WO2011117567A2

WO2011117567A2 - Support apparatus for elongate member

Info

Publication number: WO2011117567A2
Application number: PCT/GB2011/000372
Authority: WO
Inventors: Bruce Adam
Original assignee: Expro Ax-S Technology Ltd
Priority date: 2010-03-20
Filing date: 2011-03-17
Publication date: 2011-09-29
Also published as: GB201004687D0; WO2011117567A3

Abstract

A support apparatus (40) for an elongate member (24), such as a marine riser, comprises a plurality of support elements (46) configured to engage an elongate member (24) along an axial length thereof, and an articulation arrangement (48) configured to permit adjacent support elements (46) to move relative to each other to accommodate bending of an engaged elongate member (24). The articulation arrangement (48) is also configured to transmit a force between adjacent elements (46) such that movement of one element affects movement of an adjacent element.

Description

SUPPORT APPARATUS FOR ELONGATE MEMBER

FIELD OF THE INVENTION

The present invention relates to a support apparatus for an elongate member, such as a tubular member. In particular, but not exclusively, the present invention relates to a support apparatus for an elongate member which extends subsea, such as a marine riser used, for example, in the oil and gas industry.

BACKGROUND TO THE INVENTION

In many industries elongate members, such as cables, tubing strings or the like are used in numerous applications. It is often the case that the particular elongate member may be exposed to conditions which compromise or adversely affect its integrity, for example during periods of exposure to excessive forces due to unusual or extreme environmental conditions which may bring the elongate member close to or beyond its design limits or even yield point. It is therefore desirable to take appropriate steps to provide a degree of protection to the particular elongate member against such excessive forces. Furthermore, in many cases the method of supporting an elongate member and the forces experienced may result in significant localised stresses being generated, typically in the region of support.

In the offshore oil and gas industry tubing strings are used which extend between a surface vessel and fixed subsea equipment, such as subsea Christmas trees, manifolds and the like. Such tubing strings, which are typically called marine risers, may be used to define an isolated path between the surface vessel and subsea equipment for uses such as fluid communication and deployment of tools and the like into an associated wellbore. The marine riser may be formed of individual lengths of relatively rigid pipes secured together end-to-end, for example by use of threaded connectors. Also, coiled tubing may be used to provide a marine riser, as proposed by the present applicant in, for example, WO 09 016346. In many occasions a marine riser extends subsea from a floating surface vessel, such as a ship, which will therefore be subject to movement caused by sea conditions. This movement may establish stresses within the marine riser, such as tensile and compressive forces, bending stresses, torsion and the like. Also, any significant deviation of the vessel from a desired location may result in bending stresses and the like being focused at localised points within the marine riser, such as the points of connection with either the vessel or the subsea equipment. It is known in the art to seek to address problems associated with floating vessels by use of heave compensators, dynamic positioning systems and the like. However, such known systems may not adequately provide protection in extreme sea conditions, and often the contingency arrangement is to undertake a controlled emergency disconnection between the vessel and the subsea equipment, rather than be exposed to the possibility and consequences of catastrophic failure of the marine riser. However, it is often the case that the threshold conditions associated with the initiation of an emergency disconnect may be extremely conservative, and it is desirable in the art to permit such threshold conditions and thus operational envelope to be extended as much as possible.

Proposals have been made in the art to use devices known as bend restrictors, which typically consist of a structure which surrounds a portion of a tubing string and assists to limit the degree of bending. Such a proposal is made in US 6,161 ,619. However, it may be possible that even with the use of existing bend restrictors the tubing string may still be subjected to significant localised bending stresses and forces. SUMMARY OF THE INVENTION

According to a first aspect of the present invention there is provided a support apparatus for an elongate member, comprising: a plurality of support elements configured to engage an elongate member along an axial length thereof; and

an articulation arrangement configured to permit adjacent support elements to move relative to each other to accommodate bending of an engaged elongate member, and to transmit a force between adjacent elements such that movement of one element affects movement of an adjacent element.

