NL2020187B1

NL2020187B1 - A method of laying a pipeline by reel-lay.

Info

Publication number: NL2020187B1
Application number: NL2020187A
Authority: NL
Inventors: Jan Kernkamp Arend
Original assignee: Heerema Marine Contractors Nl
Priority date: 2017-12-27
Filing date: 2017-12-27
Publication date: 2019-07-02

Abstract

The invention relates to a method of laying a pipeline by reel-lay, the method comprising manufacturing at least one coiled pipeline unit at a spoolbase, comprising joining individual pipelines into a pipeline unit and winding said pipeline unit around a temporary reel into the coiled pipeline unit; securing the coiled pipeline unit in the coiled shape with a coil retaining unit; removing the coiled pipeline unit from the temporary reel; transferring the at least one coiled pipeline unit without the temporary reel onto a pipeline laying vessel, directly or indirectly via a transport vessel , the pipeline laying vessel comprising a reeling assembly comprising a lay reel; positioning the coiled pipeline unit on the lay reel; reeling the coiled pipeline unit with the reeling assembly into the water and lowering the pipeline towards the seabed.

Description

Title: A method of laying a pipeline by reel-lay.

FIELD OF THE INVENTION

The invention relates to a method of laying a pipeline by reel-lay. The invention further relates to a coiled pipeline unit for offshore pipeline laying. The invention also relates to a combination of a pipeline laying vessel and/or a transport vessel and multiple coiled pipeline units. The invention yet further relates to a pipeline laying vessel comprising a reeling assembly for reeling a coiled pipeline of a coiled pipeline unit into the water and onto a seabed. The invention further relates to a spoolbase for manufacturing the coiled pipeline unit.

BACKGROUND OF THE INVENTION

In the field of offshore pipeline laying, there are several types of laying, e.g. J-lay, S-lay and reel-lay. When using the reel-lay type, a reel with reeled pipeline is provided on a pipeline laying vessel. In order to lay the pipeline on the seabed, the pipeline is reeled from the reel, straightened and subsequently guided into the water towards the seabed. This way, high laying speeds can be achieved.

There are reel-lay vessels with one or more reels that are rigidly connected to the vessel. Other vessels use reels that can be exchanged by lifting empty or full reels to or from the vessel. Once the pipeline is completely reeled from the reel, the vessel either has to sail to a spoolbase to spool on a new length of pipe, or the empty reel is replaced with a new reel provided with new pipeline. As the pipelaying projects often span several hundreds of kilometres, a large number of trips or reels with pipeline may be required. For vessels that work with exchangeable reels this means than in order to have a continuous supply of reels with pipeline, a large number of reels may be required. This is expensive, as reels itself are expensive.

The pipelines are manufactured at a spoolbase, where individual pipeline units of a certain length, e.g. 6, 12 or 18 meters, are welded together into stalks, or pipeline units, of up to several kilometres. The stalks are then reeled on a reel which is provided on a pipeline laying vessel, or on a transport vessel. Longer stalks mean that a more efficient spooling process can be obtained as a minimum of so called tie-in welds need to be performed in critical time. As the stalks preferably have a length of several hundreds of meters up to several kilometres, the spoolbase has to be able to accommodate such lengths. It is hard for pipeline laying companies to find a suitable location for such a spoolbase, because of these lengthy stalks.

Because the travelling time of the reel between the spoolbase and the installation location can be time consuming, the spoolbase is preferably close to the pipelaying project location. When a company thus has multiple projects all over the world, it also needs spoolbases all over the world.

When the stalks are reeled, or spooled, on the reel at the spoolbase, the pipeline laying or transport vessel sails to the pipelaying location. In case of the transport vessel, the reels with pipeline are transferred onto the pipeline laying vessel. Empty reels are transferred from the pipeline laying vessel onto the transport barge. The transport vessel then sails back to the spoolbase to reel new pipeline stalks on the empty reels. This method is repeated until the project is finished.

The invention is based on the insight that there is a need for a more efficient method of laying pipeline by reel-lay.

SUMMARY OF THE INVENTION

In a first aspect, the invention has as objective to provide an improved method of laying a pipeline by reel-lay. This objective is achieved by a method, said method comprising: a) manufacturing at least one coiled pipeline unit at a spoolbase, comprising joining individual pipelines into a pipeline unit and winding said pipeline unit around a temporary reel into a coiled pipeline unit, b) securing the coiled pipeline unit in the coiled shape with a coil retaining unit, c) removing the coiled pipeline unit from the temporary reel, d) transferring the at least one coiled pipeline unit without the temporary reel onto a pipeline laying vessel, directly or indirectly via a transport vessel, the pipeline laying vessel comprising a reeling assembly comprising a lay reel, e) positioning the coiled pipeline unit on the lay reel, f) reeling the coiled pipeline unit with the reeling assembly into the water and lowering the pipeline towards the seabed.

An advantage of the method is that coiled pipeline units are manufactured at the spoolbase and are ready to be transferred on the transport vessel or a pipeline laying vessel upon arrival of these vessels. This way, the vessels do not have to wait until the pipeline is reeled on the reels provided on said vessels. This results in time savings, and thus a more efficient method of laying pipeline by reel-lay.

Another advantage of the method is that fewer reels are necessary. Only one reel is required which is located on board of the pipeline laying vessel, and one reel which is located on the spoolbase. The reel on the vessel does not need to be transferred to and from the spoolbase. This way, less transporting costs need to be made as only the coiled pipeline units need transporting. When the pipeline is transported when reeled on the reel, the reel amounts to a big part of the total weight. As cranes have a maximum lifting capacity, more pipeline can be transported using the method according to the invention compared to when also the reel is transported. As more pipeline can be transported per shipment, this leads to a more efficient method of laying pipeline by reel-lay.

Yet another advantage of the method is that the spoolbase schedule is decoupled from the transport schedule due to the possibility to pre-fabricate the coiled pipeline units. The spoolbase is thus therefore removed from the critical path of the pipeline laying process. Logistic planning becomes easier, as the spoolbase can build up more stock.

Another advantage of this concept is that a smaller spoolbase can be used, which makes it easier to find a suitable location for the spoolbase.

Furthermore, pipeline laying by reel-lay according to the method is less dependent on the location of spoolbase, as the spoolbase can build up a stock of coiled pipeline units. A single strategic located spoolbase, or a limited number of spoolbases, suffices, resulting in no recurring spoolbase set-up costs at locations all over the world.

