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EP 3 196 362 B1 |
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EUROPEAN PATENT SPECIFICATION |
(45) |
Mention of the grant of the patent: |
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27.11.2019 Bulletin 2019/48 |
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Date of filing: 19.01.2017 |
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International Patent Classification (IPC):
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(54) |
JACK-UP VESSEL AND METHOD FOR POSITIONING THE VESSEL ON AN UNDERWATER BOTTOM
HUBSCHIFF UND VERFAHREN ZUR POSITIONIERUNG DES SCHIFFS AUF EINEM UNTERWASSERBODEN
PLATE-FORME AUTOÉLÉVATRICE ET PROCÉDÉ DE POSITIONNEMENT DE LA PLATE-FORME SUR UN FOND
MARIN
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Designated Contracting States: |
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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 |
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Priority: |
21.01.2016 BE 201605049
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Date of publication of application: |
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26.07.2017 Bulletin 2017/30 |
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Proprietor: GeoSea NV |
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2070 Zwijndrecht (BE) |
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Inventors: |
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- Stempinski, Florian Uwe Paul
9120 Melsele (BE)
- Rabaut, Dieter
9000 Gent (BE)
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Representative: Brouwer, Hendrik Rogier |
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Arnold & Siedsma
Bezuidenhoutseweg 57 2594 AC The Hague 2594 AC The Hague (NL) |
(56) |
References cited: :
WO-A2-2011/116254 US-A- 3 118 283
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KR-A- 20130 143 355 US-A- 3 916 633
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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).
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FIELD OF THE INVENTION
[0001] The invention relates to a jack-up vessel comprising a horizontal work deck and a
number of legs for supporting the work deck on an underwater bottom. A lower end of
the legs comprises an enlarged foot section, adapted to engage or penetrate the underwater
bottom, and each leg is actuated by a jacking mechanism to elevate the work deck above
a water surface. The invention also relates to a method that positions a jack-up vessel
on an underwater bottom and substantially prevents settlement/eases the removal of
underwater bottom material from the legs and top side of the foot sections.
BACKGROUND OF THE INVENTION
[0002] A jack-up vessel, platform or rig comprises a horizontal work deck and at least three
legs connected to the work deck. Such a vessel can sail to an offshore position while
the legs are held in a docking position close to the work deck of the vessel. The
vessel is anchored to the underwater bottom by bringing the legs to a lowered support
position in which an enlarged foot section provided at a lower end of the legs engages
or penetrates the underwater bottom. A hydraulic or electric system is provided to
elevate the work deck upon the legs to a position above a water surface. The work
deck can then be used as a stable platform to perform a number of tasks such as oil
well drilling, mining, construction and maintenance of offshore wind turbines, bridges,
and jetty or other constructions.
[0003] The underwater bottom in many cases comprises a relatively soft material such as
mud, silt, clay, sedimentary material or other known soft material that adheres to
the leg lower end portion and/or on top of the foot section. Upon retrieval of the
legs from the underwater bottom, the additional weight of the adhered materials requires
higher pulling forces, and the remaining sediments reduce the amount of payload of
the jack-up vessel when floating. To be able to retract the legs into their docking
positions close to the work deck and avoid any jamming, the adhered materials need
to be removed, for instance by divers. This is a time-consuming operation and removing
the adhered material may take several days, in particular in high cohesive soil.
[0004] US 3,916,633 discloses a platform provided with truss-shaped legs having spud tanks that are not
enlarged laterally with respect to the legs. In order to prevent the legs from hitting
the seabed to vigorously during placement on the seabed, the truss-shaped legs may
be provided with bags made from a flexible material and filled with water or another
material in order to increase the leg's drag and inertia, and thereby contribute to
a dampening effect and an altered natural frequency of the platform.
[0005] WO 2011/116254 A2 discloses a platform with truss-shaped legs having enlarged foot sections. Water
filled ballast tanks can move up and down within the legs to change buoyancy and assist
or control the penetration of the legs into the sea floor, A tank positioned partly
above the water line adds weight to the legs, while a tank positioned completely below
the water line is neutrally buoyant and does not add penetration weight to the legs.
[0006] US 3,118,283 discloses a jack-up vessel, the legs of which can be lifted with respect to a work
deck by elevating members. The legs are also provided with buoyant members that can
be slid along a leg between the elevating members and a foot section. The buoyant
members are large enough to provide sufficient buoyancy for raising the combined weight
of the elevating members and the working platform when the legs have found support
on the bottom.
[0007] It is an aim of the invention to provide a jack-up vessel that can efficiently be
positioned on an underwater bottom as well as retrieved from it.
