EP0228955A1 - Device for supporting the leg of a jack-up oil platform, and platform using this device - Google Patents

Device for supporting the leg of a jack-up oil platform, and platform using this device Download PDF

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Publication number
EP0228955A1
EP0228955A1 EP86402805A EP86402805A EP0228955A1 EP 0228955 A1 EP0228955 A1 EP 0228955A1 EP 86402805 A EP86402805 A EP 86402805A EP 86402805 A EP86402805 A EP 86402805A EP 0228955 A1 EP0228955 A1 EP 0228955A1
Authority
EP
European Patent Office
Prior art keywords
leg
platform
riser
support device
centering
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.)
Granted
Application number
EP86402805A
Other languages
German (de)
French (fr)
Other versions
EP0228955B1 (en
Inventor
Pierre-Armand Thomas
Jean-Claude Naudin
Michel Ningler
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.)
Technip Geoproduction SA
Original Assignee
Technip Geoproduction SA
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 Technip Geoproduction SA filed Critical Technip Geoproduction SA
Publication of EP0228955A1 publication Critical patent/EP0228955A1/en
Application granted granted Critical
Publication of EP0228955B1 publication Critical patent/EP0228955B1/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • 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
    • E02B17/02—Artificial islands mounted on piles or like supports, e.g. platforms on raisable legs or offshore constructions; Construction methods therefor placed by lowering the supporting construction to the bottom, e.g. with subsequent fixing thereto
    • E02B17/021—Artificial islands mounted on piles or like supports, e.g. platforms on raisable legs or offshore constructions; Construction methods therefor placed by lowering the supporting construction to the bottom, e.g. with subsequent fixing thereto with relative movement between supporting construction and platform
    • E02B17/024—Artificial islands mounted on piles or like supports, e.g. platforms on raisable legs or offshore constructions; Construction methods therefor placed by lowering the supporting construction to the bottom, e.g. with subsequent fixing thereto with relative movement between supporting construction and platform shock absorbing means for the supporting construction
    • 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
    • E02B17/02—Artificial islands mounted on piles or like supports, e.g. platforms on raisable legs or offshore constructions; Construction methods therefor placed by lowering the supporting construction to the bottom, e.g. with subsequent fixing thereto
    • E02B17/021—Artificial islands mounted on piles or like supports, e.g. platforms on raisable legs or offshore constructions; Construction methods therefor placed by lowering the supporting construction to the bottom, e.g. with subsequent fixing thereto with relative movement between supporting construction and platform
    • 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
    • E02B2017/0039—Methods for placing the offshore structure
    • E02B2017/0043—Placing the offshore structure on a pre-installed foundation structure
    • 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
    • E02B2017/0056—Platforms with supporting legs
    • E02B2017/006—Platforms with supporting legs with lattice style supporting legs
    • 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
    • E02B2017/0056—Platforms with supporting legs
    • E02B2017/0073—Details of sea bottom engaging footing
    • E02B2017/0082—Spudcans, skirts or extended feet

Definitions

  • the present invention relates to self-elevating platforms for oil drilling and relates more particularly to production drilling platforms and / or for offshore production operations.
  • Self-elevating platforms for drilling at sea have been used until recently for depths of less than 100 m.
  • Lattice type legs are obtained with frame spacings which may be greater than 20m.
  • the increase in the dimensions of the legs results in a significant increase in weight, in a position of the center of gravity higher in towing, and therefore in a loss of stability, as well as greater drag forces in towing.
  • a self-elevating platform does not work permanently at the maximum depth it can reach.
  • Drilling operators prefer to work with self-elevating platforms, which in the elevated drilling position on their legs, are "fixed” platforms than with semi-submersible platforms which are mobile platforms.
  • the constructions in progress propose to move the border of use of the self-elevating platforms to a depth of 100 / 110m in difficult seas.
  • the invention aims to widen the field of action of the self-elevating platforms to depths of 130/150 m and more to carry out development drilling.
  • a support device for the leg of a self-elevating oil platform for operation at sea characterized in that it constitutes an individual and independent riser intended to be interposed between the leg of the platform and the seabed in order to increase the installation depth of the platform, and to improve its stability, said riser being provided with lockable, removable and adjustable means of rigid fixing at the lower end of the leg.
  • the invention also relates to a self-elevating platform for drilling at sea comprising a hull mounted movable and lockable in position along legs intended to bear on the seabed, characterized in that each leg is provided with a separable riser of the type defined above, secured to the lower end of said leg and intended to be interposed between the leg and the bottom in the operating position of the platform.
  • the self-elevating platform shown in Fig.1 mainly comprises a shell 1 of generally triangular shape mounted movable on three vertical legs 2 intended to bear on the seabed when the platform is in the operating position.
  • the platform is also equipped with a device for moving the shell 1 relative to the legs 2 and means for locking the shell relative to the legs 2 (not shown).
  • each of the legs of the platform is provided to normally allow the establishment of this platform on sites located at depths of the order of 100 to 110m.
  • risers 3 secured in a separable manner to the lower ends of the legs 2.
  • each of the legs 2 has a triangular section and it consists of a lattice of metal beams. It ends at its lower part with a leg 4 (Fig. 4) which, in the present example is hexagonal in shape.
  • a leg 4 (Fig. 4) which, in the present example is hexagonal in shape.
  • Each of the feet 4 is made for example of mechanically welded sheet metal and fixed by welding to the uprights 5 of the corresponding leg.
  • the bearing faces 6 of each foot are advantageously made with a diamond point.
  • each leg 2 of the platform is subject to an extension 3 formed by an upper plate 7 receiving the foot 4 and a lower plate 8 intended to take support on the seabed, the upper and lower plates being interconnected by tubular uprights 9.
  • the tubular uprights 9 are in turn connected to each other by lattices of metal beams 10 forming with the beams, the supporting structure of the riser.
  • the upper plate 7 of the extension 3 is made of mechanically welded sheet metal and has a housing 11 of shape corresponding to the foot 4 and in which this foot is engaged with a clearance to allow a catching up of the plate after the establishment of the platform.
  • the bottom 13 of the housing 11 intended to receive the foot 4 of the leg 2 is also made in the shape of a diamond point.
  • jacks 15 of a hydraulic trim adjustment device which will be described in detail with reference to Fig.7.
  • the inner plate 8 is also made of mechanically welded sheet. It is generally circular in shape and has on its underside a shoe 17 diamond point intended to penetrate the ground.
  • the legs of the platform are arranged in angular parts 18 enlarged from the hull 1 delimited by end walls 19 respectively parallel to the opposite sides of the hull and by side walls 20 perpendicular to the walls 19 and each connecting with one side of the shell 1.
  • Each leg 2 is arranged in the end portion of the platform so that one of its sides is parallel to the wall d end 19 of this portion.
  • the extension 13 has a frame of section similar to that of the corresponding leg 2, but of larger dimensions.
  • the upper plate 7 of the riser has tabs 22 arranged at 120 ° to which are welded the tubular sleeves 23 intended for receiving piles 24 for anchoring the riser in the ground.
  • the sleeves 23 are also fixed by welding to lugs 25 of the lower plate 8 also arranged at 120 °.
  • the sleeves 23 are arranged relative to the platform so that two of them are permanently located outside the bulk of the hull in order to allow the placement of the piles by means external to the platform.
  • the third sleeve is disposed below the shell approximately at the level of the bisector of the angle of the latter in which the corresponding leg is mounted and a well 26 is formed in the shell to access this sleeve.
  • the sleeves 23 also serve as a floatation stabilization device and are provided for this purpose with shutters 28 arranged at their upper ends.
  • the riser is further equipped with stabilization and immersion chimneys 30, arranged symmetrically with respect to the shell 1 and fixed to the upper and lower plates 7 and 8 of the riser.
  • the jacks 14 interposed between the bottom 13 of the recess 11 of the upper plate 7 of the riser and the foot 4 of the leg 2, are interconnected by conduits 32 ensuring their communication by valves 32 a . They are also each connected to a pressure accumulator 33 by means of a valve 34. Between the base 4 and the bottom 13 of the recess 11 is advantageously disposed a layer 35 of distribution material which may be of the sand trapped in an envelope making a sand box or even flexible products such as elastomers which adapt to the shape of the foot 4.
  • the risers 3 are installed under the hull 1 of the platform in the flotation position as shown in FIGS. 2 and 4. Their stability in this phase is imparted by the sleeves 23 closed and the chimneys 30 which emerge.
  • Each riser is arranged so that the recess 11 of its upper plate 7 receives the foot 4 of the corresponding leg 2.
  • the riser 4 is immobilized relative to the leg 2 by means of the latches 12. It is also immobilized relative to the hull 1 of the platform by means of the towing latches 27 ensuring the immobilization of the tubular sleeves 23 relative to the side walls 20 of the portion d the corresponding end 18 of the hull 20. Similar towing latches are advantageously provided for immobilizing the chimneys 30.
  • the assembly is then ready to be towed to the operating site.
  • the tubular sleeves 23 and the chimneys 30 ensure the float stabilization of the riser.
  • the towing latches 27 are actuated to release the riser 3 relative to the hull 1 and the legs 2 are moved from below by the displacement devices not shown carried by the shell 1.
  • the stabilization chimneys 30 are also open at their two ends to allow the penetration of water.
  • the shoe 17 of the riser On arrival of the riser in contact with the ground in the position shown in Fig.3, the shoe 17 of the riser enters the latter and the legs 25 of the lower plate 8 by resting on the ground increase stability seat on the bottom.
  • the pads 17 are larger than those of the feet 4 of the legs 2 of the platform and therefore take up the greater forces due to the increase in depth.
  • the placement of the piles 24 is ensured from the surface from the on-board crane provided on the hull 1 which handles the piles and underwater hammers.
  • the piles are then secured to the sleeves 23 by injection of cement brought to the bottom by the flexible conduit (umbilical) 36, the sleeves 23 being equipped with annular seals at each of their ends (not shown).
  • the mattress 35 of distribution material ensures at this time the distribution of the load of each leg 2 in the recess 11 of the upper plate 8 of the riser.
  • the attitude distribution device shown in Fig. 7 works in turn as a flexible ball joint or, on the contrary, as a rigid recess.
  • the jacks behave like a rigid system in rotation and elastic vertically due to the presence of the accumulators 33.
  • valves 32a ensures a re-establishment of the pressures between the jacks 15 and thereby a catching up of the base of the foot 4 which returns to the horizontal position.
  • valves 34 and the valves 32a are closed.
  • the device behaves again as a recess and a rigid support.
  • the pressure accumulator 33 can advantageously consist of an oleopneumatic accumulator battery, while the valves 34 and 32b can be remote-controlled valves using the umbilical 36.
  • the trim device which has just been described can be actuated at the same time as the latches 12 which limit or prevent any movement between the riser 3 and the leg 2 depending on whether the jacks 15 are placed in communication with one another or not .
  • the injection is made between the foot 4 of each leg 2 and the bottom 13 of the recess 11 of the riser 3 in which the foot 4 is engaged, of a cement intended to ensure the rigidity of the support of the foot 4 on the riser 3.
  • This cement is advantageously brought to the bottom by a flexible conduit 36 which is also used for the transmission of control signals necessary for the setting operations.
  • the device can remain in operating mode with surface foundation directly and only by pressing on the pads 17.
  • the structure of the risers can be simplified and not include sleeves for better but only stabilization and immersion chimneys.
  • attitude adjustment devices can also be omitted.
  • the legs of the jack-up platform are fitted with risers
  • the general construction rale is the same as that described with reference to Figs. 1 to 5 except that these risers each include four tubular sleeves 37 arranged at 90 ° relative to each other at the periphery of the riser so that three of them are located outside the footprint of the platform.
  • These sleeves also serve as flotation stabilization chimneys, so that it is not necessary to provide special chimneys for this purpose as is the case with the extensions with three sleeves shown in Figs. 1 to 5.
  • the performance increase is ensured by the riser junction installed on the site by the self-elevating platform itself and rigidly nailed or not at the bottom of the sea.
  • the self-elevating platform can be released from its support constituted by the risers on which the legs of the platform are immobilized to become again a conventional self-elevating platform retaining maneuverability. For this purpose, it suffices to release the latches 12 for fixing the legs 2 to their extensions 3.
  • Another important advantage of the invention resides in the fact that a self-elevating platform which has been thus removed by detachment of its legs from the risers on which they were initially installed can be brought back to the site and reinstalled on extensions to carry out maintenance work on wells.
  • the arrangement of the invention also makes it possible to produce small oil fields economically at depths of up to 130 to 150 m and more, and to carry out field development drilling without the installation of a fixed platform and '' thus avoiding the immobilization of drilling equipment for several years without use but requiring maintenance.
  • FIGS. 8 to 17 Another embodiment of the self-elevating platform according to the invention is shown in FIGS. 8 to 17, the installation of which on a drilling or exploitation site is carried out by the prior installation of the risers on the seabed and by subsequent positioning and securing on said risers of the legs of the platform brought in by flotation.
  • a self-elevating platform comprising a hull 101 floating on the surface of the water and provided with legs 102 capable of being displaced relative to the hull using displacement devices not shown and which can be immobilized compared to the shell using locking means also not shown.
  • the platform is brought above the location of the risers 103 fixed to the seabed, by means of winches 104 provided on the hull 101 which act on respective cables 105, the ends of which are fixed beforehand to the corresponding risers 103.
  • Each leg 102 is provided at its lower end with a foot 106 fitted with a centering stud 107 intended to be engaged in a corresponding orifice 108 formed in an upper plate 109 of the extension 103.
  • Fig.9 there is shown on a larger scale, a riser 103 placed on the seabed F and above it, the lower end of a leg 102 ready to be placed on the tray upper 109 of the extension.
  • the extension 102 has a cross section of generally triangular shape. It consists of the upper plate 109 and three soles or laying floors 110 each connected to the upper plate 109 by three tubular uprights or sleeves 111 in which are engaged piles 112 for anchoring the riser in the seabed. The reinforcement of the assembly thus formed is ensured by a wire mesh 113.
  • the centering orifice 108 formed in the plate 109 has a diameter greater than the centering stud 107 of the foot 106 of the leg 102 so as to make it possible to make up for any inaccuracies in fitting the risers.
  • the centering orifice 108 has a conical inlet 114 intended to cooperate with a conical end 115 of the centering stud 107 of the leg 102 when it engages in the orifice 108.
  • a housing 116 which opens into the centering orifice 108 and which has a section larger than the latter.
  • tilting latches 119 in the form of stirrups intended to engage with lateral projections 120 of the foot 106 of the platform leg 102 and thus lock the leg on the riser 103 against all vertical displacements.
  • the leg 102 is disposed on the riser 103 in a position offset from its axis of symmetry due to the relative imprecision of positioning the riser 103 on the seabed .
  • This is possible thanks to the possibility of positioning adaptation which the difference in diameter ensures between the centering hole 108 of the upper plate 109 of the riser and the centering stud 107 of the leg 102 shown in FIG. 9.
  • the foot 106 can occupy on the surface of the upper plate 109 of the extension 103, an area 121 shown in phantom of a surface larger than the size of the foot 106.
  • the foot 106 is placed against an edge of this area 121 and it is placed with clearances J relative to the other two edges of this area.
  • the dimensions of the locking stirrups 119 are also provided so that each of them can come into engagement with the corresponding lateral projection 120 of the platform leg 106 regardless of the position occupied by the foot on the positioning area 121 of the extension 103 delimited by an outline in phantom.
  • the riser is provided on two of its sides with docking blade ducks 122 constituted by vertical elastic tubular members.
  • FIGS. 11 and 12 The means for centering a platform leg relative to the riser intended to support it, are shown in more detail in FIGS. 11 and 12.
  • Fig.11 shows the upper plate 109 provided with its centering hole 108 with conical inlet 114 and in which is formed the housing 116 opening into the centering hole 108.
  • the centering washer 117 whose central hole 118 is occupied by the centering stud 107 of the corresponding platform leg.
  • the centering pin 107 is placed against an edge of the centering orifice 108 of the plate 109 and the centering washer 117, called the floating washer, is offset with respect to the axis of the centering orifice 108 and immobilized horizontally by clamping devices 124 mounted in the plate 109.
  • clamping devices consist of cylinders which will be described in detail with reference to Fig. 13.
  • the floating washer 117 can occupy in its recess 116 an area 125 shown in phantom corresponding to all of the positions that the centering pad 107 of the leg 102 can occupy in the centering orifice 108 of the upper plate 109 of the extension.
  • a jack body 126 movable relative to a fixed rod 127 bearing on a support 128 secured to the upper plate 109 by means of a fixing member such as a screw 129.
  • the jack body 126 is supported on an elastic annular pad 130 surrounding the fixed rod 127 between the head 131 of which and the jack body 126 is formed a chamber 132 supplied with hydraulic fluid by means of a pipe 133.
  • the force developed by the pressurization of the chamber 132 compresses the elastic annular pad 130 so that the jack body 126 is retracted inside its housing 134 formed in the upper plate 109.
  • the floating washer 117 which the absence of pressure applied to the chamber 132 is kept tight against the interior wall of the housing 116 of the upper plate 109 is then released and can slide inside the housing 116.
  • pads are advantageously constituted by a stack of elastomer washers and ron rigid ones, for example metallic ones glued to each other.
  • the seal between the movable cylinder body 126 and the fixed rod 127 of the cylinder can advantageously be obtained using elastomer sleeves 127a adhered to the cylinder body 126 and to the rod 127, these sleeves being deformable in shear.
  • a centering device of the type which has just been described with reference to FIGS. 11 to 13 is provided on only two risers of a platform with three legs each provided with a riser.
  • the centering hole 108a has an inner diameter equal to the outside diameter of the centering stud 107 of the corresponding leg, so that this third riser defines a reference of positioning of the platform.
  • each platform leg on its riser The vertical locking means of each platform leg on its riser are shown in more detail in Figs. 14 to 17.
  • each extension 103 is provided with three latches 119 in the form of stirrups mounted tilting on its upper plate 109 and which are in the separated position before the positioning of the foot 106 of the corresponding leg 102 on the plate 109.
  • the lock 119 is shown in solid lines in its blocking position of the foot 106 of the corresponding leg 102 and in phantom in its position apart.
  • the latch 119 completely releases the laying surface 121 of the plate 109 (FIG. 10).
  • Each latch 109 has a cross member 135 (Fig. 15) whose width is sufficient to cover the corresponding projection or sole 120 of the foot 106 placed randomly on the laying surface 121.
  • the underside 136 of each cross member 135 as the part upper 137 of the sole 120 are flat surfaces which come into contact with one another when the tilting latches 119 are in the closed position.
  • Each of the locks is articulated around an axis 138 and comprises two arms 139 and two locking plates 140 each provided with a light 141.
  • a sliding latch 142 maneuvered by a jack 143 is mounted in the upper plate 109 of the riser right of the lights 141 when the stirrup 119 is in the closed or locked position.
  • FIG. 16 shows a latch 142 in the released position out of the lumen 141 of the arm of corresponding locking 140 of the stirrup 119.
  • the jack 143 is in the rest position.
  • Fig.17 it can be seen that the latch 142 has been engaged in the slot 141 of the corresponding locking arm 140 under the action of the jack 143 which is held in this active position.
  • the locking is further improved by the introduction of the end of the latch 142 into a slot 144 formed in a vertical wall 145 of the upper plate 109.
  • the arrangement of self-elevating platform which has just been described makes it possible to ensure the relatively easy positioning of the legs of the platform on risers previously mounted on the operating site.
  • the platform is brought to the site and the legs 103 are lowered one after the other so that each of them comes to bear on one of the risers.
  • One begins for this purpose by lowering the leg intended to be placed on the riser provided with a centering hole 108a of diameter equal to that of the centering stud 107 of its foot 106.
  • This first leg 102 is positioned using the winches 104 arranged on the platform. A first positioning of the leg 102 relative to its riser is facilitated by the coming into contact of the leg 102 with the dolphins 22 provided on two sides of the riser 103.
  • first leg 102 When the first leg 102 is placed on its riser 103, it determines a reference axis around which the whole of the platform can be rotated until the other legs 102 of the latter are opposite corresponding extensions 103. These legs are then lowered so that their centering studs 107 penetrate into the centering orifices 108 of larger mena diameter. gés in the upper plates 109 of the other two risers and enter the central holes 118 of the corresponding floating washers 117 by moving them laterally to the position where they will be immobilized.
  • the floating washers 117 are immobilized horizontally by actuating the jacks 124 which, as seen in FIG. 12, are arranged in a ring so as to exert a uniform clamping force on the washer 117.
  • Locks 119 are then actuated in the shape of a stirrup, the cross members 135 of which are applied to the lateral projections or soles 120 of each of the feet 106.
  • the latches 119 are thus immobilized by the introduction of the latches 142 in their respective slots 141.
  • platform is then immobilized horizontally by the floating washers 117 tightened by their jacks 124 and vertically by the latches 119, and can withstand the horizontal forces as well as the vertical forces and the moments which it undergoes.
  • one of the extensions has a centering orifice 108a of the same section as the centering stud 107 of the corresponding platform leg.
  • centering hole extensions 108 with a cross section greater than that of the centering studs 107.
  • all of the extensions include a centering washer 117 and means for immobilizing the latter.

