(19)
(11)EP 3 558 809 B1

(12)EUROPEAN PATENT SPECIFICATION

(45)Mention of the grant of the patent:
18.11.2020 Bulletin 2020/47

(21)Application number: 17829968.1

(22)Date of filing:  20.12.2017
(51)International Patent Classification (IPC): 
B63B 25/16(2006.01)
(86)International application number:
PCT/EP2017/083870
(87)International publication number:
WO 2018/115152 (28.06.2018 Gazette  2018/26)

(54)

FLOATING CRYOGENIC HYDROCARBON STORAGE STRUCTURE

SCHWIMMENDE KRYOGENE KOHLENWASSERSTOFFSPEICHERSTRUKTUR

STRUCTURE FLOTTANTE DE STOCKAGE CRYOGÉNIQUE D'HYDROCARBURES


(84)Designated Contracting States:
AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

(30)Priority: 23.12.2016 EP 16206668

(43)Date of publication of application:
30.10.2019 Bulletin 2019/44

(73)Proprietor: Single Buoy Moorings, Inc.
1723 Marly (CH)

(72)Inventors:
  • BRINKEL, Theodorus Johannes Bernardus
    98000 Monaco (MC)
  • SASSEN, Wouter
    98000 Monaco (MC)

(74)Representative: Nederlandsch Octrooibureau 
P.O. Box 29720
2502 LS The Hague
2502 LS The Hague (NL)


(56)References cited: : 
WO-A1-2013/156623
US-A- 3 043 256
GB-A- 1 175 323
  
      
    Note: Within nine months from the publication of the mention of the grant of the European patent, any person may give notice to the European Patent Office of opposition to the European patent granted. Notice of opposition shall be filed in a written reasoned statement. It shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention).


    Description

    Field of the invention



    [0001] The invention relates to a floating cryogenic hydrocarbon storage structure having a hull with a center line extending in a length direction and two longitudinal side walls, the structure comprising at least three spherical storage tanks. The invention in particular relates to a floating cryogenic hydrocarbon storage structure with a double side shell hull and having a row of Moss type storage tanks on either side of the center line.

    Background of the invention



    [0002] Such a floating cryogenic hydrocarbon storage structure is known from WO2013/156623 in which a twin-hull cryogenic LNG Floating Production Storage and Offloading structure (a so-called LNG FPSO) is described that is constructed from two interconnected converted LNG carriers. The LNG carriers each comprise a row of spherical Moss tanks in which liquefied natural gas is stored at temperatures of -163°C at ambient pressure. A number of LNG tanks has been removed so that a flat topside is formed on which the processing equipment for hydrocarbon processing and for liquefaction is placed. The hulls are interconnected by a relatively wide interconnecting beam structure and the two rows of tanks on each side of the longitudinal center line are separated by a relatively large distance.

    [0003] The known structure comprises six Moss type tanks and has a capacity of 150.000 m3 LNG. It is based on existing retrofitted LNG carriers and is of relatively wide dimensions. The twin hull construction is less suitable for new built floating structures.

    [0004] From WO2010/059059 a cryogenic carrier is known comprising a single row of Moss type tanks and sponsons for supporting processing equipment.

    [0005] It is an object of the invention to provide a floating cryogenic hydrocarbon storage and processing structure that is of compact design and that utilizes reduced amounts of steel. It is also an object to provide a floating cryogenic storage structure based on Moss-type storage tanks with ample space for liquefied gas processing equipment that can be produced at reduced costs.

    Summary of the invention



    [0006] Hereto the floating structure according to the invention has two spherical tanks situated with their midpoints on spaced apart longitudinal positions along a first line extending in the length direction at a first side of the center line. A third tank is situated with its midpoint on a longitudinal position on a second line extending in the length direction at a second side of the center line. A transverse distance between the first and second lines is not larger than a diameter of the tanks and the longitudinal position of the midpoint of the third tank is situated between the longitudinal positions of the midpoints of the first and second tanks.