BRIEF SUMMARY OF THE INVENTION
[0008] The invention thereto provides a jack-up vessel according to claim 1. The jack-up
vessel in accordance with the invention comprises a horizontal work deck and a number
of legs for supporting the work deck on an underwater bottom, whereby a lower end
of the legs comprises an enlarged foot section adapted to engage or penetrate an underwater
bottom, whereby the legs are provided with at least one closable container for a compressed
medium, and the container is positioned above the foot section, and within a virtual
cylinder having the foot section as base, and extends along a leg over a distance
at least equal to the penetration depth of the leg in the underwater bottom, is made
of a flexible material and is inflatable with the medium between an empty state and
an inflated state, whereto the jack-up vessel further comprises inflating and/or deflating
means for bringing the at least one container to a state between the empty and the
inflated state, in which the at least one container is configured to shield a volume
around the leg from bottom material ingress thereby preventing accumulation of underwater
bottom material on top of the foot section of the legs. A pressurized container prevents
accumulation of underwater bottom material along the legs, within the legs and/or
on top of the foot section of the legs, before, during and/or after penetration of
the legs into the underwater bottom.
[0009] The jack-up vessel may be positioned on an underwater bottom by a method comprising
lowering the legs from a docking position close to a horizontal work deck of the jack-up
vessel to a support position in which an enlarged foot section provided at a lower
end of the legs engages or penetrates the underwater bottom, whereby the legs are
provided with at least one closable container for a compressed medium, and the container
is positioned above the foot section. An enlarged foot section is also referred to
in the art as a spud can or a mud mat.
[0010] A suitable container is adapted to at least partly prevent accumulation of underwater
bottom material at a lower end portion of the legs. Although the shape of a container
may vary, the jack-up vessel according to the invention comprises one or more containers,
wherein the at least one container extends along a leg and is positioned within a
virtual cylinder having the foot section as base. Such a container effectively shields
a volume around the leg from bottom material ingress, said volume being particularly
apt to receive such material. The at least one container in this embodiment preferably
forms an elongated body, a longitudinal axis whereof extends substantially parallel
to a longitudinal axis of the leg.
[0011] The extension along a leg of the at least one container can also be chosen within
a large range, as long as the at least one container extends along a leg over a distance
at least equal to the penetration depth of the leg in the underwater bottom. The penetration
depth of a leg may be anticipated before positioning the jack-up vessel on the underwater
bottom by determining relevant properties of the bottom material, such as its cohesiveness,
strength, etc.. A container in accordance with the invention extends up to and possibly
beyond the bottom surface when a leg has penetrated to a stable depth. This prevents
accumulation of underwater bottom material along the leg substantially over its complete
penetrated length.
[0012] The invention provides a jack-up vessel wherein the at least one container is made
of a flexible material and the container is inflatable with the medium between an
empty and an inflated state. This allows changing the volume of the container at will,
depending on the particular stage of operation of the jack-up vessel and its legs,
for instance whether the vessel is sailing, or stationary in a jacked-up state, or
whether the legs are in their docking position, or in their lowered support position,
and so on.
[0013] The at least one container may be pressurized before mounting the container on the
legs. The invention provides a jack-up vessel that further comprises inflating and/or
deflating means for bringing the at least one container to a state between the empty
and the inflated state. The inflating and/or deflating means in a useful embodiment
comprise a source of compressed medium and a medium inlet provided on the at least
one container in medium communication with the source. A suitable source of compressed
medium would be a compressor pump, provided on the work deck, that pumps medium from
a medium reservoir to an inlet of the at least one container, for instance through
hoses connecting the source with the inlet. The source (pump) may also be provided
on each container in order to draw in medium, for instance surrounding water. Another
source may comprise a number of medium jet nozzles, provided on a leg, in particular
on a top side of a foot section. Each source may be electrically connected with a
suitable controlling device provided on the work deck. A container is preferably also
equipped with a remote controlled pressure gage and/or valve to maintain the desired
pressure within the container. The pressure gage/valve may be integrated in the compressor
pump.
[0014] A useful embodiment of the jack-up vessel employs inflating and/or deflating means
that are adapted to change the pressure inside the at least one container with the
level of submersion of the at least one container. A container preferably needs to
keep its inflated volume when a leg (and the container) is lowered under water towards
the underwater bottom. This embodiment allows adjusting the internal pressure of the
container to the surrounding water pressure, which obviously increases with submersion
level (or water depth). Although internal pressure may be varied within a large range,
internal pressures may vary between 1-200 bar for instance.
[0015] The at least one container is also instrumental in removing bottom material that
may have accumulated around the leg. An embodiment of the jack-up vessel wherein a
surface of the at least one container is non-sticking, more preferably is provided
with a non-stick coating layer, facilitates such removal and also prevents accumulation
further. One skilled in the art is familiar with suitable non-sticking materials,
for instance polyolefin materials (PE, PP), silicone and other rubbers, as well as
fluor polymers, such as PTFE (Teflon®).
[0016] A suitable medium for the container(s) may be selected according to the circumstances.
In a preferred embodiment, the medium comprises air, water, or another high density
substantially non-compressible fluid. Surrounding water as medium is particularly
preferred.
[0017] The at least one container may be connected (semi-)permanently to the legs of the
jack-up vessel. Another embodiment provides a jack-up vessel wherein the at least
one container is removably connected to a leg. The (temporary or removable) connection
may be achieved with well known means, such as by riveting, welding, jointing, tying,
roping, and so on.
