solid expanding ring structure with no gaps between its elements and a smooth circular outer surface in its fully expanded state. In addition, the conical support structure resulting from the conical segments forms a solid, smooth side surface of the expanding device. This facilitates the use of the conical structure as a deployment or actuation means, or for a support structure for sealing elements and other mechanical structures, as will be described in more detail below.

[0194] Reference will now be made to Figures 16A-18B A variant of the device 80 is described. Figure 18A and Figure 18B is a longitudinal section view of the device 280, which is similar to the device 80 and will be understood from Figures 10 to 15 and the accompanying description. Figures 16A-16C are various views of the ring elements 282 of the device 280, and Figure 17A and Figure 17B are isometric views of the structural elements 286. The basic geometry of the ring elements 282 and the structural elements 286 is the same as that of the elements 82 and 86 as previously described. As with the device 80, hooks 288 are provided for engagement with the cross slots in the retaining ring. However, the elements of this embodiment differ in their configuration for connection to one another. Rather than the spherical ball and socket joint and socket provided in the components of the device 80, the device 280 has a knuckle joint 283 provided on the structural elements 286 and a corresponding socket 289 provided on the ring elements 282. The socket 289 comprises an opening on the lower contact surface for receiving the knuckle 283, and a U-shaped slot in the side wall which enables the elements to be assembled while retaining the knuckle, and allows a tension pull to be applied between the structural elements and the retaining ring (or vice versa).

[0195] The corresponding side walls of the ring elements 282 and the structural elements 286 are also provided with a cooperating arrangement of knurling 272 and sockets 274. When the device is in its expanded state, the knurling 272 self-locates in the sockets 274, as Figure 18B illustrated, and provides additional support to the structure. In this embodiment, two knurlings are provided on each side wall of each ring element, with a corresponding socket provided on the contact side walls of the structural elements, although it will be appreciated that in alternative embodiments the locations can be reversed and / or other configurations of locating structure can be provided.

[0196] Although the foregoing embodiments include a combination of a cylindrical ring structure and a conical support assembly, the principles of the invention can also be applied to alternative configurations, including expanding conical structures which are not connected to a cylindrical ring. Reference is made to Figures 19A-20C to describe exemplary embodiments.Figures 19A-19C are respectively isometric, longitudinal section and end views of the device in a collapsed state, generally designated 140. Figures 20A-20C are corresponding views of the device 140 in an expanded state. The device 140 comprises an expanded assembly 141 formed of a plurality of elements including a set of ring elements 142 assembled to form a conical ring structure 154. The elements 142 are assembled on a mandrel 150 with the first end of the elements connected to a retaining ring 147. The second end of the elements 142 is adjacent to an actuating wedge conical taper 143.

[0197] The ring elements 142 are similar to the conical segments 86 and will be understood from Figures 10A-11D their form and function from the description of the conical segments 86 and the accompanying description. The shape of the ring elements 142 results from the principles described with reference to Figures 14A-15C The conical segments include an outer surface, an upper flat contact surface and a lower flat contact surface. When assembled to form the ring structure, the contact surfaces are mutually supporting. In the first collapsed state, the device has a first outer diameter defined by the outer edge of the second end of the ring elements 142. The shape of the assembly in its collapsed state is substantially conical.

[0198] In use, the device is actuated by an axial actuation force acting on one or both of the retaining ring 147 or the wedge 143 to move said one or both relative to the mandrel 150. This force moves the wedge member 143 axially relative to the elements and imparts a component of the axial force onto the inner surface of the elements. The angle of the wedge imparts a radial force component to the elements 142 which causes them to slide relative to each other along their respective contact surfaces.

[0199] The movement of the expanded elements is tangential to a circle defined about the longitudinal axis of the device. The contact surfaces of the elements mutually support each other before, during and after expansion. The radial position of the elements increases with the continued application of the axial actuation force until the elements are at the desired outer radial position. This radial position can be defined by a controlled and limited axial displacement of the wedge member or, alternatively, can be determined by the inner surface of a bore or pipe in which the device is disposed.

