GB2402950A - An attachment apparatus for clamping objects - Google Patents

Abstract

An attachment apparatus 3 in a form of a clamp or claw comprising attaching members 4 moveable between an open configuration and a closed configuration, and arranged in such a way that they are movable relative to one another. The placing the attachment apparatus 3 on subsea structure 2 causes the attaching members 4 to automatically close around the subsea structure 2 thus securing the attachment apparatus 3 to the subsea structure 2, and locking means 10 are provided to lock the attachment members 4 in a closed configuration. The attachment apparatus 3 is attached to a guidepost 1 or other guideline or guidewire system.

Description

ATTACHMENT APPARATUS, GUIDEPOST AND GUIDEWIRE AND METHODS OF USING'1'IJE

SAME This invention relates to attachment apparatus for attaching objects to a subsea structure. More particularly this invention relates to clickon apparatus particularly suitable for attaching a guidepost or guidewire to a pipeline pre-existing or other structure (the "target" structure).

The exploitation of offshore oilfelds often requires the lowering of equipment from surface to structures fixed on the seabed, such as pipelines. In order to accomplish this, means must he provided for properly aligning the lowered equipment with the target area on the structure. The usual way this is done is by the use of guidelines which run from the surface to the tops of guideposts, which rise from subsca structures on the seabed. See, for example, the guideline system disclosed in US-A-305013') (Hayes 19G2).

Guideposts may also be used on their own to accomplish the necessary alignment without attached guidelines.

Currently guideposts are connected to the subsea structure by means of dedicated receptacles. These receptacles are typically included on a subsea structure prior to installation on the seabed. There are no adequate guidepost system designs for adding guideposts and receptacles in the operational phase, particularly when said structure is a subsea pipeline.

Attaching a guideline to a subsca pipeline when in position and without a receptacle already attached can be time-consuming and may involve digging underneath the pipeline and threading a soft sling for attachment.

I he hlvcntion disclosed herein alleviates these difficulties by providing attachment apparatus lllal is both very simple and quick lo attach, and negates the need for dedicated rcceptaclcs. 'I'hc apparatus proposed simply "clicks--'n" the pipeline, or any other suitable 3() sullsca slructurc, on contact, and locks into position.

In a first aspect of the invention there is provided atlachncul apparatus for attaching to a subsca taryct structure, the apparatus comprising a body and gripping means moveablc from act opc', configuration to a closed configuration and arranged such that placing of said À Àe Àe ee. e

À À À À À C À a À À À e Àe À À apparatus on said target structure in use will cause said gripping means to close around said subsea structure thus securing said body of the attachment apparatus to said tar-get structure.

Said attachment apparatus may be part of or attached to a guidepost, guidewire or may be an integral part of a larger functional structure.

Said attachment apparatus may also be combined used with both a guidepost and guidewire in conjunction. In accordance with a second aspect of the situation defined below. The guidepost may be adapted for movement along the guidewire from a raised position away from the attachment apparatus body to a deployed position attached to the apparatus body and vice versa. The guidepost may have locking clips for acting on a locking member attached to the guidewire, thus enabling said guidepost to be locked in both said raised and said deployed position. The portion of the guidewire between the guidepost in its raised position and the body of the attachment apparatus being of lighter rope than the portion of the guidewirc above the guidepost, optionally being oi fibre rope.

Said gripping means may comprise at least two opposing gripping members means arranged such that they are movable relative to one another to define said open configuration and closed configurations and where, when not deployed, about a target structure said gripping members are biased in an open position by biasing means, wherein, during dcgloyment, the action of said target structure on said apparatus causes said gripping 2() members to move into said closed configuration.

Preferably there is also provided locking means automatically when said gripping ananged to lock said attaching means into said closed configuration move into the closed configuration.

Preferably there is further provided a screw and nut arrangement connecting the gripping members arranged such that wher1 said gripping members are in the closed configuration and said screw is tuned in a first direction a corresponding nut acts against each gr-ipphg member in such a way that said gripping rnernbers close further together, thus tightening the grip ol the gripping means on said target structure. Prior to this tightening step the attaching means and thus the apparatus may be repositioned axially anywhere along () the structure until in the desired position (assuming the structure to be generally cylindrical).

in a preferred embodUnent if said screw is turned in a second direction, opposite to said first direction, when said gripping means are in said closed configuration, each corrcspordhg nut acts on said lockhg means causing said locking nomads to rclcasc said À tee Àa tee À À À ce. * a À À À À À À e. À À gripping means, said gripping means opening under the action of said biasing means to said open configuration.