[0018] The legs of the jack-up platform may be any leg known in the art, such as solid legs
provided at a lower end with spud cans. In particular for larger depths, a jack-up
vessel wherein the legs are truss-shaped may be the leg of choice. In such an embodiment,
at least one container is preferably positioned inside the truss, i.e. inside an outermost
contour of a (horizontal) cross-section of the truss.
[0019] In another embodiment, a jack-up vessel is provided wherein the legs are truss-shaped.
According to the invention, at least one container is positioned outside the truss,
i.e. an outermost contour of a (horizontal) cross-section of the truss. The at least
one container positioned outside the truss is made of a flexible material and the
container is inflatable with the medium between an empty and an inflated state is
preferred.
[0020] In order to further improve shedding of bottom material that accumulated along a
leg, an embodiment is provided that further comprises vibratory means for bringing
the at least one container in vibration. Preferred vibratory means comprise hydraulic
impulse means, for instance means for pulsing the output pressure of the compressor
pump that inflates the at least one container.
[0021] The invention also relates to a method for positioning a jack-up vessel on an underwater
bottom, the method comprising lowering a number of legs from a docking position close
to a horizontal work deck of the jack-up vessel to a support position in which an
enlarged foot section (or can) provided at a lower end of the legs engages or penetrates
the underwater bottom, whereby the legs are provided with at least one closable container
for a compressed medium, and the container is positioned above the foot section within
a virtual cylinder having the foot section as base, and extending along a leg over
a distance at least equal to the penetration depth of the leg in the underwater bottom,
wherein the at least one container is made of a flexible material and the container
is inflated and/or deflated with the medium between an empty state and an inflated
state, in which the at least one pressurized container shields a volume around the
leg from bottom material ingress thereby preventing accumulation of underwater bottom
material on top of the foot section of the legs. Preferred embodiments of the method
are described in the enclosed dependent claims and relate to embodiments wherein the
pressure inside the at least one container is changed with the level of submersion
of the at least one container; wherein the medium comprises air or water, preferably
surrounding water; and wherein a leg is penetrated in the underwater bottom to a penetration
depth about equal to an extension of the at least one container along the leg.
[0022] In an embodiment wherein the legs are truss-shaped and at least one container is
positioned inside the truss, the at least one container positioned inside the truss
is preferably in an inflated state during lowering of the legs. Such inside containers
when filled with pressurized water have about neutral buoyancy when submerged. The
inside container(s) are preferably kept in this state to effectively shield an inside
volume of the truss legs against ingress of bottom material. Inflated inside containers
further do not substantially hinder the movement of the truss legs, in particular
their penetration in the underwater bottom since the inside containers are confined
within a leg outer cross-sectional contour.
[0023] In a particularly useful embodiment of the method, wherein the legs are truss-shaped
and wherein at least one container is positioned outside the truss, the at least one
container positioned outside the truss is inflated prior to penetrating in the underwater
bottom. This further reduces the amount of bottom material that may adhere to the
leg.
[0024] The jack-up platform may be disconnected from the underwater bottom after it has
performed its operations at an offshore site. Thereto a method is provided that further
comprises raising the legs from a support position in which an enlarged foot section
(or can) provided at a lower end of the legs engages or penetrates the underwater
bottom to a docking position close to the horizontal work deck of the jack-up vessel.
[0025] In a preferred embodiment of the method at least one container is deflated while
the leg is still penetrated in the underwater bottom. This allows pulling the leg
from the underwater bottom with less force. In retrieving the legs from the bottom,
bottom material may accumulate on top of the (partly) deflated container(s), but the
amount is reduced, due to the presence of optional containers and/or containers that
are still inflated and occupy volume.
[0026] To shed or shake off underwater bottom material efficiently, the method according
to an embodiment provides that the at least one container that has been deflated is
inflated again after it has left the underwater bottom. This process is further facilitated
by an embodiment wherein the at least one container is brought in vibration.
[0027] In a further embodiment of the method according to the invention at least one container
and preferably each container is deflated before the legs enter their docking position.
The jack-up vessel is able to sail to another offshore site when each leg is in its
docking position. The invention allows positioning a jack-up vessel on an underwater
bottom and disconnecting the vessel from an underwater bottom in a lesser amount of
time than known in the art.
