Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
  • B63B—SHIPS OR OTHER WATERBORNE VESSELS; EQUIPMENT FOR SHIPPING 
  • B63B27/00—Arrangement of ship-based loading or unloading equipment for cargo or passengers
  • B63B27/24—Arrangement of ship-based loading or unloading equipment for cargo or passengers of pipe-lines

Definitions

• the invention relates to a hydrocarbon transfer system comprising an offshore structure with a support member extending upward from deck level of the structure, a hydrocarbon transfer duct comprising a transfer duct section extending from a free end of the support member, which free end is located outboard of the structure, to a hydrocarbon storage and/or processing unit on the structure and a connecting duct section in fluid communication with the transfer duct section and connected with a first end to the free end of the support member, a second end of the connecting duct section having a connector and being attachable to a hydrocarbon structure.
• Liquefied Natural Gas may be produced at seabed-supported platforms or spread moored or turret moored LNG liquefaction barges (FLNG) and is transferred from the production/processing site to cryogenic carriers.
• the LNG carriers may be vessels that are moored to an offshore liquefaction barge in a tandem configuration, via hawsers connecting the bow of the LNG carrier to the stern of the liquefaction barge and that are kept in position by dynamic positioning and the use of their thrusters.
• a flexible cryogenic hose connects at one end to a manifold at the bow of the carrier and at another end to a crane boom on the barge.
• a LNG transfer system in which a flexible LNG pipe is arranged at the end of a crane or boom which crane is rotatable around a horizontal axis.
• a connector in the LNG tank vessel's bow is connected to a pipe manifold leading further to the LNG tanks on the vessel.
• the crane which may be an A-frame crane, supports the flexible hose from rigid pipe swivel ducts and gives the flexible LNG pipe in its lowest point sufficient clearance above the sea to avoid being hit by waves.
• the movable crane frame compensates for slow changes in draught during the LNG transfer.
• the known crane has a relatively large footprint on the LNG barge when the crane is pivoted inboard of the vessel and the flexible hose is stored on deck.
• the known crane In order to raise the cryogenic hose above sea level when it is disconnected from the LNG tanker, the known crane must pivot around the horizontal axis.
• the drive mechanism for the crane is relatively complex and large in order to drive the large boom, and raising the cryogenic hose is therefore relatively slow.
• the known crane may not be able to raise the cryogenic hose in a sufficiently rapid manner.
• the crane in its retracted position, the crane extends above deck level of the LNG barge and has a relatively large footprint, occupying an area in which no further activities can be carried out.
• a hydrocarbon transfer system in accordance with the present invention is characterised in that the support member comprises a displacement device, connected to the first end of the connecting duct section, which displacement device is movable between a connect and a disconnect position while the support member remains substantially stationary, a vertical distance from deck level of the displacement device being larger for the disconnect position than for the connect position, a horizontal distance from the side of the structure being larger for the connect position than for the disconnect position.
• the connecting duct section in its vertical orientation is situated with its connector at a predetermined distance above sea level.
• the connecting duct section may while it is vertically depending from the support structure, be raised relatively high above seal level by movement of the displacement device only, such as at for instance a distance of between Im and 15m, preferably about 5m.
• the support structure which may comprise a crane or boom, remains substantially stationary.
• the vertically supported connecting duct section which preferably comprises a flexible cryogenic transfer hose, may next be connected to a manifold of a tanker vessel, by pulling in a cable connected to the free end of the duct section, via a winch on the tanker vessel.
• the connecting duct section thereby assumes a more horizontal position and the displacement device may be moved towards the tanker vessel to provide additional length of the transfer duct section bridging the distance between the tanker vessel and the structure.
• clearance of the connecting duct section above seal level can, in case of a quick release of the duct from the tanker vessel, be achieved rapidly via the displacement member while only driving the relatively small displacement member, which can be effected rapidly with a relatively simple and light drive member.
• the support structure can remain stationary, the footprint of the support structure on the offshore structure can be small.