In use, engagement between the support elements and an elongate member may result in movement of the support elements upon bending of the elongate member. Further, the articulation arrangement may permit adjacent elements to move relative to each other such that any bending of an engaged elongate member will result in relative movement of adjacent support elements. Also, the articulation arrangement may permit a force generated upon movement of one support element to be transmitted to an adjacent element, in order to affect movement of said adjacent element. Accordingly, each element is arranged not only to be moved by independent engagement with an elongate member, but also by any movement in an adjacent element. This may therefore permit bending of an engaged elongate member to be accommodated and distributed across adjacent elements. This may permit any bending stress to be distributed along the engaged elongate member, rather than in isolated or localised regions. Distributing the bending and associated stresses and the like may function to effectively distribute associated fatigue within the elongate member. This may extend the useful life of the elongate member.

Each element may be generally tubular, for example cylindrical. Each element may be configured to be located externally of an elongate member. Each element may be configured to be located internally of an elongate member. Each element may be configured to be mounted coaxially with the elongate member.

The articulation arrangement may be considered to provide a non-rigid connection between adjacent support elements while still permitting a force to be applied therebetween. The articulation arrangement may provide compliance between adjacent support elements.

The support apparatus may function to modify, for example increase, the bending stiffness of an engaged elongate member. For example, the process of transmitting forces between support elements by the articulation arrangement may assist to modify, for example increase, the resistance to bending within the engaged elongate member, resulting in an effective modification, such as increase, in bending stiffness. This may be particularly advantageous, although not presenting limited use, in applications where relatively slender elongate members are used, such as rods, coiled tubing or the like. Further, this effective modification of bending stiffness may be effectively achieved without requiring modifications to be made to the elongate member.

Adjacent support elements may be connected together. The plurality of support elements may be concatenated.

The articulation arrangement may be interposed between adjacent support elements. Adjacent support elements may be connected together by the articulation arrangement. The apparatus may comprise a plurality of articulation arrangements configured to concatenate the plurality of support elements. Each articulation arrangement may be similar or identical. Alternatively, different articulation arrangements may be provided.

The articulation arrangement may be configured to permit relative pivoting motion of adjacent elements. The articulation arrangement may be configured to permit relative pivoting motion of adjacent elements about one or more axes substantially transverse, such as perpendicular, to an engaged elongate member. This may permit the apparatus to accommodate and support axial bending of the elongate member. Bending may be considered to comprise deflection of the elongate member along a longitudinal axis. The articulation arrangement may be configured to permit relative pivoting motion of adjacent elements about two mutually perpendicular axes.

The articulation arrangement may be configured to limit the relative motion between adjacent support elements. This arrangement may permit the support elements to limit or restrict bending of an engaged elongate member. The apparatus may be configured such that a total bend angle of an engaged elongate member may be evenly distributed across the plurality of elements. Alternatively, the total bend angle may be distributed irregularly between the support elements. In some embodiment the distribution of bend angle across the support elements may be fixed, or alternatively may be adjustable, for example via the articulation arrangement.

The articulation arrangement may be adjustable. This may permit the support apparatus to be used with a number of different elongate members, be used in different applications and the like. The articulation arrangement may be adjustable to vary the permitted relative motion between adjacent support elements. The articulation arrangement may be adjustable to be configured to prevent relative motion between adjacent support elements. The articulation arrangement may be adjustable to vary the force transmitted between adjacent support elements. Permitting a variation in the force transmission across adjacent members may permit the effective bending stiffness of an engaged elongate member to be varied.

An articulation arrangement between one adjacent pair of support elements may provide a different effect to an articulation arrangement of another pair of adjacent support elements. For example, one articulation arrangement may be configured to transmit greater or less force, provide more or less relative movement of the associated adjacent elements or the like. This may permit a preferential distribution of bending within an engaged elongate member.

The articulation arrangement may be passive, in that the articulation arrangement may be operable upon movement of an engaged elongate member. The articulation arrangement may be active, in that the articulation arrangement may be operable to manipulate an engaged elongate member. Such active operation of the articulation arrangement may permit an engaged elongate member to be controlled, manipulated or the like to adopt a required shape, be moved in a required manner or the like.

The articulation arrangement may be configured to dampen movement between adjacent elements. Such dampening may permit a force to be transmitted between adjacent elements. This may also increase the effective bending stiffness of an engaged elongate member.