In an embodiment of the method, the coiled pipeline unit is first positioned, in particular stored, in a horizontal orientation or first inclined orientation on the pipeline laying vessel and subsequently pivoted to a second inclined orientation on the lay reel for reeling the pipeline, the second inclined orientation being more inclined relative to the horizontal orientation than the first inclined orientation.

The horizontal orientation has as an advantage that when storing the coiled pipeline unit on the vessel, seafastening is easier compared to seafastening the coiled pipeline unit in a vertical orientation. In the horizontal orientation, i.e. on a flat side, the coiled pipeline unit is already in a more stable position as the center of gravity is located at a lower point. The horizontal orientation further has as advantage that multiple coiled pipeline units may be stacked on top of each other, thereby providing efficient storage.

In an embodiment of the method, the second inclined orientation on the lay reel for reeling the pipeline is substantially vertical.

An advantage of pivoting the lay reel to the vertical orientation, is that a pipeline laying vessel which currently has laying devices configured for vertical reel-laying do not need extensive modifications.

Another advantage of laying pipe in the vertical orientation, is that the pipeline is bent in one plane. The pipeline is coiled by bending the pipeline units in a first plane. When the pipeline is reeled towards the seabed with the coiled pipeline unit in a horizontal orientation, the pipeline is also subject to bending in a second plane, the second plane being substantially perpendicular to the first plane. This may be less favourable with regard to stresses in the pipeline compared to laying pipe with the coiled pipeline unit in the vertical orientation.

In an embodiment of the method, the reeling assembly comprises: -a lay reel base connected to the hull, in particular the deck, of the pipeline laying vessel, -the lay reel pivotably connected to the lay reel base via a hinge, the lay reel having a horizontal or first inclined receiving position for receiving the coiled pipeline unit and a second inclined or vertical position for reel laying the coiled pipeline unit, the lay reel being pivotable between these positions, -a guide structure which defines a trajectory followed by the pipeline during the reeling thereof, step e) comprising: o positioning the coiled pipeline unit in a horizontal or first inclined orientation on the lay reel when the lay reel is in the receiving position, o pivoting the lay reel to the second inclined or vertical position for reeling the pipeline into the water.

This provides a simple construction for upending the coiled pipeline units.

In an embodiment of the method, after positioning the coiled pipeline unit on the lay reel the coil retaining unit is removed from the coiled pipeline.

In an embodiment of the method, the transport vessel and/or pipeline-laying vessel are configured to store multiple coiled pipeline units without any reel.

Storing multiple coiled pipeline units without any reel is more space and/or weight efficient than storing reels with reeled pipeline.

In an embodiment of the method, wherein the transport vessel and/or the pipeline laying vessel comprises a stack support for supporting a stack of coiled pipeline units in a horizontal orientation, and wherein a plurality of coiled pipeline units is stacked on top of each other on the stack support on board the transport vessel and/or on board the pipeline laying vessel.

In an embodiment of the method, an on-board crane which is provided on the pipeline laying vessel positions the coiled pipeline unit on the lay reel, and in particular moves the lay reel between the substantially horizontal or first inclined position and the second inclined or substantially vertical position.

In an embodiment of the method, the pipeline of the coiled pipeline unit has a length between 1km and 30km.

In an embodiment of the method, the pipe of the coiled pipeline unit has an outer diameter between 15 cm and 61 cm.

In an embodiment of the method, the lay reel comprises: -a first support part, in particular a support flange, configured to support a first flat side of the coiled pipeline unit, and -a central part (31) extending transversely from the first support part, the central part being configured to be positioned in a central opening (32) of the coiled pipeline unit and to engage an inner surface (33) of the coiled pipeline unit for restricting a radial movement of the coiled pipeline unit, wherein the central part defines a circular crosssection, the circular-cross section being configured to vary in order to receive or to engage the coiled pipeline unit.

In an embodiment, the central part has a truncated cone shape.

In an embodiment, the central part of the lay reel comprises first adjustable sections defining the circular cross-section and being configured to be movable, in particular radially movable, with respect to the first support part between an inner receiving position, wherein the first adjustable sections define a first outer diameter, and an outer engaged position for engaging the inner surface of the coiled pipeline unit, wherein the first adjustable sections define a second outer diameter, the second outer diameter being greater than the first outer diameter, the method comprising: a) positioning the lay reel in the horizontal or inclined receiving position, b) positioning the first adjustable sections in the inner receiving position, c) positioning the coiled pipeline unit around the central part, d) moving the first adjustable sections outward to the outer engaged position, e) pivoting the lay reel to the vertical reeling position.

An advantage of the lay reel comprising the first adjustable sections is that the outer diameter of the central part can be varied, such that coiled pipeline units with different inner diameters can be received and engaged, and thus reeled. The method is therefore less dependent on standardized reel diameters.

In an embodiment of the method, the lay reel further comprises a second support part configured to engage a second flat side of the coiled pipeline unit opposite to the first flat side when the coiled pipeline unit is positioned on the lay reel, thereby restricting an axial movement of the coiled pipeline unit in a direction away from the first support part, wherein prior to step e) of the previous method claim the second support part is moved from a disengaged position, wherein the second support part does not obstruct the positioning of the coiled pipeline unit, to an engaged position for engaging the second flat side. The engagement may however also be performed after pivoting the lay reel to the vertical reeling position.

In an embodiment of the method, wherein the temporary reel comprises a central member (41) defining a circular cross-section about which the pipeline unit can be coiled, wherein the circular-cross section is configured to vary in order to engage or to release the pipeline unit.

In an embodiment, the central member has a truncated cone shape.

In an embodiment of the method, the central member comprises second adjustable sections which together define the circular cross-section and are configured to be movable, in particular radially movable, between a coiling position and a transferring position, wherein in the coiling position an outer surface of the second adjustable sections engages an inner surface of the pipeline unit, and in the transferring position the outer surface of the second adjustable sections is released from the inner surface of the coiled pipeline, the method comprising: a) positioning the second adjustable sections in the coiling position, b) coiling the pipeline unit about the second adjustable sections in multiple layers in both an axial direction and a radial direction until the pipeline unit is coiled, c) positioning the second adjustable sections in the transferring position.

