EP0310981B1 - Procédé et dispositif pour l'installation d'une plate forme "off shore" - Google Patents

Procédé et dispositif pour l'installation d'une plate forme "off shore" Download PDF

Info

Publication number
EP0310981B1
EP0310981B1 EP88116291A EP88116291A EP0310981B1 EP 0310981 B1 EP0310981 B1 EP 0310981B1 EP 88116291 A EP88116291 A EP 88116291A EP 88116291 A EP88116291 A EP 88116291A EP 0310981 B1 EP0310981 B1 EP 0310981B1
Authority
EP
European Patent Office
Prior art keywords
platform
basin
floating
floating basin
floater
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
EP88116291A
Other languages
German (de)
English (en)
Other versions
EP0310981A1 (fr
Inventor
Hans Peter Greuner
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
EON Ruhrgas AG
Original Assignee
Ruhrgas AG
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Ruhrgas AG filed Critical Ruhrgas AG
Publication of EP0310981A1 publication Critical patent/EP0310981A1/fr
Application granted granted Critical
Publication of EP0310981B1 publication Critical patent/EP0310981B1/fr
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
    • B63B—SHIPS OR OTHER WATERBORNE VESSELS; EQUIPMENT FOR SHIPPING 
    • B63B35/00—Vessels or similar floating structures specially adapted for specific purposes and not otherwise provided for
    • B63B35/44—Floating buildings, stores, drilling platforms, or workshops, e.g. carrying water-oil separating devices