The articulation arrangement may comprise at least one deformable device configured to deform to accommodate relative movement of adjacent support elements, and to permit transmission of a force between said adjacent support elements. The deformable device may comprise one or more deformable elements, such as compressible elements. The deformable device may comprise one or more elastic elements, such as an elastomeric element, for example rubber. In such an arrangement one or more elastic elements may be interposed between adjacent support elements, such that relative movement of said support elements deforms the one or more elastic elements, for example by compression, extension or the like. The deformable device may comprise one or more o-rings. The deformable device may comprise one or more springs.

The deformable device may comprise a piston arrangement configured to stroke upon relative movement of adjacent support elements. The piston arrangement may be coupled or engaged at one end to one support element, and at another end to an adjacent support element, such that relative movement between the adjacent support elements may be permitted while transmitting a force therebetween upon stroking of the piston arrangement. The piston arrangement may be single acting. The piston arrangement may be double acting, which may permit transmission of a force during relative movement of the support elements in reverse directions. The deformable device may comprise a dampener. The deformable device may comprise a hydraulic dampener.

The articulation arrangement may comprise multiple deformable devices. The articulation arrangement may comprise multiple piston arrangements. One or more of the deformable devices may be configured to permit transmission of a force between adjacent support elements in a desired direction of relative motion. In this arrangement multiple deformable devices, such as multiple piston arrangements, may be arranged to permit force transmission in multiple directions.

In one embodiment the articulation arrangement may comprise four deformable devices. The deformable devices may be arranged equidistantly apart, for example to arrange pairs of deformable devices diametrically opposed to each other.

The support apparatus may be configured to generally laterally contain an elongate member. For example, the support apparatus may be configured to restrict, for example substantially prevent, relative lateral movement of the support apparatus and an elongate member. The support apparatus may be configured to permit relative axial movement of an elongate member and the support apparatus. This arrangement may permit an elongate member to be displaced axially relative to the support apparatus, for example for retrieval, repair, inspection, replacement or the like.

In use, one or more of the support elements may be configured to continuously engage an elongate member.

One or more of the support elements may be configured to selectively engage an elongate member. Such selective engagement may permit an elongate member to be moved axially relative to the support apparatus and the individual support elements, while minimising any contact therebetween, and possibly avoiding the requirement to completely remove the support apparatus. Further, selective engagement may permit the passage of upset regions of an elongate member, such as connectors, tools, payloads or the like.

One or more of the support elements may be configured to engage an elongate element with a constant force. One or more of the support elements may be configured to engage an elongate element with a variable force. This arrangement may permit the support apparatus to modify the effective bending stiffness of an elongate member.

One or more of the support elements may comprise an engagement arrangement configured to engage an elongate member. The engagement arrangement may be configured to provide a fixed structure. Alternatively, the engagement arrangement may be configured to provide a variable structure.

The engagement arrangement may be reconfigurable between a non- engaged configuration, in which an elongate member is not engaged, and an engaged configuration, in which an elongate member is engaged. The engagement arrangement may be configured to move within a generally annular space defined between the associated support element and the elongate member.

The engagement arrangement may comprise an expandable element adapted to be expanded to move between the non-engaged and engaged configurations. The expandable element may be radially expandable. The expandable element may be configured to be expanded mechanically, such as by axial compression to effect radial expansion. The expandable element may be configured to be expanded by inflation. For example, the engagement arrangement may comprise an inflatable bladder configured to receive a fluid to permit expansion by inflation of the bladder.

The engagement arrangement may comprise an actuator, such as a piston assembly, configured to be actuated to engage an elongate member. The engagement arrangement may comprise one or more engagement surfaces configured to intimately engage an elongate member. The engagement surface may correspond to a profile or shape of an elongate member.

The engagement arrangement may be configured to sealingly engage an elongate member.

The support apparatus may be adapted to receive a lubricant arranged to provide lubrication between an elongate member and one or more of the support elements. Such lubrication may assist to minimise damage due to relative movement of the support apparatus and an engaged elongate member.

One or more of the support elements may define a flow path with an elongate member. The flow path may be generally annular. The flow path may be configured to accommodate a lubricant. The articulation arrangement may comprise a sealing arrangement configured to provide sealing between adjacent elements. The sealing arrangement may comprise a gaiter, o-ring or the like.

The support apparatus may be configured to be mounted partially or entirely along the length of an elongate member. The support apparatus may be configured to be mounted adjacent an end region of an elongate member. The support apparatus may be configured to be mounted intermediate end regions of an elongate member.