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  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Civil Engineering (AREA)
  • Structural Engineering (AREA)
  • Earth Drilling (AREA)

Abstract

Dispositif de support pour jambe (2) de plate-forme pétrolière auto-élévatrice de forage en mer, caractérisé en ce qu'il constitue une réhausse (3) destinée à être interposée entre la jambe de la plate-forme et le fond marin afin d'accroître la profondeur d'installation de la plate-forme, ladite réhausse étant pourvue de moyens (4,7,11,12) de solidarisation amovible avec l'extrémité inférieure (4) de la jambe (2) qui en améliorent la résistance.Support device for a leg (2) of a self-elevating offshore oil drilling platform, characterized in that it constitutes a riser (3) intended to be interposed between the leg of the platform and the seabed so to increase the installation depth of the platform, said riser being provided with means (4,7,11,12) for removable securing with the lower end (4) of the leg (2) which improve the resistance.

Description

La présente invention est relative aux pla­te-formes auto-élévatrices pour forages pétroliers et se rapporte plus particulièrement à des plate-formes de forage de production et/ou pour des opérations de production en mer.The present invention relates to self-elevating platforms for oil drilling and relates more particularly to production drilling platforms and / or for offshore production operations.

Les plate-formes auto-élévatrices pour réa­liser des forages en mer sont utilisées jusqu'à récem­ment pour des profondeurs inférieures à 100 m.Self-elevating platforms for drilling at sea have been used until recently for depths of less than 100 m.

L'utilisation de telles plate-formes dans des mers difficiles (Mer du Nord, Est Canada, ..) pour des profondeurs supérieures à 100/110m avec des vagues de 30 m de hauteur est rendue difficile :
- par le comportement dynamique de la plate-­forme résultant du grand élancement des jambes de sup­port;
- par les efforts subis par la plate-forme de la part de la houle, du vent, des courants.The use of such platforms in difficult seas (North Sea, East Canada, etc.) for depths greater than 100 / 110m with waves 30 m high is made difficult:
- by the dynamic behavior of the platform resulting from the great slenderness of the support legs;
- by the forces undergone by the platform from the swell, the wind, the currents.

Certains constructeurs proposent des con­cepts qui conservent l'architecture classique des pla­te-formes auto-élévatrices pour atteindre des profon­deurs supérieures à 100/110m. Cela se traduit par un accroissement important des dimensions des jambes, et de la coque, et du déplacement en remorquage.Some manufacturers offer concepts that keep the classic architecture of jack-up platforms to reach depths greater than 100 / 110m. This results in a significant increase in the dimensions of the legs, and of the hull, and of the displacement in towing.

On obtient des jambes de type à treillis avec des écartements de membrures pouvant être supé­rieurs à 20m.Lattice type legs are obtained with frame spacings which may be greater than 20m.

L'accroissement des dimensions des jambes se traduit par un accroissement important du poids, par une position du centre de gravité plus élevée en re­morquage, et donc par une perte de stabilité, ainsi que des efforts de trainée plus importants en remor­quage.The increase in the dimensions of the legs results in a significant increase in weight, in a position of the center of gravity higher in towing, and therefore in a loss of stability, as well as greater drag forces in towing.

Indépendamment de l'aspect économique, cela rend difficiles les déplacements d'une telle plate-­forme d'un site de forage à un autre.Regardless of the economic aspect, this makes it difficult to move such a platform from one drilling site to another.

Par ailleurs, une plate-forme auto-élevatri­ce ne travaille pas en permanence à la profondeur ma­ximum qu'elle peut atteindre.In addition, a self-elevating platform does not work permanently at the maximum depth it can reach.

Donc une plate-forme auto-élévatrice conçue pour une profondeur de 130m sera amenée à travailler souvent dans des profondeurs de 100m et moins. Elle risque alors de se trouver en concurrence avec des plate-formes plus petites et donc plus aisées à ma­noeuvrer et plus économiques.So a self-elevating platform designed for a depth of 130m will often have to work in depths of 100m and less. It therefore risks being in competition with smaller platforms, which are therefore easier to maneuver and more economical.

Les opérateurs de forage préfèrent travail­ler avec des plate-formes auto-élévatrices, qui en po­sition de forage élevée sur leurs jambes, sont des plate-formes "fixes" qu'avec des plate-formes semi­submersibles qui sont des plate-formes mobiles.Drilling operators prefer to work with self-elevating platforms, which in the elevated drilling position on their legs, are "fixed" platforms than with semi-submersible platforms which are mobile platforms.

Aussi à ce jour pour des profondeurs infé­rieures à 80m, on utilise presque exclusivement des plate-formes auto-élévatrices.Also to date for depths less than 80m, almost exclusively self-elevating platforms are used.

Les constructions en cours proposent de dé­placer la frontière d'utilisation des plate-formes auto-élévatrices à une profondeur de 100/110m dans les mers difficiles.The constructions in progress propose to move the border of use of the self-elevating platforms to a depth of 100 / 110m in difficult seas.

L'invention a pour but d'élargir le champ d'action des plate-formes auto-élévatrices jusqu'à des profondeurs de 130/150 m et plus pour réaliser des forages de développement.The invention aims to widen the field of action of the self-elevating platforms to depths of 130/150 m and more to carry out development drilling.

