METHOD FOR INSTALLING A GAS TRANSPORTATION ARRANGEMENT

Abstract

A method for installing a gas transportation arrangement on a seabed between an offshore facility and at least one further facility, wherein the gas transportation arrangement includes as components at least one gas transportation tube and at least one weight, wherein the gas transportation tube and the weight are coupled prior to lowering the gas transportation arrangement to the seabed, wherein an electrical power cable and/or a further tube at least party filled with a liquid and/or solid medium is used as weight extending almost entirely over the distance bridged by the gas transportation tube.

Claims

1. A method for installing a gas transportation arrangement on a seabed between an offshore facility and at least one further facility, wherein the gas transportation arrangement comprises at least one gas transportation tube and at least one weight means, wherein the at least one gas transportation tube and the at least one weight means are coupled prior to lowering the gas transportation arrangement to the seabed, wherein an electrical power cable and/or a further tube at least party filled with a liquid and/or solid medium is used as the at least one weight means extending almost entirely over a distance bridged by the at least one gas transportation tube.

2. The method according to claim 1, wherein the at least one gas transportation tube is configured for hydrogen transport, further wherein the at least one gas transportation tube comprises a tube wall with at least a hydrogen blocking portion and/or the at least one gas transportation tube is configured for methane transport and/or that the at least one gas transportation tube is configured for ammonia transport.

3. The method according to claim 1, wherein a single-core or multicore electrical power cable and/or an electrical power cable surrounded by a tube is used as the at least one weight means.

4. The method according to claim 1, wherein the further tube is arranged in the at least one gas transportation tube, around the at least one gas transportation tube, or adjacent to the at least one gas transportation tube.

5. The method according to claim 1, wherein the liquid and/or solid medium filled in the further tube and/or the liquid and/or solid medium filled in the at least one gas transportation tube is water, oil, and/or a suspension comprising water and a sediment.

6. The method according to claim 1, wherein after lowering of the gas transportation arrangement on the seabed, a liquid medium used as filling material of the further tube and/or the at least one gas transportation tube is removed from the further tube and/or the at least one gas transportation tube.

7. The method according to claim 1, wherein the further tube is connected to a medium providing arrangement of the offshore facility and/or of the further facility, wherein the medium providing arrangement is configured to provide a tempering medium, a consumable medium and/or a maintenance medium to the further tube.

8. The method according to claim 1, wherein at least one communication cable, at least one metal cable, at least one cable-like measurement device and/or at least one supporting structure are used as components of the gas transportation arrangement, wherein the communication cable, the cable-like measurement device, the metal cable and/or the supporting structure are coupled to the gas transportation tube and/or the weight means prior to a lowering of the gas transportation arrangement on the seabed.

9. The method according to claim 1, wherein the components of the gas transportation arrangement are arranged in a bundle with an essentially circular, essentially oval, essentially triangular or essentially quadrangular cross-sectional area.

10. The method according to claim 1, wherein the components of the gas transportation arrangement are coupled using at least one coupling means, wherein the coupling means include an adhesive connection, a bonded connection, a band fastener, and/or a tape.

11. The method according to claim 1, wherein the components of the gas transportation arrangement are coupled by a shield layer surrounding an outer circumference of the gas transportation arrangement.

12. The method according to claim 1, wherein the gas transportation arrangement is lowered to the seabed from a vessel, wherein the gas transportation arrangement is provided on the vessel in a coupled state or wherein the components of the gas transportation arrangement are provided at least partly separated, wherein the components are coupled on the vessel by using a coupling apparatus.

13. The method according to claim 12, wherein the gas transportation arrangement or the components of the gas transportation arrangement are provided wound up on at least one storage drum and/or at least one turntable arranged on the vessel.

14. The method according to claim 1, wherein a further tube is used as the at least one weight means, wherein the gas transportation arrangement is arranged floating on a sea surface prior to a filling of the further tube with the liquid and/or solid medium.