BRIEF DESCRIPTION OF DRAWINGS
[0028] The invention will now be elucidated with reference to the following figures, without
however being limited thereto. In the figures:
Fig. 1 is a schematic perspective view of a jack-up vessel according to an embodiment
of the invention;
Fig. 2A is a schematic side view of a jack-up vessel according to the state of the
art in a jacked-up position;
Fig. 2B is a schematic side view of a jack-up vessel according to the state of the
art in a floating position;
Fig. 3A is a schematic top view of a truss leg according to an embodiment of the invention;
Fig. 3B is a schematic side view of the truss leg according to the embodiment shown
in figure 3A;
Fig. 4A is a schematic side view of a jack-up vessel according to an embodiment of
the invention in a jacked-up position;
Fig. 4B is a schematic side view of a jack-up vessel according to an embodiment of
the invention in a floating position;
Fig. 5A is a schematic side view of a jack-up vessel according to the embodiment shown
in figure 4 in a jacked-up position;
Fig. 5B is a schematic side view of a jack-up vessel according to the embodiment shown
in figure 4 in a floating position;
Fig. 6A is a schematic side view of a jack-up vessel according to the embodiment shown
in figure 4 in a floating position;
Fig. 6B is a schematic side view of a jack-up vessel according to the embodiment shown
in figure 4 in a sailing position;
Fig. 7 is a schematic side view of a jack-up vessel according to an embodiment of
the invention in a floating position; and
Fig. 8 finally shows a schematic side view of a truss leg according to another embodiment
of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0029] Referring to figure 1, a jack-up vessel 1 is shown for placing an object 3 on an
underwater bottom 2 or for performing other offshore operations. The jack-up vessel
1 comprises a hull 5 such that it can navigate autonomously through thrusters 8 to
an offshore location, where it can be positioned and connected to the underwater bottom
2 by lowering a number of truss legs (or spud poles) 4 onto the underwater bottom
2. The legs 4 may for this purpose be moved from a docking position 54 (see also figures
2A and 2B) provided in the hull 5 towards the underwater bottom 2 by means of a rack
and pinion system 7 such that the legs 4 engage or even penetrate the underwater bottom
2. The hull 5 of jack-up vessel 1 is then fixed relative to the underwater bottom
2 but may still be floating, as shown in figure 2A for instance. The hull 5 may also
be raised further out of the water, as shown in figure 1, such that a work deck 51
of the hull 5 is situated meters above the water surface 20. The truss legs 4 are
at a lower end provided with enlarged foot sections 40 (also referred to as mud mats)
to prevent the legs 4 from penetrating into the underwater bottom 2 too far. On the
work deck 51 of hull 5 are provided several objects 3 to be placed, as well as a crane
6, pivotable about pivot 60. The work deck 51 of hull 5 further comprises a gripping
construction 10 configured to engage an object 3 suspended from crane 6.
[0030] It should be noted that the configuration of figure 1 is given for illustrative purposes
only and any other jack-up vessel 1 having legs 4 and employed for any other purpose
may be used in the present invention.
[0031] The underwater bottom 2 in many cases comprises a relatively soft material such as
mud, silt, clay, sedimentary material or other known soft material that may adhere
to a lower portion of each leg 4, and/or may accumulate on top of the foot section
40 as a mass 2adh. Referring to figure 2A and upon retrieval of the legs 4 from the
underwater bottom 2 by moving the legs 4 in the upward direction 19, the additional
weight of the adhered materials 2adh may require higher pulling forces, and further
may hinder retracting the legs 4 into their docking positions 54 close to the work
deck 51. According to the state of the art, the adhered materials 2adh are removed,
for instance by divers, which is a time-consuming operation.
[0032] A jack-up vessel 1 according to an embodiment of the invention is partly shown in
figures 4A and 4B. The truss legs 4 are at a lower portion provided with a plurality
of closable containers 9. As also shown in figures 3A and 3B, the truss legs 4 are
triangular in cross-section, and the containers 9 comprise a first set of containers
9a positioned inside the truss. Indeed, a cross-section of the truss leg 4 is built
from outer steel members 4b, between which extend a number of inner truss members
4a that together delimit four triangular subspaces 4c. The inside containers 9a are
each contained within a substantially vertical cylinder having one of the subspaces
4c as base plane. According to the embodiment shown, the containers 9 further comprise
a second set of containers 9b positioned outside the truss. Indeed, the outside containers
9b are positioned within a virtual cylinder having the extended foot section as base
and outside a substantially vertical cylinder having the triangular cross-section
of the leg 4 as base plane. The containers 9 extend vertically along a leg 4 over
a distance 12 at least equal to the penetration depth of the leg 4 in the underwater
bottom 2.
[0033] The containers 9 are positioned above the foot section 4 and are made of a flexible
material, such as rubber, and they can be inflated with for instance compressed air
or (surrounding) water between an empty state, as for instance shown if figure 5A
for the outer containers 9b, and an inflated state, as shown in figure 5A for the
inside containers 9a. Jack-up vessel 1 is thereto provided with inflating and/or deflating
means for bringing the containers 9 to a state between the empty and the inflated
state. As shown in figures 4A and 4B, suitable means comprise a compressor pump 52,
provided on the work deck 51. The compressor pump 52 pumps water from the surrounding
sea 21 to an inlet 90 of the containers 9, for instance through hoses 55 connecting
the compressor 52 with the inlets 90. A controlling device 53 provided on the work
deck 51 may regulate the pressure inside each container 9 through remote control of
pressure gages and/or valves provided on the containers 9, in order to maintain the
desired pressure within the containers 9, and for instance change the pressure inside
the containers 9 with the submersed depth of the containers 9.
[0034] The surface of the containers 9 may be coated with a non-stick coating layer, for
instance based on a fluorinated polymer, such as PTFE. The containers are removably
connected to members (4a, 4b) of the truss leg 4, for instance by tying.