[0200] Figures 20A-20C The device is shown in its expanded state. In the best expanded state, as Figure 20B and Figure 20CAs shown, the outer surfaces of the individual components combine to form a complete conical surface, with no gaps between the components. At the second end of component 142, a cylindrical surface 145 is formed in the optimal expanded state. The outer surfaces of the individual components combine to form a complete circle, with no gaps between the components. The outer surface of the expansion device can be optimized for a specific diameter to form a perfectly smooth cone and a circular expansion ring (within manufacturing tolerances), with no extrusion gaps on the inner or outer surface of the ring structure. The design of the expansion device also has the advantage that a degree of under-expansion or over-expansion (e.g., to slightly different radial positions) does not introduce significantly larger gaps.

[0201] The described arrangement is characterized by the elements supporting each other before, throughout, and after expansion, without creating gaps between the elements during expansion or in the fully expanded position. Furthermore, the arrangement of the elements in the circumferential ring and their movement in a plane perpendicular to the longitudinal axis facilitates the provision of smooth side surfaces or lateral surfaces on the expansion ring structure. This allows the device to be used axially close to other functional elements.

[0202] Device 140 can be used in conjunction with devices from other embodiments to provide components for expanding the device. (Reference) Figures 21A-22D An exemplary implementation scheme is described. Figures 21A-21C These are, respectively, an isometric view, a longitudinal sectional view, and a cross-sectional view of a device in a collapsed state, typically marked as 160. Figure 22A and Figure 22B These are, respectively, a partially cut equidistant view and a longitudinal sectional view of the device 160 in its extended state. Figure 22C and Figure 22D They are along Figure 22B The lines CC and DD are cut off. Figure 22A and Figure 22B A cross-sectional view of the equipment.

[0203] Device 160 includes a spindle 170 supporting an extension device 162 located at its center. This extension device 162 has the same form, function, and operation as device 80. On either side of device 162 are extension devices 164a and 164b, which include conical structures with similar construction to device 140 and have the same function and operation. Axially outward of devices 164a and 164b are additional extension devices 166a and 166b, which include conical structures with similar construction to device 140 and have the same function and operation.

[0204] In use, the device 160 is actuated by an axial actuation force to expand radially to a second diameter, the axial actuation force acting on one or both of the retaining rings 167a, 167b to move one or both retaining rings relative to the mandrel 170. Relative movement of the outer retaining ring causes the expanding device to expand under the drive of the conical wedge surfaces of the respective retaining rings 163a, 163b, 165a and 165b to their expanded state.

[0205] The expanded state of the device 160 is shown in Figures 22A-22D As described above with reference to Figures 10 and 1 1, the device 162 expands into the form of first and second hollow conical support structures defined on the first and second sides of the device. The internal angles of the hollow cones formed by the expanding devices 164a and 164b correspond to the external conic angles of the device 162, and the devices 164a and 164b abut the outer sides of the device 162 to form nested, layered support structures. Similarly, the internal angles of the hollow cones formed by the expanding devices 166a and 166b correspond to the external conic angles of the devices 164a and 164b, and the devices 166a and 166b abut the outer sides defined by the devices 164a and 164b. As Figure 22B As shown most clearly in

[0206] In this embodiment, the direction of layering of the conical segments differs between adjacent devices; the layering of the conical segments in the devices 164a, 164b is reversed compared to the layering direction in the devices 162, 166a and 166b. This results in a diagonal cross effect between the support layers in the expanded state, shown most clearly in Figure 22A which enhances the mechanical support and load bearing through the device, and increases the coiling of any paths between the segments of adjacent support layers.