    [0007] By placing the spherical tanks side by side in a stepped configuration, the width of the hull can be reduced by between 10% and 15% compared to the known arrangement in which the midpoints of the two rows of tanks are at opposed positions on each side of the center line. For a hull of a length of 250 m, a width of 60m and a height of 40 m, a 6% weight reduction can be achieved corresponding to about 3000 tons of steel.

    [0008] The midpoints of the two rows of tanks may be spaced in the transverse direction at a distance corresponding to the diameter of the spherical tanks or at smaller distances, so that the footprint of the two rows of tanks can be smaller than twice the tank diameter.

    [0009] In one embodiment of a floating cryogenic storage structure according to the invention, the first and second lines are spaced at a predetermined transverse distance from a respective nearest sidewall, a predetermined minimal clearance being provided between third tank and the first and second tanks, wherein a transverse distance between the longitudinal side walls of the hull is smaller by at least 5 % compared to the transverse distance for the arrangement in which the midpoints of the first and third tanks are on the same transverse line at a corresponding minimal clearance and at a corresponding transverse distance of the lines from the side walls.

    [0010] By the stepped configuration, the spherical tanks are placed within a compact footprint with a sufficient clearance between the tanks for access and maintenance.

    [0011] Preferably, at least two tanks are situated along the first and second lines respectively, preferably at least three tanks being situated along at least one of the lines. The liquefied gas FPSO may comprise two rows of five tanks each and may have a width of 78 m and a length of 340 m.

    [0012] In another embodiment of a floating cryogenic storage structure according to the invention, on a first side of the longitudinal center line a first non-spherical tank is provided adjacent the rearmost spherical tank and on the second side of the longitudinal center line a second non-spherical tank is provided adjacent the front most spherical tank.

    [0013] In the rectangular tanks, which may be membrane tanks or SPB-type tanks, the different types of hydrocarbon fluid that are separated from the gaseous hydrocarbon feed gas may be stored. The hydrocarbon fluid tanks can be situated in the space at the start and at the end of the two stepped rows of spherical tanks, so that the overall length of the FPSO is not increased.

    [0014] A bulkhead may extend vertically from a bottom of the vessel towards the deck, the bulkhead extending in the length direction in an undulating manner at a substantially uniform distance from the tanks. In this way, the bulkhead provides a longitudinal reinforcement of the hull structure while accommodating the stepped tank configuration.

    [0015] In a further embodiment, each tank is surrounded by bulkhead sections arranged in a hexagonal pattern. In this manner, the tanks are thermally insulated from each other, and maintenance or inspection may be carried on an empty tank while the bulkheads provide for proper separation from the surrounding parts of the hull.

    [0016] In another embodiment, the sidewalls extend from a bottom to an upper deck level. The spherical tanks extend below deck level. A longitudinal beam extends along the center line of the hull between the two rows of spherical tanks. The deck space can be utilized for supporting process equipment over the tanks, the tops of which may located just below, at or above deck level. The longitudinal beam reinforces the overhead deck and fits in the top open space between the adjacent spherical tanks.

    Brief description of the drawings



    [0017] Some embodiments of a floating cryogenic storage and processing structure according to the invention, will by way of non-limiting example be described in detail with reference to the accompanying drawings. |In the drawings:

    Fig. 1 shows a plan view of a LNG FPSO known in the prior art, having two spaced-apart rows of spherical Moss tanks,

    Fig. 2 shows a longitudinal cross-sectional view of the known FPSO of fig. 1,

    Fig. 3 shows a transverse cross-sectional view of the FPSO of fig. 1,

    Fig. 4 shows a schematic plan view of a known double row FPSO having a processing deck at a longitudinal distance from the spherical tanks,

    Fig. 5 shows a schematic plan view of a known double row FPSO having a topside overlying the spherical tanks,

    Fig. 6 shows a plan view of an embodiment of an LNG FPSO according to the invention,

    having two stepped rows of spherical Moss tanks,

    Fig. 7 shows a longitudinal cross-sectional view of the FPSO of fig. 6,

    Fig. 8 shows a transverse cross-sectional view of the FPSO of fig. 6,

    Fig. 9 shows a plan view of another embodiment of an LNG FPSO according to the invention,

    Fig. 10 shows a longitudinal cross-sectional view of the LNG FPSO of fig. 9,

    Fig. 11 shows a schematic view of the width of a known double row configuration of spherical tanks, and

    Fig. 12 shows a schematic of of the reduction in width obtained by a hexagonal configuration of spherical tanks according to the invention.


