Classifications

• • E—FIXED CONSTRUCTIONS
  • E21—EARTH OR ROCK DRILLING; MINING
  • E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
  • E21B17/00—Drilling rods or pipes; Flexible drill strings; Kellies; Drill collars; Sucker rods; Cables; Casings; Tubings
  • E21B17/01—Risers
• • 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
  • B63B21/50—Anchoring arrangements or methods for special vessels, e.g. for floating drilling platforms or dredgers
  • B63B21/502—Anchoring arrangements or methods for special vessels, e.g. for floating drilling platforms or dredgers by means of tension legs
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
  • B63B—SHIPS OR OTHER WATERBORNE VESSELS; EQUIPMENT FOR SHIPPING 
  • B63B75/00—Building or assembling floating offshore structures, e.g. semi-submersible platforms, SPAR platforms or wind turbine platforms
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F03—MACHINES OR ENGINES FOR LIQUIDS; WIND, SPRING, OR WEIGHT MOTORS; PRODUCING MECHANICAL POWER OR A REACTIVE PROPULSIVE THRUST, NOT OTHERWISE PROVIDED FOR
  • F03D—WIND MOTORS
  • F03D13/00—Assembly, mounting or commissioning of wind motors; Arrangements specially adapted for transporting wind motor components
  • F03D13/20—Arrangements for mounting or supporting wind motors; Masts or towers for wind motors
  • F03D13/25—Arrangements for mounting or supporting wind motors; Masts or towers for wind motors specially adapted for offshore installation
• • 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
  • B63B2035/4433—Floating structures carrying electric power plants
  • B63B2035/446—Floating structures carrying electric power plants for converting wind energy into electric energy
• • E—FIXED CONSTRUCTIONS
  • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
  • E02B—HYDRAULIC ENGINEERING
  • E02B17/00—Artificial islands mounted on piles or like supports, e.g. platforms on raisable legs or offshore constructions; Construction methods therefor
  • E02B2017/0091—Offshore structures for wind turbines
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
  • F05B—INDEXING SCHEME RELATING TO WIND, SPRING, WEIGHT, INERTIA OR LIKE MOTORS, TO MACHINES OR ENGINES FOR LIQUIDS COVERED BY SUBCLASSES F03B, F03D AND F03G
  • F05B2240/00—Components
  • F05B2240/90—Mounting on supporting structures or systems
  • F05B2240/93—Mounting on supporting structures or systems on a structure floating on a liquid surface
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
  • F05B—INDEXING SCHEME RELATING TO WIND, SPRING, WEIGHT, INERTIA OR LIKE MOTORS, TO MACHINES OR ENGINES FOR LIQUIDS COVERED BY SUBCLASSES F03B, F03D AND F03G
  • F05B2240/00—Components
  • F05B2240/90—Mounting on supporting structures or systems
  • F05B2240/95—Mounting on supporting structures or systems offshore
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
  • Y02E10/00—Energy generation through renewable energy sources
  • Y02E10/70—Wind energy
  • Y02E10/72—Wind turbines with rotation axis in wind direction
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
  • Y02E10/00—Energy generation through renewable energy sources
  • Y02E10/70—Wind energy
  • Y02E10/727—Offshore wind turbines