An advantage of the temporary reel is that due to the second adjustable sections coiled pipeline units requiring different reel drum diameters may be manufactured. A pipe having a large outer diameter may need a larger reel drum diameter for coiling compared to a pipe having a smaller outer diameter. The second adjustable sections provide this flexibility by allowing the circular cross-section of the reel drum to vary.

In an embodiment of the method, the coil retaining unit comprises multiple retaining members, the retaining members being provided at intervals around the coiled pipeline. The coil retaining units restrict a movement of the coiled pipeline.

The invention further relates to a coiled pipeline unit for offshore pipeline-laying, the coiled pipeline unit comprising a coiled pipeline being coiled in a radial direction and an axial direction and defining a central opening, and a coil retaining unit for retaining the coiled pipeline in a coiled configuration, wherein the coiled pipeline unit is free from a lay reel for reeling of the coiled pipeline.

An advantage of the coiled pipeline unit without the lay reel is that more coiled pipeline may be transported compared to when also the lay reel has to be transported.

In an embodiment of the coiled pipeline unit, the pipeline has been plastically deformed when it is spooled from a straight to the coiled configuration.

In an embodiment of the coiled pipeline unit, the retaining unit comprises a plurality of retaining members arranged at intervals around the coiled pipeline.

The invention further relates to a combination of a pipeline laying vessel and/or a transport vessel and multiple coiled pipeline units according to the invention, wherein the coiled pipeline units are arranged on a deck of the pipeline laying vessel and/or the transport vessel.

An advantage of the combination is that due to the absence of the reels, more coiled pipeline may be transported or stored.

In an embodiment of the combination, multiple coiled pipeline units are arranged side by side and lay on their flat side .

An arrangement on the flat side, or horizontally, of the coiled pipeline units provides more stability compared to a vertical arrangement, as the center of gravity is lower compared to when the coiled pipeline unit is arranged vertically. Sea fastening therefore becomes easier.

In an embodiment of the combination, multiple coiled pipeline units are stacked on top of each other. This provides an efficient way of storing.

The invention further relates to a reeling assembly for reeling a coiled pipeline of a coiled pipeline unit into the water and towards a seabed, the reeling assembly being configured to receive and support the coiled pipeline unit in a horizontal or inclined orientation, wherein the reeling assembly comprises: -a lay reel base connected to a hull, in particular a deck, of a pipeline laying vessel, -a lay reel connected to the lay reel base, the lay reel having a horizontal or first inclined position for receiving the coiled pipeline unit, -a guide structure which defines a trajectory followed by the pipeline during the reeling thereof.

An advantage of the horizontal or inclined orientation compared to a vertical orientation, is that it is easier to position the coiled pipeline unit on the lay reel by a crane.

In an embodiment of the reeling assembly, the guide structure is a tower or a stinger.

In an embodiment of the reeling assembly, the reeling assembly is configured to facilitate the reeling of the pipe of the coiled pipeline unit in a second inclined or substantially vertical position.

In an embodiment of the reeling assembly, the lay reel is pivotably connected to the lay reel base via a hinge, the lay reel having a horizontal or first inclined position for receiving the coiled pipeline unit and a second inclined or vertical position for reel laying the coiled pipeline unit, the lay reel being pivotable between these positions.

In an embodiment of the reeling assembly, the lay reel comprises: -a first support part configured to support a first flat side of the coiled pipeline unit, and -a central part extending transversely from the first support part, the central part being configured to be positioned in the central opening of the coiled pipeline unit and to engage an inner surface of the coiled pipeline unit for restricting a radial movement of the coiled pipeline unit, wherein the central part defines a circular cross-section, the circular-cross section being configured to vary in order to receive or to engage the pipeline unit.

In an embodiment of the reeling assembly, the central part of the lay reel comprises first adjustable sections defining the circular cross-section and being configured to be movable, in particular radially movable, with respect to the first support part between an inner receiving position, wherein the first adjustable sections define a first outer diameter and an outer engaged position for engaging the inner surface of the coiled pipeline unit, wherein the first adjustable sections define a second outer diameter, the second outer diameter being greater than the first outer diameter.

In an embodiment of the reeling assembly, the reeling assembly further comprises a second support part configured to be movable between a disengaged position, wherein the second support part does not obstruct the positioning of the coiled pipeline unit on the lay reel, and an engaged position, wherein the second support part engages a second flat side of the coiled pipeline unit when the coiled pipeline unit is positioned on the lay reel, thereby restricting an axial movement of the coiled pipeline unit in a direction opposite to the first support part.

The advantages of the second adjustable sections also apply to the first adjustable sections.

The invention further relates to a pipeline laying vessel comprising the reeling assembly.

An advantage of the pipeline laying vessel with the reeling assembly is that the reeling assembly may remain on board during pipeline laying. Another advantage is that only one reeling assembly suffices without compromising on pipelaying speed. It will be understood that more than one reeling assembly can be used to further optimize the pipelay method.

In an embodiment of the pipeline laying vessel, the pipeline laying vessel comprises an onboard crane, wherein the crane is configured to lift the coiled pipeline unit onto the lay reel, wherein the lay reel is configured to receive and to support the coiled pipeline unit and to facilitate the reeling of the pipeline of the coiled pipeline unit.

In an embodiment of the pipeline laying vessel, the pipeline laying vessel comprises a storage for accommodating at least one coiled pipeline unit, and wherein the crane is configured to transfer the at least one coiled pipeline unit from the storage onto the lay reel.

In an embodiment of the pipeline laying vessel, the storage is configured to accommodate multiple coiled pipeline units which are stacked on top of each other.

The invention further relates to a spoolbase for manufacturing the coiled pipeline unit according to the invention, the spoolbase comprising: -a rotatable temporary reel comprising a central member defining a circular crosssection about which the pipeline unit can be coiled, wherein the circular-cross section is configured to vary in order to engage or to release the pipeline unit, -a temporary reel drive for rotating the temporary reel and coiling the pipeline unit about the temporary reel in multiple layers in both an axial direction and a radial direction, -a tensioning member for applying back tension on the pipeline during coiling of the pipeline on the temporary reel.

In an embodiment of the spoolbase, the central member comprises second adjustable sections which together define the circular cross-section and are configured to be movable, in particular radially movable, between a coiling position and a transferring position, wherein in the coiling position an outer surface of the second adjustable sections engages an inner surface of the pipeline unit, and in the transferring position the outer surface of the second adjustable sections is released from the inner surface of the coiled pipeline.