An engaged elongate member may be connected to a body, such as a floating vessel, subsea equipment or the like, wherein the support apparatus may be configured to be mounted on the elongate member adjacent the region of connection with the body. The support apparatus may also be connected to the body.

The support apparatus may be configured for use with a tubular elongate member, such as one or more connected pipes, coiled or coilable tubing, a hose member or the like. In one arrangement the support apparatus may be configured for use with a riser, such as a marine riser. The riser may be formed, at least partially, by coiled tubing.

In one arrangement the support apparatus may be configured for use with a marine riser which extends between a surface vessel and subsea equipment, such as a Christmas tree, wellhead, manifold or the like. In this arrangement the support apparatus may be mounted adjacent one of the surface vessel and subsea equipment. In some arrangements a support apparatus according to the first aspect may be mounted adjacent the surface vessel, and a further support apparatus according to the first aspect may be located adjacent the subsea equipment.

The support apparatus may be configured for use with a marine riser provided for workover operations. The support apparatus may be provided as part of workover equipment or as apart of a workover system.

According to a second aspect of the present invention there is provided a method of supporting an elongate member, comprising:

mounting a plurality of support elements along an axial length of an elongate member and arranging adjacent support elements to move relative to each other; and

permitting a force to be transmitted between adjacent support elements via an articulation arrangement such that movement of one element affects movement of an adjacent element.

The elongate member may comprise a marine riser, such as a coiled tubing marine riser.

The method according to the second aspect may be performed by use of a support apparatus according to the first aspect. As such, features presented above in relation to the first aspect, and their described or implied uses, may define nonessential features of the second aspect. Further aspects of the present invention may relate to a workover apparatus or system, or a method of undertaking workover operations, which include a support apparatus according to the first aspect. BRIEF DESCRIPTION OF THE DRAWINGS

These and other aspects of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

Figure 1 is a diagrammatic representation of a workover or intervention operation performed from a floating vessel, which includes the use of a support apparatus according to an embodiment of the present invention:

Figure 2 is a cross-sectional view of the support apparatus of Figure 1 ;

Figure 3 is an enlarged cross-section view of a portion of the support apparatus of Figure 1 , wherein the support apparatus is shown in a deflected state;

Figure 4 is an illustration of a support apparatus in accordance with an alternative embodiment of the present invention;

Figure 5 is an illustration of the support apparatus of Figure 4 in a deflected state;

Figure 6 is an enlarged view of an articulation arrangement of the support apparatus of Figure 4;

Figure 7 A is a view of a support element of the support apparatus of Figure 4 from above, shown with an engagement arrangement in a non-engaged configuration;

Figure 7B is a longitudinal cross-sectional view of the support apparatus of Figure 4, also shown with an engagement arrangement in a non-engaged configuration;

Figure 8A is a view of a support element of the support apparatus of Figure 4 from above, shown with an engagement arrangement in an engaged configuration; and Figure 8B is a longitudinal cross-sectional view of the support apparatus of Figure 4, also shown with an engagement arrangement in an engaged configuration.

DETAILED DESCRIPTION OF THE DRAWINGS

Figure 1 provides a diagrammatic representation of a workover system 8 for use in performing workover or intervention operations within a wellbore 10 from a surface vessel 12. In the illustrated example the wellbore 10 extends into the earth from a wellhead 14 mounted at a fixed location on the seabed 16. A subsea intervention package 18 is mounted on the wellhead 14 and comprises various valve arrangements (not shown) and a tool storage chamber 20 which contains one or more intervention tools 22 (only one shown for clarity). A marine riser 24 extends between the vessel 12 and the intervention package 18 and provides an isolated path 26 therebetween. In the embodiment shown the marine riser 24 is formed from coiled tubing that is spooled from a reel (not shown) through a moonpool 27 and then cut to the required length and supported on a frame 28 mounted on the vessel 12. A further length of coiled tubing 30 (or alternatively a wire, cable or the like) spooled from a vessel mounted reel (not shown) is run through the isolated path 26 of the marine riser 24. A leading end of the coiled tubing 30 comprises a connector 31 which is arranged to engage and pick up a tool 22 stored within the tool storage chamber 20, such that the coiled tubing 30 may be used to deploy the tool 22 into the wellbore 10 to undertake a desired workover or intervention operation, such as re- perforating of the like. Providing the tools 22 at a subsea location eliminates the requirement to trip the tools through the total depth of the sea, which in some regions can be several thousand meters, and would require the tools to be stored on the vessel 12, where space is at a premium.