    Detailed description of the invention



    [0018] Fig. 1 shows a floating cryogenic LNG production, storage and offloading (FPSO) structure 1 comprising a hull 9 that is anchored to the sea bed via a turret 2. The FPSO 1 can weathervane around the turret 2 to be aligned with the prevailing direction of winds and//or currents.

    [0019] On board of the vessel 1, spherical Moss type tanks 3, 3' are arranged in two parallel rows 4, 5. Process equipment for gas treatment and for liquefaction of the treated natural gas is situated on deck of the vessel 1 on topside 6 (see Fig. 2). The process equipment purifies the natural gas that is produced from a subsea well by removal of water, carbon dioxide and H2S from the natural gas. The liquid hydrocarbon components that are separated from the gas, or "condensate" are stored in tanks 8. Next, the treated gas is liquefied by cooling to about - 163°C and is stored in liquid state at about ambient pressure in the insulated spherical Moss type tanks 3, 3'. The tanks 3, 3' are placed at respective sides of the longitudinal center line 10 and are separated by a vertical longitudinal bulkhead 13 on the center girder 13'in the double bottom 14 (see Fig. 3) and by transverse bulkheads 11, 12.

    [0020] The tanks 3, 3' have their upper ends or "domes" 15 situated near deck level 17, so that the tanks can be easily filled and emptied from the deck 17. At the bottom 14, the tanks 3, 3' are supported by a tank support structure or skirt 16 resting on the double bottom 14. and fixing the spherical tanks in place.

    [0021] Fig. 4 schematically shows a known embodiment of an LNG FPSO 1, having a deck 18 supporting gas treatment equipment and a liquefaction plant situated in front of the two rows of spherical tanks 4, 5.

    [0022] Fig. 5 shows a known arrangement in which the process equipment deck 18 is placed over the rows of tanks 4,5, resulting in a smaller length of the vessel. Condensate is stored in aft tanks 8. Near the bow an accommodation block 19 is provided.

    [0023] All embodiments shown in Figs. 1-5 can be adapted to be equipped with the stepped storage tank configuration according to the invention and described in detail here below.

    [0024] Fig. 6 shows an LNG FPSO 20 according to the invention having a hull 21 with longitudinal sides 22, 23. On each side of the longitudinal center line 24, two rows of sherical Moss type tanks 25, 26 are placed. Tanks 27, 28 of row 25 are placed with their midpoints 29, 30 on a first line LI on a first side 32 of the center line 24. Tanks 33, 34 are placed with their midpoints 36, 37 on the line L2 on a second side 38 of the center line 24. The midpoints 29, 30 of tanks 27, 28 on side 32 are situated at longitudinal distances T1, T2 along the line L1. The midpoints 26, 27 of tanks 33, 34 on the opposite side 38 are situated halfway between the midpoints 29, 30, 31 at longitudinal distances T3, T4 along second line L2. The lines L1,L2 are spaced at a distance W1 from the sides 22,23, such that a clearance is present between the tanks and the sides.

    [0025] The distance Wt between the lines L1, L2 is at least equal to the diameter D of the tanks. In the embodiment of Fig. 1, Wt is smaller than the tank diameter D. A minimal clearance Cm is present between adjacent tanks so that each tank is separated from its neighbouring tank by an insulating wall, and access to a tank is possible from all sides.

    [0026] By the stepped pattern of the spherical tanks according to the invention, the width Ws of the cargo section of the FPSO 20 can be reduced by between 10% and 15% compared to the prior art configuration shown in Fig. 1. As a result, at a length of the hull of 250m, a width of 60 m and a depth of 40m, the amount of steel used for the construction can be reduced from about 48,000 tonnes to about 45,000 tonnes.

