GB2356233A - Device for connecting sections of a pipeline - Google Patents

Abstract

A device 1 is used for the connection of a pipe section 23 to a connection site, eg another pipe section 22, on the seabed 21. The device comprises an element, preferably a sleeve 29, movable in a longitudinal direction along the pipeline 23 and provided towards the end of this pipeline. The device 1 also includes a guide-in tool comprising retention means, preferably in the form of a guide-in tunnel 6, which receives the sleeve 29, and a guide-in shoe 8 which grips and guides the end of the pipeline 23 in towards the connection site 22 whilst the sleeve 29 is retained in the guide-in tunnel 6. A pull-in device 4,39 acts on the sleeve 29 in order to pull the end of the pipeline 23 towards the connection site 22. The sleeve 29 may be rotatable about the pipeline 23, and the pipeline may comprise a conical portion 26, the sleeve fitting over the conical portion in order to centrally align the pipeline 23 in the sleeve. A connecting device is also disclosed in which the sleeve, pull-in device and guide-in tunnel are dispensed with (figures 16 to 19).

Description

2356233 A pipeline device, a tool for the guide-in of a pipeline end and a

method for the pull-in of a pipeline end The present application relates to equipment and methods for connecting pipeline sections on the seabed, or to be more precise, a pipeline device according to the preamble of claim 1, a tool according to the preamble of claim 8, and a method according to the preamble of claim 11.

One of the objects of the present invention is to reduce the weight and size of the equipment used to connect and disconnect pipeline sections on the seabed.

Another object of the present invention is to make the equipment used during the connection cheaper and simpler, A further object of the present invention is to make the procedure for connection and disconnection of pipeline sections simpler and faster.

As will be understood after a perusal of the following description, the aforementioned and other advantages are achieved according to the invention by the characterising features which are disclosed in claims 1, 8 and/or 11.

The present invention will now be explained in more detail with reference to the accompanying figures, wherein:

Fig. I shows an embodiment of a pull-in, guide-in and tie-InJconnection tool according to the invention; Fig. 2 shows a detail of the pipe termination according to the invention with the movable sleeve in a pull-in position-, Fig. 3) shows a detail of the pipe termination according to the invention with the movable sleeve in a connection position; Fig. 4 shows the guide-in and tie-in tool according to Fig. I seen in the direction of the arrow B in Fig. 1; Fig. 5 is a sectional view along the line V-V in Fig. I seen in the direction of the arrow B; Figs. 6, 7 and 8 show the pull-in of the pipe termination with the aid of a sling-like wire, 2 in section and in three steps; Fig. 9 shows a first step in the pull-in of a pipe termination wherein the pipe termination is a relatively short distance from the connector; Fig. 10shows the securing of the pipe termination in the guide-in tunnel-, Fig. I I shows the guide-in and alignment of the pipe termination relative to the connector; Fig. 12 shows the pipe termination fully connected to the connector; Fig. 133 shows the pull-in of the pipe termination when this is at a relatively long distance from the connector; lo Fig. 14shows the pull-in of the pipe termination with hoist connection- , Fig. 15 shows the securing of the pipe termination to the guide-in tunnel-, Fig. 16 shows an instance where the pipe termination is at a very small distance from the connector and where the centre line of the pipe termination is in alignment with the centre line of the connector, Fig. 17 shows the tie-in unit in use together with a simplified guide-in unit but without the use of the pull-in unit; Fig. IS shows connection with the aid of the unit according to Fig. 17; and Fig. 19 shows a completed connection.

Fig. I shows a pull-in, guide-in and tie-in tool I according to the invention (hereinafter called the tool). It consists in general of a pullin unit 2, comprising a pull-in winch 3 and a pull-in wire 4, a guide-in unit 5 comprising a guide-in tunnel 6, one or more guide-in cylinders 7 and a guide-in shoe 8, and a tie-in unit 9, which includes inter alia a torque tool 10 for affixing a connector 11.