An advantage of the spoolbase is that the coiling position of the rotatable temporary reel may be varied, thereby allowing the manufacturing of coiled pipeline units with different inner diameters. The coiled pipeline units can be customized depending on the properties, e.g. outer diameter, wall thickness, or coating material and dimensions, of the pipe to be coiled.

Furthermore, the preparation of stalks of several kilometres to optimize the spooling time required may not be necessary, as the coiled pipeline units are pre-fabricated and thus decoupled from the vessel schedule. Therefore, a smaller spoolbase may suffice, which is easier to find than stretches of land of several kilometres long.

Is also becomes easier to assemble separate coils with shorter lengths of coiled pipe, resulting in more customizable coiled pipeline units.

In an embodiment, the spoolbase further comprises a transfer assembly for transferring the manufactured coiled pipeline unit from the temporary reel, when the temporary reel is in the transferring position to a storage location on shore or on a transport vessel or pipeline laying vessel.

In an embodiment of the spoolbase, the transfer assembly is a lifting assembly, in particular a crane, for lifting the coiled pipeline unit from the temporary reel.

In an embodiment of the spoolbase, the temporary reel comprises second adjustable sections which together define the circular cross-section and are configured to be radially movable between the coiling position and the transferring position, wherein the circular crosssection of the coiling position is greater than the circular cross-section of the transferring position.

In an embodiment, the spoolbase further comprises a guiding member for guiding the pipe during coiling in an axial and radial direction, the guide member being movable in axial direction and radial direction relative to the temporary reel. Such a guiding member is known in the art as a level winder.

In an embodiment, the spoolbase further comprises a retaining unit for installing on the coiled pipeline, for retaining the coiled pipeline unit in the coiled configuration.

BRIEF DESCRIPTION OF THE FIGURES

Embodiments of the system and the method will be described by way of example only, with reference to the accompanying schematic drawings in which corresponding reference symbols indicate corresponding parts, and in which:

Figure 1A schematically shows a method of laying a pipeline by reel-lay according to the prior art,

Figure 1B schematically shows a method of laying a pipeline by reel-lay according to a first aspect of the invention,

Figure 2A schematically shows a perspective view of a combination of a vessel and reeled pipe according to the prior art,

Figure 2B schematically shows a perspective view a combination according to a second aspect of the invention of a transport vessel and a coiled pipeline unit according to a third aspect of the invention,

Figures 3A and 3B schematically show a perspective view of a lay reel which is provided on a pipeline laying vessel according to a fourth aspect the invention,

Figure 4 schematically shows a side view of the upending of a lay reel,

Figure 5 schematically shows a spoolbase according to another aspect of the invention, Figure 6 schematically shows an embodiment of the spoolbase of figure 5,

Figure 7 schematically shows a top view of an embodiment of the spoolbase of figure 5.

DETAILED DESCRIPTION OF THE FIGURES

Turning to figure 1A, a method of laying a pipeline by reel-lay according to the prior art is shown. Four boxes 101, 102, 103, 104 with dashed lines represent a series of steps that are usually performed when laying pipeline using reel-lay in an order as shown by arrow 105.

The first box 101 shows a first phase, wherein pipeline sections 106 are joined in order to form stalks 107 of a length in the order of several hundreds of meters up to 1km or even more. The pipeline sections 106 and stalks 107 are manufactured on shore. Said stalks 107, which are located on a quay 108, are then reeled on a reel 109 which is fastened on a transport vessel 110. The reeling is performed by turning the reel 109 in a reel direction 111. The transport barge is connected to a tugboat 112. The tugboat has to wait until the stalks are reeled on the reels before it may go. This is a time consuming process.

Turning to the second box 102, the tugboat 112 is shown transporting two reeled pipeline units 113 with the transport vessel 110. The reels comprising the two reeled pipeline units 113 are transported vertically.

Third box 103 shows the transport vessel 110 being positioned next to a pipeline laying vessel 114. The two reels 109 comprising the reeled pipeline units are transferred onto the pipeline laying vessel 114. Two empty reels 115 are transferred from the pipeline laying vessel 114 onto the transport vessel 13. The reels comprising the two reeled pipeline units are stored vertically on the pipeline laying vessel. The pipeline laying vessel 114 can now continue laying pipeline on a seabed.

The transport vessel 110 comprising the two empty reels 115 is transported back to the quay. This is shown in the fourth box 104. The empty reels are then reused by reeling on new stalks 107 and the method is repeated.

Turning to figure 1B, a method of laying a pipeline by reel-lay according to the invention is shown. The method comprises: a) manufacturing at least one coiled pipeline unit 5 at a spoolbase 6, comprising joining individual pipelines 7 into a pipeline unit 8 and winding said pipeline unit 8 around a temporary reel 9 into a coiled pipeline unit 5, b) securing the coiled pipeline unit 5 in the coiled shape with a coil retaining unit 10 (figure 2B), c) removing the coiled pipeline unit 5 from the temporary reel 9, d) transferring, as indicated by arrows 11, the at least one coiled pipeline unit 5 without the temporary reel 9 onto a pipeline laying vessel 12, directly or indirectly via a transport vessel 13, the pipeline laying vessel 12 comprising a reeling assembly 14 comprising a lay reel 15, e) positioning the coiled pipeline unit 5 on the lay reel 15, f) reeling the coiled pipeline unit 5 with the reeling assembly 14 into the water and lowering the pipeline to the seabed.

The pipe is made of a metal, in particular steel. The pipeline may be coated. The pipeline of the coiled pipeline unit 5 has a length between 1km and 30km. The pipe of the coiled pipeline unit 5 has an outer diameter between 15 cm and 61 cm. The coiled pipeline unit 5 has a mass between 500mT and 9000mT.

So in figure 1B a first box 1 shows how first the coiled pipeline unit 5 is manufactured after which the coiled pipeline unit 5 is transferred onto the transport vessel 13 by a crane 16. Equipment other than a crane 16 may also be used for transferring the coiled pipeline unit 5 onto the transport vessel 13. The coiled pipeline unit 5 may also be transferred directly from the spoolbase 6 onto the pipeline laying vessel 12. As shown, the coiled pipeline units 5 are positioned on their flat side, i.e. horizontally. When the transport vessel 13 is loaded with multiple coiled pipeline units 5, the transport vessel 13 is transported to the pipeline laying vessel 12, as shown in second box 2 and third box 3.