    [0027] Fig. 6 shows a central bulk head 40 extending in a meandering manner in the direction of the longitudinal center line 24 between the two rows of tanks 25, 26. The bulkhead 40 interconnects the deck structure 41 and the bottom 42 and forms a compartmentalizing construction for the hull of the FPSO 20. Transverse bulkhead sections 43, 44 extend between adjacent tanks, from the vessel sidewalls 22, 23 in a transverse direction towards the central bulk head 40 so that the spherical tanks are contained in a hexagonal pattern in isolated compartments.

    [0028] Fig. 7 shows a topside 46 placed on top of the tanks that are located below the deck structure 41, the topside supporting the processing and liquefaction equipment.

    [0029] Fig 8 shows a box girder 47 that extends along the longitudinal center line 24 and reinforces the deck structure 41. The spherical tanks are placed in a support structure 45 in a hexagonal pattern. The support structure 45 may form ballast tanks 48 for taking in of sea water.

    [0030] Fig 9 shows in more detail an FPSO according to the invention where the tanks are placed between side supports 52 extending from the hull of the vessel, the transverse bulkheads 53 and the central bulkhead 54.

    [0031] In Fig. 10 it can be seen that the tanks and the topside level 51 extend slightly above the level of fore and aft deck 50.

    [0032] Fig. 11 schematically shows a known arrangement of two rows 4, 5 of spherical Moss tanks with a diameter D arranged with their midpoints at opposite positions of the longitudinal center line 10. The tanks are confined within individual compartments formed by transverse bulkheads 16 and longitudinal bulkhead 16'. Condensate tanks 8 are situated in a fore position.

    [0033] Fig. 12 shows the compact stepped arrangement according to the invention of the two rows 25, 26 of spherical tanks 27,28,33,34 of the same diameter D, arranged in a hexagonal pattern at a mutual minimum clearance Cm. Each tank is confined in an individual compartment formed by a first transverse bulkhead section 50 extending from longitudinal side position 51 between tanks 27, 28 on side 32 of the longitudinal center line 24. At first branch point 52, two bulkhead mid-sections 53, 54 connect to the transverse section 50, extending at an angle and connecting to transverse bulkhead sections 57, 58 on either side of tank 33. The transverse bulkhead sections 57,58 connect to second side 23 at side positions 59, 60. Condensate tanks 62, 63 are situated fore and aft of the stepped rows of tanks 25, 26.

    [0034] In an embodiment, bulkhead mid sections 53,53', 53" of the central bulkhead may be omitted to allow for different sizes of storage tanks. When re-using tanks from existing LNG carriers, the storage tanks may not all be of the same size and can be accommodated in the stepped arrangement according to the invention.


    Claims

    1. Floating cryogenic storage structure (20) comprising a hull (9) with a center line (24) extending in a length direction and two longitudinal side walls (22,23), the structure comprising at least three spherical storage tanks (27,28,33,34), two tanks (27,28) being situated with their midpoints (29,30) on spaced apart longitudinal positions (T1,T2) along a first line (L1) extending in the length direction at a first side (32) of the center line (24) and a third tank (33) being situated with its midpoint (36) on a longitudinal position (T3) on a second line (L2) extending in the length direction at a second side (38) of the center line, characterised in that a transverse distance (Wt) between the first and second lines (L1,L2) is not larger than a diameter (D) of the tanks and the longitudinal position (T3) of the midpoint of the third tank (36) is situated between the longitudinal positions (T1,T2) of the midpoints of the first and second tanks.
     
    2. Floating cryogenic storage structure (20) according to claim 1, wherein the transverse distance (Wt) between the first and second lines (L1,L2) is smaller than the diameter (D) of the tanks (27,28,33,34).
     
    3. Floating cryogenic storage structure (20) according to claim 1 or 2, the first and second lines (L1,L2) being spaced at a predetermined transverse distance (Wl) from a respective nearest sidewall (22,23), a predetermined minimal clearance (Cm) being provided between third tank (33) and the first and second tanks (27,28), wherein a transverse distance (Ws) between the longitudinal side walls (22,23) is smaller by at least 5 % compared to the transverse distance for the arrangement in which the midpoints of the first and third tanks are on the same transverse line at a corresponding minimal clearance and at a corresponding transverse distance of the lines from the side walls.
     