Figs. 4 and 5 show the guide-in and tie-in tool I according to the invention seen respectively from the end in the direction of the arrow B in Fig. I and in a section along the line V-V in Fig. 1, also in the direction of the arrow B. The tool I also comprises a frame 12 for the guide-in unit and a frame 13 for the tie-in unit 9. The frame 12 is equipped with a platform 14 on which to land a ROV, and close to the platform 14 there is arranged a ROV panel 15, from where a ROV (not shown) can operate the tool 1. The whole tool I can be lowered down from a service vessel (not shown) -with the aid of a lifting wire 16 and in part be guided with the aid of a guide wire 17 and/or the said ROV.

The tool I also comprises guide sleeves IS, which can be passed down over conical stabbing guides (19) (see Fig. 12) on a platform 20 on the seabed 2 1.

The platform 20 forms a foundation for a pipe end 22, which is to be connected to another pipe end 23, equipped with a pipe termination 24. In Fig. 1 the pipe termination 24 is shown in two positions, a first position lying on the seabed 21 and a 5 second position pulled into the guide-in tunnel 6.

In Figs. 2 and 3 the pipe termination 24 is shown in more detail. It comprises a pipe section 25 equipped with a guide-in cone 26 and a guidein collar 27. At the outermost end of the pipe section there is also arranged a connection flange 28. Around the pipe io section 25 there is arranged a movable guide-in sleeve 29, which at its outer end 30 is equipped with an internal ring 3 1, whose internal diameter is adapted to the outer diameter of the pipe section 25. At its inner end 32 the sleeve 29 is equipped with an internal ring 33, whose internal diameter corresponds to the diameter at a point on the cone 26. About haffivay along the movable sleeve 29 there is arranged a hook 34. The diameter of the rings 31 and 32 are adapted to the diameter of the pipe section 25 so as to enable the sleeve 29 to rotate freely on the pipe section 25. The cone 26 is equipped with a stop collar 3 5, which restricts the movement of the sleeve 2 9 towards the cone 26, whilst the movement of the sleeve 29 towards the outer end of the pipe termination is restricted by the guide- in collar 27.

The sleeve 29 does not necessarily need to be made in the shape of a circular cylinder. It may also conceivably be a single ring, consist of several interconnected rings or be made in the form of a slide which is movable in a groove on the pipe termination 24. For the sake of simplicity, hereinafter this element is referred to as sleeve.

A first procedure for use of the tool according to the invention will now be explained with reference to Figs. 9-12, where the tool I is to form a connection between two pipeline sections 22 and 23.

In Fig. 9 the pipe termination 24 is lying on the seabed 21 at a relatively short distance from the pipe end 22. The guide-in and tie-in tool 1 according to the invention is first lowered down to the platform 20 and positioned with the aid of the conical stabbing guides 19. A ROV (not shown) pulls an outer end of the pull-in wire 4 down to the hook 34 on the sleeve 29. The winch 3 is then set in rotation and pulls in the wire 4 so 35 that the pipe termination 24 is pulled in towards the guide- in unit 5. At the same time the sleeve 29 is urged towards the guide-in collar 27.

4 When the pipe termination 24 has reached the position shown in Fig. 10, where it is right inside the guide-in tunnel 6, the winch 3 is stopped. The sleeve 29 is now pushed right against the guide-in collar 27. The sleeve 29 is now retained in the guide-in tunnel 6, whilst the guide-in shoe 8 grips the guide-in collar 27. The guide-in cylinders 7 are now set in motion and push the guide-in shoe 8 towards the pipe end 22 until the flange 27 is inside the connector 11. During the guide-in, the cone 26, in interaction with the guide-in shoe 8, will help to align the termination 24 correctly relative to the connector I I so that the centre line of the termination 24 is in alignment with the centre line of the connector 11. The winch 3 thus need not take up great aligning forces, as io these are taken up by the guide-in tunnel 6, the guide-in shoe 8 and the guide-in cylinders 7.