The transport vessel 13 and/or pipeline-laying vessel 12 are configured to store multiple coiled pipeline units 5 without any reel.

When the transport vessel 13 is positioned adjacent to the pipeline laying vessel, the coiled pipeline units 5 are transferred from the transport vessel 13 onto the pipeline laying vessel 12. Any remaining pipeline parts 17 may be transferred from the pipeline laying vessel 12 onto the transport vessel 13. So no reels are transferred, which is beneficial, as reels are heavy and usually amount to a big part of the total weight, in case the pipeline is transferred when reeled on a reel, as is done in the prior art.

The transport vessel 13 and/or the pipeline laying vessel 12 comprises a stack support 26 for supporting a stack 27 of coiled pipeline units 5 in a horizontal orientation, and wherein a plurality of coiled pipeline units 5 is stacked on top of each other on the stack support on board the transport vessel 13 and/or on board the pipeline laying vessel 12.

The coiled pipeline is then positioned on the lay reel 15 of the reeling assembly 14 which is provided on the pipeline laying vessel 12. So the coiled pipeline unit 5 is first positioned, in particular stored, in a horizontal orientation 18 on the pipeline laying vessel 12 and subsequently pivoted to a second inclined or vertical orientation 19 on the lay reel 15 for reeling the pipeline. This is shown in figures 3A and 3B, wherein the coiled pipeline unit 5 is first positioned on the lay reel 15 in a first inclined or horizontal orientation after which the lay reel 15 is pivoted. The second inclined orientation is more inclined relative to the horizontal orientation than the first inclined orientation. A guide structure 66 (figure 1B) is provided on the pipeline laying vessel. The guide structure in figure 1B is a tower which defines a trajectory followed by the pipeline 8 during the reeling thereof.

It is also possible to reel the pipeline in the horizontal orientation, so without pivoting to the vertical orientation. A stinger may be used to guide the pipeline when for example the water depths are too shallow for unspooling via a tower.

An on-board crane 20 which is provided on the pipeline laying vessel 12 positions the coiled pipeline unit 5 on the lay reel 15, and in particular moves the lay reel 15 between the substantially horizontal or inclined position and the substantially vertical position. The pivoting may also be performed by a hydraulic device or any other suitable arrangement. A hooking member 55 of the crane engages a lifting part 56 of the lay reel 15 and subsequently moves upward, thereby pivoting the lay reel 15 to the vertical orientation (figure 3B). The lifting part 56 is provided at an end of the lay reel 15 opposite to the hinge 24. This requires the least amount of lifting force.

As shown in figures 3A and 3B, the reeling assembly 14 comprises: -a lay reel base 21 connected to the hull 22, in particular the deck 23, of the pipeline laying vessel 12, -a lay reel 15 pivotably connected to the lay reel base 21 via a hinge 24, the lay reel 15 having a horizontal or first inclined receiving position for receiving the coiled pipeline unit 5 and a second inclined or vertical position for reel laying the coiled pipeline unit 5, the lay reel 15 being pivotable between these positions. -a guide structure 66 which defines a trajectory followed by the pipeline 8 during the reeling thereof.

The abovementioned step e) further comprises: o positioning the coiled pipeline unit 5 in a horizontal or inclined orientation on the lay reel 15 when the lay reel 15 is in the receiving position, o pivoting the lay reel 15 to the second inclined or vertical position for reeling the pipeline into the water and subsequently onto the seabed.

After positioning the coiled pipeline unit 5 on the lay reel 15 the coil retaining units 10 are removed from the coiled pipeline 47.

The lay reel 15 further comprises: -a first support part 28, in particular a support flange 29, configured to support a first flat side 30 of the coiled pipeline unit 5, and -a central part 31 extending transversely from the first support part 28, the central part 31 being configured to be positioned in a central opening 32 of the coiled pipeline unit 5 and to engage an inner surface 33 of the coiled pipeline unit 5 for restricting a radial movement of the coiled pipeline unit 5.

The central part 31 of the lay reel 15 comprises first adjustable sections 34 configured to be movable, in particular radially movable, with respect to the first support part between an inner receiving position 35, wherein the first adjustable sections 34 define a first outer diameter 36, and an outer engaged position 37 for engaging the inner surface 33 of the coiled pipeline unit 5, wherein the first adjustable sections 34 define a second outer diameter 38, the second outer diameter being greater than the first outer diameter.

In operation, the following steps are performed: a) positioning the lay reel 15 in the horizontal or inclined receiving position, b) positioning the first adjustable sections 34 in the inner receiving position 35, c) positioning the coiled pipeline unit 5 around the central part 31, d) moving the first adjustable sections 34 outward to the outer engaged position 37, e) pivoting the lay reel 15 to the vertical reeling position.

The lay reel 15 further comprises a second support part 39 configured to engage a second flat side 40 of the coiled pipeline unit 5 opposite to the first flat side 30 when the coiled pipeline unit 5 is positioned on the lay reel 15. The second support part 39 thereby restricts an axial movement of the coiled pipeline unit 5 in a direction away from the first support part. In operation, the second support part 39 is moved from a disengaged position 64, wherein the second support part does not obstruct the positioning of the coiled pipeline unit, to an engaged position 65 for engaging the second flat side 40 before the lay reel 15 is pivoted to the vertical reeling position, so before the abovementioned step e).

Figure 4 shows a side view of the reeling assembly 14. The coiled pipe is positioned on the lay reel 15. The retaining unit 10 is removed. The first adjustable sections 34 are in the outer engaged position 37. The first adjustable sections 34 are movable in an adjustable direction 57 to and from the inner receiving position 35. The second support part 39 is not yet positioned on the second flat side 40 of the coiled pipeline. This may be done either before or after pivoting the lay reel 15 to the vertical orientation. In the vertical orientation the second support part 39 is shown in the engaged position, thereby restricting the movement of the coiled pipeline in the direction perpendicular to the first support part 28.

For pivoting the coiled pipeline unit 5, the hooking member 55 of the crane provided on the pipeline laying vessel 12 is connected to the lifting part 56 of the lay reel 15. Then the crane lifts the lifting part 56, thereby pivoting the lay reel 15 about the hinge 24.

Figure 2A shows a combination of a transport vessel 110 and two reeled pipeline units 113. The pipeline units are reeled on reels 109 and transported as such. The reels 109 account for a large part of the total weight to be transported and transferred.