[0035] The containers 9 are used to advantage when positioning and disconnecting the jack-up
vessel 1 on and from the underwater bottom 2. Positioning the jack-up vessel 1 on
the underwater bottom 2 involves lowering each truss leg 4 from its docking position
54 to a support position, shown in figures 4A and 5A, in which the enlarged foot section
40 of each truss leg 4 has penetrated the underwater bottom 2 over a stable distance
13. During lowering of the legs 4 and penetrating the underwater bottom 2, the containers
9a positioned inside the truss leg 4 are in an inflated state, as shown in figures
4A and 5A. This prevents bottom material from entering the inside volumes 4c of the
truss legs 4. The outside containers 9b are preferably also in an inflated state,
see figure 4A. The height 12 of the containers 9 is chosen such that the legs 4 stably
penetrate to a penetration depth 13 which is about equal to the extensional height
12 of the containers 9 along the legs 4. This prevents bottom material accumulation
on top of the containers 9.
[0036] When the legs 4 need to be retracted from the bottom 2 to free the jack-up vessel
1 from the bottom, each truss leg 4 is raised from its support position in which the
foot section 40 engages or is embedded in the underwater bottom 2 to its docking position
54. A first embodiment is shown in figure 4B in which the outside containers 9b remain
in an inflated state during raising of the truss legs 4. This considerably reduces
the amount of bottom material 2adh adhered to the foot section 40 and other parts
of the legs 4, such as the containers 9. This facilitates removing the truss legs
4 from the bottom 2.
[0037] A second embodiment is shown in figures 5A and 5B in which the inside containers
9a remain in an inflated state during raising of the truss legs 4. The outside containers
9b however are deflated while the legs 4 are still penetrated in the underwater bottom,
see figure 5A. This facilitates removing the truss legs 4 and foot sections 40 from
the bottom 2, this however having the drawback of a slightly increased amount of bottom
material 2adh adhered to the foot section 40 and other parts of the legs 4, as shown
in figure 5B. This additional amount of bottom material 2adh is relatively easy removed
from the legs 4 by a further step of the method wherein the outer containers 9b that
were deflated are inflated again to a partly or fully inflated state after the containers
9b have left the underwater bottom 2. This method step, shown in figure 6A, effectively
shakes off adhered underwater bottom material 2adh. Preferably, the containers 9b
are simultaneously brought in vibration 15 by pulsating the inner pressure of the
containers 9b, as schematically shown by hydraulic impulse means.
[0038] A last step, shown in figure 6B involves jacking up the legs 4 further until they
can be accommodated inside the docking positions 54. The outside containers 9b are
deflated before entering their docking position 54.
[0039] As shown in figure 7, the inside containers 9a and/or the outside containers 9b may
be provided with pressure valves 56 for releasing excess pressure from within the
containers 9. Stacking a plurality of smaller containers (9a-1, 9a-2,..., 9a-8) inside
a truss leg 4, as shown in figure 8, may be beneficial in terms of flexibility.
1. Jack-up vessel (1) comprising a horizontal work deck (51) and a number of legs (4)
for supporting the work deck (51) on an underwater bottom (2), whereby a lower end
of the legs comprises an enlarged foot section (40), adapted to penetrate an underwater
bottom (2) over a penetration depth (13) of the legs (4), whereby the legs (4) are
provided with at least one closable container (9) for a compressed medium, whereby
the at least one container (9) is positioned above the foot section (40) within a
virtual cylinder having the foot section as base, and extends along a leg (4) over
a distance (12) at least equal to the penetration depth (13) of the leg (4) in the
underwater bottom (2), is made of a flexible material and is inflatable with the medium
between an empty state and an inflated state, whereto the jack-up vessel further comprises
inflating and/or deflating means for bringing the at least one container to a state
between the empty and the inflated state, in which the at least one container (9)
is configured to shield a volume around the leg (4) from bottom material ingress thereby
preventing accumulation of underwater bottom material on top of the foot section (40)
of the legs (4).
2. Jack-up vessel according to claim 1, wherein the inflating and/or deflating means
comprise a source of compressed medium and a medium inlet provided on the at least
one container in medium communication with the source.
3. Jack-up vessel according to claim 1 or 2, wherein the inflating and/or deflating means
are adapted to change the pressure inside the at least one container with the level
of submersion of the at least one container.
4. Jack-up vessel according to any one of the preceding claims, wherein a surface of
the at least one container is non-sticking, more preferably is provided with a non-stick
coating layer.
5. Jack-up vessel according to any one of the preceding claims, wherein the medium comprises
air or water, preferably surrounding water.
6. Jack-up vessel according to any one of the preceding claims, wherein the at least
one container is removably connected to a leg.
7. Jack-up vessel according to any one of the preceding claims, wherein the legs are
truss-shaped and at least one container is positioned inside the truss, in addition
to at least one container being positioned outside the truss.
8. Jack-up vessel according to any one of the preceding claims, further comprising vibratory
means for bringing the at least one container in vibration.