In Fig. I I the flange 28 has been pushed right inside the connector I I and the guide-in cylinders 7 are stopped. Now the connector torque tool 10 in the tie-in unit 2 comes into function and in a conventional manner tightens the connector around the flange 28 and the corresponding flange (not shown) on the pipe end 22.

The tool I is then released from the pipeline and the connection is complete, as shown in Fig. 12.

A second procedure for forming a connection between two pipeline sections 22, 23 will now be explained with reference to Figs. 13-15.

In Fig. 13 the pipe termination 24 is at a greater distance from the pipe end 22. This also means that there may be a greater deviation between the centre line of the pipe termination 24 and the centre line of the pipe end 22. A ROV will first pull the wire 4 to the hook 34 on the sleeve 29, in the same way as explained above in connection with Figs. 9 -12. A ROV is then guided to grip a section 36 of the wire 4 which is between the winch 3 and a guiding sheave 37. The section 36 is pulled towards a second hook 38 on the sleeve 29. The winch 3 is thus provided with triple pull-in force, as now two pulling cables are formed between the pipe termination 24 and the guide-in and tie-in tool 1, in the same way as with a hoist (see Fig. 14). Now the winch is set in rotation and, as described above, pulls the pipe termination 24 towards the pipe end 22 with increased pullin force. In this way even large deviations between the centre line of the termination 24 and the centre line of the connector I I can be overcome using a relatively weak winch. This arrangement of the wire 4 can be maintained right up until the pipe termination 24 has been pulled inside the tunnel 6 (see Fig. 15). The further progression is as described under Figs. I I and 12.

A third procedure for tie-in of a connection between two pipe line sections is shown in Figs. 16 - 17. This procedure is used for an intermodular connection, where the pipeline sections are at a very small distance from one another, Fig. 16 shows a situation where the pipe termination 24 is at a very small distance from the connector 11. In this case no movable sleeve 29 is arranged on the pipe termination 24, but it may be present without having any appreciable effect on the procedure. The situation shown in Fig. 16 may exist, e.g., when a valve in the pipeline is to be removed and replaced with a new one. In this case there is no need for the pull-in unit and a simpler version of the guide-in unit can be used, which does not comprise a guide-in tunnel, but does comprise guide-in shoe 8 and guide-in cylinders 7. The frame 5 can therefore be removed and optionally replaced by a smaller and lighter frame 42. Nor is the winch 3 required for an intermodular connection of this kind, and may optionally also be removed.

In Fig. 17 the remaining tie-in unit is lowered into place for connection of the pipeline.

The guide-in shoe 8 then grips the collar 27 and the guide-in cylinders 7 are actuated to guide the flange 28 into the connector 11, as shown in Fig. 18.

Fig. 19 shows the completed connection.

The tool according to Figs. 17 and 18 may also be used to disconnect pipeline sections from one another. In such a case the tool I is lowered into place on the platform 20, the connector torque tool 10 opens the connector I I and the guide-in shoe 8 grips the guide-in collar 27, whereupon the guide-in cylinders 7 are actuated in order to pull the guide-in shoe 8 and guide-in collar 27 away from the connector 11.

The tool I according to Figs. 17 and 18 can be used in a fourth tie-in procedure, which can be used especially when laying a new pipeline, where a situation exists wherein a pipeline section, which may be an already existing pipeline 22, Is on the seabed, and a second pipeline section 23, including its termination 24, which is to be connected to the 35 pipeline section 22 on the seabed, is at the surface, e.g., on board a pipe laying vessel (not shown), 6 According to this procedure, the tool I is affixed to the pipe termination 24 whilst still at the surface, e.g., whilst the pipe termination 24 is on board the vessel. The guide-in shoe grips the guide- in collar so that the pipe termination 24 and the tool I can be lowered together to the seabed. Here the tool I is lowered with its guide sleeves IS over the conical stabbing guides 19 of the platform 20. Thus, the situation accordinc, to Fig. 17 will be reached and the connection can take place in the same way as mentioned above in connection with Figs. 17 -19.