    4. Floating cryogenic storage structure (20) according to claims 1, 2 or 3, wherein the longitudinal position (T3) of the midpoint (36) of the third tank (33) is situated midway between the longitudinal positions (T1,T2) of the midpoints (29,30) of the first and second tanks (27,28).
     
    5. Floating cryogenic storage structure (20) according to claims 1, 2, 3 or 4, wherein at least two storage tanks (33,34) are situated with their midpoints (36,37) along the second line (L2) at a mutual distance corresponding to the distance between the midpoints (29,30) of the first and second tanks (27,28).
     
    6. Floating cryogenic storage structure (20) according to any of the preceding claims, wherein at least two tanks (27,28; 33,34) are situated along the first and second lines (L1,L2) respectively, preferably at least three tanks being situated along at least one of the lines.
     
    7. Floating cryogenic storage structure (20) according to any of the preceding claims, wherein on a first side (32) of the longitudinal center line (24) a first non-spherical tank (63) is provided adjacent the foremost spherical tank and on the second side (38) of the longitudinal center (24) line a second non-spherical tank (62) is provided adjacent the rear most spherical tank (33).
     
    8. Floating cryogenic storage structure (20) according to any of the preceding claims, comprising a bulkhead (40) extending vertically from a bottom (42) of the hull (9) towards a deck (41), the bulkhead extending in the length direction in undulating manner at a substantially uniform distance from the tanks.
     
    9. Floating cryogenic storage structure (20) according to claim 8, the bulkhead (40) having a first transverse section (50) extending transversely between the first and second storage tanks (27,28) from a first side position (51) in the direction of the midpoint (36) of the third storage tank (33) to a first branch positon (52) on the first side (32) of the structure, at least one mid-section (53,54) extending obliquely to a second branch position (55,56) on one side of the third storage tank (33) on the second side (38) of the structure, and at least one second transverse section (57,58) extending from the respective second branch position (55,56) to a second side position (59,60) of the vessel.
     
    10. Floating cryogenic storage structure (20) according to claim 9, comprising two mid sections (53,54), each extending obliquely to respectively the second and a third branch position (55,56) on each side of the third storage tank (33) on the second side (38) of the structure, and on each side of the third storage tank (33) respectively, the second and a third transverse sections (57,58) extending from the respective second and the third branch position (55,56) to the second and third side positions (59,60) of the structure.
     
    11. Floating cryogenic storage structure (20) according to claim 8, 9 or 10, each tank being surrounded by bulkhead sections arranged in a hexagonal pattern.
     
    12. Floating cryogenic storage structure (20) according to any of the preceding claims, the sidewalls (22,23) extending form a bottom (42) to a deck level (41), a top of the spherical tanks extending near deck level, preferably below deck level, a longitudinal beam (47) extending along the center line (24) between the two rows (25,26) of spherical tanks.
     
    13. Floating cryogenic storage structure (20) according to claim 12, wherein a substantially horizontal deck structure (43,51) extends over the top of the spherical tanks, the deck structure being supported by the beam (47) and carrying process equipment.
     


    Ansprüche

    1. Schwimmende kryogene Speicherstruktur (20), umfassend einen Rumpf (9) mit einer in Längsrichtung verlaufenden Mittellinie (24) und zwei Längsseitenwänden (22, 23), wobei die Struktur wenigstens drei kugelförmige Speichertanks (27, 28, 33, 34) umfasst, wobei zwei Tanks (27, 28) mit ihren Mittelpunkten (29, 30) auf voneinander beabstandeten Längspositionen (T1, T2) entlang einer ersten Linie (L1) angeordnet sind, die sich in Längsrichtung an einer ersten Seite (32) der Mittellinie (24) erstreckt, und ein dritter Tank (33) mit seinem Mittelpunkt (36) in einer Längsposition (T3) auf einer zweiten Linie (L2) angeordnet ist, die sich in Längsrichtung auf einer zweiten Seite (38) der Mittellinie erstreckt, dadurch gekennzeichnet, dass ein Querabstand (Wt) zwischen der ersten und der zweiten Linie (L1, L2) nicht größer ist als ein Durchmesser (D) der Tanks ist und sich die Längsposition (T3) des Mittelpunkts des dritten Tanks (36) zwischen den Längspositionen (T1, T2) der Mittelpunkte des ersten und zweiten Tanks befindet.
     