• the connecting duct section is preferably formed by a flexible hose, such as a cryogenic transfer hose that is described in US patent no. 4,445,543, which assumes a curved configuration when connected to the tanker vessel.
• the offshore structure carrying the support member may rest on the sea bed and may comprise a column- supported platform.
• the offshore structure can also be a floating structure such as a semi-submersible structure or a turret or spread moored barge.
• the displacement device comprises an arm which is with a base end hingingly connected to the free end of the support member, a support end of the arm carrying the connecting duct section, a force member being connected to the arm for pivoting the arm between a substantially vertical disconnect position and a substantially horizontal connect position.
• the connecting duct section can be displaced along a circular trajectory from the disconnect position in which the arm extends in a generally vertical direction, to a connect position in which the arm extends in a generally horizontal direction.
• the force member can be formed by one or more hydraulic cylinders connected on one side to the support structure and on the other side to the arm of the displacement device.
• Actuation of the cylinders may be controlled by an computerised connect-release system with an emergency actuation to raise the displacement member in case of quick release of the connectors.
• the support member may comprise a frame that extends at an angle, a support surface being situated along at least a part of the length of the support member.
• the connecting duct section can be placed on the support surface to extend along the support member in the disconnected state. In the storage position, the connecting duct can remain attached to the transfer duct that is connected to a hydrocarbon storage and/or processing unit on the LNG barge.
• the transfer duct section may comprise a rigid duct which is attached at the free end of the support member to a displacement duct via a fluid swivel rotatable around a horizontal axis, a second end of the displacement duct being connected to the connecting duct section via a second swivel rotatable around a horizontal axis.
• the displacement device is in its lowest and most forward position - the connect position- while the connecting duct section is situated on the support surface.
• the connecting duct section is lifted from the support surface to become vertically oriented and depend from the raised displacement device.
• Fig. 1 shows a side view of an LNG barge being moored with its stern to the bow of an
• FIGs. 2a and 2b show an enlarged detail of a hammerhead manifold at the bow of the
• Fig. 3 shows a side view of the LNG barge and LNG carrier of Fig. 1 while the flexible hose is disconnected, and raised above sea level via the displacement device
• Fig. 4 shows an enlarged detail of the displacement device in the disconnect position
• Figs. 5a and 5b show an enlarged detail of the lower end and the upper end of the cryogenic hose respectively while extending on a support surface along the support member on the LNG barge
• Fig. 6 shows another view of the displacement device in the disconnect position while the flexible hose extends along the support member
• Figs. 7 and 8 show different stages of the connection process of the flexible hose.
• Fig. 1 shows a hydrocarbon transfer system comprising an offshore structure in the form of a floating LNG liquefaction barge 1.
• the barge 1 is at its stern 2 provided with a support frame 3 extending upward from deck level 11 at an angle ⁇ of about 45° , outboard from the barge 1.
• a LNG carrier 4 is moored with its bow 5 to the stern 2 via hawsers 6, 7.
• the carrier may be moored, i.e. kept of at a defined position, by one of its thrusters, so called dynamic positioning.
• a connecting duct section in the form of a flexible cryogenic hose 8 is with its upper end 9 attached to a displacement device 10.
• a lower connector end 12 of the hose 8 carries a connector 13 which is attached to a manifold 15 on the carrier 4.
• the manifold 15 comprises a plurality of connectors, such as a connector 17 for a liquid LNG line, a connector 18 for a hybrid line and a connector 19 for a vapour return line, such as shown in fig. 2a.
• the connector 13 and each complementary connector 17-19 are provided with a quick connect/disconnect system (QC/DC), an emergency release system (ERS) and a Break Away Connector System (BAC).
• QC/DC quick connect/disconnect system
• ERS emergency release system
• BAC Break Away Connector System
• the manifold 15 is supported on a hinged articulation, such that it can be rotated to be in line with the hose 8.
• a second flexible hose 20 is with an upper end connected to a respective displacement device for the hose 20.
• the hose rests on a support surface 25 on the support frame 3, such that the lower end 21, at which the connector 23 is provided, is situated near a lower part of the support frame 3 near deck level 11 of the barge 1.