As will be appreciated, in use the vessel 12 will be subject to motion caused by sea conditions, such as heaving motion 32 and lateral deviations 34. Such motion of the vessel 12 will cause corresponding motion of the marine riser 24, which as noted extends to a fixed location on the seabed 16. It is therefore necessary to ensure that such motion will not compromise the riser 24, which may contain wellbore and other fluids which are potentially hazardous to the environment. In the present embodiment heaving motion 32 of the vessel 12 is accommodated by providing movement compensation to the frame 28 which supports the upper end of the riser 24. Specifically, the frame 28 is hung via a wire 36 which is spooled to and from a drum (not shown) which is configured to rotate in accordance with heaving motion of the vessel 12. As such, the frame 28 may be manipulated by the wire 36 and compensated drum to hold the upper end of the marine riser 24 a substantially constant height from the seabed 16. This may therefore prevent or minimise adverse tension or compression being applied to the riser 24.

Further, in the present embodiment lateral deviation motion 34 of the vessel 12 is generally accommodated by inherent flexibility of the marine riser 24, such that the riser 24 bends in accordance with the lateral motion 34. Nevertheless, in order to provide protection to the riser 24 during such bending the workover system 8 includes a support apparatus, generally identified by reference numeral 40, in accordance with an embodiment of the present invention. The support apparatus 40 is mounted externally of the riser 24, adjacent its upper end region, and is also secured to the frame 28. In this way the support apparatus 40 is located to provide support at a region of the riser that is exposed to high loading. As will be discussed in further detail below, the support apparatus 40 assists to limit or restrict bending of the riser 24, increase the bending stiffness of the riser 24 in the critical region of connection to the frame 28, and also ensure that bending of the riser 24 and associated fatigue is more evenly distributed.

The vessel may also include dynamic positioning systems.

A longitudinal cross-sectional view of the support apparatus 40 of Figure 1 is shown in Figure 2, reference to which is now made. Figure 2 also illustrates features of the workover system 8 adjacent to the support apparatus 40, and it will be noted that the marine riser 24 is supported on the frame 28 via a slip arrangement 42, wherein for clarity and brevity the slip arrangement 42 is shown activated to engage the riser 24 on the right hand side of the drawing, and shown disengaged from the riser 24 on the left side of the drawing. Further, it will be noted that the support apparatus 40 is secured to the frame 28 via a boss arrangement 44.

The support apparatus 40 comprises a plurality of tubular support elements 46 which are arranged externally of and coaxial with the riser 24 along an axial length thereof. The support elements 46 are arranged in end-to-end relation and adjacent elements 46 are secured together by an articulation arrangement 48, which will be described later. The interconnected support elements 46 collectively define an internal bore 50 through which the riser 24 extends. Further, each support element 46 comprises an engagement arrangement 52 configured to selectively engage the riser 24. Specifically, each engagement arrangement 52 comprises an annular rubber component which is adapted to be reconfigurable between a relaxed, non- engaged position, as shown in the left side of Figure 2, and an energised, engaged position, as shown in the right side in Figure 2. The rubber element is energised by being axially compressed with an actuator assembly (not shown). Accordingly, each engagement arrangement 52 may be configured in the relaxed configuration (left side of Figure 2) while the riser 24 is being deployed through the bore 50 of the apparatus 40, and subsequently reconfigured into the engaged configuration (right side of Figure 2) to engage the riser 24 to provide support thereto.

The support apparatus 40 comprises upper and lower sealing collars 54, 56 which comprise respective annular seals 58, 60 arranged to provide a seal against the riser 24. Each seal 58, 60 is adapted to be reconfigured between a non-sealing position as shown in the left side of Figure 2, and a sealing position as shown in the right side of Figure 2. Further, each sealing collar 54, 56 comprises a lubricant port 62, 64 configured to permit a lubricant to be circulated within the bore 50 of the apparatus 40 in order to provide lubrication between the elements 46 and associated components and the riser 24. For example, lubrication may be provided while the riser 24 is being run through the bore 50.