    2. Schwimmende kryogene Speicherstruktur (20) nach Anspruch 1, bei der der Querabstand (Wt) zwischen der ersten und der zweiten Leitung (L1, L2) kleiner ist als der Durchmesser (D) der Tanks (27, 28, 33, 34).
     
    3. Schwimmende kryogene Speicherstruktur (20) nach Anspruch 1 oder 2, bei der die erste und die zweite Linie (L1, L2) in einem vorbestimmten Querabstand (WI) von einer jeweils nächstgelegenen Seitenwand (22, 23) beabstandet sind, wobei ein vorbestimmter Mindestabstand (Cm) zwischen dem dritten Tank (33) und dem ersten und dem zweiten Tank (27, 28) vorgesehen ist, wobei ein Querabstand (Ws) zwischen den Längsseitenwänden (22, 23) um wenigstens 5% kleiner ist als der Querabstand für die Anordnung, bei der sich die Mittelpunkte des ersten und des dritten Tanks auf derselben Querlinie bei entsprechendem Mindestabstand und bei entsprechendem Querabstand der Linien von den Seitenwänden befinden.
     
    4. Schwimmende kryogene Speicherstruktur (20) nach Anspruch 1, 2 oder 3, bei der die Längsposition (T3) des Mittelpunkts (36) des dritten Tanks (33) in der Mitte zwischen den Längspositionen (T1, T2) der Mittelpunkte (29, 30) des ersten und zweiten Tanks (27, 28) liegt.
     
    5. Schwimmende kryogene Speicherstruktur (20) nach den Ansprüchen 1, 2, 3 oder 4, bei der wenigstens zwei Speichertanks (33, 34) mit ihren Mittelpunkten (36, 37) entlang der zweiten Linie (L2) in gegenseitigem Abstand entsprechend dem Abstand zwischen den Mittelpunkten (29, 30) des ersten und zweiten Tanks (27, 28) angeordnet sind.
     
    6. Schwimmende kryogene Speicherstruktur (20) nach einem der vorhergehenden Ansprüche, bei der wenigstens zwei Tanks (27, 28; 33, 34) entlang der ersten bzw. zweiten Linie (L1, L2) angeordnet sind, wobei vorzugsweise wenigstens drei Tanks entlang wenigstens einer der Linien angeordnet sind.
     
    7. Schwimmende kryogene Speicherstruktur (20) nach einem der vorhergehenden Ansprüche, bei der auf einer ersten Seite (32) der Längsmittellinie (24) ein erster nicht kugelförmiger Tank (63) neben dem vordersten kugelförmigen Tank vorgesehen ist und auf der zweiten Seite (38) der Längsmittellinie (24) ein zweiter nicht kugelförmiger Tank (62) neben dem hintersten kugelförmigen Tank (33) vorgesehen ist.
     
    8. Schwimmende kryogene Speicherstruktur (20) nach einem der vorhergehenden Ansprüche, umfassend ein Schott (40), das sich vertikal von einem Boden (42) des Rumpfes (9) zu einem Deck (41) erstreckt, wobei sich das Schott in der Längsrichtung in wellenförmiger Weise in einem im wesentlichen gleichmäßigen Abstand von den Tanks erstreckt.
     
    9. Schwimmende kryogene Speicherstruktur (20) nach Anspruch 8, bei der das Schott (40) einen ersten Querschnitt (50) aufweist, der sich quer zwischen dem ersten und dem zweiten Speichertank (27, 28) von einer ersten Seitenposition (51) in Richtung des Mittelpunkts (36) des dritten Speichertanks (33) zu einer ersten Abzweigposition (52) auf der ersten Seite (32) der Struktur erstreckt, wobei sich wenigstens ein Mittelabschnitt (53, 54) schräg zu einer zweiten Abzweigposition (55, 56) auf einer Seite des dritten Speichertanks (33) auf der zweiten Seite (38) der Struktur erstreckt und sich wenigstens ein zweiter Querabschnitt (57, 58) von der jeweiligen zweiten Abzweigposition (55, 56) zu einer zweiten Seitenposition (59, 60) des Schiffes erstreckt.
     