Figure 2B shows a combination 48 of a transport vessel 13 and multiple coiled pipeline units 5 according to the invention. The coiled pipeline units 5 are arranged on a deck 23 of the transport vessel 13. Instead of the transport vessel 13, a combination of a pipeline laying vessel 12 and multiple coiled pipeline units 5 is also possible.

An advantage of transporting only the coiled pipeline units 5, and not the reels as is done in the prior art, more coiled pipeline may be transported per shipment.

Multiple coiled pipeline units 5 are arranged side by side and lay on their flat side, i.e in a horizontal orientation. It may also be possible to stack multiple coiled pipeline units 5 on top of each other. This way it is possible to transport more coiled pipeline units 5 at once.

The third box 3 in figure 1B shows a pipeline laying vessel 12 comprising the reeling assembly 14 for reeling the coiled pipeline 47 of the coiled pipeline unit 5 into the water and onto the seabed. The reeling assembly 14 is configured to receive and support the coiled pipeline unit 5 in a horizontal or first inclined orientation, and to facilitate the reeling of the pipe of the coiled pipeline unit 5 in either the horizontal or first inclined orientation, or in the second inclined or vertical orientation.

The pipeline laying vessel 12 comprises an on-board crane 20. The on-board crane 20 is configured to lift the coiled pipeline unit 5 onto the lay reel 15. The lay reel 15 is configured to receive and to support the coiled pipeline unit 5 and to facilitate the reeling of the pipeline of the coiled pipeline unit.

The pipeline laying vessel 12 has a storage 50 for accommodating at least one coiled pipeline unit 5. The on-board crane 20 is configured to transfer the at least one coiled pipeline unit 5 from the storage 50 onto the lay reel 15.

The storage 50 may accommodate multiple coiled pipeline units 5 which are stacked on top of each other.

Turning to figure 5, an embodiment of a spoolbase 6 is schematically shown. The individual pipeline units 7 are joined by welding into a continuous pipeline unit 8. The pipeline unit 8 is coiled about a rotatable temporary reel 9.

The temporary reel 9 comprises a central member 41 defining a circular cross-section about which the pipeline unit 8 is coiled. The circular cross-section is configured to vary in order to engage or to release the pipeline unit. This may be done by providing a central member with a conical shape. It may also be done by providing the central member 41 with second adjustable sections 42 which together define the circular cross-section and are configured to be movable, in particular radially movable, between a coiling position 43 and a transferring position 44. In the coiling position 43 an outer surface 45 of the second adjustable sections 42 engages the inner surface 33 of the pipeline unit. In the transferring position 44 the outer surface 45 of the second adjustable sections is released from the inner surface 33 of the coiled pipeline.

In operation, this comprises the following steps: a) positioning the second adjustable sections in the coiling position 43, b) coiling the pipeline unit 8 about the second adjustable sections in multiple layers in both an axial direction and a radial direction until the pipeline unit 8 is coiled, c) positioning the second adjustable sections in the transferring position 44.

The spoolbase further comprises a temporary reel drive 59 (figure 6) for rotating the temporary reel 9 and coiling the pipeline unit 8 about the temporary reel 9 in multiple layers in both an axial direction and a radial direction. A tensioning member is provided for applying back tension on the pipeline during coiling of the pipeline on the temporary reel 9. Also coating facilities 61 may be provided at the spoolbase.

After coiling, retaining members 46 of the coil retaining unit 10 are provided at intervals around the coiled pipeline 47, for retaining the coiled pipeline unit 5 in the coiled configuration.

The coiled pipe unit 5 is then removed from the temporary reel 9. This way a coiled pipeline unit 5 is obtained which comprises a coiled pipeline being coiled in a radial direction and an axial direction and defining a central opening 32, and a coil retaining unit 10 for retaining the coiled pipeline in a coiled configuration, wherein the coiled pipeline unit 5 is free from a lay reel 15 for reeling of the coiled pipeline.

The spoolbase 6 further comprises a transfer assembly 62. The transfer assembly 62 may be a lifting assembly, in particular a crane 16, for lifting the coiled pipeline unit 5 from the temporary reel 9. The transfer assembly 62 may be a crane 16 as shown in figure 1B for transferring the manufactured coiled pipeline unit 5 from the temporary reel 9 when the temporary reel 9 is in the transferring position 44 to a storage location 63 on shore. The coiled pipeline units 5 may also directly be transferred onto the transport vessel 13.

Figure 6 shows in cross-section an embodiment of the rotatable temporary reel 9. A second adjustable section 42 is in the coiling position 43, thereby defining the circular cross-section. When the coiling has ended, the second adjustable section 42 is moved in a transferring direction 51 as indicated by the arrow . This way, the outer surface 45 of the temporary reel 9 is released from the inner surface 33 of the coiled pipeline. So the circular cross-section of the coiling position 43 is greater than the circular cross-section of the transferring position 44.

The spoolbase 6 further comprises a guiding member 52 for guiding the pipeline during coiling in an axial 53 and radial direction 54, the guide member being also movable in the axial direction 53 and radial direction 54 relative to the temporary reel 9.

Figure 7 schematically shows a top view of an embodiment of the rotatable temporary reel 9, in particular the different radial positions of the second adjustable sections 42. The dashed parts indicate the coiling position 43 from where the second adjustable section 42 moved in a radial direction to the transferring position 44. The second adjustable sections are driven by actuators 58. In figure 7 the pipeline unit 8 is coiled around the temporary reel 9 and retained in its coiled configuration by four retaining members 46. The second adjustment sections 42 radially move from the coiling position 43 to the transferring position 44 after the retaining member 46 are provided on the coiled pipeline. As the temporary reel 9 is now released from the inner surface 33 of the coiled pipeline unit 5, it is easier to remove the coiled pipeline unit 5 with a crane or any other lifting device.

The reel assembly provided on the pipeline laying vessel 12 may also comprise similar second adjustable sections 42 as first adjustable sections 34.

The lay reel and the temporary reel may have a conical shaped central part or central member, respectively. The conical shapes of the central part and the central member correspond with each other. This way, the coiled pipe unit may be easily transferred from the central member of the temporary reel, and positioned on the central part of the lay reel.

As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention, which can be embodied in various forms. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present invention in virtually any appropriately detailed structure. Further, the terms and phrases used herein are not intended to be limiting, but rather, to provide an understandable description of the invention.