In the prcfcrrcd embodiment one half of the screw has a right hand thread, along which the first nut is threaded, and the other half has a left hand thread, along which the second nut is threaded thus allowing the device to be locked and unlocked from either side.

Preferably there is separate locking means for each gripping member.

The gripping member may have their inside surfaces shaped to substantially match the exterior shape of a specific target structure.

Each gripping member may be pivoted approximately halfway along its length.

They may have pads at the bottom for gripping the underside of said substantially cylindrical subsea structure.

Said biasing means may be springs.

Said guidepost may be used on its own, or in combination with a guideline.

It should be noted that for the purposes of the working of the invention, substantially cylindrical structures include structures, or parts thereof, with a polygonal cross section, which for the purposes of the working of the invention, approximate to cylindrical structures.

Said attachment apparatus may be anned subsea.

The invention further provides a guidepost incorporating the attachment apparatus disclosed herein.

ha a further Independent aspect of the invention there is provided a guide apparatus comprising a guidepost and a guidewire having an end termination for attachment to a target structure subsca and wherein said guidepost is adapted for movement along the guidcwire from a raised position away from said end termination to a deployed position rigidly connected to said end termination.

Said guidcwire may be provided with a boss fixed at a point away Irom said end tcnnh1ation, said guidepost being provided with a clip for cooperation with said boss to lock the guidepost in said raised position. The guidepost may be provitiCd with a second clip to enable locking of'said guidepost in troth deployed and raised positions.

3() 'I'hc tcnnhation may include a stub adapted to be rcccivcd by a socket within a lower cad of the guidepost. Nccdless to say, the socket and stub may be reversed. A last section ol'said guidcwh-e may be made more llcxiblc than the guidewire itself, so that the end terni'ation with guidepost hi raised position is more easily unanswered by ROV. 'I'hc À c e ce. e À À À boss mentioned above may form the connection between the guide wire and said last SCCtiO'1.

Said end termination form part of attachment apparatus according to the f rst aspect of the invention as set forth above.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the invention will now be described, by way of example only, by reference to the accompanying drawings, in which: Figure I shows a guidepost being lowered onto a pipeline; Figure 2 shows the attachment apparatus in detail before deployment of the guidepost; Figure 3 shows the attachment apparatus in detai I during deployment of the 1 5 guidepost; Figure 4 shows the attachment apparatus locked into the closed position around the pipeline; Figure 5 shows the attachment apparatus locked into the closed position around the pipeline with the grip tightened by the screw and nut system; Figure 6 shows a close up of the locking mechanism during unlocking of the attachment apparatus; Figure 7 shows the attachment apparatus in its open state, being removed from the pipeline; Figure shows the attachment apparatus, with altcnativc guidepost design, being lowered onto a pipeline with the guidepost in a raised position; Figure 9 shows the attachment apparatus attached to the pipeline and the guidepost of figrc in its deployed position; Figure 1() shows a cut away of the guidepost of figure 8 in its raised position; leisure] 1 shows a cut away of the guidepost of figure hi its deployed position; 3() Figure 12 shows an ROV manipulating the attachment apparatus to facilitate lowering ot an antenna frame; Figure 13 shows the antenna frame bchlg lowered assisted by the REV; and À À . . . À À À . À À . À c. . À . À . À À À À c.

Figure 14 shows the antenna frame being positioned on and attached to the pipeline by the ROV.

DETAII,ED DIISCRIPTION OF THE EMBODIMF,NTS Figure I shows a guidepost I being lowered onto a target structure, in this case an existing subsea pipeline 2. The guidepost 1 has a attachment claw 3 at the end. Said attachment claw 3 can be in an open and closed configuration, and is shown here in the open configuration. The positioning of the guidepost I onto the pipeline 2 is usually done using a remotely operated vehicle (ROY) (not shown in Figure 1). Figures 12 to 14 described further below show an example of the use of the apparatus.

Eigurc 2 shows the attachment claw 3 in detail in its open configuration and before it has been positioned onto the pipeline 2. The claw 3 comprises a main body 5 and two attaching members 4. Each of the attaching members is pivoted approximately half-way along its Icngtl1 by pivots 6 such that they are movable relative to the claw's main body 5.

The attaching members 4 are curved such that they can close around the pipeline 2, thus attaching the guidepost I to the pipeline 2. At one end of each attaching member 4 there is a gripping pad 7. Each of the attaching members 4 has a corresponding spring 8 which bias the claw 3 in the open configuration. At the other end oI each of the attaching members 4 is 2() a locking member 10. Each of these locking members is pivoted at one end by pivots 11. A screw 16 and nut 17 system is provided to tighten the claw's 3 grip when in the closed configuration and locked around the pipeline 2.