Definitions

• the present invention relates to a marine platform, -% being able to be ' stiné in oil drilling, or more generally jf lly in any drilling in order to search for coal or ores, or else to capture the energy of the swell, currents or winds.
• Other uses of the invention are also conceivable.
• the present invention also relates, more precisely, to a drilling platform.
• the present invention also relates to a method 10 of placing the platform on the site of use.
• a platform comprising a submerged float carrying the working installations by means of legs crossing the surface of the water.
• the float is dimensioned so as to maintain its buoyancy even if the loading in installations or others is maximum. It is connected, by a series of stretched cables, to massive caissons resting at the bottom of the sea.
• the float is submerged to a sufficient depth so that the swell can never discover it, so that the platform has a certain insensitivity to bad weather.
• some of the cables are arranged obliquely between the platform and the caissons. This known platform has certain drawbacks
• this platform is inevitably sensitive to lateral forces. Indeed, the elasticity of the oblique cables does not completely avoid the drift. The float also has the ability to tilt, allowing it to drift even more than would be expected from the simple elasticity of the cables. It is thus clear that in the known platform, we 'must admit a certain sensitivity • bad time and a certain sensitivity to lateral forces. These sensitivities are difficult to assess during construction, and in any case have prohibitive values for certain applications.
• the object of the invention is to remedy these drawbacks by providing a marine platform which makes it possible to easily adjust, during construction, the sensitivity to swell and to lateral forces, and to give these sensitivities acceptable values for the almost all applications.
• the invention thus relates to a marine platform comprising a body of density less than unity, this body carrying a load and being connected to means
• the body is dimensioned so that the upper structure, comprising said body and its load, has positive buoyancy even when the load reaches its maximum expected mass.
• the marine platform is characterized in that the connecting means have their own deformability allowing the upper structure to drift under lateral force such that these connecting means come substantially in alignment with the resulting from the efforts undergone by the upper structure.
• the maximum drift is defined - which is considered acceptable for the platform with respect to the vertical coming from the anchoring means.
• the proportion between this drift and the depth of the water is calculated at the location where the platform is to be installed.
• the vertical upward force applied to the upper structure is then chosen so that the proportion between the lateral forces expected from currents, winds, etc., and said vertical force is equal to the abovementioned proportion between the maximum drift admissible and the depth of the water.
• the marine platform intended for oil or mining drilling comprising installations in particular for bringing down a drill rod towards the bottom of the water, a body of density less than 1 carrying these installations and dimensioned so as to have a positive buoyancy even with the maximum loading envisaged, this body being connected to means of anchoring to the bottom of the water by means of connection under tension so that it is in service submerged substantially in its entirety, is characterized in that the connection means comprise a reed tube, inside which the v drill pipe.
• the invention teaches an embodiment which makes it possible to benefit from the advantages of the first object of the invention, and which is also particularly advantageous in the context of drilling techniques.
• the waterproof connection tube behaves like a flexible clip even if a connection of the embedding type connects it to the anchoring means. Its flexibility is sufficient for this.
• the tube is particularly advantageous in its role of guiding the drill pipe. If, for example, the drilling tool has to be changed, there is no longer any problem in finding the drilling.
• the method for setting up a platform of the above kind is characterized by the following steps: the body is floated freely at the place where it is desired to install the platform; an attachment is unwound from the body intended to form part of the connecting means subsequently, until the free end of this attachment reaches the bottom of the water; 25. the tie is moored at the bottom of the water; and the tie is pulled from the body, so as to push it into the water to the desired depth.
• FIG. 1 is a schematic side elevation view of a platform according to the invention
• Figure 2 is a side elevation view and axial section of the platform being set up
• Figure 3 is a schematic side elevational view in axial section of a drilling rig according to the invention
• Figure 4 is an axial sectional view of the anchoring means;