[0207] Retracting the device to the collapsed state is performed by releasing or reversing the axial force on the outermost retaining rings 167a, 167b. This is facilitated by the lip 171 provided on the inner surface of the conical segments, as Figure 21B and Figure 22AThe lips 171 of the conical segments of the expansion cones are engaged with the outer edges of the retaining rings of the adjacent expansion cones when the expansion cones are in a collapsed state. When the outermost pair of expansion cones 166a, 166b are collapsed under tension, the lips engage the edges of the retaining rings 165a, 165b to apply tension to the retaining rings and retract the expansion cones 164a, 164b. Similarly, when the expansion cones 164a, 164b are collapsed under tension, the lips 171 engage the edges of the retaining rings 163a, 163b to apply tension to the retaining rings and retract the expansion device 162.

[0208] While two pairs of expansion cones are provided in the embodiment of FIGS. 21-22 to support the device 162, in alternative embodiments, fewer or greater numbers of expansion cones can be used, depending on the application. In some applications, support can be provided by a single expansion cone abutting only one side of the device 162. Alternatively, multiple expansion cones can be used in a nested configuration to support only one side of the device 162. Alternatively, unequal numbers of expansion cones can be used to support opposite sides of the device 162.

[0209] Within the scope of the present application, the expansion devices used in the nested configuration described with reference to FIGS. 21 and 22 can have different physical attributes, including but not limited to configuration, size, wall thickness, cone angle, and / or material selection, depending on the application. For example, in a variation of the embodiment described with reference to FIGS. 21 and 22, the conical segments of the devices 164a and 164b are different from the conical segments of the devices 162, 166a, and 166b to provide improved sealing effects. The conical segments of the devices 164a, 164b are formed of metal coated with a compliant polymeric material such as a coating of silicone polymer. All surfaces of the elements are coated, and the mutually supporting arrangement of the conical segments within the devices 164a, 164b in combination with the support from the adjacent devices 162, 166a, and 166b causes them to remain compressed in their operational state. This enables the combined devices to effectively function as a fluid barrier, and in some applications, the resulting barrier is sufficient to seal a pressure differential to create a fluid seal.

[0210] In variations of the embodiments described, the material chosen for the conical segment itself is a compliant or elastomeric material such as an elastomer, polymer, or rubber, rather than a coated metal or other rigid material. Alternatively, the segment may comprise a skeleton or internal structure formed of a metal or other rigid material coated or encased within a compliant or elastomeric material such as an elastomer, polymer, or rubber. All, some, or one of the conical segments of the extension device may be formed from these alternative materials, or different materials may be used for different extension devices. A single extension device of the present invention may be configured to provide a sealing function and therefore may similarly be formed wholly or partially from a compliant or elastomeric material.

[0211] Now for reference Figures 23A-24C This illustrates an expansion and collapse device according to an alternative embodiment of the invention, configured for sealing a fluid conduit or borehole. The device, generally designated 180, includes an expansion assembly 181 formed of a plurality of elements, including a set of ring elements 182 assembled to form a conical ring structure 184. Elements 182 are assembled on a mandrel 190, with a first end of the element connected to a retaining ring 187. A second end of element 182 is adjacent to an actuating wedge-shaped cone 183. The ring elements 182 are similar to the cone segments 86 and 142, and will... Figures 10A-11D , Figures 19A-20B Their form and function can be understood from the accompanying description. The shape of the ring element 182 is derived from the reference. Figures 14A-15C The described principle is as follows. The conical segment includes an outer surface, an upper flat contact surface, and a lower flat contact surface. When assembled to form a ring structure, the contact surfaces support each other. In a first collapsed state, the device has a first outer diameter defined by the outer edge of the second end of the ring element 182. The shape of the assembly in its collapsed state is substantially conical.

[0212] The device 180 differs from device 140 in that it features a pleated layer 195 of a compliant sealing material. Layer 195 surrounds the retaining ring 187 and the extension assembly 181 for most of its length and is pleated to follow the shaped surfaces of the upright edges and grooves defined by the collapse assembly 181. The device is actuated by an axial force acting on one or both of the retaining ring 187 or the wedge 183. When the device extends... Figures 24A-24C In the extended state shown, layer 195 unfolds to form a compliant conical sheath 197 surrounding the extended conical structure.