Definitions

  • the invention relates to a method and a device for erecting an offshore installation at the place of use, wherein at least one floating body is anchored to the ground with a plurality of preferably evenly distributed tension elements in such a way that the tension elements are held taut by the buoyancy forces of the floating body, and a platform is used for this Floating body is placed so that it is not flooded even in unfavorable sea conditions.
  • the platform In conventional offshore plants, the platform is built over a central column or several columns directly on the seabed.
  • Such column-supported drilling rigs or platforms with foundations in the seabed represent a not inconsiderable operational risk. They must also be located sufficiently high above the sea surface so that they cannot be reached even by a wave of the century. For safety reasons, changes in the seabed structure of such ground-based systems make extraordinarily expensive renovation work necessary in order to keep the platform level at the intended height above the water level and within narrow tolerances in the intended position.
  • a device of the generic type is known from the journal "Ocean Industry", August 1984, pages 35 to 46, in which the actual platform is supported on a floating body anchored at a predetermined height above the sea floor.
  • the floating body itself consists of a completely in the water-immersed frame-shaped pipe hull and in its four corner areas support columns for the platform held above the water surface. Both the support pillars and the fuselage tubes running at right angles to each other can be walked on and accommodate, among other things, the tensioning devices for the tension elements designed as tubes.
  • the advantage of these floating offshore plants is, above all, the expansion of production possibilities to deep-water drilling sites up to more than 500 m.
  • the assembly and maintenance effort for floating offshore systems that are to be anchored at the place of use above the drilling site is also lower than for ground-based systems.
  • the tensioning devices can only be arranged at a few locations located at a relatively large distance from one another, namely in each case in the area of one of the vertical support columns.
  • the fixed position of the floating body carrying the drilling platform via a few concentrated tension elements is not without problems and requires complex anchor structures in the subsurface.
  • the support pillars must hold the platform at a sufficient height above the sea surface so that at least the upper deck of the platform cannot be washed over and damaged in extreme sea conditions, for example in a century wave.
  • the invention has for its object to reduce the assembly and maintenance costs of float-based offshore systems and at the same time to increase operational safety for people and materials.
  • this object is achieved by the features of claim 1, wherein the platform is inserted into a floating pool forming the floating body, the length of the tension elements is set so that the platform is sealed off from the surrounding side walls from the surrounding water and from rough seas is protected, the pool interior is partially flooded and the buoyancy forces transmitted by the tension elements are controlled by changing the flooding level.
  • the floating body itself forms a protective wall surrounding the platform, which keeps the surrounding water away from the pool interior receiving the platform far beyond the normal water level.
  • there is considerable space, especially below the platform which can be used by flooding and suitable selection of the flooding level to adjust the respectively effective buoyancy forces and thus to adapt to the prevailing sea conditions.
  • the pool interior is pumped empty to a minimum level, so that maximum buoyancy forces are transmitted by the tension elements and can be used, among other things, to stabilize the pool against correspondingly increased horizontal forces.
  • a buoyancy is generated which reaches about four times the value of the forces acting horizontally on the swimming pool.
  • the overall effective buoyancy can be reduced by increasing the flooding level. This relieves the tension elements that absorb the effective buoyancy, even though the platform's offshore system is optimally protected.
  • a particularly simple and cost-saving construction of the platform is possible in a further development of the invention in that the platform is placed on a foundation in the pool interior and the maximum flooding level of the pool interior is limited so that the platform's own weight is always greater than that acting on the platform Is buoyant. This means that the platform can not float and in extreme sea conditions and accordingly low flooding levels with higher weight pressure on the Foundation is resting. Lateral securing of the platform is done, for example, with the aid of several suitable spacers, for example fenders, which are inserted between the platform and the circumferential side wall of the swimming pool.
  • the device for erecting an offshore installation at the place of use according to claim 6 has at least one floating body which is anchored to the ground with a plurality of preferably evenly distributed tension elements in such a way that the tension elements are held taut by the buoyancy forces of the floating body, and means for holding a platform on the Floating body and is characterized according to the invention in that the floating body is designed as a floating pool with essentially watertight lockable bottom and side walls, that the platform is inserted in a fixed position in the pool in such a way that it is surrounded by the bottom walls that the tension elements have such an effective length between the ground anchorage and the swimming pool that the side walls protrude upward from the surface of the water surrounding the pool and form a protective wall against the sea around the platform, and means for flooding and emptying the Pool interior are provided on the floating pool.