The terms "a" or "an", as used herein, are defined as one or more than one. The term plurality, as used herein, is defined as two or more than two. The term another, as used herein, is defined as at least a second or more. The terms including and/or having, as used herein, are defined as comprising (i.e., open language, not excluding other elements or steps). Any reference signs in the claims should not be construed as limiting the scope of the claims or the invention.

It will be apparent to those skilled in the art that various modifications can be made to the system and method according to the invention without departing from the scope as defined in the claims.

Claims

Method for laying a pipeline by means of reeling, the method comprising: - fabricating at least one rolled up pipeline unit (5) at a coil base (6), comprising connecting individual pipelines (7) to a pipeline unit ( 8) and winding said pipeline unit on a temporary reel (9) into a rolled up pipeline unit, - holding the rolled up pipeline unit in the rolled up form with a coil holding unit (10), - removing the rolled up pipeline unit from the temporary reel, - moving the at least one rolled up pipeline unit without the temporary reel on a pipeline laying vessel (12), directly or indirectly via a transport vessel (13), wherein the pipeline laying vessel comprises a unwinding assembly (14) comprising a laying reel (15) comprises - positioning the rolled-up pipeline unit on the laying reel, - unwinding the rolled-up pipeline unit n the water with the reeling assembly and lowering the pipeline towards the seabed.

Method as claimed in claim 1, wherein the rolled up pipeline unit is first positioned, in particular stored, in a horizontal orientation or first inclined orientation on the pipeline laying vessel and subsequently pivoted to a second inclined orientation on the laying reel for unwinding the pipeline, wherein the second inclined orientation is more inclined with respect to the horizontal orientation than the first inclined orientation.

Method according to claim 2, wherein the second inclined orientation on the laying reel for unwinding the pipeline is substantially vertical.

Method according to claim 2 or 3, wherein the unwinding assembly comprises: - a laying reel base (21) connected to the ship's hull, in particular the deck, of the pipeline laying vessel, - the laying reel (15) pivotally connected to the laying reel base via a hinge (24), wherein the laying reel has a horizontal or first inclined receiving position for receiving the rolled up pipeline unit and a second inclined or vertical position for rolling the rolled up pipeline unit, the laying reel being pivotable between these positions - a guide structure (66) defining a path followed by the pipeline during its unwinding, step e) comprising: - positioning the rolled up pipeline unit in a horizontal or first inclined orientation on the laying reel when the laying reel is in the receiving position, - pivoting the laying reel to the second inclined or vertical position for the removal the pipeline in the water.

A method according to any one of the preceding claims, wherein after positioning of the rolled-up pipeline unit, the laying reel is removed from the coil-holding pipeline retaining unit.

A method according to any one of the preceding claims, wherein the transport vessel and / or the pipeline laying vessel are arranged to store a plurality of rolled-up pipeline units without a reel.

A method according to any one of the preceding claims, wherein the transport vessel and / or the pipeline laying vessel comprises a stacking support (26) for supporting a stack (27) of rolled up pipeline units in a horizontal orientation, and wherein a plurality of rolled up pipeline units stacked on top of each other the stacking support on board the transport vessel and / or on board the pipeline laying vessel.

A method according to any one of claims 3-7, wherein an on-board crane (20) mounted on the pipeline laying vessel positions the rolled up pipeline unit on the laying reel, and in particular the laying reel between the substantially horizontal or first inclined position and the second inclined or substantially vertical position.

A method according to any one of the preceding claims, wherein the pipeline of the rolled up pipeline unit has a length between 1 km and 30 km.

The method of any one of the preceding claims, wherein the pipe of the pipeline unit has an outer diameter between 15 cm and 61 cm.

A method according to any one of the preceding claims, wherein the laying reel comprises: - a first support part (28), in particular a support flange (29), adapted to support a first flat side (30) of the rolled up pipeline unit, and - a central part (31) extending transversely from the first support part, the central part being adapted to be positioned in a central opening (32) of the rolled-up pipeline unit and to engage an inner surface (33) of the rolled-up pipeline unit for limiting a radial movement of the pipeline unit, the central portion defining a circular cross-section, the circular cross-section being adapted to vary to receive or engage the rolled-up pipeline unit.

Method according to the preceding claim, wherein the central part of the laying reel comprises first adjustable parts (34) which define the circular cross-section and are adapted to move, in particular to move radially, with respect to the first support part between an inner receiving position (35), wherein the first adjustable parts define a first outer diameter (36), and an outer engaging position (37) for engaging the inner surface of the rolled up pipeline unit, the first adjustable parts defining a second outer diameter (38), wherein the second outer diameter is larger than the first outer diameter, the method comprising: a) positioning the laying reel in the horizontal or inclined receiving position, b) positioning the first adjustable parts in the inner receiving position, c) positioning the rolled up pipeline unit about the central part, d) moving the first adjustment outwards parts to the outer engagement position, e) pivoting the laying reel to the vertical unwinding position.

The method of the preceding claim, wherein the laying reel further comprises a second support member (39) adapted to engage a second flat side (40) of the rolled-up pipeline unit opposite the first flat side when the rolled-up pipeline unit is positioned on the laying reel. is, whereby an axial movement of the rolled up pipeline unit in a direction away from the first support part is limited, wherein prior to step e) of the preceding method claim the second support part has been moved from a released position (64), the second support part does not prevent the positioning of the rolled-up pipeline unit to an engagement position (65) for engaging the second flat side.

A method according to any one of the preceding claims, wherein the temporary reel comprises a central member (41) defining a circular cross-section around which the pipeline unit can be wound, the circular cross-section being adapted to vary in order to engage or freely engage the pipeline unit to give.

Method according to the preceding claim, wherein the central member comprises second adjustable parts (42) which together define the circular cross-section and are adapted to move, in particular to move radially, between a roll-up position (43) and a displacement position (44) ), wherein in the winding position an outer surface (45) of the second adjustable parts engage an inner surface (33) of the pipeline unit, and wherein in the displacement position the outer surface of the second adjustable parts are released from the inner surface of the rolled up pipeline, the method comprising: - positioning the second adjustable parts in the roll-up position, - rolling up the pipeline unit around the second adjustable parts in several layers in both an axial direction and a radial direction until the pipeline unit is rolled up, - positioning the second adjustable parts parts in the moving position.