[0213] Device 180 is merely one example of how the present invention can be applied to a fluid barrier or sealing device, and other fluid barrier or sealing configurations are within the scope of the present invention. For example, the device can be configured to operate in conjunction with a sealing element such as an elastomeric body or an inflatable bladder disposed beneath the hollow conical structure formed by the expanding conical segments.

[0214] The present invention can be used to provide an anti-extrusion or support ring for various expanding, radially expanding, or inflatable elements. For example, the device can be used as an anti-extrusion or support ring for a compressible, inflatable, and / or inflatable packer system. Alternatively or additionally, the expanding device can provide support or backup for any suitable fluid barrier or sealing element in a fluid conduit. This can be used to improve the integrity of the fluid barrier or seal, and / or to enable a reduction in the axial length of the sealing element or fluid barrier without compromising its functionality. A particular advantage is that a device incorporating the expanding device of the present invention can be rated for a higher maximum working pressure.

[0215] In the foregoing embodiments, where a seal is formed using the expanding and collapsing device, the seal is typically provided between two expanding ring structures. In an alternative embodiment (not shown), the expanding ring structure can be used to provide a seal or at least a restrictive fluid barrier directly. To facilitate this, the elements assembled together to form the ring structure can be formed from a metal or metal alloy coated with a polymeric, elastomeric, or rubber material. One example of such a material is a silicone polymer coating. All surfaces of the elements can be coated, for example by a dip or spray coating process, and the mutual supporting arrangement of the elements causes them to remain compressed in their operational state. This enables the ring structure itself to act as a fluid barrier, and in some applications the barrier produced is sufficient to seal a pressure differential to produce a fluid seal.

[0216] Another application of the present invention is a fluid conduit repair tool and device. A typical repair application requires the placement and setting of a tubular section over a damaged portion of a fluid conduit, such as a wellbore casing. The repair tool includes a tubular and a pair of setting mechanisms on the outside of the conduit at axially separated locations for securing the tubular to the interior of the fluid conduit. It is desirable for the setting mechanisms to provide an effective fluid barrier, but existing repair systems are often insufficient to provide a fluid seal with the inner surface of the fluid conduit.

[0217] A repair tool incorporating the expanding device of the present invention has the advantage of high expandability for an elongate outer diameter profile, which enables the tool to pass through restrictions in the fluid conduit to repair a damaged portion of the conduit having a larger inner diameter than the restriction. For example, the repair tool can pass through a portion of the fluid conduit that has already been repaired.

[0218] In another alternative embodiment of the application (not shown), the base plate supporting the sealing element or another deformable element is provided with the properties of the expansion / collapse device. As described herein, the expanded ring structure of the application provides a smooth cylindrical surface and / or a smooth conical surface in its optimally expanded state. This facilitates its application as a functional inner skeleton of a surrounding sheath. In one exemplary application, a deformable elastomeric sheath is disposed over the expanded ring structure. When in the collapsed state, the sheath is supported by the collapsed ring structure. The ring structure is deployed in the manner described with reference to Figures 10 and 11, overcoming the retaining force of the circumferential spring element and any additional retaining force provided by the sheath, and the sheath deforms to come into contact with the surrounding surface as the ring structure expands. The sheath is sandwiched between the smooth outer surface of the ring structure and the surrounding surface to form a seal.

[0219] It will be appreciated that the device can be used as an inner skeleton to provide structural support for components other than deformable sheaths, including tubulars, expansion sleeves, locking structures, and other components in fluid conduits or wellbores.