Figure 3 shows said attachment claw 3 being placed in position around the pipeline 2. The claw 3 is positioned over the pipeline 2 such that the attaching members 4 are either side ol the pipcldle 2. The apparatus is then lowered or pushed down onto the pipeline 2.

This downward force results in an opposing force acting on the pads 12 at the top end of the attaching memUcrs 4 which, in turn, results h1 the attaching members 4 rotating around their pivots 6 thus acting against the springs 8. rI hcrefo)-e the claw 3 latches mechanically onto the pipeline 2 upon contact.

3() The movement of the attaching members 4 also results hi a li,o 13 at the top ol each of the attaching members 4 to act on the bottom edge ol a corrcspontlblg locking member 10. T he bottom edge of each of the lockhlg members is contoured hi such a way that this action by the lip 13 pushes the locking members 1() upwards with each locking member 10 ÀÀ À . . À À. . . À À 8 À À À . pivoting around pivots 11 and consequently acting against the springs 14. This movement ol' the locking members 10 ensures that they do not hinder the closing of the attaching members 4.

I'igure 4 shows the claw 3 after the claw has been pushed further on to the pipeline 2 such that it is now in its closed configuration. The attaching members 4 have rotated far enough around their pivots 6 such that the bottom end oi'the attaching means are around the underside of the pipeline 2 thus preventing the claw 3 from being lifted up, off the pipeline 2. Such a problem may occur with other conventional systems as a result of the heave of the surface vessel. However it should be noted that the pads 7 are not yet in contact with the pipeline 2. This grip is loose enough, therefore, to enable the guidepost I to be moved to its desired position along the pipeline 2 by, for instance, an ROV. This ability to move the guidepost along the pipeline once clicked on is an important feature of the invention.

The attachment members 4 arc retained in the closed position by the locking members 10. 'thcsc work in much the same way as a ratchet mechanism. Each attachment member 4 has a lip 13 at its top end, while each of the locking members 10 also have a lip, on their bottom edge. As the locking members move into the closed configuration, the locking members 10 are first moved out of the way by the lips 13, until in the closed configuration where the locking members 10 fall into place. The lips 13 of the attaching members 4 now abut the lips 15 on the locking members 10 thus locking the claw 3 in the closed position.

Figure 5 shows the claw in place, with its grip tightened by the screw 16 and nut 17 system provided. This fixes the guidepost I to the pipeline 2 and is done after the guidepost 1 has been positioned along the pipeline 2 as required.

One half of the screw has a right hand thread, along whicl1 the first nut is threaded, and tile other half has a left hand thread, along which the second nut is threaded.

Accordingly, each nut is also oppositely threaded to correspond with its half of the screw.

Tllis allows the device to be locked and unlocked from either side by the ROV. The tightening of the claw 3 is achieved by the turning of the screw in a first direction. This turning of'the screw is usually done by an ROV. As the screw IG is turned in the tightening 3() direction, talc action ol'its threads causes the nuts 17 to move along each thread outwards fi-om the ccntr c of the claw 3 assembly, where it abuts the Bat face of the attaching members 4. As tills turning of the screw IG is continued, the nuts 17 act against the attaching mcmhcrs 4 and consequently, the springs 8. The attaching members arc caused f'urtller to À À. À À À À . . . . À . . À À À . . . . . . . 7.. À . . move around the pivots 6, bringing the gripping pads 7 at each end in contact with the underside of the pipeline 2, gripping the pipeline 2, and thereafter, tightening this grip. This prevents any further movement of the guidepost along or around the pipeline 2.

Figure 6 shows a close up of the locking and release mechanism, while the claw is being unlocked, allowing release of the guidepost I from the pipeline 2. To unlock the claw, the screw 16 is turned in the opposite direction to that of tightening. This causes the nuts 17 to move along the thread in the opposite direction away from the attaching members. A nipple 18 is provided on each nut 17, protruding out from the side. As each nut 17 travels along the thread 16, its nipple 18 catches a curved edge on the underside of the corresponding locking member 10. The action of the nipple 18 on the locking member 10 forces the locking member 10 upwards against the springs 14, rotating around pivots 11.

The lip 15 of each locking member is consequently rifled clear of the lip 13 of each attaching member 4.