The method of any one of the preceding claims, wherein the coil holding unit comprises a plurality of holding members (46), the holding members being arranged at intervals around the rolled up pipeline.

A rolled up pipeline unit (5) for offshore pipeline laying, wherein the rolled up pipeline unit comprises a rolled up pipeline (25) rolled up in a radial direction (54) and an axial direction (53) and defining a central opening (32), and a coil holding unit (10) for holding the rolled up pipeline in a rolled up configuration, the rolled up pipeline unit being free from a laying reel for unwinding the rolled up pipeline.

The rolled-up pipeline unit of claim 17, wherein the pipeline is plastically deformed when rolled from a straight configuration to a rolled-up configuration.

The rolled-up pipeline unit of claim 18, wherein the holding unit comprises a plurality of holding members (46) disposed at intervals around the rolled-up pipeline.

A combination of a pipeline laying vessel (12) and / or a transport vessel (13) and a plurality of rolled-up pipeline units (5) according to any of claims 17-19, wherein the rolled-up pipeline units are arranged on a deck (23) of the pipeline -legging vessel and / or the transport vessel.

The combination of claim 20, wherein a plurality of rolled up pipeline units are arranged side by side and lie on a flat side.

A combination according to claim 20 or 21, wherein a plurality of rolled-up pipeline units are stacked on top of each other.

A unwind assembly (14) for unwinding a rolled-up pipeline (25) from a rolled-up pipeline unit (5) in water and on a seabed, the unwinding assembly being adapted to receive the rolled-up pipeline unit according to any of claims 17-19 and to be supported in a horizontal or first inclined orientation, the unwinding assembly comprising: - a laying reel base (21) adapted to be connected to a ship's hull (22), in particular a deck (23), of a pipeline laying vessel ( 12), - a laying reel (15) connected to the laying reel base, the laying reel having a horizontal or first inclined position for receiving the rolled-up pipeline unit, - a guide structure (66) defining a path followed by the pipeline during the unwinding thereof.

The unwinding assembly of claim 23, wherein the unwinding assembly is adapted to facilitate unwinding of the pipe from the rolled-up pipeline unit in a second inclined or a substantially vertical position.

The unwinding assembly according to claim 23 or 24, wherein the laying reel is pivotally connected to the laying reel base via a hinge (24), wherein the laying reel has a horizontal or first inclined position for receiving the rolled up pipeline unit and has a second inclined or vertical position for rolling the rolled up pipeline unit, wherein the laying reel is pivotable between these positions.

The unwinding assembly according to any of claims 23-25, wherein the laying reel comprises: - a first support part (28) adapted to support a first flat side (30) of the rolled up pipeline unit, and - a central part (31) extending transversely from the first support member, the central member being adapted to be positioned in a central opening (32) of the rolled-up pipeline unit and to engage an inner surface (33) of the rolled-up pipeline unit for limiting a radial movement pipeline unit, the central part defining a circular cross-section, the circular cross-section being adapted to vary to receive or engage the rolled-up pipeline unit.

The unwinding assembly according to the preceding claim, wherein the central part of the laying reel comprises first adjustable parts (34) which define the circular cross section and are adapted to move, in particular to move radially, with respect to the first support part between an inner receiving position (35), wherein the first adjustable parts define a first outer diameter (36), and an outer engaging position (37) for engaging the inner surface of the rolled up pipeline unit, the first adjustable parts defining a second outer diameter (38), wherein the second outside diameter is larger than the first outside diameter.

The unwinding assembly according to claim 26 or 27, further comprising a second support member (39) adapted to move between a released position (64), wherein the second support member does not prevent the positioning of the rolled-up pipeline unit on the laying reel, and an engagement position (65), wherein the second support member engages a second flat side (40) of the rolled-up pipeline unit when the rolled-up pipeline unit is positioned on the laying reel, thereby limiting axial movement of the rolled-up pipeline unit in a direction opposite to the first support member.

A pipeline laying vessel (12) comprising the unwinding assembly (14) according to any of claims 23-28.

A pipeline laying vessel according to claim 29, comprising an on-board crane (20), the crane being adapted to lift a rolled up pipeline unit (5) according to one of claims 17-19 onto the laying reel, the laying reel being arranged to receive and support the rolled-up pipeline unit and to facilitate unwinding of the pipeline from the rolled-up pipeline unit.

The pipeline laying vessel according to claim 30, wherein the pipeline laying vessel comprises a storage (50) for accommodating at least one rolled up pipeline unit, and wherein the on-board crane is adapted to move the at least one rolled up pipeline unit from the storage at the laying reel.

The pipeline laying vessel of claim 31, wherein the storage is adapted to accommodate a plurality of rolled up pipeline units that are stacked on top of each other.

A spool base (6) for manufacturing the rolled up pipeline unit (5) according to any of claims 17-19, the spool base comprising: - a rotatable temporary reel (9) comprising a central member (41) defining a circular cross section where the pipeline unit can be wound around, the circular cross-section being adapted to vary to engage or release the pipeline unit, - a temporary reel drive (59) for rotating the temporary reel and winding the pipeline unit around the multi-layer temporary reel in both an axial direction and a radial direction, - a tensioning member (60) for applying tensile stress to the pipeline during winding the pipeline on the temporary reel.

The spool base of the preceding claim, wherein the central member comprises second adjustable parts (42) which together define the circular cross-section and are adapted to move, in particular to move radially, between a roll-up position (43) and a displacement position (44) ), wherein in the winding position an outer surface (45) of the second adjustable parts engages an inner surface (33) of the pipeline unit, and wherein in the displacement position the outer surface of the second adjustable parts is released from the inner surface of the rolled up pipeline.

The spool base of claim 34, further comprising a displacement assembly (62) for displacing the fabricated rolled up pipeline unit from the temporary reel, when the temporary reel is in the displacement position, to a storage location (63) on land or on a transport vessel (13) ) or pipeline laying vessel (12).

A spool base according to claim 35, wherein the displacement assembly is a lifting assembly, in particular a crane (16), for lifting the rolled up pipeline unit of the temporary reel.

The spool base of any one of claims 33 to 36, further comprising a guide member (52) for guiding the pipe during rolling up in an axial and radial direction, the guide member being movable in an axial direction and radial direction relative to the temporary reel.

The spool base of any one of claims 33-37, further comprising a retaining unit (10) for installing on the rolled-up pipeline, for holding the rolled-up pipeline unit in the rolled-up configuration.