15. The method according to claim 1, wherein prior to the lowering of the gas transportation arrangement on the seabed, a trench is formed on the seabed, wherein the gas transportation arrangement is arranged in the trench.

16. The method according to claim 1, wherein after arrangement of the gas transportation arrangement on the seabed, a measurement instrument is moved through a tube of the gas transportation arrangement, wherein the measurement instrument measures a course of the gas transportation arrangement.

17. The method according to claim 1, wherein a measurement instrument comprising at least one gyroscope sensor and/or an instrument body movable by applying a fluid pressure to the tube is used.

18. The method according to claim 1, wherein as offshore facility, an electrolysis facility is used, wherein gas produced by the electrolysis facility is transported using the gas transportation arrangement.

Description

[0044] Some of the embodiments will be described in detail, with reference to the following figures, wherein like designations denote like members, wherein:

[0045] FIG. 1 depicts an embodiment of a method for installing a gas transportation arrangement according to the embodiment of the present invention;

[0046] FIG. 2 depicts an embodiment of a gas transportation tube for a gas transportation arrangement;

[0047] FIG. 3 depicts an embodiment of an electrical power cable for a gas transportation arrangement;

[0048] FIG. 4 depicts an embodiment of a gas transportation arrangement which may be installed using the method according to the present invention;

[0049] FIG. 5 depicts an embodiment of a gas transportation arrangement which may be installed using the method according to the present invention;

[0050] FIG. 6 depicts an embodiment of a gas transportation arrangement which may be installed using the method according to the present invention;

[0051] FIG. 7 depicts an embodiment of a gas transportation arrangement which may be installed using the method according to the present invention;

[0052] FIG. 8 depicts an embodiment of a gas transportation arrangement which may be installed using the method according to the present invention;

[0053] FIG. 9 depicts an embodiment of a gas transportation arrangement which may be installed using the method according to the present invention;

[0054] FIG. 10 depicts an embodiment of a gas transportation arrangement which may be installed using the method according to the present invention;

[0055] FIG. 11 depicts an embodiment of a gas transportation arrangement which may be installed using the method according to the present invention;

[0056] FIG. 12 depicts an embodiment of a gas transportation arrangement which may be installed using the method according to the present invention;

[0057] FIG. 13 depicts an embodiment of a gas transportation arrangement which may be installed using the method according to the present invention;

[0058] FIG. 14 depicts an embodiment of a gas transportation arrangement which may be installed using the method according to the present invention;

[0059] FIG. 15 depicts an embodiment of a gas transportation arrangement which may be installed using the method according to the present invention;

[0060] FIG. 16 depicts an embodiment of a gas transportation arrangement which may be installed using the method according to the present invention;

[0061] FIG. 17 depicts an embodiment of a gas transportation arrangement which may be installed using the method according to the present invention;

[0062] FIG. 18 depicts an embodiment of a gas transportation arrangement which may be installed using the method according to the present invention;

[0063] FIG. 19 depicts an embodiment of a gas transportation arrangement which may be installed using the method according to the present invention;

[0064] FIG. 20 depicts an embodiment of a gas transportation arrangement which may be installed using the method according to the present invention;

[0065] FIG. 21 depicts an embodiment of a vessel which may be used in an embodiment of the method according to the present invention;

[0066] FIG. 22 depicts an embodiment of a vessel which may be used in an embodiment of the method according to the present invention; and

[0067] FIG. 23 depicts a gas transportation arrangement in an installed state.

DETAILED DESCRIPTION

[0068] In FIG. 1, a method for installing a gas transportation arrangement 1 on a seabed 2 between an offshore facility 3 and at least one further facility 4 is shown. The offshore facility 3 is an electrolysis facility, which produces gas, in particular hydrogen and/or oxygen, using electrical energy produced by a wind turbine 5 connected to the offshore facility 3 via a connection 6. As technique used for the electrolysis, alkaline electrolysis, proton exchange membrane (PEM) electrolysis, anion exchange membrane (AEM) electrolysis and/or high temperature electrolysis (HTEL) may be used.