Elle a donc pour objet un dispositif de support pour jambe de plate-forme pétrolière auto-élé­vatrice d'opération en mer, caractérisé en ce qu'il constitue une réhausse individuelle et indépendante destinée à être interposée entre la jambe de la pla­te-forme et le fond marin afin d'accroître la profon­deur d'installation de la plate-forme, et d'améliorer sa stabilité, ladite réhausse étant pourvue de moyens verrouillables, amovibles et réglables de fixation rigide à l'extrémité inférieure de la jambe.It therefore relates to a support device for the leg of a self-elevating oil platform for operation at sea, characterized in that it constitutes an individual and independent riser intended to be interposed between the leg of the platform and the seabed in order to increase the installation depth of the platform, and to improve its stability, said riser being provided with lockable, removable and adjustable means of rigid fixing at the lower end of the leg.

L'invention a également pour objet une pla­te-forme auto-élévatrice pour forages en mer compre­nant une coque montée déplaçable et verrouillable en position le long de jambes destineées à prendre appui sur le fond marin, caractérisée en ce que chaque jambe est pourvue d'une réhausse séparable du type défini ci-dessus, assujettie à l'extrémité inférieure de ladite jambe et destinée à être interposée entre la jambe et le fond en position d'exploitation de la pla­te-forme.The invention also relates to a self-elevating platform for drilling at sea comprising a hull mounted movable and lockable in position along legs intended to bear on the seabed, characterized in that each leg is provided with a separable riser of the type defined above, secured to the lower end of said leg and intended to be interposed between the leg and the bottom in the operating position of the platform.

L'invention sera mieux comprise à l'aide de la description qui va suivre, donnée eniquement à titre d'exemple et faite en se référant aux dessins annexés, sur lesquels :

  • - la Fig.1 est une vue schématique en plan d'une plate-forme auto-élévatrice dont les jambes sont pourvues de réhausses suivant l'invention;
  • - la Fig.2 est une vue partielle en éléva­tion représentant une jambe de la plate-forme auto-­élévatrice équipée d'une réhausse suivant l'invention placée en position de remorquage;
  • - la Fig.3 est une vue partielle en éléva­tion d'une jambe de la plate-forme auto-élévatrice de la Fig.1 placée en position d'exploitation;
  • - la Fi.4 est une vue en élévation avec arrachement partiel d'une réhausse suivant l'invention équipant la plate-forme auto-élévatrice des Fig.1 à 3;
  • - la Fig.5 est une coupe suivant la ligne 5-5 de la Fig.4;
  • - la Fig.6 est une vue partielle en plan d'une plate-forme auto-élévatrice équipée de réhausse selon un autre mode de réalisation de l'invention;
  • - la Fig.7 est une vue partielle en coupe à plus grande échelle de la partie supérieure d'une ré­ hausse équipée de moyens de rattrapage d'assiette;
  • - la Fig.8 est une vue schématique partielle d'une plate-forme suivant l'invention en cours d'ins­tallation sur des rehausses mises en place au préala­ble sur un site;
  • - la Fig.9 est une vue en élévation avec ar­rachement partiel d'une rehausse et d'une jambe de plate-forme disposée au-dessus de celle-ci avant sa mise en place sur la rehausse;
  • - la Fig.10 est une vue de dessus, en coupe partielle d'une jambe de plate-forme fixée sur sa re­hausse;
  • - la Fig.11 est une vue partielle en éléva­tion et en coupe à plus grande échelle montrant les moyens de centrage de deux des jambes de plate-forme sur leurs rehausses correspondantes;
  • - la Fig.11a est une vue partielle en élé­vation et en coupe des moyens de centrage de la troi­sième jambe;
  • - la Fig.12 est une vue de dessus à échelle réduite des moyens représentés à la Fig.11;
  • - la Fig.13 est une vue en élévation et en coupe à échelle agrandie d'un vérin faisant partie des moyens de centrage représentés aux Fig.11 et 12;
  • - la Fig.14 est une vue partielle en éléva­tion à plus grande échelle des moyens d'immobilisation d'une jambe de plate-forme sur sa rehausse;
  • - la Fig.15 est une vue suivant la flèche G avec arrachement partiel de la Fig.14;
  • - la Fig.16 est une vue en élévation et en coupe d'un loquet qui fait partie des moyens d'immobi­lisation de la Fig.14 représenté en position dégagée; et
  • - la Fig.17 est une vue correspondant à celle de la Fig.16 du loquet en position de blocage.
The invention will be better understood with the aid of the description which follows, given only by way of example and made with reference to the appended drawings, in which:
  • - Fig.1 is a schematic plan view of a self-elevating platform whose legs are provided with risers according to the invention;
  • - Fig.2 is a partial elevational view showing a leg of the self-elevating platform equipped with a riser according to the invention placed in the towing position;
  • - Fig.3 is a partial elevational view of a leg of the self-elevating platform of Fig.1 placed in the operating position;
  • - Fi.4 is an elevational view with partial cutaway of an extension according to the invention fitted to the self-elevating platform of Fig.1 to 3;
  • - Fig.5 is a section along line 5-5 of Fig.4;
  • - Fig.6 is a partial plan view of a self-elevating platform equipped with riser according to another embodiment of the invention;
  • - Fig.7 is a partial sectional view on a larger scale of the upper part of a re rise equipped with means of adjusting the attitude;
  • - Fig.8 is a partial schematic view of a platform according to the invention during installation on risers previously installed on a site;
  • - Fig.9 is an elevational view with partial cutaway of a riser and a platform leg arranged above the latter before it is placed on the riser;
  • - Fig.10 is a top view, in partial section of a platform leg fixed on its riser;
  • - Fig.11 is a partial elevational view in section on a larger scale showing the means for centering two of the platform legs on their corresponding risers;
  • - Fig.11a is a partial elevational view in section of the centering means of the third leg;
  • - Fig.12 is a top view on a reduced scale of the means shown in Fig.11;
  • - Fig.13 is an elevational view in section on an enlarged scale of a jack forming part of the centering means shown in Fig.11 and 12;
  • - Fig.14 is a partial elevational view on a larger scale of the means for immobilizing a platform leg on its riser;
  • - Fig.15 is a view along arrow G with partial cutaway of Fig.14;
  • - Fig.16 is an elevational and sectional view of a latch which is part of the immobilization means of Fig.14 shown in the released position; and
  • - Fig.17 is a view corresponding to that of Fig.16 of the latch in the locked position.

La plate-forme auto-élévatrice représentée à la Fig.1 comporte principalement une coque 1 de forme générale triangulaire montée déplaçable sur trois jam­bes verticales 2 destinées à prendre appui sur le fond marin lorsque la plate-forme est en position d'exploi­tation.The self-elevating platform shown in Fig.1 mainly comprises a shell 1 of generally triangular shape mounted movable on three vertical legs 2 intended to bear on the seabed when the platform is in the operating position.

La plate-forme est par ailleurs équipée d'un dispositif de déplacement de la coque 1 par rapport aux jambes 2 et de moyens de verrouillage de la coque par rapport aux jambes 2 (non représentés).The platform is also equipped with a device for moving the shell 1 relative to the legs 2 and means for locking the shell relative to the legs 2 (not shown).

La longueur de chacune des jambes de la pla­te-forme est prévue pour permettre normalement la mise en place de cette plate-forme sur des sites situés à des profondeurs de l'ordre de 100 à 110m.The length of each of the legs of the platform is provided to normally allow the establishment of this platform on sites located at depths of the order of 100 to 110m.

Afin d'accroître la profondeur à laquelle la plate-forme peut être mise en exploitation, celle-ci est pourvue suivant l'invention de réhausses 3 assu­jetties de façon séparable aux extrémités inférieures des jambes 2.In order to increase the depth to which the platform can be put into operation, it is provided according to the invention with risers 3 secured in a separable manner to the lower ends of the legs 2.

Comme représenté plus en détail aux Fig.1 à 4, chacune des jambes 2 présente une section triangu­laire et elle est constituée d'un treillis de poutrel­les métalliques. Elle se termine à sa partie inférieu­re par un pied 4 (Fig.4) qui, dans le présent exemple est de forme hexagonale. Chacun des pieds 4 est réali­sé par exemple en tôle mécanosoudée et fixé par souda­ge aux montants 5 de la jambe correspondante. Les fa­ces d'appui 6 de chaque pied sont avantageusement réalisées de pointe de diamant.As shown in more detail in Fig. 1 to 4, each of the legs 2 has a triangular section and it consists of a lattice of metal beams. It ends at its lower part with a leg 4 (Fig. 4) which, in the present example is hexagonal in shape. Each of the feet 4 is made for example of mechanically welded sheet metal and fixed by welding to the uprights 5 of the corresponding leg. The bearing faces 6 of each foot are advantageously made with a diamond point.

Comme représenté à la Fig.4, au pied 4 de chaque jambe 2 de la plate-forme est assujettie une réhausse 3 formée d'un plateau supérieur 7 recevant le pied 4 et d'un plateau inférieur 8 destiné à prendre appui sur le fond marin, les plateaux supérieur et inférieur étant reliés entre eux par des montants tu­bulaires 9.As shown in Fig.4, at the foot 4 of each leg 2 of the platform is subject to an extension 3 formed by an upper plate 7 receiving the foot 4 and a lower plate 8 intended to take support on the seabed, the upper and lower plates being interconnected by tubular uprights 9.

Les montants tubulaires 9 sont à leur tour reliés entre eux par des treillis de poutrelles métal­liques 10 formant avec les poutrelles,la structure porteuse de la réhausse. Le plateau supérieur 7 de la réhausse 3 est réalisé en tôle mécano-soudée et com­porte un logement 11 de forme correspondante au pied 4 et dans lequel ce pied est engagé avec un jeu pour permettre un rattrapage d'assiette après la mise en place de la plate-forme.The tubular uprights 9 are in turn connected to each other by lattices of metal beams 10 forming with the beams, the supporting structure of the riser. The upper plate 7 of the extension 3 is made of mechanically welded sheet metal and has a housing 11 of shape corresponding to the foot 4 and in which this foot is engaged with a clearance to allow a catching up of the plate after the establishment of the platform.

Il est également possible de réaliser la structure porteuse et les plateaux 7 et 8 sous la forme de plateaux et de jupes en béton.It is also possible to produce the supporting structure and the plates 7 and 8 in the form of concrete plates and skirts.

La fixation de la réhausse 3 à la jambe 2 est assurée par des verrous 12 disposés à la périphé­rie de la face supérieure du plateau 7.The attachment of the extension 3 to the leg 2 is ensured by latches 12 arranged at the periphery of the upper face of the plate 7.

Le fond 13 du logement 11 destiné à recevoir le pied 4 de la jambe 2 est lui aussi réalisé en forme de pointe de diamant.The bottom 13 of the housing 11 intended to receive the foot 4 of the leg 2 is also made in the shape of a diamond point.

En position de remorquage, représentée aux Fig.2 et 4 et lors de la descente par les jambes, la réhausse 3 est maintenue en suspension sur le pied 4 par les verrous 12. Un léger jeu 14 est ménagé entre la face d'appui 6 du pied 4 et le fond 13 du logement 11.In the towing position, shown in Fig. 2 and 4 and when lowering by the legs, the riser 3 is held in suspension on the foot 4 by the latches 12. A slight clearance 14 is provided between the bearing face 6 of foot 4 and bottom 13 of housing 11.

A la périphérie du fond 13 sont disposés des vérins 15 d'un dispositif hydraulique de rattrapage d'assiette qui sera décrit en détail en référence à la Fig.7.At the periphery of the bottom 13 are arranged jacks 15 of a hydraulic trim adjustment device which will be described in detail with reference to Fig.7.

Le plateau intérieur 8 est lui aussi réalisé en tôle mécano-soudée. Il est de forme générale circu­laire et présente sur sa face inférieure un patin 17 en pointe de diamant destiné à pénétrer dans le sol.The inner plate 8 is also made of mechanically welded sheet. It is generally circular in shape and has on its underside a shoe 17 diamond point intended to penetrate the ground.

Ainsi qu'on peut le voir à la Fig.1, les jambes de la plate-forme sont disposées dans des par­ties angulaires 18 élargies de la coque 1 délimitée par des parois d'extrémité 19 respectivement parallè­les aux côtés opposés de la coque et par des parois latérales 20 perpendiculaires aux parois 19 et se rac­cordant chacune avec un côté de la coque 1. Chaque jambe 2 est disposée dans la portion d'extrémité de la plate-forme de façon qu'un de ses côtés soit parallè­le à la paroi d'extrémité 19 de cette portion.As can be seen in Fig.1, the legs of the platform are arranged in angular parts 18 enlarged from the hull 1 delimited by end walls 19 respectively parallel to the opposite sides of the hull and by side walls 20 perpendicular to the walls 19 and each connecting with one side of the shell 1. Each leg 2 is arranged in the end portion of the platform so that one of its sides is parallel to the wall d end 19 of this portion.

Ainsi qu'on peut le voir aux Fig.2 à 4, la réhausse 13 présente une ossature de section semblable à celle de la jambe 2 correspondante, mais de dimen­sions plus importantes. Le plateau supérieur 7 de la réhausse comporte des pattes 22 disposées à 120° aux­quelles sont soudés les manchons tubulaires 23 desti­nés à la réception de pieux 24 d'ancrage de la réhaus­se dans le sol. Les manchons 23 sont également fixés par soudage à des pattes 25 du plateau inférieur 8 disposées elles aussi à 120°.As can be seen in Fig. 2 to 4, the extension 13 has a frame of section similar to that of the corresponding leg 2, but of larger dimensions. The upper plate 7 of the riser has tabs 22 arranged at 120 ° to which are welded the tubular sleeves 23 intended for receiving piles 24 for anchoring the riser in the ground. The sleeves 23 are also fixed by welding to lugs 25 of the lower plate 8 also arranged at 120 °.