9. Method for positioning a jack-up vessel (1) on an underwater bottom (2), the method
comprising lowering a number of legs (4) from a docking position close to a horizontal
work deck (51) of the jack-up vessel (1) to a support position in which an enlarged
foot section (40) provided at a lower end of the legs (4) penetrates the underwater
bottom (2) over a penetration depth (13) of the leg (4), whereby the legs (4) are
provided with at least one closable container (9) for a compressed medium, and the
container (9) is positioned above the foot section (40) within a virtual cylinder
having the foot section as base, and extending along a leg (4) over a distance (12)
at least equal to the penetration depth (13) of the leg (4) in the underwater bottom
(2), wherein the at least one container (9) is made of a flexible material and the
container (9) is inflated and/or deflated with the medium between an empty state and
an inflated state, in which the at least one pressurized container (9) shields a volume
around the leg (4) from bottom material ingress thereby preventing accumulation of
underwater bottom material on top of the foot section (40) of the legs (4).
10. Method according to claim 9, wherein accumulation of underwater bottom material is
prevented during penetration of the legs into the underwater bottom.
11. Method according to claim 10, wherein the pressure inside the at least one container
is changed with the level of submersion of the at least one container.
12. Method according to claim 10 or 11, wherein the legs are truss-shaped, wherein at
least one container is positioned inside the truss, and wherein the at least one container
positioned inside the truss is in an inflated state during lowering of the legs.
13. Method according to any one of claims 10-12, wherein the legs are truss-shaped, and
wherein the at least one container positioned outside the truss is inflated prior
to penetrating in the underwater bottom.
14. Method according to any one of claims 10-13, further comprising raising a leg from
a support position in which an enlarged foot section provided at a lower end of the
leg engages or penetrates the underwater bottom to a docking position close to the
horizontal work deck of the jack-up vessel, wherein at least one container is deflated
while the leg is still penetrated in the underwater bottom.
15. Method according to claim 14, wherein the at least one container that has been deflated
is inflated again after it has left the underwater bottom to shake off underwater
bottom material.
16. Method according to claim 15, wherein the at least one container is brought in vibration.
17. Method according to any one of claims 14-16, wherein at least one container is deflated
before entering the docking position.
1. Hubschiff (1), das ein horizontales Arbeitsdeck (51) und mehrere Beine (4) aufweist,
um das Arbeitsdeck auf einem Unterwasserboden (2) zu halten, wobei ein unteres Ende
der Beine einen vergrößerten Fußabschnitt (40) aufweist, der dazu ausgelegt ist, in
einen Unterwasserboden (2) über eine Eindringtiefe (13) der Beine (4) einzudringen,
wobei die Beine (4) mit wenigstens einem verschließbaren Behälter (9) für ein komprimiertes
Medium vorgesehen sind, wobei der wenigstens eine Behälter (9) über dem Fußabschnitt
(40) in einem virtuellen Zylinder angeordnet ist, der den Fußabschnitt als Basis hat,
und entlang eines Beines (4) über eine Entfernung (12) verläuft, die mindestens gleich
der Eindringtiefe (13) des Beines (4) in den Unterwasserboden (2) ist, aus einem flexiblem
Material hergestellt ist und mit dem Medium zwischen einem entleerten Zustand und
einem aufgeblasenen Zustand aufblasbar ist, wobei das Hubschiff weiterhin Aufblas-
und/oder Entleerungsmittel aufweist, um den wenigstens einen Behälter in einen Zustand
zwischen dem entleerten und dem aufgeblasenen Zustand zu bringen, wobei der wenigstens
eine Behälter (9) ausgestaltet ist, ein Volumen um das Bein (4) vor einer Materialeindringung
von Bodenmaterial zu schützen, wodurch eine Anhäufung von Unterwasserbodenmaterial
auf dem Fußabschnitt (40) der Beine (4) verhindert wird.
2. Hubschiff nach Anspruch 1, wobei die Aufblase- und/oder Entleerungsmittel eine Quelle
des komprimierten Mediums und einen Mediumeinlass aufweisen, der an dem wenigstens
einen Behälter in Medienaustausch mit der Quelle vorgesehen ist.
3. Hubschiff nach Anspruch 1 oder 2, wobei die Aufblase- und/oder Entleerungsmittel ausgelegt
sind, den Druck in dem wenigstens einen Behälter mit dem Grad des Eintauchens des
wenigstens einen Behälters zu ändern.
4. Hubschiff nach einem der vorhergehenden Ansprüche, wobei eine Oberfläche des wenigstens
einen Behälters haftungsfrei ist, bevorzugter mit einer haftungsfreien Beschichtungsschicht
vorgesehen ist.
5. Hubschiff nach einem der vorhergehenden Ansprüche, wobei das Medium Luft oder Wasser
aufweist, vorzugsweise Umgebungswasser.
6. Hubschiff nach einem der vorhergehenden Ansprüche, wobei der wenigstens eine Behälter
entfernbar mit einem Bein verbunden ist.
7. Hubschiff nach einem der vorhergehenden Ansprüche, wobei die Beine eine Trägerform
haben und wenigstens ein Behälter im Träger angeordnet ist, zusätzlich dazu, dass
wenigstens ein Behälter außerhalb des Trägers angeordnet ist.