[0069] The gas transportation arrangement 1, which is installed between the offshore facility 3 and the further facility 4, is used to transfer gas created during the electrolysis process in the offshore facility 3 to the further facility 4. The further facility 4 is located onshore and is adapted to receive in particular the hydrogen gas created at the offshore facility 3. Therefore, the gas transportation arrangement 1 has to be arranged connecting the offshore facility 3 and the further facility 4. Additionally or alternatively to the hydrogen, also other types of gases, for instance methane or ammonia, may be transported between the offshore facility 3 and the further facility 4 using the gas transportation arrangement 1.

[0070] The gas transportation arrangement 1 is lowered to the seabed 2 from the deck of a vessel 7. The gas transportation arrangement 1 may be arranged directly on the seabed 2 or a trench 8 may be ploughed or excavated prior to the lowering of the gas transportation arrangement 1 on the seabed 2, so that the gas transportation arrangement 1 is arranged in the trench 8. After depositing the gas transportation arrangement 1 in the trench 8, the trench 8 may be closed, or filled, respectively, using soil and/or sea ground for fixating the gas transportation arrangement 1 in the seabed 2.

[0071] As will be described in the following in more detail, the gas transportation arrangement 1 comprises at least one gas transportation tube 9 used for transporting gas, in particular hydrogen, from the offshore facility 3 to the further facility 4. Additionally, the gas transportation arrangement 1 comprises at least one weight means 10, which is coupled to the gas transportation tube 9 to counteract a buoyancy of the at least one gas transportation tube 9, so that the gas transportation arrangement 1 remains on the seabed 2.

[0072] As the at least one weight means 10 of the gas transportation arrangement 1, an electrical power cable and/or a further tube at least partly filled with a liquid and/or solid medium is used. The weight means 10 extends almost entirely over the distance bridged by the gas transportation tube 9 of the gas transportation arrangement 1. During installation, the weight means 10 of the gas transportation arrangement 1 ensures a stable resting of the gas transportation arrangement on the seabed 2.

[0073] After installation of the gas transportation arrangement 1, the weight means 10 may be advantageously used for an additional purpose in between the offshore facility 3 and the further facility 4. Therefore, a weight means 10 is used that extends almost entirely over the distance bridge by the gas transportation arrangement 1, in particular over the distance, in which the gas transportation arrangement 1 is arranged under water, especially the distance in which the gas transportation arrangement 1 is arranged on the seabed 2.

[0074] The coupling of the one or more gar transportation tubes 9, the one or more weight means and/or one or more additional components of the gas transportation arrangement 1 may occur in all embodiments by the usage of at least one coupling means, wherein a bonded connection and/or an adhesive connection between the tubes and/or a steel band fastener or a tape wound around an outer circumference of a bundle of components of the gas transportation arrangement 1 are used as coupling means. Additionally or alternatively, a coupling of the components of the gas transportation arrangement may occur using a shield layer surrounding the components.

[0075] In FIG. 2, an embodiment of a gas transportation tube 9 for a gas transportation arrangement 1 is shown. The gas transportation tube 9 is adapted for a transport of hydrogen in an interior 11 of the tube 9. The gas transportation tube 9 comprises an inner layer 12 surrounding the interior 11 of the gas transportation tube 9. The gas transportation tube 9 comprises further an outer layer 13 and a middle layer 14 arranged in between the inner layer 12 and the outer layer 13. The inner layer 12 and the outer layer 13 may consist in particular of a plastic material, for instance polyethylene (PE) and/or high-density polyethylene (HDPE), wherein the middle layer 14 is used as a hydrogen blocking portion. The middle layer 14 may consist for instance of steel, stainless steel, aluminium and/or another metal which blocks a diffusion of hydrogen encapsulated in the interior 11 of the gas transportation tube 9. The composition of the materials of the gas transportation tube 9 may be different in the end sections of the gas transportation tube 9, where the gas transportation tube 9 is connected to termination parts for entry into a structure or the like of the offshore facility 3, or the further facility 4, respectively.