• Figures 5 and 6 are views showing two stages of the establishment of the platform of Figure 3;
• Figure 7 is a partial side elevational view in axial section, of an alternative embodiment;
• Figure 8 is a side elevational view of a platform carrying a wind turbine;
• Figure 9 is a sectional view along line IX-IX of Figure 8.
• the platform shown schematically in Figure 1 can be applied to different uses such as drilling or capturing energy from swells, winds or currents.
• It comprises a body 1, of density less than 1, consisting of a hollow waterproof sphere, immersed so that the hollows of the swell cannot discover it, even if the swell has its maximum foreseeable amplitude, run the site.
• the body 1 carries a load essentially consisting of installations, the nature of which is linked to the use intended for the platform.
• the load also includes a tray
• the plate 6 intended to allow ships to dock or helicopters to land.
• the plate 6 is supported by the body 1 by means of a leg 7 which crosses the surface of the water 8.
• the body 1 is connected to means 9 for anchoring to the bottom of the water 11 by connection means 12.
• the assembly constituted by the body 1 and its load (comprising in particular the installations the plate 6, the leg 7 " etc.) has a positive buoyancy, that is to say to say that it tends to rise towards the surface.
• the connecting means 12 which by their tension prevent this ascent of the body 1.
• the connecting means 12 have their own deformability allowing the platform to drift under lateral force such that these connecting means come into alignment with the result of the forces applied to the upper assembly which comprises the body 1 and its load.
• the water depth is _h at the location of the platform and, under the effect of the force L, the float 1 undergoes a drift _d.
• connection means 12 are a single flexible attachment, such as a cable, and the condition stated amounts to saying that the resultant R of the forces P and L is substantially aligned with the cable 12.
• this angle can be made as small as desired by increasing the thrust P, that is to say by increasing the difference between the buoyancy of Archimedes on the body 1 on the one hand and the weight of the body 1 and its load on the other hand.
• the mass of water displaced by the body 1 is at least about twice the mass of the body 1 and of its maximum expected loading.
• the thrust P is given a value such that the ratio d / h is at most equal to 5%, in the case of a substantially maximum lateral force L.
• An anchor 9 is prepared at the bottom of the water 11 and the body 1 provided with a free float on the site provided with a chimney intended to serve later as a jamb 7.
• the chimney 7 is surmounted by a winch 10 on which the cable 12 is wound.
• the cable 12 is unwound which enters the body 1 through the chimney 7, and leaves the body 1 through an orifice 15 provided with sealing means preventing any entry of water into the body 1.
• the cable When the cable reaches the bottom of the water 11, it is fixed to the anchor 9, for example using personnel traveling to the site by means of an underwater vehicle.
• the cable 12 is rewound using the winch 10 so as to lower the body 1 to the desired depth. This is the step shown in Figure 2.
• the cable 12 constitutes the final attachment of the body 1 to the anchor 9-
• the connecting means 9 here comprise a single tube 13 rigidly fixed to the anchoring means 9 and to the sphere 1. Despite this rigid fixing, the tube 13 behaves like a flexible fastener making it possible to ensure that the condition L / P ⁇ - d / h is fulfilled.
• the tube 13 is waterproof and the construction has been made to contain no water.
• we chose a steel tube whose the thickness _e satisfies with the diameter D of this tube the relation e D / 31.2.
• the diameter D is chosen as a function of the stresses undergone by the tube, in particular in tension under the effect of forces such as P, and in radial compression under the effect of the water pressure.
• the anchoring means 9 which are shown in detail in the figure, comprise a tubular pile 14, reed with water, sealed with a cement or a resin 16 in a well 17 dug vertically at the bottom of the water. This type of anchoring is described in detail in French patent application No. 78 19 897 in the names of the Applicants.
• the tube 13 " whose diameter is less than the internal diameter of the tubular pile 14 extends to the bottom of the well 17 " coaxial with the latter.
• a concrete seal 18 is interposed between the tube 13 and the pile 14.
• the seal 18 is extended upwards by a corolla 19 intended to limit the radius of curvature in bending of the tube 13 - View in straight section, the face 21 of the corolla 19 which faces the tube 13 is tangent to the tube 13 at the mouth of the well 17, then moves away from the tube 13 in an arc.
• the radius of this circular arc 21 is the maximum radius that is allowed for the curvature of the tube 13 -