Ainsi qu'on peut le voir aux Fig.1 et 5, les manchons 23 sont disposés par rapport à la plate-forme de manière que deux d'entre eux soient en permanence situés en dehors de l'encombrement de la coque afin de permettre la mise en place des pieux par des moyens extérieurs à la plate-forme.As can be seen in Fig. 1 and 5, the sleeves 23 are arranged relative to the platform so that two of them are permanently located outside the bulk of the hull in order to allow the placement of the piles by means external to the platform.

Le troisième manchon est disposé au-dessous de la coque à peu près au niveau de la bissectrice de l'angle de celle-ci dans lequel est montée la jambe correspondante et un puits 26 est ménagé dans la coque pour accéder à ce manchon.The third sleeve is disposed below the shell approximately at the level of the bisector of the angle of the latter in which the corresponding leg is mounted and a well 26 is formed in the shell to access this sleeve.

Comme représenté à la Fig.4, lorsque la pla­te-forme se trouve en position de remorquage, et que les jambes 2 sont totalement sorties au-dessus de la coque 1, les manchons 23 des réhausses 3 sont immobi­lisés par rapport à la coque au moyen de verrous de remorquage 27.As shown in Fig. 4, when the platform is in the towing position, and the legs 2 are completely extended above the hull 1, the sleeves 23 of the risers 3 are immobilized relative to the hull by means of towing latches 27.

Les manchons 23 servent également de dispo-sitif de stabilisation en flottaison et sont pourvus à cet effet d'obturateurs 28 disposés à leurs extrémités supérieures.The sleeves 23 also serve as a floatation stabilization device and are provided for this purpose with shutters 28 arranged at their upper ends.

La réhausse est en outre équipée de chemi­nées 30 de stabilisation et d'imersion, disposées de façon symétrique par rapport à la coque 1 et fixée aux plateaux supérieur et inférieur 7 et 8 de la réhausse.The riser is further equipped with stabilization and immersion chimneys 30, arranged symmetrically with respect to the shell 1 and fixed to the upper and lower plates 7 and 8 of the riser.

Comme réprésenté à la Fig.7, les vérins 14 interposés entre le fond 13 de l'évidement 11 du pla­teau supérieur 7 de la réhausse et le pied 4 de la jambe 2, sont reliés entre eux par des conduits 32 assurant leur mise en communication par des vannes 32a. Ils sont en outre reliés chacun à un accumulateur de pression 33 par l'intermédiaire d'une vanne 34. Entre le pied 4 et le fond 13 de l'évidement 11 est avantageusement disposée une couche 35 de matériau de répartition qui, peut être du sable emprisonné dans une enveloppe réalisant une boîte à sable ou encore des produits souples comme des élastomères qui s'adaptent à la forme du pied 4.As shown in Fig.7, the jacks 14 interposed between the bottom 13 of the recess 11 of the upper plate 7 of the riser and the foot 4 of the leg 2, are interconnected by conduits 32 ensuring their communication by valves 32 a . They are also each connected to a pressure accumulator 33 by means of a valve 34. Between the base 4 and the bottom 13 of the recess 11 is advantageously disposed a layer 35 of distribution material which may be of the sand trapped in an envelope making a sand box or even flexible products such as elastomers which adapt to the shape of the foot 4.

Les réhausses 3 sont installées sous la coque 1 de la plate-forme en position de flottaison comme représenté aux Fig.2 et 4. Leur stabilité dans cette phase est conférée par les manchons 23 obturés et les cheminées 30 qui émergent.The risers 3 are installed under the hull 1 of the platform in the flotation position as shown in FIGS. 2 and 4. Their stability in this phase is imparted by the sleeves 23 closed and the chimneys 30 which emerge.

Chaque réhausse est disposée de manière que l'évidement 11 de son plateau supérieur 7 reçoive le pied 4 de la jambe 2 correspondante.Each riser is arranged so that the recess 11 of its upper plate 7 receives the foot 4 of the corresponding leg 2.

La réhausse 4 est immobilisée par rapport à la jambe 2 au moyen des verrous 12. Elle est en outre immobilisée par rapport à la coque 1 de la plate-forme au moyen des verrous de remorquage 27 assurant l'immo­bilisation des manchons tubulaires 23 par rapport aux parois latérales 20 de la portion d'extrémité corres­pondante 18 de la coque 20. Des verrous de remorquage similaires sont avantageusement prévus pour immobili­ser les cheminées 30.The riser 4 is immobilized relative to the leg 2 by means of the latches 12. It is also immobilized relative to the hull 1 of the platform by means of the towing latches 27 ensuring the immobilization of the tubular sleeves 23 relative to the side walls 20 of the portion d the corresponding end 18 of the hull 20. Similar towing latches are advantageously provided for immobilizing the chimneys 30.

L'ensemble est alors prêt à subir un remor­quage vers le site d'exploitation. Les manchons tubu­laires 23 et les cheminées 30 assurent la stabilisa­tion en flottaison de la réhausse.The assembly is then ready to be towed to the operating site. The tubular sleeves 23 and the chimneys 30 ensure the float stabilization of the riser.

A l'arrivée de la plate-forme sur le site d'exploitation, les verrous de remorquage 27 sont ac­tionnés pour libérer la réhausse 3 par rapport à la coque 1 et les jambes 2 sont déplacées par le bas par les dispositifs de déplacement non représentés portés par la coque 1.On arrival of the platform on the operating site, the towing latches 27 are actuated to release the riser 3 relative to the hull 1 and the legs 2 are moved from below by the displacement devices not shown carried by the shell 1.

Les cheminées de stabilisation 30 sont éga­lement ouvertes à leurs deux extrémités pour permet­tre la pénétration de l'eau.The stabilization chimneys 30 are also open at their two ends to allow the penetration of water.

A l'arrivée de la réhausse au contact avec le sol dans la position représentée à la Fig.3, le patin 17 de la réhausse pénètre dans celui-ci et les pattes 25 du plateau inférieur 8 en prenant appui sur le sol accroîssent la stabilité de l'assise sur le fond. Les patins 17 sont de dimensions supérieures à celles des pieds 4 des jambes 2 de la plate-forme et reprennent donc les efforts plus importants dûs à l'augmentation de la profondeur.On arrival of the riser in contact with the ground in the position shown in Fig.3, the shoe 17 of the riser enters the latter and the legs 25 of the lower plate 8 by resting on the ground increase stability seat on the bottom. The pads 17 are larger than those of the feet 4 of the legs 2 of the platform and therefore take up the greater forces due to the increase in depth.

On procède alors à l'ancrage de la réhausse par enfoncement des pieux 24 dans le sol qui, au préa­lable, ont été mis en place dans les manchons tubulai­res 23 soit par l'extérieur de la plate-forme pour les manchons 23 situés en dehors de la portion d'extrémité 18 correspondante de la coque, soit par engagement dans le puit 26 de la coque 1 (Fig.1) pour le manchon tubulaire situé au-dessous de cette coque et qui,pour cette raison présente une longueur inférieure à celle des deux manchons tubulaires extérieurs à la coque comme représenté à la Fig.4.We then proceed to anchor the riser by driving the piles 24 into the ground which, beforehand, were put in place in the tubular sleeves 23 either from outside the platform for the sleeves 23 located outside the corresponding end portion 18 of the shell, either by engagement in the well 26 of the shell 1 (Fig.1) for the tubular sleeve located below this shell and which, for this reason has a length less than that of the two tubular sleeves outside the hull as shown in Fig. 4.

La mise en place des pieux 24 est assurée depuis la surface à partir de la grue de bord prévue sur la coque 1 qui assure la manutention des pieux et de marteaux sous-marins.The placement of the piles 24 is ensured from the surface from the on-board crane provided on the hull 1 which handles the piles and underwater hammers.

Les pieux sont ensuite solidarisés des man­chons 23 par injection de ciment amené au fond par le conduit souple (ombilical) 36, les manchons 23 étant équipés de joints annulaires à chacune de leurs extré­mités (non représenté).The piles are then secured to the sleeves 23 by injection of cement brought to the bottom by the flexible conduit (umbilical) 36, the sleeves 23 being equipped with annular seals at each of their ends (not shown).

Le matelas 35 de matière de répartition as­sure à ce moment la répartition de la charge de chaque jambe 2 dans l'évidement 11 du plateau supérieur 8 de la réhausse.The mattress 35 of distribution material ensures at this time the distribution of the load of each leg 2 in the recess 11 of the upper plate 8 of the riser.

Le dispositif de répartition d'assiette re­présenté à la Fig.7 fonctionne tour à tour comme une rotule souple ou au contraire comme un encastrement rigide .The attitude distribution device shown in Fig. 7 works in turn as a flexible ball joint or, on the contrary, as a rigid recess.

Initialement, le circuit hydraulique des vérins 15 est rempli d'un liquide, les vannes 32a sont fermées, les vannes 34 restant ouvertes.Initially, the hydraulic circuit of the jacks 15 is filled with a liquid, the valves 32a are closed, the valves 34 remaining open.

Lorsque la réhausse 3 vient en contact avec le fond sous-marin, les vérins se comportent comme un système rigide en rotation et élastique verticalement en raison de la présence des accumulateurs 33.When the riser 3 comes into contact with the seabed, the jacks behave like a rigid system in rotation and elastic vertically due to the presence of the accumulators 33.

Si la réhausse 3 placée sur le fond présente une légère inclinaison par rapport à la verticale, on procède alors à l'ouverture partielle des verrous 12 de maintien de la réhausse par rapport à la jambe 2 correspondante. La jambe 2 est alors libre d'osciller légèrement par rapport à la réhausse en raison des jeux ménagés entre l'évidement 11 du plateau supérieur 7 de la réhausse et le pied 4 de la jambe.If the extension 3 placed on the bottom has a slight inclination relative to the vertical, we then proceed to the partial opening of the latches 12 for maintaining the riser relative to the corresponding leg 2. The leg 2 is then free to oscillate slightly relative to the riser due to the clearances made between the recess 11 of the upper plate 7 of the riser and the leg 4 of the leg.

L'ouverture des vanne 32a assure un réta­blissement des pressions entre les vérins 15 et de ce fait un rattrapage de l'assiette du pied 4 qui se re­place en position horizontale.The opening of the valves 32a ensures a re-establishment of the pressures between the jacks 15 and thereby a catching up of the base of the foot 4 which returns to the horizontal position.

Les excédents de pression résultant des ef­forts exercés par la jambe sur la réhausse au contact avec le fond, sont absorbés par les accumulateurs de pression 33 ce qui produit un léger enfoncement du dispositif qui dégage un jeu supplémentaire sous les verrous 12 complètant celui obtenu par l'ouverture partielle des verrous et autorisant une rotation rela­tive entre le pied 4 et la rehausse.The excess pressure resulting from the forces exerted by the leg on the riser in contact with the bottom, are absorbed by the pressure accumulators 33 which produces a slight depression of the device which gives off an additional clearance under the latches 12 completing that obtained by the partial opening of the latches and allowing relative rotation between the leg 4 and the riser.

Le rattrapage d'assiette étant terminé, on ferme les vannes 34 et les vannes 32a. Le dispositif se comporte à nouveau comme encastrement et appui ri­gide.The trim adjustment having been completed, the valves 34 and the valves 32a are closed. The device behaves again as a recess and a rigid support.

Il suffit alors de bloquer les verrous 12 qui rattraperont les jeux pour assurer la solidarisa­tion entre la réhausse 3 et la jambe 2 correspondante.It then suffices to block the locks 12 which will make up for the clearances to ensure the connection between the riser 3 and the corresponding leg 2.

L'accumulateur de pression 33 peut être avantageusement constitué par une batterie d'accumula­teurs oléopneumatiques, tandis que les vannes 34 et 32b peuvent être des vannes télécommandées à l'aide de l'ombilical 36.The pressure accumulator 33 can advantageously consist of an oleopneumatic accumulator battery, while the valves 34 and 32b can be remote-controlled valves using the umbilical 36.

Le dispositif de rattrapage d'assiette qui vient d'être décrit peut être actionné en même temps que les verrous 12 qui limitent ou empêchent tout mou­vement entre la réhausse 3 et la jambe 2 selon que les vérins 15 sont mis en communication entre eux ou non.The trim device which has just been described can be actuated at the same time as the latches 12 which limit or prevent any movement between the riser 3 and the leg 2 depending on whether the jacks 15 are placed in communication with one another or not .

Lorsque le rattrapage d'assiette décrit plus haut est terminé, on procède à l'injection entre le pied 4 de chaque jambe 2 et le fond 13 de l'évidement 11 de la réhausse 3 dans lequel est engagé le pied 4, d'un ciment destiné à assurer la rigidité de l'appui du pied 4 sur la réhausse 3. Ce ciment est avantageu­sement amené au fond par un conduit souple 36 qui est également utilisé pour la transmission de signaux de commande nécessaires aux opérations de mise ne place.When the trim adjustment described above is completed, the injection is made between the foot 4 of each leg 2 and the bottom 13 of the recess 11 of the riser 3 in which the foot 4 is engaged, of a cement intended to ensure the rigidity of the support of the foot 4 on the riser 3. This cement is advantageously brought to the bottom by a flexible conduit 36 which is also used for the transmission of control signals necessary for the setting operations.