[0076] In FIG. 3, an embodiment of an electrical power cable 15 used as weight means 10 is shown. The electrical power cable 15 is a multicore cable comprising three conductors 16 adapted for guiding an alternating current, for instance at a voltage level between 100 kV and 500 kV, in particular 132 kV, 220 kV, or 400 kV. The electrical power cable 15 may be used to transfer electrical power of at least one wind turbine 5 and/or electrical power, which is not used in the offshore facility 3, from the offshore facility 3 to the further facility 4 or vice versa.

[0077] Each of the conductors 16 comprises an insulation 17 arranged around the conductor 16. The electrical power cable 15 further comprises three communication cables 18, which each comprise a bundle of glass fibres and which are embedded together with the conductors 16 and the insulation 17 in an additional insulating material 19. The electrical power cable 15 is surrounded by an armour 20, for instance comprising a plurality of steel rods, which are embedded in an outer serving 21, for instance a layer of yarn and/or bitumen.

[0078] In FIG. 4, an embodiment of a gas transportation arrangement 1 is depicted. The gas transportation arrangement 1 comprises a gas transportation tube 9 and an electrical power cable 15. It is in particular possible that in this and in the further embodiments, the gas transportation tube 9 is provided as depicted in FIG. 2. As electrical power cable 15, an embodiment of an electrical power cable 15 like shown in FIG. 3 can be used in this and in the further embodiments comprising an electrical power cable 15. Alternatively, a single core electrical power cable 15 comprising one single core 16 may be used and/or unarmoured electrical power cables without armour 20 and/or outer serving 21 may be used.

[0079] For forming the gas transportation arrangement 1, the gas transportation tube 9 is coupled to the electrical power cable 15, where the electrical power cable 15 is used as weight means 10 of the gas transportation arrangement 1 to counteract a buoyancy of the gas transportation tube 9, hence to prevent the gas transportation arrangement 1 from floating when being arranged under water.

[0080] In FIG. 5, a second embodiment of a gas transportation arrangement 1 is shown. The gas transportation arrangement 1 comprises a gas transportation tube 9 and an electrical power cable 15 arranged inside a further tube 22. The gas transportation tube 9 is coupled to the further tube 22, wherein the electrical power cable 15 arranged in the further tube 22 is used as weight means 10 for counteracting the buoyancy of the gas transportation tube 9. The arrangement of the electrical power cable 15 inside a further tube 22 is in particular advantageous, if an unarmoured electrical power cable 15 is used, since by the further tube 22, an additional protection of the electrical power cable 15 is achieved.

[0081] In FIG. 6, a third embodiment of a gas transportation arrangement 1 is shown. The gas transportation arrangement 1 comprises a gas transportation tube 9 as well as a further tube 22, wherein an electrical power cable 15 is arranged in the further tube 22. Furthermore, an interior 23 of the further tube is filled with a liquid and/or solid medium 24. The medium 24 may be for instance water, which is filled in the interior 23 surrounding the electrical power cable 15, so that the electrical power cable 15 may be cooled after installation of the gas transport arrangement 1 and/or during operation of the gas transportation arrangement 1 using the water in the interior 23 of the further tube 22 and/or a thermal connection created by the water in the interior 23 of the further tube 22 to the surrounding seawater at the seabed 2.

[0082] In this embodiment, both the electrical power cable 15 and the further tube 22 can be used as weight means increasing the weight of the gas transportation arrangement 1 so that a stable and secure arrangement of the gas transportation arrangement 1 at the seabed 2 may be conducted.