[0220] The expanded device of the application can be applied to a high expansion packer or plug, and in particular to a high expansion retrievable bridge plug. The ring structure can be arranged to provide a high expansion anti-extrusion ring for the sealing element of the plug. Alternatively or in addition, the elements of the ring structure of the device can be provided with engagement means to provide anchoring force against movement in the upward and / or downward directions. Thus, the elements of the ring structure can function as a sliding element, and in some cases as an integrated sliding element and anti-extrusion ring. Advantages over previously proposed plugs include: providing a highly efficient anti-extrusion ring; providing an integrated sliding element and anti-extrusion assembly, which reduces the axial length of the tool; providing a sliding element with an engagement surface that extends around the entire circumference of the tool to create an increased anchoring surface, which enables the axial length of the sliding element to be reduced for the same anchoring force; the ability of a sliding element of a particular size of ring structure to work effectively over a wider range of tubular inner diameters and tubular weight / thickness.

[0221] Alternatively or in addition, by providing the surface of the elements with engagement means to provide anchoring force against movement in the upward and / or downward directions, the device can be used to anchor any wide range of tools in a wellbore.

[0222] Variations of the embodiments of the application include providing functional structures on the basic elements in various arrangements. These can include knurling and sockets for positioning and support, hooks, ball and socket or hinging for axial connection, and / or pins and recesses to prevent relative rotation of the elements relative to each other and / or to the underlying structure of the device.

[0223] The present invention also has the benefit of creating a seal and / or filling the annular space, and further exemplary applications are for downhole locking tools. Typical locking tools use one or more radially expanding components deployed on a running tool. The radially expanding components engage a pre-formed locking profile at a known location in the wellbore completion. Typical locking profiles and locking mechanisms include recesses for mechanical engagement by the radially expanding components of the locking tool. A seal bore is typically provided in the profile, and a seal on the locking tool is designed to seal the seal bore.

[0224] One advantage of applying the present invention to a locking mechanism is that the locking mechanism can be provided with integrated seal elements between the two expanding ring structures, and no seal assembly is required at the axial separation point. This enables the length of the tool to be reduced. The integrated seal is surrounded at its upper and lower edges by the surface of the ring structure, which avoids extrusion of the seal.

[0225] Additionally, each ring structure provides a smooth, uninterrupted circumferential surface that can engage the locking recess, providing an upper and lower annular surface in a plane perpendicular to the longitudinal axis of the bore. This annular surface can be smooth and uninterrupted around the circumference of the ring structure, and thus the lock is in full abutment with the upper and lower shoulders defined in the locking profile. This contrasts with conventional locking mechanisms, which can only contact the locking profile at a number of discrete, circumferentially separated locations around the device. The increased surface contact can support greater axial forces being directed through the lock. Alternatively, equivalent axial support can be provided in a lock with reduced size and / or mass.

[0226] Another advantage of this embodiment of the present invention is that the seal bore (i.e. the completion portion against which the elastomer forms a seal) can be recessed in the locking profile. The benefit of this configuration is to protect the seal bore from the tool and equipment passing through the locking profile. This avoids impacts on the seal bore, which can damage the seal bore, reducing the likelihood of a successful seal being reliably formed.

[0227] Similar benefits can be achieved in a latching arrangement used in a connector, such as a so-called "quick connect" mechanism for latching connections of tubular components. One significant advantage of the present invention in a connection system application is that the expanding device forms a solid, smooth ring at the expanded latching position. When expanded, the arrangement of radially separated elements will form a ring, with space between the elements around the sides of the ring. In contrast, providing a continuous engagement surface on the expanded ring that provides full annular contact with the recess results in a latch being formed that can support greater axial forces. Additionally, by minimising or eliminating gaps between the elements, the device is less prone to ingression of foreign matter that can impede the collapsing action of the mechanism. These principles can also be applied to subsea connectors such as back-up connectors, the release mechanism of which is actuated by optional hydraulic pressure.

[0228] Other applications of the principles of the present invention include variable diameter tools, examples of which include variable diameter drift tools and variable diameter centering tools. The position of the wedge members and mating surfaces can be continuously adjusted or adjusted to a plurality of discrete positions to provide a continuously variable diameter or a plurality of discrete diameters.