8. Hubschiff nach einem der vorhergehenden Ansprüche, das weiterhin Vibrationsmittel
aufweist, um den wenigstens einen Behälter in Vibration zu bringen.
9. Verfahren zum Positionieren eines Hubschiffs (1) auf einem Unterwasserboden (2), wobei
das Verfahren das Absenken mehrerer Beine (4) von einer Andockposition nahe einem
horizontalen Arbeitsdeck (51) des Hubschiffs in eine Halteposition aufweist, in der
ein am unteren Ende der Beine (4) vorgesehener vergrößerter Fußabschnitt (40) in den
Unterwasserboden (2) über eine Eindringtiefe (13) des Beins (4) eindringt, wobei die
Beine (4) mit wenigstens einem verschließbaren Behälter (9) für ein komprimiertes
Medium vorgesehen sind, und der Behälter (9) über dem Fußabschnitt (40) in einem virtuellen
Zylinder angeordnet ist, der den Fußabschnitt als Basis hat und entlang eines Beins
(4) über eine Entfernung (12) verläuft, die mindestens gleich der Eindringtiefe (13)
des Beins (4) in den Unterwasserboden (2) ist, wobei der wenigstens eine Behälter
(9) aus einem flexiblem Material hergestellt ist und der Behälter (9) mit dem Medium
zwischen einem leeren Zustand und einem aufgeblasenen Zustand aufblasbar und/oder
entleerbar ist, wobei der wenigstens eine unter Druck stehende Behälter (9) ein Volumen
um das Bein (4) vor Eindringung von Bodenmaterial schützt, wodurch eine Anhäufung
von Unterwasserbodenmaterial auf dem Fußabschnitt (40) der Beine (4) verhindert wird.
10. Verfahren nach Anspruch 9, wobei die Anhäufung von Unterwasserbodenmaterial während
der Eindringung der Beine in den Unterwasserboden verhindert wird.
11. Verfahren nach Anspruch 10, wobei der Druck in dem wenigstens einen Behälter gemäß
dem Grad des Eintauchens von dem wenigstens einem Behälter geändert wird.
12. Verfahren nach Anspruch 10 oder 11, wobei die Beine eine Trägerform haben, wobei wenigstens
ein Behälter im Träger angeordnet ist und wobei der wenigstens eine im Träger angeordnete
Behälter beim Absenken der Beine in einem aufgeblasenen Zustand ist.
13. Verfahren nach einem der Ansprüche 10 bis 12, wobei die Beine eine Trägerform haben,
und wobei der wenigstens eine außerhalb des Trägers angeordnete Behälter vor dem Eindringen
in den Unterwasserboden aufgeblasen wird.
14. Verfahren nach einem der Ansprüche 10 bis 13, das weiterhin das Anheben eines Beins
aus einer Halteposition, in der ein an einem unteren Ende des Fußes vorgesehener vergrößerter
Fußabschnitt in den Unterwasserboden eingreift oder eindringt, in eine Andockposition
nahe dem horizontalen Arbeitsdeck des Hubschiffs aufweist, wobei der wenigstens eine
Behälter entleert ist, während das Bein immer noch in dem Unterwasserboden eingedrungen
ist.
15. Verfahren nach Anspruch 14, wobei der wenigstens eine Behälter entleert und wieder
aufgeblasen wird, nachdem er den Unterwasserboden verlassen hat, um das Unterwasserbodenmaterial
abzuschütteln.
16. Verfahren nach Anspruch 15, wobei der wenigstens eine Behälter in Vibration gebracht
wird.
17. Verfahren nach einem der Ansprüche 14 bis 16, wobei der wenigstens eine Behälter entleert
wird, bevor er in die Andockposition eintritt.
1. Plate-forme autoélévatrice (1) comprenant un ponton de travail (51) horizontal et
un nombre de jambes (4) pour supporter le ponton de travail (51) sur un fond marin
(2), moyennant quoi une extrémité inférieure des jambes comprend une section de pied
(40) élargie, adaptée pour pénétrer dans un fond marin (2) sur une profondeur de pénétration
(13) des jambes (4), moyennant quoi les jambes (4) sont dotées d'au moins un réservoir
(9) refermable pour un milieu comprimé, moyennant quoi l'au moins un réservoir (9)
est positionné au-dessus de la section de pied (40) à l'intérieur d'un cylindre virtuel
ayant comme base la section de pied, et s'étend le long d'une jambe (4) sur une distance
(12) au moins égale à la profondeur de pénétration (13) de la jambe (4) dans le fond
marin (2), est composé d'un matériau flexible et peut être gonflé avec le milieu entre
un état vide et un état gonflé, la plate-forme autoélévatrice comprend en outre des
moyens de gonflage et/ou de dégonflage pour amener l'au moins un réservoir vers un
état entre l'état vide et l'état gonflé, où l'au moins un réservoir (9) est configuré
pour protéger un volume autour de la jambe (4) de l'afflux de matière de fond, empêchant
ainsi l'accumulation de matière de fond marin sur le dessus de la section de pied
(40) des jambes (4).