[0083] In FIG. 7, a fourth embodiment of a gas transportation arrangement 1 is shown. The gas transportation arrangement 1 comprises a gas transportation tube 9 and a further tube 22, wherein the interior 23 of the further tube 22 is filled with the liquid or solid medium 24. In this embodiment, the further tube 22 is used as a weight means increasing the weight of the gas transportation arrangement 1. The further tube 22 may be filled with a material like water and/or with a liquid comprising a higher density than the seawater, for instance an oil or the like.

[0084] The medium 24 may be in particular a mixture of a liquid and a solid, which has a higher density than water increasing the weight of the gas transportation arrangement 1, for instance a mixture of water and a clay, in particular a mixture of water and bentonite, which significantly increases the weight of the further tube 22, or the gas transportation arrangement 1, respectively. It is also possible that as the medium 24, a solid material, for instance a solidified liquid, which is solidified after being filled into the tube 22, is used. A further tube 22 filled with a solid material is in particular advantageous, when the gas transportation arrangement 1 is not arranged within a trench 8 on the seabed 2, for permanently providing a weight sufficient for fixating the gas transportation arrangement 1 on the seabed 2.

[0085] The usage of a liquid medium 24 has the advantage that after installation of the gas transportation arrangement 1, the liquid medium 24 can be removed from the interior 23 of the further tube 22, so that the further tube 22 may be used for a further purpose. For instance, the further tube 22 may be used to connect the offshore facility 3 to the further facility 4 and for supplying a tempering medium, a consumable medium and/or a maintenance medium to the offshore facility 3 or the further facility 4, respectively. For instance, the further tube 22 may be used for providing fresh water to an offshore facility 3 comprising an electrolysis apparatus, so that the electrolysis can be performed with fresh water supply via the further tube 22 instead of using the seawater surrounding the offshore platform 3. Additionally or alternatively, the or a further tube 22 may be used for providing a maintenance medium like oil or another lubricant to the offshore facility 3. Also a tempering medium for heating and/or cooling at the offshore facility 3, or for heating and/or cooling of the gas transport arrangement 1, respectively, may be provided using the or a further tube 22.

[0086] In FIG. 8, a fifth embodiment of a gas transportation arrangement 1 is shown. In this embodiment, the gas transportation tube 9 is arranged inside the interior 23 of the further tube 22. Hence, the gas transportation tube 9 is surrounded by the medium 24 filled in the interior 23 of the further tube 22.

[0087] In FIG. 9, a sixth embodiment of a gas transportation arrangement 1 is shown. In this embodiment, the further tube 22 is arranged in the interior 11 of the gas transportation tube 9.

[0088] In both the fifth embodiment depicted in FIG. 8 and the sixth embodiment depicted in FIG. 9, a liquid medium 24 filled in the interior 23 of the further tube 22 may be used to cool and/or heat the gas transportation tube 9 or a gas transported in the gas transportation tube 9, respectively.

[0089] In FIG. 10, a seventh embodiment of a gas transportation arrangement 1 is shown comprising a gas transportation tube 9 and two further tubes 22 filled at least partly with a solid or liquid medium 24. Furthermore, the gas transportation arrangement 1 comprises in this embodiment an additional component 25, which may be a communication cable, a metal cable like, at least one cable-like measurement device and/or at least one supporting structure.

[0090] For instance, a glass fibre cable may be provided as component 25 in between the gas transportation tube 9 and the further tubes 22 arranged for exhibiting essentially a triangular cross-section of the gas transportation arrangement 1. As additional component 25 also a metal cable, for instance a steel cable, and/or at least one cable-like measurement device for measuring a temperature and/or a vibration of the gas transportation arrangement 1 may be used. As cable-like measurement device, for instance one or more glass fibres for measuring a temperature and/or a vibration of the gas transportation arrangement 1 may be used. Also a temperature sensor connected to one or more cables may be used as component 25.

