EP2195232A2

EP2195232A2 - Installation for transferring a fluid between a tanker and a fixed structure

Info

Publication number: EP2195232A2
Application number: EP08834750A
Authority: EP
Inventors: Jean-Pascal Biaggi; Virginie Lehning
Original assignee: Technip France SAS
Current assignee: Technip Energies France SAS
Priority date: 2007-09-12
Filing date: 2008-09-05
Publication date: 2010-06-16
Anticipated expiration: 2028-09-05
Also published as: AU2008306796A1; ATE545577T1; BRPI0816853A2; US8590472B2; WO2009044052A3; FR2920753A1; WO2009044052A2; AU2008306796B2; US20100300545A1; EP2195232B1; FR2920753B1; ES2380513T3

Abstract

Said installation (16) comprises a transport duct (34) at least partly submerged in an expanse of water (14), a device (65, 48) for conveying fluid between the tanker (12) and the duct (34) and a floating quay (42) for tying up the tanker (12). The quay (42) has a support structure (60) partially submerged in the expanse of water (14). The support structure (60) has an open trellis (66), defining internal volumes (68) for circulation of water opening out into the expanse of water (14). The floating quay (12) further comprises flexible anchoring lines (64) for the support structure (60) on the bed (20) of the expanse of water (14). The ratio of the volume of the internal volumes (68) to the sum of the volume of the open trellis (66) and the volume of the internal volumes (68) is greater than 09.

Description

Installation for transferring a fluid between a transport vessel and a fixed structure.

The present invention relates to a facility for transferring a fluid between a transport vessel and a fluid reservoir on a fixed structure, of the type comprising:

a conduit for transporting the fluid to the fixed structure, at least partly immersed in a body of water; - A fluid conveying device between the ship and the transport conduit, connected to a connecting end of the transport conduit; and

a floating mooring dock of the ship, placed in the vicinity of the connecting end, and movable locally in the body of water, the floating dock comprising:

. a bearing structure intended to be partially immersed in the body of water, the supporting structure comprising a perforated lattice defining interior water circulation spaces intended to open into the body of water,

. flexible anchoring lines of the structure on the bottom of the body of water; and

. means for fixing the ship's mooring lines on the supporting structure.

The present invention is particularly applicable to the transfer of liquid hydrocarbons such as liquefied gases such as liquefied natural gas (LNG) or liquefied petroleum gas (LPG) between a transport vessel and a fixed structure. This fixed structure is, for example, a liquefaction unit or a regasification terminal during the loading of the vessel, or a fluid reservoir during unloading.

Given certain safety constraints and vessel movements, it is preferable to carry out fluid transfer operations by keeping the ship out of a port, in deeper waters, for example a few hundred meters from the coast. . To carry out such operations on the high seas, there are in particular ship loading and unloading stations comprising a fluid transfer platform fixed on the seabed by a fixing structure placed on the bottom of the sea called "jacket ". The platform supports articulated fluid transfer arms to be connected to ship manifold systems called manifolds on the ship.

Known loading stations further include a set of dolphins (commonly referred to as "dolphins") to absorb the ship's docking energy and moor it after docking. The dolphins are also set on the seabed by rigid metal piles.

The fluid transfer platform is connected to a reservoir located on the coast or on a fixed platform at sea by a flexible pipe or a partially or totally immersed pipeline.

This type of transfer station requires a sufficient depth of water for the ship's draft. Nevertheless, when the ship is moored to the dolphins, it is not free to orient itself to the elements. In addition, without adequate protection against swells generally provided by a dyke, the relative movements between the ship and the loading station are very significant. The forces applied on the mooring lines between the vessel and the dolphins are therefore important, which implies that the transfer station must be placed in a sheltered site.

To overcome this problem, US 2004/0216485 describes a transfer installation of the above-mentioned type, in which the dolphins are replaced by semi-submersible perforated assemblies anchored on the seabed by means of anchor lines. flexible.