L'agencement qui vient d'être décrit est destiné à l'installation d'une plate-forme auto-éléva­trice munie de réhausses suivant l'invention sur des sols sous-marins relativement mous et inégaux, dans lesquels il y a des risques d'affouillement.The arrangement which has just been described is intended for the installation of a self-elevating platform provided with risers according to the invention on relatively soft and uneven underwater soils, in which there are risks of scour.

Dans le cas de bons sols et/ou les risques d'affouillements sont faibles, le dispositif peut res­ter en mode de fonctionnement à fondation superficiel­le directement et uniquement en appui sur les patins 17.In the case of good soils and / or the risks of scouring are low, the device can remain in operating mode with surface foundation directly and only by pressing on the pads 17.

Dans un tel cas, la structure des réhausses peut être simplifiée et ne pas comporter de manchons pour mieux mais seulement des cheminées de stabilisa­tion et d'imersion.In such a case, the structure of the risers can be simplified and not include sleeves for better but only stabilization and immersion chimneys.

Par ailleurs, pour des sites à fond très plat, les dispositifs de rattrapage d'assiette peuvent également être omis.Furthermore, for sites with very flat bottoms, the attitude adjustment devices can also be omitted.

Dans l'example qui vient d'être décrit, il est prévu trois pieux 24 pour assurer le clouage de la réhausse sur le sol.In the example which has just been described, there are provided three piles 24 to ensure the nailing of the riser on the ground.

On peut bien entendu envisager la mise en place d'un nombre de pieux plus important.One can of course consider the establishment of a larger number of piles.

Dans le mode de réalisation représenté à la Fig.6, les jambes de la plate-forme auto-élévatrice sont équipées de réhausses dont la construction géné­ rale est la même que celle décrite en référence aux Fig.1 à 5 à l'exception du fait que ces hausses com­portent chacune quatre manchons tubulaires 37 disposés à 90° les uns par rapport aux autres à la périphérie de la réhausse de façon que trois d'entre eux soient situés à l'extérieur de l'encombrement de la plate-­forme.In the embodiment shown in Fig. 6, the legs of the jack-up platform are fitted with risers, the general construction rale is the same as that described with reference to Figs. 1 to 5 except that these risers each include four tubular sleeves 37 arranged at 90 ° relative to each other at the periphery of the riser so that three of them are located outside the footprint of the platform.

Ces manchons servent également de cheminées de stabilisation en flottaison, de sorte qu'il n'est pas nécessaire de prévoir de cheminées spéciales à cet effet comme c'est le cas pour les réhausses à trois manchons représentés aux Fig.1 à 5.These sleeves also serve as flotation stabilization chimneys, so that it is not necessary to provide special chimneys for this purpose as is the case with the extensions with three sleeves shown in Figs. 1 to 5.

L'installation qui vient d'être décrite pré­sente vis à vis des installations classiques, les avantages suivants.The installation which has just been described has the following advantages over conventional installations.

Elle met en oeuvre une plate-forme auto-élé­vatrice de base ayant une capacité d'imersion à des profondeurs de l'ordre de 100 à 110m.It implements a basic self-elevating platform with an immersion capacity at depths of the order of 100 to 110m.

L'accroissement des performances est assuré par la jonction de réhausse installée sur le site par la plate-forme auto-élévatrice elle-même et clouée rigidement ou non au fond de la mer.The performance increase is ensured by the riser junction installed on the site by the self-elevating platform itself and rigidly nailed or not at the bottom of the sea.

Après achèvement des opérations de forage, la plate-forme auto-élévatrice peut être libérée de son support constitué par les réhausses sur lesquelles les jambes de la plate-forme sont imobilisées pour redevenir une plate-forme auto-élévatrice classique conservant la manoeuvrabilité. Il suffit à cet effet de dégager les verrous 12 de fixation des jambes 2 à leurs réhausses 3.After completion of drilling operations, the self-elevating platform can be released from its support constituted by the risers on which the legs of the platform are immobilized to become again a conventional self-elevating platform retaining maneuverability. For this purpose, it suffices to release the latches 12 for fixing the legs 2 to their extensions 3.

Ceci est un avantage important car une telle plate-forme peut ainsi rester concurrentielle avec les plate-formes classiques destinées à des profondeurs d'eau de 100 à 110m.This is an important advantage because such a platform can thus remain competitive with conventional platforms intended for water depths of 100 to 110m.

Un autre avantage important de l'invention réside dans le fait qu'une plate-forme auto-élévatrice qui a été retirée ainsi par désolidarisation de ses jambes par rapport aux réhausses sur lesquelles elles étaient initialement installées peut être ramenée sur le site et réinstallée sur les réhausses pour réaliser les travaux d'entretien sur des puits.Another important advantage of the invention resides in the fact that a self-elevating platform which has been thus removed by detachment of its legs from the risers on which they were initially installed can be brought back to the site and reinstalled on extensions to carry out maintenance work on wells.

L'agencement de l'invention permet également de mettre en production de petits champs pétroliers de façon économique à des profondeurs pouvant atteindre 130 à 150 m et plus, et de réaliser des forages de dé­veloppement de champs sans installation de plate-forme fixe et d'éviter ainsi l'immobilisation d'un équipe­ment de forage pendant plusieurs années sans utilisa­tion mais nécessitant une maintenance.The arrangement of the invention also makes it possible to produce small oil fields economically at depths of up to 130 to 150 m and more, and to carry out field development drilling without the installation of a fixed platform and '' thus avoiding the immobilization of drilling equipment for several years without use but requiring maintenance.

Bien entendu les rehausses de l'agencement qui vient d'être décrit sont adaptables à tous types de plate-forme comportant des jambes de section car­rée, circulaire ou autre et des pieds de section autre qu'hexagonale.Of course, the extensions of the arrangement which has just been described are adaptable to all types of platform comprising legs of square, circular or other section and feet of section other than hexagonal.

On a représenté aux Fig.8 à 17 un autre mode de réalisation de la plate-forme auto-élevatrice sui­vant l'invention dont la mise en place sur un site de forage ou d'exploitation est réalisée par l'installa­tion préalable des rehausses sur le fond marin et par mise en place et solidarisation ultérieures sur les­dites rehausses des jambes de la plate-forme amenée par flottaison.Another embodiment of the self-elevating platform according to the invention is shown in FIGS. 8 to 17, the installation of which on a drilling or exploitation site is carried out by the prior installation of the risers on the seabed and by subsequent positioning and securing on said risers of the legs of the platform brought in by flotation.

On a représenté schématiquement sur la Fig. 8, une plate-forme auto-élévatrice comportant une coque 101 flottant à la surface de l'eau et pourvue de jambes 102 susceptibles d'être déplacées par rapport à la coque à l'aide de dispositifs de déplacement non représentés et pouvant être immobilisées par rapport à la coque à l'aide de moyens de verrouillage également non représentés. La plate-forme est amenée au-dessus de l'emplacement des rehausses 103 fixées au fond marin, au moyen de treuils 104 prévus sur la coque 101 qui agissent sur des câbles respectifs 105 dont les extrémités sont fixées au préalable aux rehausses 103 correspondantes. Chaque jambe 102 est pourvue à son extrémité inférieure d'un pied 106 équipé d'un plot de centrage 107 destiné à être engagé dans un orifice correspondant 108 ménagé dans un plateau supérieur 109 de la rehausse 103.There is shown schematically in FIG. 8, a self-elevating platform comprising a hull 101 floating on the surface of the water and provided with legs 102 capable of being displaced relative to the hull using displacement devices not shown and which can be immobilized compared to the shell using locking means also not shown. The platform is brought above the location of the risers 103 fixed to the seabed, by means of winches 104 provided on the hull 101 which act on respective cables 105, the ends of which are fixed beforehand to the corresponding risers 103. Each leg 102 is provided at its lower end with a foot 106 fitted with a centering stud 107 intended to be engaged in a corresponding orifice 108 formed in an upper plate 109 of the extension 103.

Sur la Fig.9, on a représenté à plus gande échelle, une rehausse 103 mise en place sur le fond marin F et au-dessus de celle-ci, l'extrémité inférieure d'une jambe 102 prête à être placée sur le plateau supérieur 109 de la rehausse.In Fig.9, there is shown on a larger scale, a riser 103 placed on the seabed F and above it, the lower end of a leg 102 ready to be placed on the tray upper 109 of the extension.

Ainsi qu'on peut le voir à la Fig.10, la rehausse 102 présente une section transversale de forme générale triangulaire. Elle est constituée du plateau supérieur 109 et de trois semelles ou plan­chers de pose 110 reliés chacun au plateau supérieur 109 par trois montants tubulaires ou fourreaux 111 dans lesquels sont engagés des pieux 112 d'ancrage de la rehausse dans le fond marin. Le renforcement de l'ensemble ainsi constitué est assuré par un treillis métallique 113.As can be seen in FIG. 10, the extension 102 has a cross section of generally triangular shape. It consists of the upper plate 109 and three soles or laying floors 110 each connected to the upper plate 109 by three tubular uprights or sleeves 111 in which are engaged piles 112 for anchoring the riser in the seabed. The reinforcement of the assembly thus formed is ensured by a wire mesh 113.

Dans deux des rehausses 103, l'orifice 108 de centrage ménagé dans le plateau 109 présente un diamètre supérieur au plot de centrage 107 du pied 106 de la jambe 102 de manière à permettre de rattraper des imprécisions éventuelles de pose des rehausses.In two of the risers 103, the centering orifice 108 formed in the plate 109 has a diameter greater than the centering stud 107 of the foot 106 of the leg 102 so as to make it possible to make up for any inaccuracies in fitting the risers.

L'orifice de centrage 108 présente une en­trée conique 114 destinée à coopérer avec une extré­mité conique 115 du plot de centrage 107 de la jambe 102 lors de son engagement dans l'orifice 108.The centering orifice 108 has a conical inlet 114 intended to cooperate with a conical end 115 of the centering stud 107 of the leg 102 when it engages in the orifice 108.

Dans le plateau 109 est en outre ménagé un logement 116 qui débouche dans l'orifice de centrage 108 et qui présente une section supérieure à celui-ci. Dans le logement 116 est engagée une rondelle 117 d'immobilisation horizontale du plot 107 par rapport à la rehausse 102 et qui présente en son centre un trou 118 à entrée tronconique, de diamètre égal au diamètre du plot de centrage 107.In the tray 109 is also formed a housing 116 which opens into the centering orifice 108 and which has a section larger than the latter. In the housing 116 is engaged a washer 117 for horizontal immobilization of the pad 107 relative to the extension 102 and which has at its center a hole 118 with a frustoconical entry, of diameter equal to the diameter of the centering pad 107.

Sur le plateau supérieur 109 de la rehausse sont en outre prévus trois verrous basculants 119 en forme d'étriers destinés à venir en prise avec des saillies latérales 120 du pied 106 de la jambe de plate-forme 102 et verrouiller ainsi la jambe sur la rehausse 103 à l'encontre de tous déplacements verti­caux.On the upper plate 109 of the riser, there are further provided three tilting latches 119 in the form of stirrups intended to engage with lateral projections 120 of the foot 106 of the platform leg 102 and thus lock the leg on the riser 103 against all vertical displacements.

Ainsi qu'on peut le voir sur la Fig.10,la jambe 102 est disposée sur la rehausse 103 dans une position décalée par rapport à son axe de symétrie en raison de l'imprécision relative de pose de la rehaus­se 103 sur le fond marin. Ceci est permis grâce à la possibilité d'adaptation de positionnement qu'assure la différence de diamètre entre le trou de centrage 108 du plateau supérieur 109 de la rehausse et du plot de centrage 107 de la jambe 102 représentés à la Fig. 9. On voit que grâce à cette différence de diamètre, le pied 106 peut occuper sur la surface du plateau supérieur 109 de la rehausse 103, une zone 121 repré­sentée en trait mixte de surface plus importante que l'encombrement du pied 106.As can be seen in Fig.10, the leg 102 is disposed on the riser 103 in a position offset from its axis of symmetry due to the relative imprecision of positioning the riser 103 on the seabed . This is possible thanks to the possibility of positioning adaptation which the difference in diameter ensures between the centering hole 108 of the upper plate 109 of the riser and the centering stud 107 of the leg 102 shown in FIG. 9. It can be seen that, thanks to this difference in diameter, the foot 106 can occupy on the surface of the upper plate 109 of the extension 103, an area 121 shown in phantom of a surface larger than the size of the foot 106.

C'est ainsi que dans l'exemple représenté à la Fig.10, le pied 106 est placé contre un bord de cette zone 121 et il est placé avec des jeux J par rapport aux deux autres bords de cette zone.Thus in the example shown in Fig.10, the foot 106 is placed against an edge of this area 121 and it is placed with clearances J relative to the other two edges of this area.

Les dimensions des étriers de verrouillage 119 sont également prévues de manière que chacun d'entre eux puisse venir en prise avec la saillie latérale correspondante 120 du pied de plate-forme 106 quelle que soit la position qu'occupe le pied sur la zone de positionnement 121 de la rehausse 103 délimi­tée par un contour en trait mixte.The dimensions of the locking stirrups 119 are also provided so that each of them can come into engagement with the corresponding lateral projection 120 of the platform leg 106 regardless of the position occupied by the foot on the positioning area 121 of the extension 103 delimited by an outline in phantom.