[0229] In one aspect, the present invention provides an expansion and collapse device and methods of use thereof. The device includes a plurality of elements assembled together to form a ring structure about a longitudinal axis. The ring structure is operable to move between an expanded state and a collapsed state by actuation of movement of the plurality of elements by an axial force. At least one set of structural elements each having a first end and a second end is operable to move between the expanded state and the collapsed state by moving the first end along an axial direction and by moving the second end along at least a radial dimension. The plurality of elements includes at least one set of elements operable to move between the expanded state and the collapsed state by sliding relative to one another along a direction tangent to a circle concentric with the ring structure.

[0230] In another aspect, an expansion and collapse ring includes a plurality of elements assembled together to form a ring structure oriented in a plane about a longitudinal axis. The plurality of elements includes at least one set of structural elements extending longitudinally on the device and operable to slide relative to one another in a selected plane perpendicular to the longitudinal axis, wherein the sliding movement in the selected plane is tangent to a circle located in the selected plane and concentric with the longitudinal axis. Applications of the present invention include oilfield devices, including crush resistant rings, plugs, packers, locks, repair tools, connection systems, and variable diameter tools run into a wellbore.

[0231] The present invention in various forms benefits from the novel structure and mechanism of the device. The present invention also enables high expansion applications.

[0232] Additionally, in the best expanded state, the outer surfaces of the individual elements combine to form a complete circle, there are no gaps between the individual elements, and thus the device can be optimized for a particular diameter to form an expanded ring that is perfectly circular (within manufacturing tolerances) and there are no crush gaps on the inner or outer surface of the ring structure. The design of the expansion device also has the advantage that a certain degree of under-expansion or over-expansion (e.g., to a slightly different radial position) does not introduce significantly larger gaps.

[0233] One aspect of the present invention features elements that support one another before, throughout, and after expansion, and no gaps are created between the individual elements during expansion or at the fully expanded position. Additionally, the arrangement of the elements in the circumferential ring facilitates providing a smooth side surface or face on the expanded ring structure. This enables the device to be used in close axial proximity to other functional elements, and / or as a ramp or surface for deploying other expansion structures.

[0234] Additionally, each ring structure provides a smooth, uninterrupted circumferential surface that can be used for joining or anchoring applications including plugs, locks, and connectors. This can provide increased anchoring force, or complete abutment with upper and lower shoulders defined in a locking or latching profile, enabling a tool or device to be rated for higher maximum working pressure.

[0235] Various modifications can be made to the above described embodiments within the scope of the present invention and the present invention extends to combinations of features other than those specifically stated herein. In particular, different embodiments described herein can be combined and features of particular embodiments can be used in applications other than those specifically described in relation to that embodiment.

Claims

1. An expansion and collapse device comprising: a plurality of elements assembled together to form a ring structure around a longitudinal axis, wherein the ring structure is operable to move between an expanded state and a collapsed state by moving the plurality of elements; wherein the plurality of elements comprises at least one set of structural elements each having a first end and a second end, wherein the structural elements are operable to move between the expanded state and the collapsed state by moving the first end in an axial direction and by moving the second end in at least a radial direction; wherein the plurality of elements comprises at least one set of ring elements operable to move between the expanded state and the collapsed state by sliding relative to each other in a direction tangential to a circle concentric with the ring structure, and the ring elements are connected to the structural elements at the second ends of the structural elements; wherein the ring elements comprise first and second contact surfaces for contacting adjacent ring elements, respectively oriented in first and second planes; and wherein the first and second planes are tangential at a point of tangency to a circle centered on the longitudinal axis and having a radius, the circle being defined on an inner surface of the ring structure formed by the ring elements, and the first and second planes intersect each other in a radial plane P bisecting two radial planes extending through a center of the ring structure formed by the ring elements and the point of tangency.

2. The device of claim 1, wherein the set of structural elements together form a conical structure in the expanded state.