[0091] In FIG. 11, an eighth embodiment of a gas transportation arrangement 1 is shown. In this embodiment, the gas transportation arrangement 1 comprises two gas transportation tubes 9 and two further tubes 22 as weight means. Furthermore, the gas transportation arrangement 1 comprises five additional components 25, which each may be a communication cable, a metal cable, a cable-like measurement device and/or a supporting structure supporting the gas transportation tubes 9 and the further tubes 22 against each other.

[0092] All components of the transportation arrangement 1 are arranged such that a bundle is formed which comprises a high fill factor of the quadrangular cross-sectional area of the bundle. Therefore, the components with smaller radii, here the additional components 25, are arranged in between two or more of the gas transportation tubes and/or the further tubes 22, which comprise a larger diameter. It is also possible that also the diameter of the gas transportation tubes 9 and/or the further tubes 22 are different.

[0093] In FIG. 12, a ninth embodiment of a gas transportation arrangement 1 is shown. In this embodiment, an electrical power cable 15 arranged inside a further tube 22 is used as a weight means for counteracting the buoyancy of the two gas transportation tubes 9 of the transportation arrangement 1. Furthermore, the gas transportation arrangement 1 comprises four additional components 25, as previously described. It is in particular possible that at least one of the additional components 25 arranged adjacent to the further tube 22 surrounding the electrical power cable 15 is used for temperature measurement, so that for instance water can be applied to the interior 23 as liquid medium 24 during or after the installation of the gas transportation arrangement 1 for cooling the electrical power cable 15 using a flow of water in the interior 23 of the further tube 22. The components are coupled together using a coupling means 26 surrounding an outer circumference of the bundle of components, wherein for instance a steel band fastener is used as coupling means 26.

[0094] In FIG. 13, a tenth embodiment of a gas transportation arrangement 1 is shown. In this embodiment, the gas transportation arrangement 1 comprises four gas transporting tubes 9 and two further tubes 22, which surround an electrical power cable 15 arranged in the interior 23 of the respective further tubes 22. In this embodiment, the further tubes 22 and the electrical power cables 15 are used as weight means supplying weight to the gas transportation arrangement 1. Furthermore, the gas transportation arrangement 1 comprises eight additional components 25. It is in particular possible that the two additional components 25 arranged each in the middle of the bundle in between the two further tubes 22 and two of the gas transportation tubes 9 are communication cables and/or unshielded electrical power cables, since a protection of these components 25 is obtained by the further tubes 22 and the gas transportation tubes 9. The additional components 25 arranged on the outer circumference of the bundle may be for instance steel cables, adding additional weight and stability to the gas transportation arrangement 1.

[0095] In FIG. 14, an eleventh embodiment of a gas transportation arrangement 1 is shown. The gas transportation arrangement 1 comprises an electrical power cable 15 as weight means 12 as well as three gas transportation tubes 9. The gas transportation arrangement 1 comprises further a coupling means 26 surrounding the gas transportation tubes 9 and the electrical power cable 15.

[0096] The electrical power cable 15 comprises three electrical conductors 16, which are each surrounded by the insulating layer 17. Furthermore the electrical power cable 15 is surrounded by a shield 20 consisting at least partly of metal rods, wherein the shield 20 is surrounded by the outer serving 21 comprising at least partly of yarn and/or bitumen. The electrical power cable 15 comprises two communication cables 18 as well as three supporting elements 27 supporting the conductors 16 and/or the communication cables 18 against each other providing a circular outer circumference of the electrical power cable 15, which is wrapped by the shield 20.

[0097] As previously described, the coupling means 26 may be a band fastener like a steel band fastener or a tape surrounding the components of the gas transportation tube 1. It is in particular possible that more than one coupling means 26 is arranged at the outside of the gas transportation arrangement 1 in particular in regular intervals, for instance once every few meters.