On voit en outre sur la Fig.10 que la re­hausse est pourvue sur deux de ses côtés de ducs d'albe d'accostage 122 constitués par des organes tubulaires élastiques verticaux.It can also be seen in FIG. 10 that the riser is provided on two of its sides with docking blade ducks 122 constituted by vertical elastic tubular members.

Les moyens de centrage d'une jambe de plate-­forme par rapport à la rehausse destinée à la suppor­ter, sont représentés plus en détail aux Fig. 11 et 12.The means for centering a platform leg relative to the riser intended to support it, are shown in more detail in FIGS. 11 and 12.

La Fig.11 montre le plateau supérieur 109 pourvu de son orifice de centrage 108 à entrée conique 114 et dans lequel est ménagé le logement 116 débou­chant dans l'orifice de centrage 108. Dans le logement 116 est disposée la rondelle de centrage 117 dont le trou central 118 est occupé par le plot de centrage 107 de la jambe de plate-forme correspondante. Le plot de centrage 107 est placé contre un bord de l'orifice de centrage 108 du plateau 109 et la rondelle de cen­trage 117, appelée rondelle flottante, est décalée par rapport à l'axe de l'orifice de centrage 108 et immo­bilisée horizontalement par des dispositifs de serrage 124 montés dans le plateau 109.Fig.11 shows the upper plate 109 provided with its centering hole 108 with conical inlet 114 and in which is formed the housing 116 opening into the centering hole 108. In the housing 116 is disposed the centering washer 117 whose central hole 118 is occupied by the centering stud 107 of the corresponding platform leg. The centering pin 107 is placed against an edge of the centering orifice 108 of the plate 109 and the centering washer 117, called the floating washer, is offset with respect to the axis of the centering orifice 108 and immobilized horizontally by clamping devices 124 mounted in the plate 109.

Ces dispositifs de serrage sont constitués par des vérins qui seront décrits en détail en réfé­rence à la Fig.13.These clamping devices consist of cylinders which will be described in detail with reference to Fig. 13.

Comme le montre la Fig.12, la rondelle flot­tante 117 peut occuper dans son évidement 116 une zone 125 représentée en trait mixte correspondant à l'en­semble des positions que peut occuper le plot de cen­trage 107 de la jambe 102 dans l'orifice de centrage 108 du plateau supérieur 109 de la rehausse.As shown in Fig. 12, the floating washer 117 can occupy in its recess 116 an area 125 shown in phantom corresponding to all of the positions that the centering pad 107 of the leg 102 can occupy in the centering orifice 108 of the upper plate 109 of the extension.

L'un des vérins 124 de serrage de la ron­ delle flottante 117 contre le plateau 109 est repré­senté à la Fig.13. Il comporte un corps de vérin 126 mobile par rapport à une tige fixe 127 prenant appui sur un support 128 solidaire du plateau supérieur 109 par l'intermédiaire d'un organe de fixation tel qu'une vis 129. Le corps de vérin 126 prend appui sur un pa­tin annulaire élastique 130 entourant la tige fixe 127 entre la tête 131 de laquelle et le corps de vérin 126 est ménagée une chambre 132 alimentée en fluide hy­draulique par l'intermédiaire d'un tuyauterie 133.One of the cylinders 124 for tightening the ron delle floating 117 against the plate 109 is shown in Fig.13. It comprises a jack body 126 movable relative to a fixed rod 127 bearing on a support 128 secured to the upper plate 109 by means of a fixing member such as a screw 129. The jack body 126 is supported on an elastic annular pad 130 surrounding the fixed rod 127 between the head 131 of which and the jack body 126 is formed a chamber 132 supplied with hydraulic fluid by means of a pipe 133.

L'effort développé par la mise en pression de la chambre 132 comprime le patin annulaire élasti­que 130 de sorte que le corps de vérin 126 est escamo­té à l'intérieur de son logement 134 ménagé dans le plateau supérieur 109. La rondelle flottante 117 qui en l'absence de pression appliquée à la chambre 132 est maintenue serrée contre la paroi intérieure du logement 116 du plateau supérieur 109 est alors libé­rée et peut glisser à l'intérieur du logement 116.The force developed by the pressurization of the chamber 132 compresses the elastic annular pad 130 so that the jack body 126 is retracted inside its housing 134 formed in the upper plate 109. The floating washer 117 which the absence of pressure applied to the chamber 132 is kept tight against the interior wall of the housing 116 of the upper plate 109 is then released and can slide inside the housing 116.

Lorsque le plot de centrage 107 de la jambe de plate-forme engagé dans le trou central 118 de la rondelle 117 est venu se placer dans la position ap­propriée dans l'orifice de centrage 108 du plateau 109, il suffit, pour immobiliser horizontalement la rondelle 117 et par conséquent, le plot 107 d'inter­rompre la mise en pression de la chambre 132 de chacun des vérins. Le corps de vérin 126 est alors fortement pressé contre la rondelle sous l'action de la force de rappel élastique exercée par le patin annulaire 130. L'immobilisation de la rondelle 117 dans son logement 116 est d'autant plus efficace que les surfaces en contact de ces deux éléments sont rendues rugueuses.When the centering stud 107 of the platform leg engaged in the central hole 118 of the washer 117 has come to be placed in the appropriate position in the centering orifice 108 of the plate 109, it suffices to immobilize the washer horizontally 117 and consequently, the pad 107 to interrupt the pressurization of the chamber 132 of each of the jacks. The cylinder body 126 is then strongly pressed against the washer under the action of the elastic restoring force exerted by the annular shoe 130. The immobilization of the washer 117 in its housing 116 is all the more effective as the surfaces in contact of these two elements are made rough.

Ces patins sont avantageusement constitués par un empilage de rondelles en élastomère et de ron­ delles rigides, par exemple métalliques collées les unes aux autres.These pads are advantageously constituted by a stack of elastomer washers and ron rigid ones, for example metallic ones glued to each other.

L'étanchéité entre le corps de vérin mobile 126 et la tige fixe 127 du vérin peut avantageusement être obtenu à l'aide de manchons en élastomère 127a adhérisés sur le corps de vérin 126 et sur la tige 127, ces manchons étant déformables en cisaillement.The seal between the movable cylinder body 126 and the fixed rod 127 of the cylinder can advantageously be obtained using elastomer sleeves 127a adhered to the cylinder body 126 and to the rod 127, these sleeves being deformable in shear.

Un dispositif de centrage du type qui vient d'être décrit en référence aux Fig.11 à 13 est prévu sur deux rehausses seulement d'une plate-forme à trois jambes pourvues chacune d'une rehausse. Comme repré­senté à la Fig.11a dans le plateau supérieur 109 de la troisième rehausse, l'orifice de centrage 108a présen­te un diamètre intérieur égal au diamètre extérieur du plot de centrage 107 de la jambe correspondante, de sorte que cette troisième rehausse définit une réfé­rence de positionnement de la plate-forme.A centering device of the type which has just been described with reference to FIGS. 11 to 13 is provided on only two risers of a platform with three legs each provided with a riser. As shown in Fig.11a in the upper plate 109 of the third riser, the centering hole 108a has an inner diameter equal to the outside diameter of the centering stud 107 of the corresponding leg, so that this third riser defines a reference of positioning of the platform.

Il suffit donc pour mettre en place la pla­te-forme sur ses rehausses d'engager tout d'abord le plot de centrage 107 de la jambe 102 dans la rehausse de référence, cette jambe étant alors parfaitement centrée par rapport à sa rehausse en raison de l'iden­tité des diamètres du plot de centrage 107 et de l'o­rifice central 108a de son plateau 109, et de déplacer ensuite par tout moyen approprié l'ensemble de la plate-forme autour de sa jambe 102 engagée dans la rehausse de référence jusqu'à ce que les plots de cen­trage 107 et deux autres jambes de la plate-forme soient engagés dans les orifices de centrage 108 de plus grand diamètre des deux autres rehausses 103. Ces dernières étant munies chacune d'un dispositif de cen­trage du type décrit en référence aux Fig.8 à 13, il suffit alors d'actionner les vérins de serrage de cha­cun de ces dispositifs pour assurer l'immobilisation horizontale de l'ensemble de la plate-forme.It is therefore sufficient to set up the platform on its risers to first engage the centering stud 107 of the leg 102 in the reference riser, this leg then being perfectly centered with respect to its riser due to the identity of the diameters of the centering stud 107 and of the central orifice 108a of its plate 109, and then of displacing by all appropriate means the whole of the platform around its leg 102 engaged in the reference riser until 'in that the centering pads 107 and two other legs of the platform are engaged in the centering orifices 108 of larger diameter of the other two risers 103. The latter being each provided with a centering device of the type described with reference to Figs. 8 to 13, it then suffices to actuate the clamping cylinders of each of these devices to ensure immobilization horizontal of the whole platform.

Les moyens de verrouillage vertical de cha­que jambe de plate-forme sur sa rehausse sont repré­sentés plus en détail aux Fig.14 à 17.The vertical locking means of each platform leg on its riser are shown in more detail in Figs. 14 to 17.

Ainsi qu'on l'a représenté à la Fig.9, chaque rehausse 103 est pourvue de trois verrous 119 en forme d'étriers montés basculants sur son plateau supérieur 109 et qui sont en position écartée avant la mise en place du pied 106 de la jambe 102 correspon­dante sur le plateau 109.As shown in FIG. 9, each extension 103 is provided with three latches 119 in the form of stirrups mounted tilting on its upper plate 109 and which are in the separated position before the positioning of the foot 106 of the corresponding leg 102 on the plate 109.

Sur la Fig.14, le verrou 119 est représenté en traits pleins dans sa position de blocage du pied 106 de la jambe 102 correspondante et en trait mixte dans sa position écartée.In Fig.14, the lock 119 is shown in solid lines in its blocking position of the foot 106 of the corresponding leg 102 and in phantom in its position apart.

En position écartée, le verrou 119 dégage complétement la surface de pose 121 du plateau 109 (Fig.10).In the separated position, the latch 119 completely releases the laying surface 121 of the plate 109 (FIG. 10).

Chaque verrou 109 comporte une traverse 135 (Fig.15) dont la largeur est suffisante pour recouvrir la saillie ou semelle 120 correspondante du pied 106 placé de façon aléatoire sur la surface de pose 121. La face inférieure 136 de chaque traverse 135 comme la partie supérieure 137 de la semelle 120 sont des surfaces planes qui viennent en contact l'une de l'au­tre lorsque les verrous basculants 119 sont en posi­tion fermée. Chacun des verrous est articulé autour d'un axe 138 et comporte deux bras 139 et deux plaques de verrouillage 140 munies chacune d'une lumière 141. Un loquet coulissant 142 manoeuvré par un vérin 143 est monté dans le plateau supérieur 109 de la rehausse au droit des lumières 141 lorsque l'étrier 119 est en position de fermeture ou de verrouillage.Each latch 109 has a cross member 135 (Fig. 15) whose width is sufficient to cover the corresponding projection or sole 120 of the foot 106 placed randomly on the laying surface 121. The underside 136 of each cross member 135 as the part upper 137 of the sole 120 are flat surfaces which come into contact with one another when the tilting latches 119 are in the closed position. Each of the locks is articulated around an axis 138 and comprises two arms 139 and two locking plates 140 each provided with a light 141. A sliding latch 142 maneuvered by a jack 143 is mounted in the upper plate 109 of the riser right of the lights 141 when the stirrup 119 is in the closed or locked position.

On montre sur la Fig.16 un loquet 142 en position dégagée hors de la lumière 141 du bras de verrouillage 140 correspondant de l'étrier 119. Le vérin 143 est en position de repos.FIG. 16 shows a latch 142 in the released position out of the lumen 141 of the arm of corresponding locking 140 of the stirrup 119. The jack 143 is in the rest position.

Sur la Fig.17, on voit que le loquet 142 a été engagé dans la lumière 141 du bras de verrouillage 140 correspondant sous l'action du vérin 143 qui est maintenu dans cette position active. Le verrouillage est encore amélioré par l'introduction de l'extrémité du loquet 142 dans une lumière 144 ménagée dans une paroi verticale 145 du plateau supérieur 109.In Fig.17, it can be seen that the latch 142 has been engaged in the slot 141 of the corresponding locking arm 140 under the action of the jack 143 which is held in this active position. The locking is further improved by the introduction of the end of the latch 142 into a slot 144 formed in a vertical wall 145 of the upper plate 109.

L'agencement de plate-forme auto-élévatrice qui vient d'être décrit permet d'assurer la mise en place relativement aisée des jambes de la plate-forme sur des rehausses préalablement montées sur le site d'exploitation. La plate-forme est amenée sur le site et les jambes 103 sont descendues l'une après l'autre de façon que chacune d'elles vienne prendre appui sur une des rehausses. On commence à cet effet par des­cendre la jambe destinée à être placée sur la rehausse pourvue d'un trou de centrage 108a de diamètre égal à celui du plot de centrage 107 de son pied 106.The arrangement of self-elevating platform which has just been described makes it possible to ensure the relatively easy positioning of the legs of the platform on risers previously mounted on the operating site. The platform is brought to the site and the legs 103 are lowered one after the other so that each of them comes to bear on one of the risers. One begins for this purpose by lowering the leg intended to be placed on the riser provided with a centering hole 108a of diameter equal to that of the centering stud 107 of its foot 106.