The support apparatus 40 is configured such that the riser 24 may be laterally contained. That is, the support apparatus 40 generally limits or restricts the available lateral movement between the riser 24 and the apparatus 40. This may therefore provide protection to the riser 24 against applied lateral forces, for example from the sea. Further, the support apparatus 40 is configured to permit the riser 24 to move axially therethrough. This may therefore allow protection to be afforded to the riser 24 while being axially displaced, for example during deployment, or during retrieval, for example for inspection, maintenance, repair, replacement or the like.

Each articulation arrangement 48 in the embodiment shown will now be described in detail with reference to both Figures 2 and 3. Each articulation arrangement 48 comprises a coupling ring 66 engaged within annular recesses 68 of opposing ends of adjacent elements 46. The coupling ring 66 and associated recesses 68 are formed and dimensioned to permit a degree of relative motion to be achieved between adjacent elements 46, specifically a degree of pivoting motion about one or more axes which are transverse or perpendicular to the central axis of the bore 50. In use, bending of the riser 24 when engaged by the support apparatus 40 will cause the elements 46 to move relative to each other about the respective articulation arrangements 48, thus accommodating the deflection in the riser 24. Such relative motion is demonstrated in Figure 3, in which the elements 46 collectively define a curved profile. In Figure 3 the riser 24 is not shown for clarity. The arrangement of each coupling ring 66 and associated recesses 68 is such that relative motion between adjacent elements 46 is restricted, which will have the effect of providing a limit to bending of the riser 24. Such restriction to bending of the riser 24 may provide a degree of protection to the riser 24 when in use.

Each articulation arrangement 48 further comprises a deformable device in the form of an elastomeric ring member 70 interposed between profiled end faces of adjacent elements 46. Each ring member 70 is deformable to permit adjacent elements 46 to move relative to each other, and functions to transmit a force between adjacent elements 46 such that movement of one element affects movement of an adjacent element. Accordingly, each element 46 is arranged not only to be moved by independent engagement with the riser 24, but also by any movement in an adjacent element. This may therefore permit bending of the riser 24 to be accommodated and distributed across each element 46. This may permit any bending stress to be distributed along the riser 24, rather than in isolated or localised regions. Furthermore, the process of transmitting forces between adjacent support elements 46 by the ring member 70 may assist to increase the resistance to bending within the riser 24, resulting in an effective increase in bending stiffness.

Reference is now made to Figure 4 in which there is shown a support apparatus 140 in accordance with an alternative embodiment of the present invention. Support apparatus 140 is similar in many respects to support apparatus 40 shown in Figure 2, and as such like features share like reference numerals, incremented by 100. The support apparatus 140 therefore comprises a plurality of support elements 146 concatenated by respective articulation arrangements 148. The support apparatus 140 is configured to be secured to a suspended frame 28 via a boss arrangement 44, and receives and supports a riser 24. As demonstrated in Figure 5, each articulation arrangement 148 permits adjacent elements 146 to move relative to each other to accommodate bending of the riser 24. As will be discussed in more detail below, and similar to the previous embodiment, each articulation arrangement 148 limits the relative motion between adjacent elements 148, and permits a force to be transmitted between adjacent elements 46 to establish a desired distribution of bending across the elements 46 while increasing the effective bending stiffness of the riser 24.

A detailed description of an articulation arrangement 148 will now be given with reference to Figure 6, which is an enlarged view in the region of end portions of adjacent elements 146a, 146b. A pair of diametrically opposed pivot brackets 172 are secured to the lower support element 146a, and similarly a pair of diametrically opposed pivot brackets 174 (only one shown) are secured to the upper support element 146b. As shown, each pair of pivot brackets 172, 174 are disposed at 90 degrees relative to each other. Each pivot bracket 172, 174 is pivotally secured to a pivot ring 176 which is interposed between the support elements 146a, 146b, wherein the pivot brackets 172 of the lower support element 146a are arranged to provide pivoting about a first pivot axis 178, and the pivot brackets 174 of the upper support element 146b are arranged to provide pivoting about a second pivot axis 180. The first and second pivot axes 178, 180 are arranged perpendicular to each other and also to a longitudinal axis 181 of the support apparatus 140. Accordingly, the articulation arrangement 148 is configured to permit the adjacent support elements 146a, 146b to move relative to each other in multiple pivoting directions to accommodate any bending of an associated riser 24 (not shown in Figure 6). Further, relative movement of the adjacent elements 146a, 146b will eventually result in engagement with the pivot ring 1 6, which therefore functions to limit the relative motion, and thus the maximum achievable bend of the riser 24.