According to this procedure, the connector I I may already be on the pipeline section 22 io at the seabed or is carried down whilst retained by the tool 11.

In the aforementioned procedure the laying of a new pipeline can take place at a substantially higher speed. Today, the termination of a new pipeline would have to be laid at a reasonable distance from the pipeline section to which it is to be connected.

The tie-in tool must then be lowered and a ROV must make the connection between the tool and the pipe termination. This also involves a search operation for the ROV, which must find the pipe termination. After the connection between the tool and the pipe termination has been made, the pull-in and alignment can begin. With the aforementioned procedure and the aforementioned tool according to the invention, several of these steps can be omitted. The connection may therefore take place considerably faster and without any need for a separate tool for lowering the pipe termination to the seabed.

Figs. 6, 7 and 8 show another pull-in device which can be used if it is not possible to pull the pipe termination 24 all the way inside the guide-in tunnel 6 with the aid of the winch 3. Figs. I and 4 show two so-called sling wires 39 which are connected at one end thereof to a sling cylinder 40. Figs. 6, 7 and 8 show this more clearly in a section.

In Fig. 6 the pipe termination 24 has been pulled almost inside the guidein tunnel 6. A ROV fetches the outer end of a sling wire 3)9, guides it around the pipe termination 24 and fastens it in a receiving member 41 on the opposite side of the guide- in tunnel to the sling cylinder 40, as shown in Fig. 7. The sling cylinder 40 is then actuated, as shown in Fig. 8, and the pipe termination 24 is pulled right inside the guide-in tunnel 6. Preferably, at least- two sling wires are provided, but is some cases one wire may in fact be sufficient.

By means of the device according to the present invention it is possible to reduce substantially the size of the winch used. The winch need no longer take up large guide- 7 in forces, and can therefore be adapted so that it is merely capable of pulling the pip eline into the immediate vicinity of the gulde-in tunnel. The actual guide-in and alignment of the pipe termination 24 takes place without the winch being loaded to any appreciable extent. This means that a lighter winch may be chosen. As a li liter and g smaller winch is used, the whole tool can also be proportioned to be lighter and the tool is thus more manoeuvrable, requires less powerful lifting tackle and can be operated by a smaller vessel than has been possible hitherto.

With lighter and smaller tackle, the pull-in, guide-in and tie-in process can be io performed more speedily and readily than with conventional connection tools.

8

Claims (1)

1. Claims:

   1. A tool for guiding a pipeline end section towards a connection site, wherein the tool comprises means for retaining an element relative to the connection site, the element being positioned on the pipeline end section so as to be longitudinally movable relative thereto, and wherein the tool comprises a guide-in shoe for gripping and guiding the end of the pipeline towards the connection site whilst the element is retained relative to the connection site in the retaining means.

   2. A tool according to claim 1, when used with a pipeline end section which comprises a conical portion acting as a centering means f6r the pipeline end section relative to the longitudinally moveable element during guide- in.

   3. A tool according to claim I or claim 2, comprising a first wire attached to a winch for retaining the element in the retaining means.

   4. A tool according to claim 1, 2 or 3, comprising a second wire which extends from one side of the retaining means, around and under the element to the other side of the retaining means to retain the element in the retaining means.

   9 5. A tool according to any one of the preceding claims, wherein the element is a sleeve and the retaining means comprises a guide-in tunnel in which the sleeve is retained.

   6. A tool for the guiding of a pipeline end towards a connection site substantially as herein described with reference to the accompanying drawings. 7. A method for pulling a pipeline end section into a tool and for guiding 10 the pipeline end section towards a connection site on the seabed, wherein an element, which is movable in the longitudinal direction of the pipeline, provided at the pipeline end section, is retained in a retaining means, and that a guide-in shoe grips the pipeline end section and guides the pipeline end section towards the connection site, whilst the element is retained relative to 15 the connection site. 8. A method according to claim 7, wherein an outer end of a first wire attached to a winch is connected to a hook attachment means on the pipeline end section, and the winch pulls the pipeline end section towards the retaining 20 means on the tool.