3. The device of claim 1, wherein the set of structural elements together form a conical structure in the collapsed state and / or a partially expanded state.

4. The device of claim 1, wherein each of the ring elements forms an angle (Θ1) between the first and second contact surfaces in a range of 10 to 20 degrees.

5. The device of claim 1, wherein the first and second planes are tangential to the inner surface of the ring structure formed by the ring elements at respective lines of intersection.

6. The device of claim 1, wherein the structural elements comprise structural ring elements operable to move between the expanded state and the collapsed state by sliding relative to each other in a direction tangential to a circle concentric with the ring structure.

7. The device of claim 6, wherein the structural ring elements extend longitudinally on the device and are operable to slide relative to each other, wherein the sliding movement in a selected plane perpendicular to the longitudinal axis is tangential to a circle located in the selected plane and concentric with the longitudinal axis.

8. The device of claim 1, wherein each structural element is pivotally connected to a ring element at its second end.

9. The device of claim 1, comprising a retaining ring, wherein the structural elements are connected at their first ends to the retaining ring by connectors capable of transmitting tension between the structural elements and the retaining ring.

10. The apparatus of claim 1, wherein the set of structural elements together form a conical structure that includes openings between the structural elements in the conical surface.

11. The apparatus of claim 1, wherein the structural elements are struts or spokes, and the apparatus includes a plurality of struts or spokes distributed circumferentially around the longitudinal axis.

12. The apparatus of claim 1, comprising a structure configured to apply a radial expansion or collapse force component to the structural elements of the ring structure from an axial actuation force.

13. The apparatus of claim 12, wherein the structure comprises a wedge or wedge profile.

14. An expansion and collapse apparatus, comprising: a plurality of identical ring elements assembled together to form a ring structure around a longitudinal axis, wherein the plurality of identical ring elements are operable to move between an expanded state and a collapsed state by sliding relative to one another in a direction tangent to a circle concentric with the ring structure; and at least one set of structural elements extending longitudinally on the apparatus and operable to slide relative to one another, wherein the sliding movement in a selected plane perpendicular to the longitudinal axis is tangent to a circle located in the selected plane and concentric with the longitudinal axis, wherein the structural elements each have a first end and a second end, wherein the structural elements are operable to move between the expanded state and the collapsed state by moving the first end in an axial direction and by moving the second end in at least a radial direction; wherein the ring elements are connected to the structural elements at the second ends of the structural elements, the ring structure is operable to move between an expanded state and a collapsed state by moving the plurality of identical ring elements, each identical ring element in contact with an adjacent identical ring element in the expanded state and the collapsed state.

15. The apparatus of claim 14, wherein the structural elements extend longitudinally on the apparatus and are operable to slide relative to one another, wherein the sliding movement in any selected plane along the length of the structural elements and perpendicular to the longitudinal axis is tangent to a circle located in the selected plane and concentric with the longitudinal axis.

16. A method of expanding or collapsing an expansion and collapse apparatus, the method comprising: A plurality of elements are provided assembled together to form a ring structure around a longitudinal axis, wherein the plurality of elements comprises at least one set of structural elements each having a first end and a second end, and at least one set of ring elements, each ring element having first and second contact surfaces for contacting adjacent ring elements, respectively oriented on first and second planes, wherein the ring elements are connected to the structural elements at the second ends of the structural elements, and wherein the first and second planes are tangent to a circle centered on the longitudinal axis and having a radius at a point of tangency, the circle being defined on an inner surface of the ring structure formed by the ring elements, and the first and second planes intersect each other on a radial plane P bisecting two radial planes extending through a center of the ring structure formed by the ring elements and the point of tangency; moving the first ends of the structural elements in an axial direction, and moving the second ends of the structural elements in at least a radial direction; and moving the at least one set of ring elements of the plurality of elements between the expanded state and the collapsed state by sliding the at least one set of ring elements of the plurality of elements relative to each other in a direction tangent to a circle concentric with the ring structure.

Images