I<igure 7 shows the guidepost mechanism being removed from the pipeline 2 after unlocking. '[he unlocked claw 3 has been lifted clear of the pipeline 2. This results in the rotational movement of the attachment members 4 under action of the springs 8 around pivots 6. This brings the claw 3 again into the open configuration The unit can now be brought up to the surface for anning. Alternatively the unit can be anned subsea.

It will be apparent to the skilled artisan that variations to the apparatus described above can be accommodated without falling outside the scope of the invention. Different mechanisms for tightening the grip or releasing the claw can be envisaged. Also the position of the pivots or springs or shape of the components do not have to be necessarily as described above. The scope of the invention is therefore only to be Ih1lited by the scope of the clahlls.

Figures 8 to 11 shows an option where the guidepost is first suspended on the guidewh-e (which may be wire or fibrc rope or a combination of both) and is subsequently positioned hi place once the attachment claw is locked into place. This has the advantages of making the claw lighter and more manoeuvrablc by the ROV. It also allows the guidepost to be rclcascd after the equipment has been guided into place, which may be 3() necessary as the guidepost itself' can obstruct tl1c functioning of the cquipn1ent. Af'tcr release the guidepost can he returned to the surface or altenativcly, can be abandoned by beh1g, lilted a f'cw metros and pulling to one side, thus saving costs h1 deep water appl ications.

À À À À À. À 8 C À À ce. À e À À . À e Refenring first to Figure 8, the attachment claw 3 is attached to the pipeline 2 and is the same as that described previously. It is attached to the end of guidewirc 20 and has been lowered onto the pipeline 2 by the lowering/paying out of guidewire 2(). The guidepost 1 is suspended on the guide.

The attachment claw 3 is lowered onto the pipeline 2 as previously described, and locks into place. When this is done, the guidepost I is unclipped and allowed to fall on to the claw 3 where it is then clipped into position (as shown in Figure 9).

Figures 10 and 11 show a cut-away of the guidepost 1 before and after deployment along the guidewire.

Figure 10 shows the guidepost whilst still suspended at a raised position a short way above the attachment claw. There is provided an upper locking clip 30 and a lower locking clip 31 attached to the guidepost 1. There is also provided, inside the guidepost I and attached to a point away from the bottom of the guidcwirc 20, a locking boss 32, said locking boss having a groove 33. The locking boss 32 is connected to the claw 3 via a short length of fibrc rope 2()a, which facilitates manocuvrability (a section of lighter wire rope could be used to the same effect). The lower locking clip 31 retains the locking boss by locating in the groove 33 thus is retaining the guidepost I in its suspended position.

The guidepost is deployed by releasing the lower locking clip 31 with the ROV The guidepost then stalks onto the claw 3 and engages. The length of the fibre rope 20a and the 2() distance between the upper and lower clips 30, 31 is sucl1 that once engaged, the upper locking clip locates into the groove 33 and retains the locking boss 32 in place.

Consequently the guidepost is locked into the engaged position (Figure 11) . This locking prevents undcsh-cd uplift during landing/renoval operations.

To retune the guidepost I to its elevated position, the wire tension is first released.

The ROV releases the upper clip 30 and the guidcwire 20 is payed out, SUCH that the fibre rope 2()a coils up below the locking boss. Therefore the locking boss 32 slides down until it reaches the lower lockhlg clip 31 where it locks into position. I he guidewirc 20 can then be hoisted up, taking the guidepost 1 with due to it being lilted by the locking boss 32. The guidclyost I nary then be lifted up, or alternatively, pulled to the side, as far as the fibre rope 3() 2()a permits. Also, hi this position, the guidcwirc anchor nay be released and the guidepost I lifted to the surface, leaving the claw behind.

I'igures 12 to 14 show the mounthlg of an antenna France 21 to a subsea structure 22 by an R()V 23. A lost attacllmcut claw 3a of tile type clashed hcrch, with guidcwh-c 20 Àc À À . À À À À À À À . À À À À À À À À . . À À À 9.... . . . attached, is taken to the structure by the ROV 23, and lowered into place, clicking on so that it is still movable axially along the structure as described above.

Figure 13 shows the actual antenna frame 21 being lowered into position Irom the surface hi a three leg lifting set, assisted by the ROV 23 and guided by the guideline 20 attached to the claw 3a. The frame has a further attachment claw 3b at one end, mounted directly to the frame 21. At its other end is an eye through which the guidewire attached to the first attachment means 3a is threaded through. This allows the frame 21 to be guided down onto the right part of the structure 22 simply, and assures the correct distance between the two attachment means 3a,3b when the fixed attachment claw 3b is clicked on. The attaelment claws 3a,3b can then be tightened.