The articulation arrangement 148 also comprises a pair of diametrically opposed deformable devices 170a (only one shown) mounted on the lower support element 146a, and a pair of diametrically opposed deformable devices 170b mounted on the upper support element 146b. The deformable devices 170a, 170b in the embodiment shown are identical and each is provided in the form of a hydraulic dampener which includes a piston member 182a, 182b which strokes within a hydraulic cylinder 183a, 183b. The piston members 182a of the hydraulic dampeners 170a are arranged to engage respective land portions 184 of the pivot brackets 174 secured to the upper support element 146b, such that relative pivoting motion of the support elements 146a, 146b about pivot axis 178 will result in stroking of the piston members 182a. Similarly, the piston members 182b of the hydraulic dampeners 170b are arranged to engage respective land portions 186 of the pivot brackets 172 secured to the lower support element 146a, such that relative pivoting motion of the support elements 146a, 146b about pivot axis 180 will result in stroking of the piston members 182b. Stroking of the respective piston members 182a, 182b will establish dampening to the relative movement and result in the transmission of a force between the adjacent elements 146a, 146b such that movement of one element will affect movement of the adjacent element. This may therefore permit any bending of a riser 24 to be distributed across the various elements 146, and also to increase or modify the effective bending stiffness of the riser 24.

The support apparatus 140 also includes arrangements within the individual support elements 146 for selectively engaging the riser 24, as will now be described with reference to Figures 7 and 8, wherein Figure 7 illustrates an engagement arrangement 152 of a support element 146 in a non-engaged configuration, and Figure 8 illustrates the same engagement arrangement 152 in an engaged configuration. Specifically, Figures 7A and 8A show a support element 146 from above in the different configurations, and Figures 7B and 8B are longitudinal cross sectional views through a portion of the support apparatus 140.

Each support element 146 comprises an engagement arrangement 152 in the form of an annular inflatable bladder which is configured to receive a fluid via a port 188 to radially expand the bladder into engagement with the riser 24. The pressure within each bladder 152 may be varied to vary the contact force with the riser 24. This may therefore permit a variation in the effective bending stiffness of the riser 24 to be achieved, for example.

Still referring to Figures 7 and 8, the support apparatus 140 defines an internal bore 150 through which the riser 24 extends. In order to seal the bore 150 from the environment upper and lower sealing collars 154, 156 (see Figure 4) are provided, and also each articulation arrangement 148 comprises a flexible gaiter 190 which extends between adjacent support elements 146. In a similar manner to the embodiment shown in Figure 2, the upper and lower sealing collars 154, 156 may be configured to permit communication of a lubricant to and from the bore 150.

It should be understood that the embodiments described herein are merely exemplary and that various modifications may be made thereto without departing from the scope of the invention. For example, the support apparatuses may be used in combination with any elongate member, and are not limited to use with tubular members, such as the coiled tubing riser described above. Furthermore, the articulation arrangements may be configured to be actively controlled to permit variations in, for example, the available relative motion between support elements, the force transmitted between support elements and the like. For example, it may be desirable in some arrangements to configure the support apparatus to provide a greater effective stiffness at one region of an elongate member than at other regions. This may be achieved by effectively stiffening some articulation arrangements within the support apparatus. Further, the articulation arrangements may be actively controlled so as to function as actuators, for example to cause movement in an engaged elongate member. Furthermore, in the specific embodiments described the support apparatuses are located at an upper end of a riser, adjacent a vessel. However, the support apparatuses may also be used at any other location of the riser, such as adjacent the subsea equipment. Also, the embodiments described illustrate exemplary uses in which the support apparatus is mounted externally of an elongate member. However, other embodiments may be configured to be mounted internally of an elongate member.

Claims

CLAIMS:

1. A support apparatus for an elongate member, comprising:

a plurality of support elements configured to engage an elongate member along an axial length thereof; and

2. The support apparatus according to claim 1, configured to increase the bending stiffness of an engaged elongate member.