The semi-submersible assemblies are placed away from the loading platform, on either side of it for the respective mooring of the front and the rear of the ship. These bearing structures are massive since they include pillars about 10 meters in diameter and uprights having a very large water contact surface with respect to the overall volume of the structure.

Thus, the load-bearing structures, when connected to the ship by the mooring lines have a significant inertia, so that the assembly constituted by the structure and the ship absorb the swell in short time. Such an installation does not, however, give complete satisfaction. Indeed, the support structure being dynamically heavy, it can have a significant inertia compared to the inertia of the ship which is docked to him considering the high mass the water which the weight, and the surface of high contact with the expanse of water in which it floats. Significant constraints therefore continue to apply on the mooring lines between the ship and the supporting structures.

In addition, although the load-bearing structures allow, by their weight, to absorb the swell in the small time, they remain nevertheless, by their large surface of contact with the water, very sensitive to the waves or the swell on the extent of water in conditions of very bad weather, especially when the swell is greater than six very. As a result, the anchor lines of the load-bearing structures must be overdimen- tated to resist swell in the event of heavy weather.

An object of the invention is to obtain a transfer facility that can be used easily away from the coast by limiting the dynamic forces due to docking, mooring constraints between the ship and the supporting structure, and which can nevertheless withstand waves of very high heights under extreme conditions.

For this purpose, the subject of the invention is a transfer installation of the aforementioned type, characterized in that the ratio of the volume of the interior spaces to the sum of the volume of the perforated lattice and the volume of the interior spaces is greater than 0.9.

The installation according to the invention may comprise one or more of the following characteristics, taken separately or in any technically possible combination:

the conveying device comprises a fluid transfer assembly mounted on the perforated lattice, the transfer assembly comprising at least one upstream flexible fluid transfer pipe intended to be connected to the vessel;

the installation comprises a fixed support platform, comprising at least one pillar fixed on the bottom of the body of water, the conveying device comprising a connection assembly to the transport duct, carried by the support platform, the connecting end of the transport conduit being connected to the connection assembly on the support platform;

the transfer assembly comprises at least one flexible fluid transfer downstream pipe intended to be connected to the connection assembly on the support platform; - The support platform and the carrier structure delimit between them an intermediate space, the or each downstream flexible pipe being provided with emergency disconnection means extending opposite the intermediate space;

the carrying structure has an elongated shape along an axis delimiting a lateral docking surface of the ship and an opposite lateral surface, said lateral surfaces extending between two ends of the carrying structure, the support platform being placed opposite the opposite surface between said ends or in the axial extension of the bearing structure facing one of said ends; - The conveying device comprises a connection assembly to the transport conduit carried by the carrier structure, the connecting end of the transport conduit being connected to the connection assembly on the carrier structure;

the or each upstream flexible pipe is capable of protruding at least partially away from the bearing structure towards the ship, the or each upstream flexible pipe being provided with emergency disconnecting means;

the ratio of the volume of the interior spaces to the sum of the volume of the openwork lattice and the volume of the interior spaces is between 0.95 and 0.99;

- The perforated lattice comprises a plurality of tubular beams connected together, the perimeter of the carrier structure, taken in projection in a horizontal plane, being greater than at least fifty times the maximum diameter of the beams.

The invention further relates to a fluid transport assembly comprising:

- a fluid transport vessel; and an installation as defined above, the vessel being moored to the floating dock via mooring lines fixed to the means for fixing the mooring lines so that the vessel moves vertically together with the dock. floating.

The transport assembly may include one or more of the following features, taken in isolation, or in any technically feasible combination:

- the weight of the supporting structure is less than 5% of the weight of the ship; and

- the installation includes a single floating mooring dock, the vessel being moored exclusively to the single mooring floating dock.

The subject of the invention is also a method for transferring a fluid into a transport assembly as defined above, characterized in that it comprises the following steps:

- moving the vessel to the floating dock to dock against a berthing surface of the supporting structure;

- Establishment of mooring lines to secure the ship and the carrier structure, the supporting structure then being movable vertically together with the ship;

- Hydraulic connection between a fluid reservoir carried by the vessel and the connecting end of the transport conduit through the conveying device through or above the floating dock; and - Transfer of fluid between the vessel and the fluid transport conduit.