• Stairs are provided on the support structure 3 to allow access to the hose 20 for inspection, testing, repair and maintenance.
• a rigid cryogenic transfer duct 27 is provided that extends to a LNG storage or processing unit 28, such as a cryogenic tank, on the barge 1.
• a displacement duct 30 that interconnects the rigid transfer duct 27 and the flexible connecting duct 8 via swivels 38, 39.
• the displacement duct 30 extends along the displacement device 10, as shown in fig. 2b.
• the displacement device 10 comprises a frame 33 which is with a base end 36 connected to the free end 35 of the support structure 3, via a pivot joint 34.
• the free end 35 of the frame 33 carries the flexible hose 8, which is via the swivel 39 connected to the displacement duct 30 which is attached to the frame 33 and which can pivot together with the frame from the horizontal connect position, as shown in fig. 1, to a vertical disconnect position as shown in fig. 3.
• the height H 3 of the displacement device 10 above deck level 11 can be for instance about 40m.
• the distance Dl of the upper end 9 of the connecting duct 8 from the side of the barge 1 is for instance 50 m.
• the frame 33 of the displacement device 10 is placed in the vertically upright opposition such that the free end 35 is raised by a height H 2 of about 10 m and the connector 13 at the end of the flexible hose 8, comprising the complex QC/DC, ERS and BAC components, is positioned well above sea level by a height H 1 of for instance about 3-7 m.
• the distance H 4 above deck level 11 is for instance about 50 m and the distance D 2 of the vertical hose 8 from the side of the barge 1 is for instance 40 m.
• hoses 8', 8" are supported along the support frame 3, with their respective displacement devices 10', 10" in a horizontal position.
• the hoses 8', 8" are supported on a surface on the support frame 3 and are accessible for inspection, maintenance or repair via stairs 40.
• the connector ends 12', 12" of the hoses 8', 8" are supported on a substantially horizontal platform 42 and are fixed in place by U-shaped brackets 43, which may be provided with a clamping device.
• Fig. 5b shows the displacement device 10 of the flexible hose 8 in the vertical position, while the hose is supported along the support frame 3.
• the U-shaped brackets 43 on the lower platform 42 may be opened and the hose 8 may be pushed from the support surface by personnel, such that the hose 8 becomes vertically oriented, depending from the displacement device 10.
• the frame 33 of the displacement device 10 can be seen to comprise a transverse reinforcing member 45 for carrying the weight of the flexible duct 8.
• Fig. 6 shows the displacement 10 form the stern looking towards the bow of the barge 1.
• the flexible duct is connected to a hinge articulation integrated in the boom extremity 46 which is adapted for suspending the flexible duct from the frame 33 and which interconnects the duct in a fluid transport manner to the displacement duct 30 via the cryogenic swivel 39.
• a force member 41 is provided, such as for instance one or more hydraulic cylinders, for pivoting the frame 33 around the pivot joint 34 from a horizontal connect position to a vertical disconnect position.
• the force member 41 may be driven by an emergency control system for rapidly raising the frame 33 upon occurrence of an emergency in order to keep the connector end 12 clear from the water at all times upon quick release or break away of the connector 13.
• Fig. 7 shows the flexible hose 8 being connected via a cable 50 at its connecter end 13 to a winch 51 on the bow of the vessel.
• the connector end 12 of the hose 8 is pulled towards the vessel 5 until the connector 13 is in line with the connectors 17-19 of the manifold 15 on the bow of the vessel 5.
• the displacement device 10 is lowered as shown in figure 8, and the connector 13 on the flexible hose 8 is pulled inboard of vessel 5 via the winch 51 and is connected to the manifold.
• the connector 13 can be disengaged while the displacement device 10 is quickly up righted so that the connector 13 at the free end of the hose 8 remains well above water level.

Landscapes

• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• Ocean & Marine Engineering (AREA)
• Filling Or Discharging Of Gas Storage Vessels (AREA)
• Fittings On The Vehicle Exterior For Carrying Loads, And Devices For Holding Or Mounting Articles (AREA)
• Supports For Pipes And Cables (AREA)

Priority Applications (4)

Applications Claiming Priority (2)

Publications (2)

Family

ID=40718255

Family Applications (1)

Country Status (5)

Cited By (7)

Family Cites Families (5)

• 2008
  • 2008-12-03 BR BRPI0820714-3A patent/BRPI0820714A2/pt not_active IP Right Cessation
  • 2008-12-03 WO PCT/EP2008/066667 patent/WO2009071563A2/en not_active Ceased
  • 2008-12-03 RU RU2010127275/11A patent/RU2489303C2/ru not_active IP Right Cessation
  • 2008-12-03 AU AU2008333240A patent/AU2008333240B2/en not_active Ceased
  • 2008-12-03 EP EP08857856A patent/EP2240362B1/de not_active Not-in-force

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