   9. A method according to claim 8, wherein the pipeline end section is axially aligned relative to the connection site at the same time as the guide-in shoe guides pipeline end section towards the connection site.

   10. A method of connecting or disconnecting a pipeline end to another pipeline end substantially as herein described with reference to the accompanying drawings. 11. A tool for the guide-in of a pipeline end towards a connection site, 10 characterised in that it comprises a guidein tunnel which is adapted to receive a sleeve positioned on the end of the pipeline so as to be longitudinally movable, and that the tool comprises a guide-in shoe for gripping and guiding the end of the pipeline in towards the connection site whilst the sleeve is retained in the guide-in tunnel. 15 12. A tool according to claim 11, characterised in that it comprises a wire attached to a winch to retain the sleeve in the tunnel. 13. A tool according to claim I I or 12, characterised in that it comprises a 20 wire which extends from one side of the tunnel, around and under the sleeve to the other side of the tunnel to retain the sleeve.

   11 14. A method for the pull-in of a pipeline end in a tool and for guiding the pipeline end in towards a connection site on the seabed, characterised in that an outer end of a first wire attached to a winch is passed to a hook attachment means on the end of the pipeline, that the winch pulls the pipeline end in towards a guide-in tunnel on the tool, that an element, movable in the longitudinal direction of the pipeline, provided at the end of the pipeline, is retained in the guide-in tunnel, and that a guide-in shoe grips the pipeline end and shifts this towards the connection site, whilst the movable element is retained relative to the connection site.

   15. A method according to claim 14, characterised in that the end of the pipeline is centred relative to the connection site at the same time as the guide-in shoe shifts the end of the pipeline towards the connection site.

   16. A pipeline device, comprising at least one end for connection to a connection site, eg on another pipeline, on the seabed, characterised in that there is provided at the end of the pipeline an element, movable in the longitudinal direction of the pipeline, on which element a pull-in device is arranged to act in order to pull the end of the pipeline towards the connection site.

   17. A device according to claim 16, characterised in that the movable element is a sleeve which encircles the pipeline at the end thereof and is 12 movable over a limited section between a collar close to the end of the pipeline and a stop collar at a greater distance from the end of the pipeline.

   18. A device according to one of the preceding claims, characterised in that the element (the sleeve) is arranged so as to be capable of rotation around the longitudinal axis of the pipeline.

   19. A device according to one of claims 17-18, characterised in that a conical portion is provided on the pipeline in connection with the stop collar, that the sleeve during guide-in of the end of the pipeline towards the connection site is adapted to enter the conical portion, and that the end of the pipeline is thereby centred relative to the sleeve.

   20. A device according to one of claims 17-19, characterised in that the sleeve is equipped with an internal ring at its end closest to the end of the pipeline and an internal ring at its end furthest from the pipeline end.

   21. A device according to claims 17-19, characterised in that the sleeve is equipped with at least one hook approximately in the centre of its length onto which a pull-in wire can be hooked.

   13 22. A device according to claim 21, characterised in that the sleeve is equipped with another hook onto which a loop of pull-in wire can be hooked, to permit pull-in with triple pull-in force.

   23. A tool for use in connecting a first pipeline end to a second pipeline end comprising means for gripping the first pipeline end, means for positioning the two pipeline ends in axial alignment but axially spaced apart, and means for moving the gripping means such that, in use, the first pipeline end is moved thereby axially towards the second pipeline end. 10 24. A method of connecting a first pipeline end to a second pipeline end comprising moving the first pipeline end into axial alignment with the second pipeline end but axially spaced apart therefrom, for example using a winch, gripping the first pipeline end with a ripping means and moving the gripping 15 means, for example by actuating by piston and cylinder means, to cause the first pipeline end to be moved axially towards the second pipeline end into a position relative thereto for connection thereto. 25. A pipeline device for the end of a pipeline substantially as herein 20 described with reference to the accompanying drawings.