The invention will be better understood on reading the following description, given solely by way of example, and with reference to the appended drawings, in which: FIG. 1 is a diagrammatic view from above of a first transfer installation according to the invention, before the docking of a hydrocarbon transport vessel;

- Figure 2 is a view similar to Figure 1 after the docking of the ship;

FIG. 3 is a sectional view taken along a transverse plane of the installation of FIG. 2 during a transfer of hydrocarbons between the installation and the vessel;

FIG. 4 is a view similar to FIG. 1 of a second transfer installation according to the invention.

FIG. 5 is a view similar to FIG. 3 of a third transfer installation according to the invention; and FIG. 6 is a view similar to FIG. 3 of a fourth installation according to the invention.

In all that follows, the terms "longitudinal" and "transverse" refer to the elongated direction of a ship or a supporting structure. The terms "upstream" and "downstream" refer to the direction of flow of a fluid during the unloading of this fluid from the vessel to the transfer facility.

Figures 1 to 4 illustrate a first set 10 of liquid hydrocarbon transport according to the invention.

This assembly 10 applies to the transport and transfer of liquefied hydrocarbons, especially liquefied gas, such as liquefied natural gas (LNG), liquefied petroleum gas (LPG), or any other type of liquefied gas.

The transport assembly comprises a transport vessel 12, floating on a body of water 14, a fluid transfer installation 16 disposed in the body of water 14 to receive the ship 12, and a fixed or terminal structure 18 located on the coast away from the transfer facility 16 to receive the fluid discharged by the transfer facility 16, or to produce or store the fluid to be loaded on the ship 12 by the transfer facility 16 .

In all that follows, it will be readily understood that the transport assembly 10 is entirely reversible, that is to say that the transfer installation 16 can be used either to load the vessel 12 with a fluid stored or produced in the the terminal 18, either conversely, discharge a fluid contained in the ship 12 and convey it to the terminal

18. Only the latter case will be described by way of example in all that follows.

The body of water 14 is an expanse of salt water such as a sea or an ocean, or an expanse of fresh water such as a lake. The body of water rests on a solid bottom 20. The installation 16 is advantageously mounted in a body of water 14 with a depth of between 25 meters and 70 meters, although greater depths, notably up to 150 meters can be considered.

The transport vessel 12 comprises a floating hull 22 delimiting a mooring lateral edge 24, and at least one liquefied fluid storage tank 26 disposed in the hull 22.

The ship 12 further comprises, along its mooring edge 24, mooring lines 28 fixed respectively at the front, at the rear and in the median part of the ship 12. These lines comprise in particular a point located at the bow of the ship 12, a point located at the stern of the ship 12 and cross lines in the central part of the ship.

The reservoir 26 comprises a plurality of manifolds 30 which open transversely with respect to the vessel 12, substantially in the middle part of the vessel 12.

Each manifold 30 is provided at its outer end with a connection flange and advantageously with a removable connection piece 32 adapted to protrude beyond the side edge 24 for the connection of a fluid transfer line. Such connections are described for example in the French applications No. 06 05 434 and No. 07 54 438 of the Applicant.

The terminal 18 is disposed for example on the coast, or at sea, away from the transfer facility 16. The terminal 18 comprises liquefied hydrocarbon storage tanks. These tanks are located for example at the output of a liquefied hydrocarbon production plant equipped with a liquefaction train, in the case where the transfer facility 16 is used to charge fluid into the ship 12.

The terminal 18 is connected to the transfer installation 16 via a cryogenic conduit 34 immersed in the body of water 14 and connected to at least one fluid reservoir of the terminal 18. The conduit 34 is for example of the "Pipe-in-Pipe" type, marketed by Flexi France under the trade name C-PIP (Cryogenics Pipe in Pipe). The distance between the facility 16 and the terminal 18 is greater than 100 meters and generally between 500 meters and 1500 meters. The transfer facility 16 includes a fixed platform 40 for connecting the cryogenic conduit 34, and a floating dock 42 for receiving and docking the vessel 12 at the facility 16.