• the height of the corolla 19 is such that the angle at the top of the circular arc 21 is at least equal to the maximum angle of inclination allowed for the tube 13, this angle being defined by the ratio d / h.
• the wall of the tube 13 is thickened from the bottom of the well 17 to the top of the corolla 19 because it is in this zone that the tube 13 works in flexion, as will be seen below.
• the drilling rod 22 used for petroleum exploration is mounted in a guide tube 23 which in turn is installed in the tube 13.
• the drilling 24 is carried out from the bottom of the well 17.
• the tube 23 is used to cover the wall of the borehole 24 and to evacuate upwards the materials resulting from the drilling work.
• a safety shutter device 26 ( Figure 3) is installed in the anchoring means 9 to prevent the eventual sudden spurting of oil or gas.
• the drilling installations shown diagrammatically in FIG. 3 in the form of a derrick 27, are installed in the body 1 which is a hollow sphere.
• Platform 6 allows ships to dock and / or helicopters to land.
• the tube 13 behaves like a cable, that is to say that under the effect of the resultant R it tends to align with this resultant as soon as it leaves the means of anchoring 9. Thanks to the corolla 19, the effective stress in the tube 13 is limited by the radius of curvature of the face 21. Thus, any curvature of the tube 13 takes place in abutment against a part or, in extreme cases, the entire height of the face 21. Above, the tube is stretched in a rectilinear manner under the effect of the resultant R.
• FIGS. 5 and 6 show two steps of the method for placing the platform of FIGS. 3 e on the site. This method comprises the following steps:
• the pile 14 is sealed in the well 17 and the float 1 is allowed to float freely on the site.
• the tube 13 is constructed by elements 28 inside the sphere 1, and it is brought out of the sphere 1 downwards, through an orifice 29 formed at the base of the sphere 1. This is the step shown in FIG. 5.
• a technique for unwinding a tube from a sealed enclosure without risking the intrusion of water into the enclosure is described in French patent application No. 78 19 467 of June 29, 1978 in the names of the Applicants .
• the body 1 is of oblong horizontal shape and can pivot around the tube 13 thanks to a sealed pivot 32.
• the derrick 27 is mounted on a shoulder 33 of the tube 13.
• This embodiment allows the float to orient itself in its direction of least resistance to sea currents.
• the platform is intended to support a wind turbine 35.
• the platform comprises three cylindrical bodies 15 1a, of interior density at 1 , arranged in an equilateral triangle pattern (Figure 9).
• Each body 1a is connected to a respective anchor 9, for example of the kind with hollow pile such as 14 driven into a well such as 17, by connection means 20 9 each time comprising a rod 34 articulated to the anchor 9 corresponding by a universal joint 36 acting as a ball joint.
• the anchors 9 are arranged according to the same diagram as the bodies la, so that the rods 34, which are of the same length, are parallel to each other.
• a frame 37 which rests on the three bodies 1a by means of three feet 38 which cross the surface of the water 8, carries the wind turbine 35.
• the bodies 30 1a are interconnected by three spacers 39 which materialize the equilateral triangle diagram of the assembly.
• the platform obeys the general conditions laid down according to the invention and explained with reference to
• the thrust P is equal to the difference between the weight of the water displaced by the upper structure and the total weight of the upper structure comprising the wind turbine 35., the plate 37, the three legs 38 and the three bodies 1a_.
• the bars 34 are rigidly fixed to the bodies there. * In the event of lateral force on the upper structure, they can undergo a very significant bending moment. To limit this moment, corollas 41, of a design similar to the corolla 19 of FIG. 4, but directed downwards, surround the rods 3 at their junction with the bodies 1_a_.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Life Sciences & Earth Sciences (AREA)
• Mining & Mineral Resources (AREA)
• Geology (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Ocean & Marine Engineering (AREA)
• Environmental & Geological Engineering (AREA)
• Physics & Mathematics (AREA)
• Fluid Mechanics (AREA)
• Structural Engineering (AREA)
• Architecture (AREA)
• General Life Sciences & Earth Sciences (AREA)
• Geochemistry & Mineralogy (AREA)
• Sustainable Energy (AREA)
• General Engineering & Computer Science (AREA)
• Sustainable Development (AREA)
• Earth Drilling (AREA)

Applications Claiming Priority (2)

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ID=9259270

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• 1981
  • 1981-06-05 FR FR8111254A patent/FR2507146A1/fr active Granted
• 1982
  • 1982-06-04 EP EP82901600A patent/EP0080471A1/de not_active Ceased
  • 1982-06-04 WO PCT/FR1982/000094 patent/WO1982004233A1/en not_active Application Discontinuation

Non-Patent Citations (1)

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