Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
  • B63B—SHIPS OR OTHER WATERBORNE VESSELS; EQUIPMENT FOR SHIPPING 
  • B63B21/00—Tying-up; Shifting, towing, or pushing equipment; Anchoring
  • B63B21/24—Anchors
  • B63B21/26—Anchors securing to bed
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
  • B63B—SHIPS OR OTHER WATERBORNE VESSELS; EQUIPMENT FOR SHIPPING 
  • B63B21/00—Tying-up; Shifting, towing, or pushing equipment; Anchoring
  • B63B21/24—Anchors
  • B63B21/26—Anchors securing to bed
  • B63B2021/265—Anchors securing to bed by gravity embedment, e.g. by dropping a pile-type anchor from a certain height

Definitions

• the depositors have written to the French register No. 85. 09355 the pr inc ip of a machine intended to move within an unlimited fluid, of the type whose front and rear forms are fixed by known technological considerations, this machine being characterized in that, for the purpose of lower the drag coefficient, avoid the separation of the boundary layer and eliminate cavitation and instability phenomena, the profile of the portion connecting the front and the rear is determined in such a way that the coefficient of pressure remains constant at all points of this connection portion.
• this French patent cited, among other things, the recognition of the seabed, in particular their nature and their resistance to penetration, the device then having a vertical displacement.
• the present invention relates to another application of these vertical displacement machines in the marine environment and of similar performance machines, namely the deep underwater anchoring of large structures.
• the invention consists in associating, with an anchoring member proper, which may be of a conventional nature or be designed in a new way, adapted to a particular structure to be immobilized, a machine as defined in the aforementioned patent or similar machine, the assembly thus formed, released from a surface support, that is to say from the structure to be immobilized, reaching the bottom at a high speed in particular thanks to its profile, then penetrating into the submarine soil over a significant depth, ensuring the anchoring of said body.
• an anchoring member proper which may be of a conventional nature or be designed in a new way, adapted to a particular structure to be immobilized, a machine as defined in the aforementioned patent or similar machine
• analogous device is meant any device whose The whole is determined to obtain a high speed.
• a machine comprising three parts: the penetration machine itself, means for connecting or hooking the anchor line or mooring to.
• this t machine which will also be designated in the remainder of this description by anchor head, fixed to the tail of this machine and a connecting member between the first two parts; in this case, the unwinding reel of the guide wire connecting the machine to the surface support during the dropping can be arranged in the anchoring head; moreover, the connection member mentioned above may be a resistant cable or a concrete injection tube; in this case again, the masses and the profile of the assembly of the three parts are determined, on the one hand for obtaining a desired depth of penetration into the ground of the underwater soil, on the other hand, for that, during penetration into this terrain, the kinetic energy acquired and the Archimedes' thrust on the anchor head are made up to keep the connecting cable in tension or to prevent the pruning of the connecting tube.
• the machine itself constitutes the anchoring member, its profile being smooth and remaining so throughout the descent, and comprising side panels deploying under the effect of any effort of traction exerted after the arrival and positioning of the anchor, for example using explosive bolts or equivalent means, so as to constitute a sort of grapple opposing the tearing, which contributes to the solidity of anchoring.
• Mooring of the anchor line on the anchor head can be done by any appropriate means -, depending on how the latter is connected to the machine at great depth of penetration, either by a resistant connection cable, either by a tube allowing the injection of concrete.
• the invention therefore relates, firstly, to a method for deep underwater anchoring of floating structures, characterized in that an assembly is used for this purpose comprising a penetration device at high speed for fastening the fastening means and means for permanently locating this machine and means for connecting between said machine and said hooking and locating means, said assembly being designed so that, being dropped from said structure, the penetrating machine is buried in the seabed at the calculated depth desired to ensure the anchoring of said structure while said locating means remain above the bottom, and in that said assembly is released from the surface, or locating is ensured and fixed finally the anchor line on said attachment means.