As illustrated in FIG. 3, the platform 40 comprises a support 44 situated above the surface of the body of water 14, the pillars 46 for fixing the support 44 on the bottom of the body of water 14, and an assembly 48 for connection to the cryogenic duct 34 carried by the support 44.

The pillars 46 are for example made in the form of parallel members interconnected by a lattice of metal beams, or are made by tubular boxes. They are fixed at their lower end on the bottom 20 of the body of water on which they rest, and at their upper end, under the support 44. Thus, the platform 40 remains substantially immobile vertically whatever the conditions of agitation of the body of water 14.

The connection assembly 48 receives an upstream end of the cryogenic duct 34.

As illustrated in FIGS. 1 to 3, the floating dock 42 comprises a perforated load-bearing structure 60, mooring fixing studs 28 on the structure 60, docking defenses 63, and flexible anchoring lines 64 of the Bearing structure 60 on the bottom 20 of the water body 14. The transfer installation 16 further comprises a fluid transfer assembly 65 between the vessel 12 and the connection assembly 48, for connection hydraulically. the manifolds 30 of the reservoir 14 to the connection assembly 48.

According to the invention, the carrier structure 60 comprises a light perforated lattice 66 defining interior spaces 68 for circulating water of large volume, so that the carrier structure 60 is substantially transparent to the agitation of the body of water 14 and especially to the swell.

As illustrated by FIGS. 1 and 2, the structure 60 and its mesh 66 are elongated along an axis YY 'substantially parallel to the longitudinal axis XX' of the ship 12 when the ship 12 is moored on the platform 42 In the example shown in Figures 1 to 3, the mesh 66 has a substantially constant horizontal section over its entire height. The horizontal section is of polygonal outline. The height of the mesh 66 is moreover substantially constant.

The trellis 66 comprises a plurality of vertical beams 70, a plurality of horizontal struts 72 connecting the beams 70 to define elementary meshes. 73 parallelepipedic and a plurality of oblique cross members 74 each connecting a beam 70 to a post 72 through a mesh 73.

The beams 70, the uprights 72 and the sleepers 74 are all made of hollow metal tubes assembled together. These tubes have a small maximum diameter, so that the perimeter of the carrier structure 60, projected in a horizontal plane is greater than at least 50 times the maximum diameter of the tubes forming the beams 70, the uprights 72 and the cross members 74. The cavities delimited within the hollow tubes are separated from the water circulation spaces 68 by the sealed walls forming the tubes. Thus, the carrier structure 60 floats spontaneously away from the bottom when immersed in the body of water 14, having at least one upper region of non-zero height which protrudes above the surface of the body. water body 14.

The beams 70 have a diameter greater than that of the cross members 74, which sleepers 74 have a diameter greater than that of the uprights 72. The beams 70 are distributed along the contour of the supporting structure 60 and along the central axis YY ' within the support structure 60. The diameter of the beams 70 is of the order of 2 m (about 80 inches), and between 1 m and 4 m and their height, which defines the constant height of the structure 60 is the order of 24 m and between 15 m and 30 m. The posts 72 connect the beams 70 perpendicularly to the axis of the structure 60. They have a diameter of the order of 0.6 m (24 inches) and between 0.3 m and 0.9 m.

The sleepers 74 have a diameter between 0.6 m and 0.9 m (between 30 and 50 inches). Thus, the weight of the structure is generally of the order of 3200 tons to be less than 5% of the maximum weight of the ship 12.

The trellis 66 of the structure 60 thus defines, according to its outer envelope, an upstream vertical surface 80 for docking the ship, a downstream vertical surface 82, opposite to the upstream surface 80 and extending facing the platform 40, a horizontal upper surface 84 for supporting the transfer assembly 65, and a lower surface 86 extending facing the bottom 20 of the body of water, away from this bottom 20.