3. The support apparatus according to claim 1 or 2, wherein adjacent support elements are concatenated.

4. The support apparatus according to claim 1 , 2 or 3, wherein the articulation arrangement is interposed between and functions to connect together adjacent support elements.

5. The support apparatus according to any preceding claim, wherein the apparatus comprises a plurality of articulation arrangements configured to concatenate the plurality of support elements.

6. The support apparatus according to any preceding claim, wherein the articulation arrangement is configured to permit relative pivoting motion of adjacent elements.

7. The support apparatus according to any preceding claim, wherein the articulation arrangement is configured to permit relative pivoting motion of adjacent elements about two mutually perpendicular axes which are perpendicular to an engaged elongate member.

8. The support apparatus according to any preceding claim, wherein the articulation arrangement is configured to limit relative motion between adjacent support elements to limit or restrict bending of an engaged elongate member.

9. The support apparatus according to any preceding claim, configured such that a total bend angle of an engaged elongate member is evenly distributed across the plurality of elements.

10. The support apparatus according to any one of claims 1 to 8, wherein the total bend angle is distributed irregularly between the support elements.

1 1. The support apparatus according to any preceding claim, wherein the articulation arrangement is adjustable.

12. The support apparatus according to any preceding claim, wherein the articulation arrangement is adjustable to vary a permitted relative motion between adjacent support elements.

13. The support apparatus according to any preceding claim, wherein the articulation arrangement is adjustable to vary the force transmitted between adjacent support elements.

14. The support apparatus according to any preceding claim, wherein an articulation arrangement between one adjacent pair of support elements provides a different effect to an articulation arrangement of another pair of adjacent support elements.

15. The support apparatus according to any preceding claim, wherein the articulation arrangement is operable upon movement of an engaged elongate member.

16. The support apparatus according to any preceding claim, wherein the articulation arrangement is operable to manipulate an engaged elongate member.

17. The support apparatus according any preceding claim, wherein the articulation arrangement comprises at least one deformable device configured to deform to accommodate relative movement of adjacent support elements, and to permit transmission of a force between said adjacent support elements.

18. The support apparatus according to claim 17, wherein the deformable device comprises one or more deformable elements

19. The support apparatus according to claim 17 or 18, wherein the deformable device comprises a piston arrangement configured to stroke upon relative movement of adjacent support elements.

20. The support apparatus according to claim 17, 18 or 19, wherein the deformable device comprises a dampener.

21. The support apparatus according to any preceding claim, configured to generally laterally contain an elongate member.

22. The support apparatus according to any preceding claim, configured to permit relative axial movement of an elongate member and the support apparatus.

23. The support apparatus according to any preceding claim, wherein one or more of the support elements is configured to selectively engage an elongate member.

24. The support apparatus according to any preceding claim, wherein one or more of the support elements comprises an engagement arrangement configured to engage an elongate member.

25. The support apparatus according to claim 24, wherein the engagement arrangement is reconfigurable between a non-engaged configuration, in which an elongate member is not engaged, and an engaged configuration, in which an elongate member is engaged.

26. The support apparatus according to claim 25, wherein the engagement arrangement comprises an expandable element adapted to be expanded to move between the non-engaged and engaged configurations.

27. The support apparatus according to claim 26, wherein the expandable element is radially expandable.

28. The support apparatus according to claim 26 or 27, wherein the expandable element is configured to be expanded mechanically.

29. The support apparatus according to claim 26, 27 or 28, wherein the expandable element is configured to be expanded by inflation.

30. The support apparatus according to any preceding claim, adapted to receive a lubricant arranged to provide lubrication between an elongate member and one or more of the support elements.

31 , The support apparatus according to any preceding claim, configured to be mounted adjacent an end region of an elongate member.

32. The support apparatus according to any preceding claim, configured to be secured to a support structure which also supports an engaged elongate member.

33. The support apparatus according to any preceding claim, configured for use with a tubular elongate member.

34. The support apparatus according to any preceding claim, configured for use with a riser.

35. The support apparatus according to any preceding claim, configured for use with a coiled tubing marine riser.

36. A method of supporting an elongate member, comprising:

mounting a plurality of support elements along an axial length of an elongate member and arranging adjacent support elements to move relative to each other; and permitting a force to be transmitted between adjacent support elements via an articulation arrangement such that movement of one element affects movement of an adjacent element.