2. Plate-forme autoélévatrice selon la revendication 1, dans laquelle les moyens de gonflage
et/ou de dégonflage comprennent une source de milieu comprimé et d'entrée de milieu
prévue sur l'au moins un réservoir en communication du milieu avec la source.
3. Plate-forme autoélévatrice selon la revendication 1 ou 2, dans laquelle les moyens
de gonflage et/ou de dégonflage sont adaptés pour modifier la pression à l'intérieur
de l'au moins un réservoir en fonction du niveau d'immersion de l'au moins un réservoir.
4. Plate-forme autoélévatrice selon l'une quelconque des revendications précédentes,
dans laquelle une surface de l'au moins un réservoir est antiadhérente, de manière
préférée est dotée d'une couche de revêtement antiadhérent.
5. Plate-forme autoélévatrice selon l'une quelconque des revendications précédentes,
dans laquelle le milieu comprend de l'air ou de l'eau, de préférence de l'eau environnante.
6. Plate-forme autoélévatrice selon l'une quelconque des revendications précédentes,
dans laquelle l'au moins un réservoir est relié de manière amovible à une jambe.
7. Plate-forme autoélévatrice selon l'une quelconque des revendications précédentes,
dans laquelle les jambes sont en forme de treillis et au moins un réservoir est positionné
à l'intérieur du treillis, outre le fait qu'au moins un réservoir est positionné à
l'extérieur du treillis.
8. Plate-forme autoélévatrice selon l'une quelconque des revendications précédentes,
comprenant en outre des moyens vibratoires pour faire vibrer l'au moins un réservoir.
9. Procédé pour positionner une plate-forme autoélévatrice (1) sur un fond marin (2),
le procédé comprenant l'abaissement d'un nombre de jambes (4) d'une position d'ancrage
proche d'un ponton de travail (51) horizontal de la plate-forme autoélévatrice (1)
à une position de support où une section de pied (40) élargie prévue au niveau d'une
extrémité inférieure des jambes (4) pénètre dans le fond marin (2) sur une profondeur
de pénétration (13) de la jambe (4), moyennant quoi les jambes (4) sont dotées d'au
moins un réservoir (9) refermable pour un milieu comprimé, et le réservoir (9) est
positionné au-dessus de la section de pied (40) à l'intérieur d'un cylindre virtuel
ayant comme base la section de pied, et s'étendant le long d'une jambe (4) sur une
distance (12) au moins égale à la profondeur de pénétration (13) de la jambe (4) dans
le fond marin (2), dans lequel l'au moins un réservoir (9) est composé d'un matériau
flexible et le réservoir (9) est gonflé et/ou dégonflé avec le milieu entre un état
vide et un état gonflé, où l'au moins un réservoir (9) sous pression protège un volume
autour de la jambe (4) de l'afflux de matière de fond, empêchant ainsi l'accumulation
de matière de fond marin sur le dessus de la section de pied (40) des jambes (4).
10. Procédé selon la revendication 9, dans lequel l'accumulation de matière de fond marin
est empêchée lors de la pénétration des jambes dans le fond marin.
11. Procédé selon la revendication 10, dans lequel la pression à l'intérieur de l'au moins
un réservoir est modifié en fonction du niveau d'immersion de l'au moins un réservoir.
12. Procédé selon la revendication 10 ou 11, dans lequel les jambes sont en forme de treillis,
dans lequel au moins un réservoir est positionné à l'intérieur du treillis, et dans
lequel l'au moins un réservoir positionné à l'intérieur du treillis est dans un état
gonflé au cours de l'abaissement des jambes.
13. Procédé selon l'une quelconque des revendications 10 à 12, dans lequel les jambes
sont en forme de treillis, et dans lequel l'au moins un réservoir positionné à l'extérieur
du treillis est gonflé préalablement à la pénétration dans le fond marin.
14. Procédé selon l'une quelconque des revendications 10 à 13, comprenant en outre l'élévation
d'une jambe d'une position de support où une section de pied élargie prévue à une
extrémité inférieure de la jambe se met en prise avec ou pénètre dans le fond marin
dans une position d'ancrage proche du ponton de travail horizontal de la plate-forme
autoélévatrice, dans lequel au moins un réservoir est dégonflé alors que la jambe
pénètre encore dans le fond marin.
15. Procédé selon la revendication 14, dans lequel l'au moins un réservoir qui a été dégonflé
est gonflé à nouveau après qu'il a quitté le fond marin pour se débarrasser de la
matière de fond marin.
16. Procédé selon la revendication 15, dans lequel un conteneur est mis en vibration.
17. Procédé selon l'une quelconque des revendications 14 à 16, dans lequel au moins un
réservoir est dégonflé avant d'entrer dans la position d'ancrage.
REFERENCES CITED IN THE DESCRIPTION
This list of references cited by the applicant is for the reader's convenience only.
It does not form part of the European patent document. Even though great care has
been taken in compiling the references, errors or omissions cannot be excluded and
the EPO disclaims all liability in this regard.
Patent documents cited in the description