The platform 40 extends facing a median portion of the opposite surface 82, away from it. The distance between the surface 82 of the platform 40 is between 15 m and 30 m. The structure 60 further defines two substantially transverse vertical end surfaces 88, 90 connecting the upstream and downstream surfaces 80, 82 to the longitudinal ends of the supporting structure 60.

The structure 60 thus defines, within the envelope between the surfaces 80 to 90, an overall volume which is the sum of the volume of the tubes forming the lattice 60 and the volume of the internal spaces 68 delimited between the tubes.

The interior spaces 68 are defined between the tubes forming the lattice 66. They open out from the supporting structure 60 through the surfaces 80 to 90 to allow the circulation of water through the structure 60, making the structure 60 transparent to the swell.

According to the invention, and to ensure this transparency to the swell, the ratio of the volume occupied by the interior spaces 68 to the sum of the volume of the interior spaces 68 and the volume occupied by the tubes forming the trellis 66 is greater than 0.9 . Preferably, this ratio is between 0.95 and 0.99. Thus, the carrier structure 60 is highly perforated, so that it offers locally in all points of the structure 60, a small surface in contact with the water per unit volume, and a large space for the circulation of water through the structure.

When the structure 60 is disposed in the body of water 14, it floats in the body of water 14 by being immersed substantially at mid-height. The upper surface 84 is thus disposed above the surface of the body of water.

The fastening pads 62 of the mooring lines 28 are arranged on the upper surface 84, along the vertical docking surface 80. They are distributed at the front, at the rear and in the middle of the structure 60. The anchor lines 64 are distributed around the structure 60 to limit its movement in a horizontal plane. In the example shown in FIG. 1, the floating dock 42 comprises two pairs of anchor lines 64 extending outwardly of the structure 60, in opposite axial directions, each pair extending respectively from the vertical docking surface 80 and the opposing vertical surface 82.

Each line 64 comprises an anchoring means 92, fixed in the bottom 20 of the body of water 14, and a joint link 94 connecting the anchoring means 92 to a tube of the mesh 66. The composite link 94 comprises a combination of a chain and a cable forming a catenary. The composite link 94 has, at rest, a relaxed form in J. It is likely to stretch linearly during a displacement of the supporting structure 60, in particular during the docking of the ship along the surface 80. Thus, the carrier structure 60 is displaceable locally horizontally on a limited stroke around a central rest position. This race is for example between 15 m and 30 m from the perimeter of the structure 60 in its rest position.

The tusks 63 are fixed on the mesh 66 along the vertical docking surface 80. They are intended to be interposed between the lateral edge 24 of the ship 12 and the supporting structure 60, when the ship is moored on the structure 60.

In the example shown in FIG. 3, the structure 60 comprises two parallel series of tusks 63 placed at different heights on the surface 80.

In a variant, the structure 60 comprises, for example, a first series of horizontal defenses 63 and a second series of vertical defenses 63.

The fluid transfer assembly 65 is mounted on the upper surface 84 of the carrier structure 60. It comprises, from upstream to downstream, a ship connection station 100 located in the vicinity of the docking surface 80, and a platform connection station 102, located in the vicinity of the opposite surface 82. The ship connection station 100 comprises flexible pipes upstream

104 to the ship, a fixed gantry 106 for supporting the pipes 104 and a mobile gantry 108 for moving the pipes 104 to the ship 12.

In a conventional manner, the pipes 104 are formed by transport hoses, flexible over substantially their entire length. Each duct 104 extends between a fixed end secured to the fixed gantry 108 and a movable free end 110 provided with a connecting piece to a connector 32, and an emergency disconnect valve.

The upstream flexible pipes 104 are hydraulically connected to the connection station 102 through the fixed gantry 106.

The mobile gantry 108 is movable relative to the fixed gantry 106 to the outside of the ship between a retracted position on the upper surface 84, and a laterally projecting position outside the upper surface 84.

The gantry 108 is provided, for each pipe 104, with a winch 112 for suspending the free end 110 of the flexible pipe 104. The pipe 104 then extends in a chain between its fixed end and its free end 110 in a vertical plane substantially perpendicular to the axis YY '. The pipe 104 is thus movable in this plane between a recessed position, in which the free end 1 10 extends facing the upper surface 84, and a position of connection to the vessel 12, in which the end free 110 protrudes away from the surface 84 beyond the surface 80 facing the body of water 14.