  • a large number, for example 200 to 500, of cables which are uniformly distributed around the circumference of the basin are preferably used as tension elements.
  • the hawser acting pretensioners can both the immersion depth of the swimming pool as well as its horizontal position be adjusted or corrected.
  • the easy accessibility of such pretensioning devices, for example on the outboard of the protector basin also enables a subsequent position correction if, for example, the seabed conditions change during the use of the offshore installation and bring about a change in the position of the floating basin.
  • the hawser can be made of aramid fibers, for example, which have proven to be particularly tensile and durable.
  • the new offshore plant is shown in its installation position above the drilling site. It has a floating body in the form of a floating basin 1 with a circular cross section, a foundation ring 3 embedded in the seabed 2, a large number of anchoring cables 5 which anchor the floating basin 1 to the foundation ring 3 and are held taut by the buoyancy forces of the floating basin.
  • a central riser 7 connects the borehole to the platform 9 supported in the interior of the swimming pool 1, which is indicated by dashed lines in FIG. 1.
  • the riser 7 can be of conventional design, as can the platform 9 itself, which can be designed in accordance with the particular application requirements and is not subject to any particular shape or dimension restrictions.
  • the anchoring cables 5 are shown at the minimum azimuth angle ⁇ of 45 ° for anchoring arrangements of this type.
  • ⁇ azimuth angle
  • the anchoring cables in addition to the buoyancy forces in the vertical direction, approximately equally large forces occur in the horizontal direction and load the anchoring cables 5.
  • the latter should have an azimuth angle ⁇ 'at or near 90 °, so that the tensile loads are limited to the effective buoyancy forces.
  • An anchoring system idealized in this sense with a large number of vertical hawser evenly distributed over the circumference of the swimming pool 1 5 is shown in Figure 2.
  • the floating basin 1 shown in vertical section in FIG. 3 is a steel construction with a circular peripheral side wall 11 and a bottom wall 13 inclined in a funnel-like manner.
  • the riser 7 shown in broken lines in FIG. 3 passes through a central floor opening 15 and is connected to the platform 9 in a suitable manner.
  • the floating basin 1 is designed to be essentially watertight in the region of the side walls and floor walls, including the floor opening 15 serving as a passage.
  • the anchoring cables 5 are preferably made of aramid fibers or another high tensile, corrosion-resistant material.
  • Each anchoring cable 5 can be assigned its own prestressing hydraulics 15; Prestressing hydraulics can, however, also be assigned to a plurality of anchoring cables 5 together.
  • the platform 9 is placed on a foundation 17 in the interior 10 of the floating pool 1.
  • the latter is firmly connected to the swimming pool 1 or the bottom wall 13 by suitable means, not shown in the drawing.
  • the platform 9 rests on the foundation 17 only under its own weight.
  • Fenders 19 (FIG. 4) clamped in between the corners of the platform 9 and the inside of the circumferential side wall 11 hold the platform 9 aligned over the central opening 15.
  • the floating basin 1 acting as a buoyant body generates a buoyancy of approximately 2 GN in the example shown, which is approximately four times the value of the forces acting horizontally on the basin 1 (0.4-0.5 GN).
  • the buoyancy is adjustable. This is done by partially flooding the interior 10 of the swimming pool 1 in the area H between the flood levels H 1 and H 2.
  • the water exchange for flooding or emptying the interior 10 of the swimming pool 1 takes place with the aid of known ballast pumps 21.
  • the diameter of the tank 1 is approximately 150 m
  • the draft of the tank 1 to the lower edge of the side wall is approximately 15 m
  • the draft to the lower edge of the floor wall is approximately 25 m
  • the freeboard dimension is approximately 20 m.
  • a multi-unit foundation ring 3 is provided in the exemplary embodiment described, the total diameter of which depends on the water depth, pool diameter and azimuth angle and is between approximately 150-900 m.
  • a section of the foundation ring 3 is shown in FIG. 5; an individual member designed as a steel pontoon 23 is shown in FIG.
  • Any box-shaped steel pontoon 23 is hollow, floats per se and can be filled with sand or ash.
  • the length dimensions of each steel pontoon depend on the ring diameter. Its height and width dimensions must be selected so that they can reliably absorb the tensile forces of the anchor cables when filled with sand, for example.
  • the adjacent links 23 are connected to one another by suitable connecting elements 24 in such a way that they can be inclined to one another to a limited extent.
  • Foundation piles 25 are hammered into the floor 2, around which the foundation ring 23 with its members 23 is placed in order to hold the foundation ring in position.
  • the dead weight of the pontoons 23 filled with sand or another relatively heavy free-flowing material is generally sufficient as a bottom-side abutment for the anchoring cables 5.
  • each foundation ring member 23 hooks 26 are provided at regular intervals for hawser attachment.