    10. Schwimmende kryogene Speicherstruktur (20) nach Anspruch 9, umfassend zwei Mittelabschnitte (53, 54), die sich jeweils schräg zu der zweiten bzw. einer dritten Abzweigposition (55, 56) auf jeder Seite des dritten Speichertanks (33) auf der zweiten Seite (38) der Struktur bzw. auf jeder Seite des dritten Speichertanks (33) erstrecken, wobei sich der zweite und ein dritter Querabschnitt (57, 58) von der jeweiligen zweiten und der dritten Abzweigposition (55, 56) zur zweiten und dritten Seitenposition (59, 60) der Struktur erstrecken.
     
    11. Schwimmende kryogene Speicherstruktur (20) nach Anspruch 8, 9 oder 10, bei der jeder Tank von Schottabschnitten umgeben ist, die in einem sechseckigen Muster angeordnet sind.
     
    12. Schwimmende kryogene Speicherstruktur (20) nach einem der vorhergehenden Ansprüche, bei der sich die Seitenwände (22, 23) von einem Boden (42) bis zu einer Deckhöhe (41) erstrecken, sich eine Oberseite der kugelförmigen Tanks vorzugsweise nahe der Deckhöhe, vorzugsweise unter Deckhöhe erstrecken und sich ein Längsträger (47) entlang der Mittellinie (24) zwischen den beiden Reihen (25, 26) von Kugeltanks erstreckt.
     
    13. Schwimmende kryogene Speicherstruktur (20) nach Anspruch 12, bei der sich eine im Wesentlichen horizontale Deckstruktur (43, 51) über die Oberseite der kugelförmigen Tanks erstreckt, wobei die Deckstruktur von dem Träger (47) getragen wird und Prozessgerät trägt.
     


    Revendications

    1. Structure flottante de stockage cryogénique (20) comprenant une coque (9) ayant un axe longitudinal (24) s'étendant dans une direction de longueur et deux parois latérales longitudinales (22, 23), la structure comprenant au moins trois réservoirs de stockage sphériques (27, 28, 33, 34), deux réservoirs (27, 28) étant situés avec leurs points médians (29, 30) sur des positions longitudinales espacées (T1, T2) le long d'une première ligne (L1) s'étendant dans la direction de longueur d'un premier côté (32) de l'axe longitudinal (24) et un troisième réservoir (33) étant situé avec son point médian (36) sur une position longitudinale (T3) sur une seconde ligne (L2) s'étendant dans la direction de longueur d'un second côté (38) de l'axe longitudinal, caractérisée par le fait qu'une distance transversale (Wt) entre les première et seconde lignes (L1, L2) n'est pas plus grande qu'un diamètre (D) des réservoirs et que la position longitudinale (T3) du point médian du troisième réservoir (36) est située entre les positions longitudinales (T1, T2) des points médians des premier et deuxième réservoirs.
     
    2. Structure flottante de stockage cryogénique (20) selon la revendication 1, dans laquelle la distance transversale (Wt) entre les première et seconde lignes (L1, L2) est plus petite que le diamètre (D) des réservoirs (27, 28, 33, 34).
     
    3. Structure flottante de stockage cryogénique (20) selon la revendication 1 ou 2, les première et seconde lignes (L1, L2) étant espacées d'une distance transversale prédéterminée (W1) d'une paroi latérale la plus proche respective (22, 23), un dégagement minimal prédéterminé (Cm) étant prévu entre le troisième réservoir (33) et les premier et deuxième réservoirs (27, 28), une distance transversale (Ws) entre les parois latérales longitudinales (22, 23) étant plus petite d'au moins 5 % par rapport à la distance transversale pour l'agencement dans lequel les points médians des premier et troisième réservoirs se trouvent sur la même ligne transversale à un dégagement minimal correspondant et à une distance transversale correspondante des lignes par rapport aux parois latérales.
     