The station 102 comprises a manifold 120 fixed on the upper surface 84, and downstream flexible pipes 122 connecting the manifold 120 to the connection assembly 48 on the platform 40. The manifold 120 is hydraulically connected upstream to the upstream flexible pipes 104, and downstream, to the downstream flexible pipes 122.

The downstream flexible pipes 122 are flexible over substantially their entire length. They are hung in a chain between the connection assembly 48 and the collector 120, facing the intermediate space 124 that is exposed downwards, extending above the water body 14 between the floating dock 42 and the fixed platform 40. They extend in a vertical plane substantially perpendicular to the axis YY ', substantially in the extension of the upstream flexible pipes 104.

Each duct 122 is provided with an emergency disconnection device 126 disposed opposite the space 124 to separate the duct 122 into an integral upstream section of the platform 42 and free with respect to the platform 40, and an integral downstream section. platform 40 and free from dock 42.

The transfer assembly 65 located on the carrier structure 60, and the connection assembly 48 located on the fixed platform thus form, when connected together, a fluid conveying device between the vessel 12 and the conduit of transport 34.

The operation of the transport assembly 10 according to the invention, during an unloading operation of the fluid contained in a transport vessel 12 for transfer to a tank of the terminal 18, will now be described.

Initially, in the absence of ship 12 or when approaching, the floating dock 42 is maintained anchored in the bottom 20 of the body of water 14 via the anchor lines 64. The fixed platform 40 s then extends opposite the opposite vertical surface 82 of the supporting structure 60, substantially in the middle of this surface 82. The downstream flexible pipes 122 hydraulically connect the connection station 102 on the supporting structure 60 to the connection assembly 48 on the platform 40.

In addition, the mobile gantry 108 is placed in its retracted position to maintain the free ends of the upstream flexible pipes 104 facing the upper surface 84.

The mesh 66 of the supporting structure 60 is light and very perforated, so it is insensitive to the agitation of the body of water 14 at the surface or depth resulting from the swell or currents. The water of the expanse 14 thus circulates almost freely through the interior spaces 68.

The floating dock 42 is therefore able to withstand extreme difficult conditions, in particular a swell with a vertical amplitude greater than 6 meters.

Then, when meteorological conditions are encountered, for example when the swell is less than 2.5 meters in amplitude, the ship 12 approaches the floating dock 42 for docking, as shown in Figure 1.

The lateral edge 24 of the ship is brought opposite the vertical docking surface 80 by aligning the axis X-X 'of the ship 12 parallel to the axis YY' of the supporting structure 60.

The carrying structure 60 is anchored in the bottom 20 of the body of water by flexible lines 64, it is likely to move slightly from its rest position to the fixed platform 40 during the docking of the ship, by tension flexible lines 64 fixed on the docking surface 80. This allows the ship 12 to dock with a speed of between 0.3 m / s and 1 m / s without causing damage to the transfer installation 16, while by allowing damping of the docking shock. When the edge of the ship 24 is placed parallel to the surface 80, in contact with the absorption defenses 63, the mooring lines 28 of the ship are fixed on the attachment studs 62 of the floating dock 42. The flexible lines 64 then resume their J configuration, thus reducing the carrier structure 60 to its rest position.

The ship 12 is then secured to the carrier structure 60 and moves together with it under the effect of the agitation of the body of water.

However, the carrier structure 60 has a negligible mass compared to that of the ship 12, and a low local interaction with the water circulating in the interior spaces 68, it has a very low inertia compared to that of the ship 12, which which strongly limits the tensions exerted on the mooring lines 28 and the fixing studs 62.

In this configuration, the vessel 12 is kept substantially stationary relative to the platform 40 via the carrier structure 60 and the anchor pins 64. The flexible anchor lines 64 take up just the forces due to the local movement of the ship 12, the inertia of the carrier structure 60 being negligible. Lines 64 do not therefore need to be dimensioned for considerable effort.