• FIG. 1 shows a first embodiment of an anchoring device according to the invention
• FIG. 3 illustrates a means for reducing the cyclic horizontal displacements of the anchor point
• FIG. 4 schematically illustrates the application of the invention to the immobilization of an oil drilling platform.
• the machine shown in Figure 1 is in the form of an axisymmetric machine with vertical movement 1, optionally equipped with pilot vanes 2, and intended to be connected by an anchor line (not shown) to a support structure of surface to be immobilized, as shown in Figure 4.
• the machine 1 comprises four housings in the form of radial slots 3, in which the panels 4 are enclosed, pivotally mounted around horizontal axes 5 situated towards the head of the machine 5.
• the machine dropped from its support, arrives on the bottom with a high speed, of the order of 40 to 60 m / sec. thanks to its profile, as defined in the aforementioned patent, and sinks into the ground to a significant depth, of the order of 20 to 50 meters.
• the panels 4 tilt outwards, as shown in 4 ′, and in addition pivoting by 90 ° around their axis under the effect of off-center friction which occurs from that the machine is under traction, so as to flourish flat in soft underwater terrain.
• the result of the friction forces is applied to the barycenter of the panel 4 which is laterally offset with respect to its axis of rotation.
• the anchoring is then provided in an extremely solid manner and can withstand significant pulls.
• the machine shown in Figure 2 differs from the previous one in that it has no slots, panels 6 being curved so as to be pressed against the outer surface of the machine 1.
• the deployment "umbrella" of these panels 6 is primed, for example by explosive bolts arranged at their upper part 7 and triggering their rocker which continues until said panels lie flat in the soft underwater terrain as before.
• FIG. 3 there is shown a surface support S, floating on the sea M, and connected by an anchor line 10 to a machine according to the invention, 11, buried in the ground and whose panels are deployed.
• a mooring system such as a dead body 13 remains on the ground surface 14 threaded on the cable or on the connecting tube 10 '.
• the anchoring line 10 is attached to the whole of the machine and the dead body by an anchoring head 15 and can be ensured by an automatic connector system.
• the guidance of the dead body for its incorporation into the machine with a large depth of penetration-anchor head, as well as the "clamping" of the anchor line, can be carried out by any appropriate means, depending on the type of connection.
• anchor head and penetration device for example by means of a guide line unwound from the anchor head during firing, or by petroleum-type equipment, based on hydrojets, guided by transmitters ultrasound (pingers) and video camera for the final phase.
• FIG. 4 represents an oil drilling platform P resting on floating load-bearing structures F, connected by anchor lines 10 to dead bodies 13, resting on the bottom 14, and joined to machines according to l 'invention, 11, by resistant cables 10', hooked to rings 15.
• This system ensures an anchoring of the platform capable of withstanding tensile forces of the order of 5000 tonnes.
• the present invention also relates to a certain number of measures, relating to the consolidation of such an anchoring, and to the installation and immobilization of pipelines.
• the machines according to the invention can be placed with a precision of the order of 20 meters relative to a target, but with appropriate piloting, this precision can be refined unless of one meter, which allows in particular the last aforementioned applications.
• One of the essential advantages of the invention is that the machine at high limit speed is separated, when it is dropped, from the anchor line, the drag of which would considerably limit its speed if it were attached to the rear of this machine.
• the speed limit reached is that of the vehicle and of the attachment and connection means associated therewith with background tracking means such as ultrasonic emitters; in the case where the locating means consist of a guide wire unwound from the machine or the associated anchoring head, this wire, of small section, is immobile in water and only induces a very slight increase drag, which hardly penalizes the speed limit.

Landscapes

• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• Ocean & Marine Engineering (AREA)
• Earth Drilling (AREA)
• Piles And Underground Anchors (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=9325411

Family Applications (1)

Country Status (3)

Families Citing this family (4)

Family Cites Families (2)

• 1985
  • 1985-12-02 FR FR8517906A patent/FR2590862A2/fr active Pending
• 1986
  • 1986-12-01 WO PCT/FR1986/000411 patent/WO1987003260A1/fr unknown
  • 1986-12-01 EP EP19860906863 patent/EP0247112A1/de not_active Withdrawn

Non-Patent Citations (1)

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