    4. Structure flottante de stockage cryogénique (20) selon les revendications 1, 2 ou 3, dans laquelle la position longitudinale (T3) du point médian (36) du troisième réservoir (33) est située à mi-chemin entre les positions longitudinales (T1, T2) des points médians (29, 30) des premier et deuxième réservoirs (27, 28).
     
    5. Structure flottante de stockage cryogénique (20) selon les revendications 1, 2, 3 ou 4, dans laquelle au moins deux réservoirs de stockage (33, 34) sont situés avec leurs points médians (36, 37) le long de la seconde ligne (L2) à une distance mutuelle correspondant à la distance entre les points médians (29, 30) des premier et deuxième réservoirs (27, 28).
     
    6. Structure flottante de stockage cryogénique (20) selon l'une quelconque des revendications précédentes, dans laquelle au moins deux réservoirs (27, 28 ; 33, 34) sont respectivement situés le long des première et seconde lignes (L1, L2), de préférence au moins trois réservoirs étant situés le long d'au moins l'une des lignes.
     
    7. Structure flottante de stockage cryogénique (20) selon l'une quelconque des revendications précédentes, dans laquelle, d'un premier côté (32) de l'axe longitudinal (24), un premier réservoir non-sphérique (63) est disposé adjacent au réservoir sphérique le plus en avant et, du second côté (38) de l'axe longitudinal (24), un deuxième réservoir non-sphérique (62) est disposé adjacent au réservoir sphérique le plus en arrière (33).
     
    8. Structure flottante de stockage cryogénique (20) selon l'une quelconque des revendications précédentes, comprenant une cloison (40) s'étendant verticalement à partir d'un fond (42) de la coque (9) vers un pont (41), la cloison s'étendant dans la direction de longueur de manière ondulante à une distance sensiblement uniforme des réservoirs.
     
    9. Structure flottante de stockage cryogénique (20) selon la revendication 8, dans laquelle la cloison (40) a une première section transversale (50) s'étendant transversalement entre les premier et deuxième réservoirs de stockage (27, 28) à partir d'une première position latérale (51) dans la direction du point médian (36) du troisième réservoir de stockage (33) jusqu'à une première position de ramification (52) du premier côté (32) de la structure, au moins une section intermédiaire (53, 54) s'étend de manière oblique jusqu'à une deuxième position de ramification (55, 56) d'un côté du troisième réservoir de stockage (33) du second côté (38) de la structure, et au moins une seconde section transversale (57, 58) s'étendant à partir de la deuxième position de ramification respective (55, 56) jusqu'à une deuxième position latérale (59, 60) du navire.
     
    10. Structure flottante de stockage cryogénique (20) selon la revendication 9, comprenant deux sections intermédiaires (53, 54), s'étendant chacune de manière oblique jusqu'à, respectivement, la deuxième et une troisième position de ramification (55, 56), de chaque côté du troisième réservoir de stockage (33) du second côté (38) de la structure, et de chaque côté du troisième réservoir de stockage (33), respectivement, la deuxième et une troisième section transversale (57, 58) s'étendant à partir des deuxième et troisième positions respectives de ramification (55, 56) jusqu'aux deuxième et troisième positions latérales (59, 60) de la structure.
     
    11. Structure flottante de stockage cryogénique (20) selon la revendication 8, 9 ou 10, chaque réservoir étant entouré par des sections de cloison disposées selon un motif hexagonal.
     
    12. Structure flottante de stockage cryogénique (20) selon l'une quelconque des revendications précédentes, les parois latérales (22, 23) s'étendent à partir d'un fond (42) jusqu'à un niveau de pont (41), une partie supérieure des réservoirs sphériques s'étend près du niveau de pont, de préférence sous le niveau de pont, et une poutre longitudinale (47) s'étend le long de l'axe longitudinal (24) entre les deux rangées (25, 26) de réservoirs sphériques.
     
    13. Structure flottante de stockage cryogénique (20) selon la revendication 12, dans laquelle une structure de pont sensiblement horizontale (43, 51) s'étend au-dessus de la partie supérieure des réservoirs sphériques, la structure de pont étant supportée par la poutre (47) et portant un équipement de traitement.
     




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    Cited references

    REFERENCES CITED IN THE DESCRIPTION



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    Patent documents cited in the description