Then, the removable connectors 32 are attached to the free end of the manifolds 30 to protrude beyond the side edge 24 of the vessel to the supporting structure 60.

The mobile gantry 108 is then moved from its retracted position to its extended position to bring the free end 110 of each upstream flexible pipe 104 into contact with a connector 32 to connect them.

A continuous passage of fluid circulation is then achieved. This passage extends from upstream to downstream, successively in the manifold 30 and the coupling 32, in the upstream flexible pipe 104, in the gantry 106, in the manifold 120, in the downstream flexible pipe 122, in the assembly of connection 48, then in the cryogenic conduit 34.

The liquefied fluid contained in the reservoir 26 is then discharged through this circulation passage, from the vessel 12, through the transfer assembly 65 located on the floating dock 42, through the connection assembly 38 on the platform 40 , and through the conduit 34, to the terminal 18.

In the event of a problem during the transfer, the emergency disconnection valves on the upstream flexible pipe 104 or on the downstream flexible pipe 122 are disconnectable, which avoids accidentally discharging fluid on the vessel 12, on the floating dock 42, or on the platform 40.

The second transport assembly 140 according to the invention, shown in FIG. 4, differs from the first set 10 by the arrangement of the transfer installation 16.

Indeed, the fixed platform 40 is placed in the axial extension of the floating dock 42, facing an end surface 90 of this quay.

The downstream flexible pipes 122 are therefore parallel to the axis YY 'of the platform 42, perpendicular to the axis of the upstream flexible pipes 104.

The operation of the assembly 140 is moreover analogous to that of the assembly 10. The third transport assembly 150, shown in FIG. 5, differs from the first assembly in that the transfer installation 16 is devoid of a fixed platform 40.

The transport duct 34 comprises a substantially rigid section 152 immersed, and a rising flexible section 156.

The submerged section 152 connects the terminal 18 to the coast at a point 154 on the bottom 20 located in the vicinity of the carrier structure 60.

The flexible section 156 is fixed on the structure 60 at its upstream connecting end 59. It has an S-shaped configuration. The supporting structure 60 carries the connection assembly 48 which is connected to the connecting end 59.

The fourth transport assembly 160 differs from the third assembly 150 in that the rigid section 152 of the transport duct 34 is connected to a reservoir 162 situated on a platform 164 situated at sea and fixed on the seabed by pillars 166. More generally, the invention also relates to a facility for transferring a fluid between a transport vessel and and a fluid reservoir on a fixed structure, of the type comprising:

. flexible anchoring lines of the structure on the bottom of the body of water;

. means for fixing the ship's mooring lines to the carrier structure, the conveying device comprising a fluid transfer assembly mounted on the perforated lattice, the transfer assembly comprising at least one upstream fluid transfer flexible pipe, intended to be connected to the ship. In this installation, the ratio of the volume of the interior spaces to the sum of the volume of the perforated lattice and the volume of the interior spaces is not specified and can be less than 0.9.

Claims

1 .- Installation (16) for transferring a fluid between a transport vessel (12) and a fluid reservoir on a fixed structure (18), of the type comprising:

- A conduit (34) for transporting the fluid to the fixed structure (18), at least partially immersed in a body of water (14);

- a fluid conveying device (65, 48) between the ship (12) and the transport pipe (34), connected to a connecting end (59) of the transport pipe (34); and

- a floating dock (42) for docking the ship (12), placed in the vicinity of the connecting end (59), and movable locally in the body of water (14), the floating dock

(42) comprising:

. a support structure (60) intended to be partially immersed in the body of water (14), the supporting structure (60) comprising a perforated lattice (66) delimiting internal spaces (68) for circulating water intended to unclog in the body of water (14),

. flexible lines (64) for anchoring the structure to the bottom (20) of the body of water (14);

. means (62) for fastening mooring lines (28) of the ship to the supporting structure (60); characterized in that the ratio of the volume of the interior spaces (68) to the sum of the volume of the latticework (66) and the volume of the interior spaces (68) is greater than 0.9.