Cette première jambe 102 est positionnée à l'aide des treuils 104 disposés sur la plate-forme. Un premier positionnement de la jambe 102 par rapport à sa rehausse est facilité par l'entrée en contact de la jambe 102 avec les ducs d'albe 22 prévus sur deux côtés de la rehausse 103.This first leg 102 is positioned using the winches 104 arranged on the platform. A first positioning of the leg 102 relative to its riser is facilitated by the coming into contact of the leg 102 with the dolphins 22 provided on two sides of the riser 103.

Lorsque la première jambe 102 est mise en place sur sa rehausse 103, elle détermine un axe de référence autour duquel l'ensemble de la plate-forme peut être tourné jusqu'à ce que les autres jambes 102 de celle-ci se trouvent en regard des rehausses 103 correspondantes. On abaisse alors ces jambes de maniè­re que leurs plots de centrage 107 pénètrent dans les orifices de centrage 108 de plus grand diamètre ména­ gés dans les plateaux supérieurs 109 des deux autres rehausses et pénètrent dans les trous centraux 118 des rondelles flottantes 117 correspondantes en les dépla­çant latéralement vers la position où elles seront immobilisées.When the first leg 102 is placed on its riser 103, it determines a reference axis around which the whole of the platform can be rotated until the other legs 102 of the latter are opposite corresponding extensions 103. These legs are then lowered so that their centering studs 107 penetrate into the centering orifices 108 of larger mena diameter. gés in the upper plates 109 of the other two risers and enter the central holes 118 of the corresponding floating washers 117 by moving them laterally to the position where they will be immobilized.

On procède ensuite à l'immobilisation hori­zontal des rondelles flottantes 117 en actionnant les vérins 124 qui, comme on le voit sur la Fig.12 sont disposés en couronne de manière à exercer sur la ron­delle 117 une force de serrage homogène.Next, the floating washers 117 are immobilized horizontally by actuating the jacks 124 which, as seen in FIG. 12, are arranged in a ring so as to exert a uniform clamping force on the washer 117.

On actionne ensuite des verrous 119 en forme d'étrier dont les traverses 135 sont appliquées sur les saillies latérales ou semelles 120 de chacun des pieds 106. Les verrous 119 sont ainsi immobilisés par l'introduction des loquets 142 dans leurs lumières respectives 141. La plate-forme est alors immobilisée horizontalement par les rondelles flottantes 117 ser­rées par leurs vérins 124 et verticalement par les verrous 119, et peut supporter les efforts horizontaux ainsi que les efforts verticaux et les moments qu'elle subit.Locks 119 are then actuated in the shape of a stirrup, the cross members 135 of which are applied to the lateral projections or soles 120 of each of the feet 106. The latches 119 are thus immobilized by the introduction of the latches 142 in their respective slots 141. platform is then immobilized horizontally by the floating washers 117 tightened by their jacks 124 and vertically by the latches 119, and can withstand the horizontal forces as well as the vertical forces and the moments which it undergoes.

Si l'on souhaite retirer la plate-forme du site où elle est placée, il suffit de désolidariser les jambes 102 de celle-ci de leurs rehausses 103 en libérant les moyens de verrouillage 119.If it is desired to remove the platform from the site where it is placed, it suffices to separate the legs 102 thereof from their risers 103 by releasing the locking means 119.

Bien entendu, il est également possible de revenir à nouveau sur le site et de recommencer alors les opérations de mise en place de la plate-forme de la manière décrite plus haut.Of course, it is also possible to return to the site again and then start again the operations of setting up the platform in the manner described above.

Dans le mode de réalisation décrit en réfé­rence aux Fig.9 à 17, l'une des rehausses comporte un orifice de centrage 108a de même section que le plot de centrage 107 de la jambe de plate-forme correspon­dante. On peut cependant envisager de munir toutes les rehausses d'orifices de centage 108 de section supé­rieure à celle des plots de centrage 107.In the embodiment described with reference to Figs. 9 to 17, one of the extensions has a centering orifice 108a of the same section as the centering stud 107 of the corresponding platform leg. We can however consider providing all the centering hole extensions 108 with a cross section greater than that of the centering studs 107.

Dans ce cas, toutes les rehausses comportent une rondelle de centrage 117 et des moyens d'immobili­sation de celle-ci.In this case, all of the extensions include a centering washer 117 and means for immobilizing the latter.

Lorsque la plate-forme doit rester longtemps sur le site, il est également possible d'utiliser à la place des rondelles flottantes 117 et des vérins d'im­mobilisation de celles-ci, des scellements en béton ou en résine d'immobilisation des plots de centage 107 dans les orifices de centrage 108 de plus grand diamè­tre.When the platform is to remain on the site for a long time, it is also possible to use floating washers 117 and immobilizing cylinders instead, concrete or resin immobilization seals for the studs. centering 107 in the centering holes 108 of larger diameter.

Claims (31)