I;igure 14 shows the antenna frame 21 in position on the structure 21, with the ROV 23 tightening the attachment claw 3b and the other end of the frame attached to the other attachment claw 3a.

The skilled person will recognise that the above examples are intended for illustration only, and many variations arc possible without departing from the spirit and scope of the invention.

Claims (1)

1. À can ce À ee.

   C À C À À C À À À C À À À À C À

   1. Attachment apparatus for attaching to a subsea structure comprising attaching means moveablc trom an open configuration to a closed configuration and wherein the placing of said apparatus on said subsea structure causes said attaching means to close around said subsea structure thus securing said attachment apparatus to said subsea structure.

   2. Attachment apparatus as claimed in claim I wherein said apparatus is an integral part of a structure.

   3. Attachn1cnt apparatus as claimed in claim I wherein said apparatus forms a part, or is attached to a guidepost and/or guidewire.

   4. Attachment apparatus as claimed in any preceding claim wherein said attachment apparatus comprises at least two opposing attaching means arranged such that they are movable relative to one another to and front said open configuration to said closed configuration.

   5. Attachment apparatus as claimed in claim 4 wherein, when not deployed, said 2() attaching means are biased in an open position by biasing means, and wherein, during deployment, the action of said structure on said apparatus causes said attaching means to move into said closed configuration.

   6. Attachment apparatus as claimed in claim 5 wherein said biashlg means are springs.

   7. Attachment apparatus as claimed in claims 4 to 6, wherein prior to any tightening of the attaching means, the attachment apparatus may he repositioned axially anywhere along said structure until in tl1e desired position.

   8. Attachment apparatus as claimed in claims 4 to 7 wherein there is further provided locking Scans such that when said attaching means move into the closed configuration, said locking means lock said attaching means into said closed ccnfiguratio.

   c - e *e À À À À À C À À À À C 9. Attachment apparatus as claimed in claim 8 wherein there arc separate locking means for each attaching means...CLME: 10. Attachment apparatus as claimed in claim 4 to 9 wherein there is further provided a screw and nut arrangement for the attaching means, arranged SOCK that when said attaching means are in the closed configuration and said screw is turned in a first direction the corresponding nut acts against its corresponding attaching means in such a way that said attaching means close further together, thus tightening its grip on said cylindrical subsea structure.

   11. Attachment apparatus as claimed in claim 10, wherein prior to any tightening of the attaching means, the attachment apparatus may be repositioned axially anywhere along said structure until in the desired position.

   12. Attachment apparatus as claimed in claim 10 or 11 wherein, when said screw is turned in a second direction, opposite to said first direction, and when said attaching means are in said closed configuration, each corresponding nut acts on said locking means causing said locking means to release said attaching means.

   13. Attachment apparatus as claimed h1 claims 1() to 12 whcrch1 one half of the screw has a right hand thread, along which the first nut is thrcadcd, and the other half has a left hand thread, along which the second nut is threaded thus allowing the device to be locked and unlocked from either side.

   14. Attachment apparatus as claimed in claims 4 to 13 wherein the attachment means may be have their inside surfaces shaped to substantially match the exterior shape of said substantially cylindrical subsea structure.

   15. Attachment apparatus as claimed h1 claims 4 to 14 wherein said attachment means () arc pivoted approximately halfway along their Icng,th.

   . a À 1 . I À 4 t À ' À 1O.'s À 16. Attachment apparatus as claimed in claims 4 to 15 wherein said attachment means have pads at the bottom for gripping the underside of said substantially cylindrical subsea structure.

   17. Attachment apparatus as claimed in any preceding claim wherein said attachment apparatus is amled subsea.

   18. A guidepost incorporating the attachment apparatus as claimed in any of claims I to 17.

   21. Guide apparatus comprising a guidepost and guidewire, used in conjunction and wherein said guidepost is capable of movement along the guidewire from a raised position to a deployed position and vice versa.

   22. Guidc apparatus as claimed h1 claim 21 wherein said guidcwire is provided with a fixed boss and said guidepost is provided with at least one clip for cooperation with said boss to lock said guidepost in a desired position.

   23. Guide apparatus as claimed in claim 22 wherein said guidepost is provided with two 2() clips to enable locking of said guidepost in both deployed and raised positions.

   24. Guide apparatus as claimed in claims 21 to 23 wherein said apparatus incorporates the attachment apparatus of any of claims I to 17.