2 - Installation (16) according to claim 1, characterized in that the conveying device (65, 48) comprises a set (65) of fluid transfer mounted on the latticework (66), the transfer assembly (65 ) comprising at least one upstream flexible fluid transfer pipe (104) for connection to the vessel (12).

3.- Installation (16) according to one of claims 1 or 2, characterized in that it comprises a fixed platform (40) of support, comprising at least one pillar (46) fixed on the bottom of the extension d water (141), the conveying device (65, 48) comprising a connection assembly (48) to the transport conduit (34), carried by the support platform (40), the connecting end (59) of the transport duct (34) being connected to the connection assembly (48) on the support platform (40).

4. Installation (16) according to claim 3, taken in combination with claim 2, characterized in that the transfer assembly (65) comprises at least one a fluid transfer downstream pipe (122) for connection to the connection assembly (48) on the support platform (40).

5. Installation (16) according to claim 4, characterized in that the support platform (40) and the carrier structure (60) delimit between them an intermediate space (124), the or each downstream flexible pipe (122) being provided with means (126) for emergency disconnection extending opposite the intermediate space.

6. Installation (16) according to any one of claims 3 to 5, characterized in that the carrier structure (60) has an elongate shape along an axis (Y-Y ') defining a lateral surface (80) berthing of the ship and an opposing lateral surface (82), said side surfaces (80, 82) extending between two ends of the supporting structure (60), the support platform (40) facing the opposite surface (82) between said ends or in the axial extension of the carrier structure (60) facing one of said ends.

7. Installation according to claim 2, characterized in that the conveying device (65, 48) comprises a connection assembly (48) to the transport duct (34) carried by the carrier structure (60), the connecting end (59) the transport conduit (34) being connected to the connection assembly (48) on the carrier structure (60).

8. Installation (16) according to any one of claims 2 to 7, characterized in that the or each upstream flexible pipe (104) is adapted to project at least partially away from the carrier structure (60) to the vessel (12), the or each upstream flexible pipe (104) being provided with emergency disconnecting means.

9. Installation (16) according to any one of the preceding claims, characterized in that the ratio of the volume of the interior spaces (68) to the sum of the volume of the perforated lattice (66) and the volume of the interior spaces (68) is between 0.95 and 0.99.

10. Installation (16) according to any one of the preceding claims, characterized in that the perforated lattice comprises a plurality of tubular beams (70, 72, 74) connected together, the perimeter of the carrier structure (60), taken in projection in a horizontal plane, being greater than at least fifty times the maximum diameter of the beams (70, 72, 74).

1 1. Installation according to any one of the preceding claims, characterized in that the mesh has a substantially constant horizontal section over its entire height.

12. A fluid transport assembly (10; 140), characterized in that it comprises:

a vessel (12) for transporting the fluid; and

- An installation (16) according to any one of the preceding claims, the ship (12) being moored on the floating dock (42) via mooring lines (28) fixed to the means for fixing the lines mooring (62) for the vessel (12) to move vertically together with the floating dock (42).

13. Assembly (10; 140) according to claim 12, characterized in that the weight of the carrier structure (60) is less than 5% of the weight of the ship (12).

14. Assembly (10; 140) according to one of claims 12 or 13, characterized in that the installation (16) comprises a single floating dock (42) for docking the ship (12), the ship (12) being moored exclusively to the single mooring floating dock (42).

15. A method of transferring a fluid in a transport assembly (10; 140) according to any one of claims 12 to 14, characterized in that it comprises the following steps:

- moving the vessel (12) to the floating dock (42) for docking opposite a docking surface (80) of the carrier structure (60);

- Establishment of mooring lines (28) to secure the ship (12) and the supporting structure (60), the supporting structure (60) then being movable vertically together with the ship;

- Hydraulic connection between a tank (26) of fluid carried by the ship and the connecting end of the transport duct (34) via the conveying device (65, 48) through or above the floating dock (42).

- Transfer of fluid between the vessel (12) and the fluid transport conduit (34).