Landscapes

  • Engineering & Computer Science (AREA)
  • Architecture (AREA)
  • Civil Engineering (AREA)
  • Structural Engineering (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • Ocean & Marine Engineering (AREA)
  • Revetment (AREA)
  • Foundations (AREA)
  • Earth Drilling (AREA)

Claims (15)

  1. Procédé pour l'installation d'une structure "offshore" au lieu d'utilisation où au moins un flotteur est ancré au sol par plusieurs éléments de tension, répartis de préférence régulièrement, de la sorte que les éléments de tension sont maintenus raides par les forces portantes du flotteur et où une plate-forme est disposée sur le flotteur à une hauteur de façon à ce que sa surface se trouve au-dessus de la surface d'eau de mer, même à une agitation désavantageuse de la mer, caractérisé par le fait que le flotteur est conçu sous forme de corps creux en forme de bassin (bassin flottant) muni de bordages circonférentiels, dans lequel est placée la plate-forme, que la longeur des éléments de tension est choisie de façon à ce que la plate-forme est enfermée par les bordages circonférentiels de l'eau ambiante et protégée contre l'agitation de la mer, que l'intérieur du bassin flottant est en partie remplie d'eau et que les forces portantes transmises par les éléments de tension sont réglées par le niveau de remplissage d'eau de l'intérieur du bassin.
  2. Procédé selon la revendication 1, caractérisé par le fait que le niveau de remplissage d'eau à l'intérieur du bassin flottant est varié en fonction de l'agitation de la mer.
  3. Procédé selon l'une quelconque des revendications 1 ou 2, caractérisé par le fait que la plate-forme est posée sur un fondement à l'intérieur du bassin flottant et que le niveau maximal de remplissage d'eau de l'intérieur du bassin est limité de la sorte que le poids propre de la plate-forme est toujours supérieur aux forces portantes exercées sur la plate-forme.
  4. Procédé selon l'une quelconque des revendications 1 à 3, caratérisé par le fait que les forces portantes sont réparties en principe régulièrement sur une multitude de câbles d'ancrage et que les câbles sont tendus sous des angles azimutaux essentiellement uniformes.
  5. Procédé selon la revendication 4, caractérisé par le fait que les angles azimutaux, sous lesquels les câbles d'ancrage sont tendus, se trouvent à l'intérieur d'une plage de 90° à 45 °.
  6. Dispositif pour l'installation d'une structure "offshore" au lieu d'utilisation avec au moins un flotteur (1) ancré au sol (2) par plusieurs éléments de tension (5), répartis de préférence régulièrement de la sorte que les éléments de tension sont maintenus raides par les forces portantes dudit flotteur, et avec des moyens (17, 19) pour la fixation de la plate-forme (9) sur le-dit flotteur, caractérisé par le fait que le flotteur est conçu sous forme de bassin flottant (1) avec des parvis de fond et de bordage (11, 13) à fermeture essentiellement étanche à l'eau, que la plate-forme (9) est placée dans le bassin flottant (1) en position stabile de la sorte qu'elle est enfermée par les bordages (11), que les éléments de tension (5) ont une longueur entre l'ancrage au sol (3) et le bassin flottant (1) de façon à ce que lesdit bordages s'élèvent au-dessus de l'eau entourant le bassin flottant (1) et forment un mur de protection autour de ladite plate-forme contre l'agitation de la mer, et que des moyens (21) sont prévus au bassin flottant (1)) pour le remplissage et le vidange de l'intérieur (11) du bassin.
  7. Dispositif selon la revendication 6, caractérisé par le fait qu'une multitude de câbles (5) répartis autour de la circonférence du bassin (1) est prévue comme éléments de tension, un dispositif de prétension (15) actionné par une force extérieure étant attribué auxdit câbles, soit individuellement, soit par groupes, pour le réglage de la profondeur d'immersion du bassin flottant.
  8. Dispositif selon la revendication 7, caractérisé par le fait que les câbles (5) sont tendus sous des angles azimutaux essentiellement uniformes (2, 2') à l'intérieur d'une plage de 90 à 45 ° par rapport à l'axe horizontal.
  9. Dispositif selon l'une quelconque des revendications 6 à 8, caractérisé par le fait que le bassin flottant (1) possède une bordage en forme de cercle.
  10. Dispositif selon l'une quelconque des revendications 6 à 9, caractérisé par le fait que la hauteur libre du bordage s'élève à 15 à 25 m.
  11. Dispositif selon l'une quelconque des revendications 6 à 10, caractérisé par le fait que le bassin flottant (1) est conçu, du point de vue grandeur, profondeur d'immersion et poids propre, de la sorte que sa force portante correspond à-peu-près à 3,5 à 4 fois la valeur des forces excercées horizontalement audit bassin.
  12. Dispositif selon l'une quelconque des revendications 6 à 11, caractérisé par le fait qu'un anneau de fondement à plusieurs éléments (3) dont les éléments (23) sont reliés les uns aux autres de préférence par des articulations, est prévu pour l'ancrage des éléments de tension (5) au sol (2).
  13. Dispositif selon la revendication 12, caractérisé par le fait que l'anneau de fondement (3) est centré autour du forage à l'aide de pilotis (25) enfoncés dans le sol (2) et répartis sur la circonférence intérieure dudit anneau, attaquant les parties intérieures des articulations (23).
  14. Dispositif selon l'une quelconque des revendications 12 ou 13, caractérisé par le fait que chaque élément (23) est conçu sous forme de pontont fermé en acier flottable, rempli de préférence d'une matière solide grenue ou granuleuse, par exemple du sable ou de la scorie, et maintenu au sol par son poid propre.
  15. Dispositif selon l'une quelconque des revendications 6 à 14, caractérisé par le fait que la plate-forme (9) est posée sur un fondement fixe (17) du bassin et qu'elle possède un poids propre étant sensiblement supérieur aux forces portantes excercées sur ladite plate-forme au niveau maximal de remplissage d'eau (H₂).
EP88116291A 1987-10-08 1988-10-01 Procédé et dispositif pour l'installation d'une plate forme "off shore" Expired - Lifetime EP0310981B1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE3733952 1987-10-08
DE19873733952 DE3733952A1 (de) 1987-10-08 1987-10-08 Verfahren und vorrichtung zur errichtung einer offshore-anlage

Publications (2)

Publication Number Publication Date
EP0310981A1 EP0310981A1 (fr) 1989-04-12
EP0310981B1 true EP0310981B1 (fr) 1992-01-15

Family

ID=6337837

Family Applications (1)

Application Number Title Priority Date Filing Date
EP88116291A Expired - Lifetime EP0310981B1 (fr) 1987-10-08 1988-10-01 Procédé et dispositif pour l'installation d'une plate forme "off shore"

Country Status (3)

Country Link
EP (1) EP0310981B1 (fr)
DE (2) DE3733952A1 (fr)
NO (1) NO171836C (fr)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2005045304A1 (fr) * 2003-10-29 2005-05-19 Shell Internationale Research Maatschappij B.V Structure de stockage de gaz naturel liquefie dotee de fondations s'etendant a la partie inferieure d'un plan d'eau
EP1826695A1 (fr) 2006-02-28 2007-08-29 Microsoft Corporation Descriptions de contenu sécurisées