[0098] In FIG. 15, a twelfth embodiment and in FIG. 16 a thirteenth embodiment of a gas transportation arrangement 1 are shown. These embodiments correspond to the eleventh embodiment shown in FIG. 14, wherein in the twelfth embodiment, a gas transportation arrangement comprising two gas transportation tubes 9 is depicted. In the thirteenth embodiment, the gas transportation arrangement 1 comprises one gas transporting tube 9, which has a diameter smaller than the diameter of the electrical power cable 15 used as weight means of the gas transportation arrangement 1.

[0099] In FIG. 17, a fourteenth embodiment of a gas transportation arrangement 1 is shown comprising an electrical power cable 15 as weight means as well as eleven gas transportation tubes 9, which are arranged circumferentially around the electrical power cable 15 located in the centre of the bundle. The electrical power cable 15 is provided as described in conjunction with the eleventh embodiment depicted in FIG. 14. Instead of eleven gas transporting tubes 9, also a larger or smaller number of gas transporting tubes 9, may be arranged circumferentially around the other surface of the electrical power cable 15, in particular such that a circular cross-sectional area of the bundle is obtained.

[0100] In FIG. 18, a fifteenth embodiment of a gas transportation arrangement 1 is shown. In this embodiment, an electrical power cable 15 is used as weight means for two gas transportation tubes 9 of the gas transportation arrangement 1. To obtain a circular shape of the cross section, three supporting structures 28 are provided as additional components of the gas transportation arrangement 1. These supporting structures 28 are arranged in between the two gas transportation tubes or one of the gas transportation tubes 9 and the electrical power cable 15, respectively, so that overall a circular cross-sectional area of the gas transportation arrangement 1 is obtained. The components of the gas transport arrangement 1 are surrounded by a shield layer 29, which couples the components together. The shield layer 29 surrounds the components and comprises a plurality of metal rods 30 providing a shielding and/or an armouring of the components of the gas transportation arrangement 1. The rods 30 are surrounded by a protective layer 31, which may consist for instance of bitumen and/or yarn providing a protection of the components of the gas transportation arrangement 1 from environmental influences at the seabed 2.

[0101] In FIG. 19, a sixteenth embodiment of a gas transportation arrangement 1 is shown, wherein the gas transportation arrangement 1 comprises an electrical power cable 15 as weight means as well two gas transporting tubes 9. The gas transportation arrangement 1 comprises six additional components 25 as well as three further tubes 22. Furthermore, the gas transportation arrangement comprises three supporting structures 28, which each surround one of the further tubes 22 as well as two of the additional components 25. The additional component 25 may each be a communication cable, a metal cable and/or a cable-like measurement device as previously described. The supporting structures 28 provide an essentially circular outer circumference of the components of the gas transportation arrangement 1 arranged in a bundle. The components of the gas transportation arrangement 1 are coupled by the shield layer 29.

[0102] It is in particular possible that one or more of the further tubes 22 are used to provide a tempering medium like cooling water for cooling and/or heating of the gas transportation tubes 9 and/or the electrical power cable 15, a maintenance medium and/or a consumption medium to the offshore facility 3 and/or the further facility 4, respectively. The components of the gas transportation arrangement 1 are coupled by the shield layer 29.

[0103] In FIG. 20, a seventeenth embodiment of the present invention is shown. This embodiment resembles the sixteenth embodiment, wherein one of the further tubes 22 has been replaced by an additional power conductor 32. The additional power conductor 32 comprises a smaller diameter than the power cable 15, so that for instance the power cable 15 can be used to conduct power from offshore wind turbines 5 to the further facility 4, wherein the additional electrical power cable 32 is used to provide starting energy or the like from the further facility 4 to the offshore facility 3. It is in particular possible that also one of the other further tubes 22 shown in the sixteenth embodiment is replaced by an additional electrical power cable 32.