Family Cites Families (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
SE355000B (fr) * 1969-08-25 1973-04-02 Knorring Enar Von
DE2054946A1 (de) * 1969-11-20 1971-05-27 Corso, Giorgio, Messina (Italien) Hydrostatisches Gerüst mit Plattform
US4010704A (en) * 1973-08-10 1977-03-08 Energy Systems Corporation Buoyant sphere
DE2349879A1 (de) * 1973-10-04 1975-04-10 Khd Pritchard Gmbh Ges Fuer Pl Schwimmende einrichtung fuer den einsatz auf dem meer zur aufbereitung von bodenschaetzen, insbesondere zur verfluessigung von gasen
GB1462401A (en) * 1974-05-23 1977-01-26 British Petroleum Co Platforms
GB1495932A (en) * 1974-12-12 1977-12-21 Submerged Buoyant Structures L Marine platforms
JPS5277401A (en) * 1975-12-19 1977-06-29 Karlskronavarvet Ab Floating platform capable of being anchored
US4170186A (en) * 1976-06-21 1979-10-09 J. Ray Mcdermott & Co., Inc. Anchored offshore structure with sway control apparatus
GB1585123A (en) * 1977-05-31 1981-02-25 Exton & Gold Ltd Structures having buoyant chambers
EP0184407B1 (fr) * 1984-12-04 1990-03-14 Canadian Patents and Development Limited Structure marine flottante en forme de disque mince

Also Published As

Publication number Publication date
NO171836B (no) 1993-02-01
DE3867788D1 (de) 1992-02-27
DE3733952A1 (de) 1989-04-20
EP0310981A1 (fr) 1989-04-12
NO884412L (no) 1989-04-10
NO884412D0 (no) 1988-10-05
NO171836C (no) 1993-05-12

Similar Documents

Publication Publication Date Title
EP1288122B1 (fr) Support flottant pour une construction s'élevant au dessus de la surface de l'eau
DE102008003647B4 (de) Schwimmendes Gründungstragwerk mit Auftriebskomponenten, in aufgelöster Bauweise
DE60034695T2 (de) Methode und einrichtung zum transport und zum aufbau einer windenergieanlage auf see
DE69927791T2 (de) Verfahren zur installation einer windturbine ins meer, ein fundament für windturbinen und der gebrauch der fundamente
DE69938526T2 (de) Halbtauchende offshorestruktur mit grossem tiefgang
EP1174336A1 (fr) Positionnement fixe d'unités fonctionnelles sur ou dans l'eau
DE10349109A1 (de) Gründung für eine Offshore-Windenergieanlage
DE102011052024A1 (de) Serienbaufähiges schwimmfundament
DE1291246B (de) Schlingerdaempfungseinrichtung fuer einen schwimmenden, hohlen Tragkoerper
DE102010020995B4 (de) Gründungssystem für die Gründung einer Offshore-Windenergieanlage
EP3693261B1 (fr) Champ d'installation solaire en mer et son procédé de montage
DE102017104640B4 (de) Autark schwimmfähige Schwergewichtsgründung zur Verbindung mit einer schwimmfähigen Offshore-Anlage
DE2416357A1 (de) Verfahren und vorrichtung zum umwandeln eines schwimmponton in ein halb-tauchfaehiges schwimmfahrzeug, insbesondere eine schwimmende arbeitsinsel
WO2016177783A1 (fr) Ancre-poids flottante permettant d'ancrer une structure porteuse flottant en pleine mer à une éolienne, une station-service ou une station de conversion
EP1336559B1 (fr) Méthode pour baisser sous l'eau le flotteur d'un support flottant
EP2623674A1 (fr) Infrastructure pour une plateforme offshore et procédé d'installation d'une telle infrastructure
EP0310981B1 (fr) Procédé et dispositif pour l'installation d'une plate forme "off shore"
DE2457536A1 (de) Offshore-plattform
DE202010010094U1 (de) Gründungssystem für die Gründung einer Offshore-Windenergieanlage
DE102011012450A1 (de) Verfahren zum Einbau eines Schwergewichtsgründungssystems für eine Offshore-Windenergieanlage (WEA)
EP3922845A1 (fr) Ouvrage en mer flottant et son procédé d'installation
DE2845192A1 (de) Schwimmender turm
AT516670B1 (de) Pontonbrücke
DE3520181A1 (de) Schwimmende plattform fuer universelle verwendung
EP2860314B1 (fr) Fondations gravitaires

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): DE FR GB SE

17P Request for examination filed

Effective date: 19891002

17Q First examination report despatched

Effective date: 19910314

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): DE FR GB SE

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: SE

Effective date: 19920115

Ref country code: GB

Effective date: 19920115

Ref country code: FR

Effective date: 19920115

REF Corresponds to:

Ref document number: 3867788

Country of ref document: DE

Date of ref document: 19920227

EN Fr: translation not filed
GBV Gb: ep patent (uk) treated as always having been void in accordance with gb section 77(7)/1977 [no translation filed]
PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

26N No opposition filed
PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 19940914

Year of fee payment: 7

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Effective date: 19960702