[0104] In FIG. 21, a vessel 7 used in an embodiment of a method for installing a gas transportation arrangement 1 is shown. The vessel comprises a storage drum 33, on which the gas transportation arrangement 1 is provided in a coupled state. For lowering the gas transportation arrangement 1 on the seabed, the storage drum 33 can be actuated so that the gas transportation arrangement 1 can be stooled from the storage drum 33 and lowered to the seabed 2. Beside the drum 33, also a turntable carrying the gas transportation arrangement 1 may be used.

[0105] In FIG. 22, a further embodiment of a vessel 7 for usage in a method for installing a gas transportation arrangement 1 is shown. In this embodiment, the vessel 7 comprises a plurality of storage drums 33, which each store a different component or a combination of different components of the gas transportation arrangement 1. Using a coupling apparatus 34 of the vessel 7, the individual components, or groups of components, respectively, stored on the storage drums 33 are coupled and then lowered to the seabed 2 from the vessel 7.

[0106] In addition to the coupling apparatus 34, also a tensioning device (not depicted) can be used at the vessel 7 for tensioning the components, in particular to facilitate the usage of a coupling means like band fasteners, tapes, or the provision of a shielding around the individual components as coupling means, respectively.

[0107] When at least one further tube 22 is used as weight means, it is also possible that the gas transportation arrangement 1 is arranged floating on a sea surface prior to a filling of the further tube 22 with a liquid and/or solid medium. The gas transport arrangement may be dragged on the sea surface by a vessel, wherein by filling the liquid and/or solid medium into the further tube used as a weight means, the weight, or the density, respectively, of the gas transportation arrangement may be increased to lower it from the sea surface to the seabed. The gas transportation arrangement 1 may be arranged on the sea surface for instance on the entire or almost the entire distance between the offshore facility 3 and the further facility 4.

[0108] As is depicted in FIG. 23, after installing the gas transportation arrangement 1 on, or in the seabed 2, respectively, the gas transportation arrangement 1 is connected to the offshore facility 3 and/or the further facility 4. In particular an electrical power cable 15 or a further tube 22 to us as a weight means 10 of the gas transportation arrangement 1 may be used for providing electricity and/or a fluid media from the offshore facility 3 to the further facility 4 or vice versa. Therefore, the further tube 22 is connected to a medium providing arrangement of the offshore facility 3 and/or of the further facility 4, wherein the medium providing arrangement is adapted to provide a tempering medium, a consumable medium and/or a maintenance medium to the further tube 22. It is also possible that in one or more of the further tubes 22, electrical cables like electrical power cables and/or electrical or optical communication cables are inserted connecting the offshore facility 3 and the further facility 4.

[0109] After installation of the gas transportation arrangement 1, a measurement instrument 35 is moved through a tube of the gas transportation arrangement 1, for instance through one of the gas transportation tubes 9 and the further tube 22 to use as weight means 10 during the installation of the gas transportation arrangement 1. The measurement instrument 35 measure a course of the gas transportation arrangement 1 on the seabed 2 between the offshore facility 3 and the further facility 4. As measurement instrument 35, in particular an instrument within an instrument body movable by applying a fluid pressure to the tube is used. As measurement instrument 35, for instance a so-called pig can be used. The measurement instrument 35 comprises a gyroscope sensor measuring for instance an acceleration in three orthogonal directions, so that based on the information collected during the movement of the measurement instrument 35 through for example a gas transportation tube 9, the course of the gas transportation arrangement 1 can be controlled.

[0110] Although the present invention has been described in detail with reference to the exemplary embodiment, the present invention is not limited by the disclosed examples from which the skilled person is able to derive other variations without departing from the scope of the invention.

[0111] Although the present invention has been disclosed in the form of preferred embodiments and variations thereon, it will be understood that numerous additional modifications and variations could be made thereto without departing from the scope of the invention.

[0112] For the sake of clarity, it is to be understood that the use of “a” or “an” throughout this application does not exclude a plurality, and “comprising” does not exclude other steps or elements.