1. Dispositif de support pour jambe (2) de plate-forme pétrolière auto-élévatrice d'opération en mer, caractérisé en ce qu'il constitue une réhausse individuelle et indépendante (3;103) destinée à être interposée entre la jambe de la plate-forme et le fond marin afin d'accroître la profondeur d'installation de la plate-forme, et d'améliorer sa stabilité, ladite réhausse (3;103) étant pourvue de moyens verrouilla­bles, amovibles et réglables (4,7,11,12; 116,117,119) de fixation rigide à l'extrémité inférieure (4;106) de la jambe (2;102).1. Support device for a leg (2) of a self-elevating oil platform for operation at sea, characterized in that it constitutes an individual and independent riser (3; 103) intended to be interposed between the leg of the platform and the seabed in order to increase the installation depth of the platform, and to improve its stability, said riser (3; 103) being provided with lockable, removable and adjustable means (4,7, 11,12; 116,117,119) rigid attachment to the lower end (4; 106) of the leg (2; 102). 2. Dispositif de support suivant la reven­dication 1, caractérisé en ce que ladite réhausse com­porte un plateau supérieur (7) par lequel la réhausse est destinée à être reliée à la jambe (2) de la plate-­forme, un plateau inférieur (8) d'appui de la réhausse sur le fond et une structure porteuse (9,10) reliant lesdits plateaux supérieur et inférieur entre eux.2. Support device according to claim 1, characterized in that said extension comprises an upper plate (7) by which the extension is intended to be connected to the leg (2) of the platform, a lower plate (8) of supporting the riser on the bottom and a support structure (9,10) connecting said upper and lower plates together. 3. Dispositif de support suivant l'une des revendications 1 et 2, caractérisé en ce que le plateau supérieur (7) comporte un évidement (11) destiné à re­cevoir le pied (4) de la jambe (2) correspondante, et des verrous (12) d'immobilisation du pied (4) dans le­dit évidement.3. Support device according to one of claims 1 and 2, characterized in that the upper plate (7) comprises a recess (11) intended to receive the foot (4) of the corresponding leg (2), and latches (12) immobilization of the foot (4) in said recess. 4. Dispositif de support suivant la revendi­cation 3, caractérisé en ce que le fond (14) de l'évi­dement (11) a une forme adaptée à celle de la face d'appui (6) du pied (4) de la jambe correspondante.4. Support device according to claim 3, characterized in that the bottom (14) of the recess (11) has a shape adapted to that of the bearing face (6) of the foot (4) of the corresponding leg . 5. Dispositif de support suivant l'une des revendications 3 et 4, caractérisé en ce que le fond (13) de l'évidement (11) est garni d'une couche (35) de matériau de répartition des efforts du pied (4) sur la réhausse (3) constituée par du sable emprisonne dans une enveloppe réalisant une boîte à sable ou par un produit souple tel qu'un élastomère qui s'adapte à la forme du pied (4).5. Support device according to one of claims 3 and 4, characterized in that the bottom (13) of the recess (11) is lined with a layer (35) of material for distributing the forces of the foot (4 ) on the extension (3) consisting of trapped sand in an envelope making a sandbox or by a flexible product such as an elastomer which adapts to the shape of the foot (4). 6. Dispositif de support suivant l'une des revendications 1 à 5, caractérisé en ce que le plateau inférieur (8) comporte un patin (17) destiné à péné­trer dans le sol.6. Support device according to one of claims 1 to 5, characterized in that the lower plate (8) comprises a shoe (17) intended to penetrate the ground. 7. Dispositif de support suivant l'une des revendications 1 à 6, caractérisé en ce que la struc­ture porteuse de la réhausse est constituée par des montants tubulaires (9) reliant le plateau supérieur (7) au plateau inférieur (8), lesdits montants étant à leur tour reliés entre eux par des treillis de pou­trelles métalliques (10).7. Support device according to one of claims 1 to 6, characterized in that the supporting structure of the extension consists of tubular uprights (9) connecting the upper plate (7) to the lower plate (8), said amounts being in turn interconnected by lattices of metal beams (10). 8. Dispositif de support suivant l'une des revendications 2 à 7, caractérisé en ce que la réhaus­se (3) est munie de manchons tubulaires (23;37) de mise en place de pieux (24) d'ancrage dans le sol, lesdits manchons servant de moyens de stabilisation en remorquage de la réhausse montée sur la jambe (2) cor­respondante de la plate-forme et étant pourvus à cet effet d'obturateurs amovibles respectifs (28) au moins à l'une de leurs extrémités.8. Support device according to one of claims 2 to 7, characterized in that the extension (3) is provided with tubular sleeves (23; 37) for placing piles (24) anchoring in the ground, said sleeves serving as stabilization means for towing the riser mounted on the corresponding leg (2) of the platform and being provided for this purpose with respective removable shutters (28) at least at one of their ends. 9. Dispositif suivant la revendication 8, caractérisé en ce que lesdits manchons tubulaires (23;­37) sont fixés à des pattes radiales (22,25) des pla­teaux supérieur et inférieur (7,8) répartis angulaire­ment à la périphérie desdits plateaux, la longueur desdites pattes étant telle que les manchons tubulai­res (23;37) se trouvent en dehors de l'encombrement de la coque (1) de la plate-forme recevant le dispositif à l'exception du manchon destiné à se trouver sous la coque.9. Device according to claim 8, characterized in that said tubular sleeves (23; 37) are fixed to radial lugs (22,25) of the upper and lower plates (7,8) angularly distributed at the periphery of said plates, the length of said legs being such that the tubular sleeves (23; 37) are outside the size of the hull (1) of the platform receiving the device with the exception of the sleeve intended to be located under the hull. 10. Dispositif de support suivant la reven­ dication 9, caractérise en ce que lesdits manchons tubulaires (23) sont au nombre de trois et sont répar­tis à 120° à la périphérie de la réhausse (3).10. Support device according to the income dication 9, characterized in that said tubular sleeves (23) are three in number and are distributed at 120 ° at the periphery of the extension (3). 11. Dispositif de support suivant la reven­dication 10, caractérisé en ce qu'il comporte en outre des cheminées de stabilisation en flottaison (30) fi­xées à la réhausse destinées à la mise en place des rehausses sous le pied (4) par immersion contrôlée.11. Support device according to claim 10, characterized in that it further comprises flotation stabilization chimneys (30) fixed to the riser intended for the establishment of the risers under the foot (4) by controlled immersion. 12. Dispositif de support suivant la reven­dication 9, caractérisé en ce que lesdits manchons tu­bulaires sont au nombre de quatre et sont répartis à 90° à la périphérie de la réhausse.12. Support device according to claim 9, characterized in that said tubular sleeves are four in number and are distributed at 90 ° to the periphery of the riser. 13. Dispositif de support suivant l'une des revendications 2 à 12, caractérisé en ce qu'il compor­te en outre un dispositif (15,32,32a,33,34) de rattra­page d'assiette entre ladite réhausse et la jambe (2) de la plate-forme sur laquelle elle est montée.13. Support device according to one of claims 2 to 12, characterized in that it further comprises a device (15,32,32a, 33,34) for adjusting the trim between said riser and the leg (2 ) of the platform on which it is mounted. 14. Dispositif de support suivant la reven­dication 13, caractérisé en ce que le dispositif de rattrapage d'assiette comporte des vérins hydrauliques (15) disposés à la périphérie du fond (13) dudit évi­dement (11), lesdits vérins étant reliés entre eux par des conduits (32) et des vannes (32a) et à des accumu­lateurs de pression (33) par l'intermédiaire de vannes (34).14. Support device according to claim 13, characterized in that the trim device comprises hydraulic cylinders (15) disposed at the periphery of the bottom (13) of said recess (11), said cylinders being interconnected by conduits (32) and valves (32a) and to pressure accumulators (33) via valves (34). 15.- Dispositif de support suivant l'une des revendications 1 à 14, caractérisé en ce que les pla­teaux supérieur et inférieur (7,8) et la structure porteuse de la rehausse (3) sont constitués par des plateaux et des jupes en béton.15.- Support device according to one of claims 1 to 14, characterized in that the upper and lower plates (7,8) and the supporting structure of the extension (3) consist of plates and concrete skirts . 16. Plate-forme auto-élévatrice pour forages en mer comprenant une coque (1) montée déplaçable et verrouillable en position le long de jambes (2) desti­nées à prendre appui sur le fond marin, caractérisée en ce que chaque jambe (2) est pourvue d'une réhausse séparable (3) suivant l'une quelconque des revendica­tions 1 à 15, assujettie à l'extrémité inférieure (4) de ladite jambe (2) et destinée à être interposée entre la jambe (2) et le fond en position d'exploita­tion de la plate-forme.16. Self-elevating platform for drilling at sea comprising a hull (1) mounted movable and lockable in position along legs (2) intended to bear on the seabed, characterized in that each leg (2) is provided with a separable riser (3) according to any one of claims 1 to 15, secured to the lower end (4) of said leg (2) and intended to be interposed between the leg (2) and the bottom in the operating position of the platform. 17. Plate-forme suivant la revendicatin 16, caractérisée en ce que les réhausses (3) sont fixées aux jambes (2) en position de remorquage de la plate-­forme, celle-ci servant d'installation de pose des ré­hausses sur le site d'exploitation.17. Platform according to claim 16, characterized in that the risers (3) are fixed to the legs (2) in the towing position of the platform, the latter serving as installation for placing the risers on the site operating. 18. Plate-forme suivant l'une des revendica­tions 16 et 17, caractérisée en ce que la coque (1) est munie de verrous de remorquage (27) destinés à assurer la fixation à la coque des réhauses (3) par leurs manchons tubulaires (23;27) qui s'étendent hors de l'encombrement de ladite coque, en vue d'assurer la solidarisation des réhausses avec la coque pendant les opérations de remorquage.18. Platform according to one of claims 16 and 17, characterized in that the hull (1) is provided with towing latches (27) intended to ensure the attachment to the hull of the risers (3) by their tubular sleeves (23; 27) which extend outside the bulk of said hull, in order to ensure the joining of the risers with the hull during the towing operations. 19. Dispositif de support suivant la reven­dication 1, caractérisé en ce que ladite rehausse (103) est destinée à être fixée au préalable sur le fond marin et en ce que lesdits moyens de fixation rigide de la rehausse (103) à l'extrémité inférieure de la jambe (102) comprennent des moyens (108, 116, 117,124) de centrage de la jambe (102) de la plate-­forme sur la rehausse (103) et des moyens (119,142) de verrouillage vertical de la jambe (102) sur la rehaus­se.19. Support device according to claim 1, characterized in that said riser (103) is intended to be fixed beforehand on the seabed and in that said rigid fixing means of the riser (103) at the lower end of the leg (102) comprise means (108, 116, 117,124) for centering the leg (102) of the platform on the riser (103) and means (119,142) for vertical locking of the leg (102) on the extension. 20. Dispositif de support suivant la reven­dication 19, caractérisé en ce que ladite rehausse comporte un plateau supérieur (109) dans lequel est ménagé un orifice de centage (108,108a) pour un plot de centrage (107) prévu à l'extrémité inférieure (106) de la jambe (102).20. Support device according to claim 19, characterized in that said extension comprises an upper plate (109) in which is formed a centering orifice (108, 108a) for a centering stud (107) provided at the lower end ( 106) leg (102). 21. Dispositif de support suivant la reven­dication 20, caractérisé en ce que la section de l'o­rifice de centrage (108) ménagé dans le plateau supé­rieur (109) de la rehausse (103) est supérieure à la section du plot de centrage (107) porté par la jambe (102) et en ce que lesdits moyens de centrage compor­tent en outre une rondelle de centrage (117) montée déplaçable horizontalement dans un logement (116) du plateau supérieur (109), ledit logement débouchant dans ledit orifice de centrage (108), ladite rondelle comportant un trou central (118), destiné à recevoir ledit plot de centrage (107) de la jambe (102) et dont la section est égale à celle dudit plot de centrage (107), lesdits moyens de centrage comprenant de plus des moyens (124) d'immobilisation de la rondelle de centrage (117) dans son logement (116).21. Support device according to claim 20, characterized in that the section of the centering orifice (108) formed in the upper plate (109) of the extension (103) is greater than the section of the centering stud (107 ) carried by the leg (102) and in that said centering means further comprises a centering washer (117) mounted horizontally displaceable in a housing (116) of the upper plate (109), said housing opening into said centering orifice (108), said washer having a central hole (118), intended to receive said centering pin (107) of the leg (102) and whose section is equal to that of said centering pin (107), said centering means further comprising means (124) for immobilizing the centering washer (117) in its housing (116). 22. Dispositif de support suivant la reven­dication 21, caractérisé en ce que la rehausse (103) comporte sur son plateau supérieur une zone de pose (121) de la jambe (102) de surface supérieure à l'en­combrement de l'extrémité inférieure (106) de ladite jambe correspondant au degré de liberté de déplacement horizontal de la jambe (102) par rapport à la rehausse (103), dû à la différence de section de l'orifice de centrage (108) et du plot de centrage (107).22. Support device according to claim 21, characterized in that the extension (103) comprises on its upper plate a fitting zone (121) of the leg (102) with a surface greater than the size of the lower end ( 106) of said leg corresponding to the degree of freedom of horizontal movement of the leg (102) relative to the extension (103), due to the difference in section of the centering orifice (108) and of the centering stud (107 ). 23. Dispositif de support suivant la reven­dication 22, caractérisé en ce que les moyens d'immo­bilisation de la rondelle de centrage (117) dans son logement (116) sont constitués par des vérins de ser­rage (124) montés dans le plateau supérieur (109) et répartis autour dudit orifice de centrage (108) de celui-ci.23. Support device according to claim 22, characterized in that the means for immobilizing the centering washer (117) in its housing (116) consist of clamping cylinders (124) mounted in the upper plate (109 ) and distributed around said centering orifice (108) thereof. 24. Dispositif de support suivant la reven­ dication 23, caractérisé en ce que chacun desdits vé­rins (124) comporte un corps de vérin mobile (126) en­gagé dans un logement (134) du plateau supérieur (109), une tige centrale fixe (127) solidaire du plateau supérieur (109), le corps (126) et la tige (127) définissant entre eux une chambre (132) alimen­tée en fluide sous pression par une conduite (133) et un patin annulaire élastique (130) de rappel du corps de vérin (126) en position de serrage lors de l'in­terruption de la mise en pression de la chambre (132), ledit patin coopérant avec le corps de vérin et en­tourant ladite tige (127).24. Support device according to revenue dication 23, characterized in that each of said jacks (124) comprises a movable jack body (126) engaged in a housing (134) of the upper plate (109), a fixed central rod (127) integral with the upper plate (109) , the body (126) and the rod (127) defining between them a chamber (132) supplied with pressurized fluid by a pipe (133) and an elastic annular pad (130) for returning the jack body (126) to the position tightening during the interruption of the pressurization of the chamber (132), said shoe cooperating with the cylinder body and surrounding said rod (127). 25. Dispositif de support suivant la reven­dication 20, caractérisé en ce que l'orifice de cen­trage (108a) dudit plateau supérieur (109) de la re­hausse présente une section égale à la section du plot de centrage (107) de ladite jambe (102).25. Support device according to claim 20, characterized in that the centering orifice (108a) of said upper plate (109) of the riser has a section equal to the section of the centering stud (107) of said leg (102 ). 26. Dispositif de support suivant l'une queconque des revendications 19 à 25, caractérisé en ce que ladite jambe (102) est terminée à son extrémité destinée à venir en contact avec la rehausse (103) par un pied (106) qui porte ledit plot de centrage (107) et en ce que lesdits moyens de verrouillage vertical de la jambe (102) sur la rehausse (103) comportent des verrous (119) montés basculants sur le plateau supé­rieur (109) de la rehausse et coopérant avec des sail­lies latérales (120) dudit pied pour en assurer le blocage sur la rehausse (103).26. Support device according to any one of claims 19 to 25, characterized in that said leg (102) is terminated at its end intended to come into contact with the extension (103) by a foot (106) which carries said centering stud (107) and in that said vertical locking means of the leg (102) on the riser (103) comprise latches (119) pivotally mounted on the upper plate (109) of the riser and cooperating with projections lateral (120) of said foot to block it on the riser (103). 27. Dispositif de support suivant la reven­dication 26, caractérisé en ce que lesdits verrous (119) sont réalisés en forme d'étriers et en ce qu'il comporte en outre des loquets (142) d'immobilisation des verrous (119) en position de blocage desdits ver­rous par engagement dans des lumières (142) ménagées dans des plaques de verouillage (14) solidaires de chacun desdits verrous (119), lesdits loquets (142) étant placés en position de blocage par des vérins (143) correspondants.27. Support device according to claim 26, characterized in that said latches (119) are made in the form of stirrups and in that it further comprises latches (142) for immobilizing the latches (119) in position for blocking said locks by engagement in openings (142) in locking plates (14) integral with each of said latches (119), said latches (142) being placed in the locking position by corresponding jacks (143). 28. Dispositif de support suivant l'une quelconque des revendications 20 à 27, caractérisé en ce que ladite rehausse (103) comporte en outre des planchers de pose (110) reliés chacun au plateau su­périeur (109) par des montants tubulaires (111) des­tinés à recevoir des pieux (112) d'ancrage de la re­hausse dans le fond marin, l'ensemble ainsi constitué étant renforcé par un treillis métallique (113).28. Support device according to any one of claims 20 to 27, characterized in that said extension (103) further comprises laying floors (110) each connected to the upper plate (109) by tubular uprights (111) intended to receive piles (112) for anchoring the riser in the seabed, the assembly thus formed being reinforced by a wire mesh (113). 29. Dispositif de support suivant l'une quelconque des revendications 19 à 28, caractérisé en ce que ladite rehausse (103) est pourvue sur deux de ses côtés de ducs d'albe d'accostage (122).29. Support device according to any one of claims 19 to 28, characterized in that said riser (103) is provided on two of its sides with docks of docking albe (122). 30. Plate-forme auto-élévatrice comprenant une coque (101) montée déplaçable et verrouillable en position le long de jambes (102) destinées à prendre appui sur le fond marin, caractérisée en ce qu'au moins certaines des jambes (102) sont fixées rigide­ment de façon séparable sur des dispositifs de support suivant l'une quelconque des revendications 19 à 24 et 26 à 29 ancrés au préalable dans le fond marin.30. Self-elevating platform comprising a hull (101) mounted movable and lockable in position along the legs (102) intended to bear on the seabed, characterized in that at least some of the legs (102) are rigidly separably fixed on support devices according to any one of claims 19 to 24 and 26 to 29 anchored beforehand in the seabed. 31. Plate-forme suivant la revendication 30, caractérisée en ce que l'une desdites jambes (102) est fixée à un dispositif de support suivant la revendica­tion 25 qui constitue un support de référence , la mise en place des autres jambes de la plate-forme étant assurée par déplacement de l'ensemble de la pla­te-forme autour dudit support de référence.31. Platform according to claim 30, characterized in that one of said legs (102) is fixed to a support device according to claim 25 which constitutes a reference support, the positioning of the other legs of the platform -form being ensured by displacement of the entire platform around said reference support.
EP86402805A 1985-12-19 1986-12-15 Device for supporting the leg of a jack-up oil platform, and platform using this device Expired - Lifetime EP0228955B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR8518884 1985-12-19
FR8518884A FR2592075B1 (en) 1985-12-19 1985-12-19 SUPPORT DEVICE FOR A LEG OF A SELF-LIFTING OIL PLATFORM FOR SEA DRILLING, AND A PLATFORM INCLUDING ITS APPLICATION

Publications (2)

Publication Number Publication Date
EP0228955A1 true EP0228955A1 (en) 1987-07-15
EP0228955B1 EP0228955B1 (en) 1990-04-18

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Family Applications (1)

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EP86402805A Expired - Lifetime EP0228955B1 (en) 1985-12-19 1986-12-15 Device for supporting the leg of a jack-up oil platform, and platform using this device

Country Status (9)

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US (1) US4762442A (en)
EP (1) EP0228955B1 (en)
JP (1) JPS62215710A (en)
BR (1) BR8606289A (en)
CA (1) CA1264229A (en)
DK (1) DK165760C (en)
FI (1) FI87477C (en)
FR (1) FR2592075B1 (en)
NO (1) NO174355C (en)

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EP0580513A1 (en) * 1992-07-23 1994-01-26 Bouygues Apparatus and method for making an off-shore foundation on vertical piles, more specifically a bridge-pier foundation
FR2996892A1 (en) * 2012-10-16 2014-04-18 Technip France DAMPING ASSEMBLY FOR AT LEAST PARTLY INSTALLED INSTALLATION IN A WATER EXTEND, ASSOCIATED INSTALLATION AND METHOD

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GB9111680D0 (en) * 1991-05-31 1991-07-24 British Nuclear Fuels Plc Inspection apparatus
US5445476A (en) * 1993-09-30 1995-08-29 Shell Oil Company Reusable offshore platform jacket
US5447391A (en) * 1993-09-30 1995-09-05 Shell Oil Company Offshore platform structure and system
GB2292406B (en) * 1994-08-19 1998-04-22 Mcdermott Int Inc Offshore structures for the support of jack-up rigs
US5741089A (en) * 1994-12-23 1998-04-21 Shell Offshore Inc. Method for enhanced redeployability of hyjack platforms
US5593250A (en) * 1994-12-23 1997-01-14 Shell Offshore Inc. Hyjack platform with buoyant rig supplemental support
US5551801A (en) * 1994-12-23 1996-09-03 Shell Offshore Inc. Hyjack platform with compensated dynamic response
GB0210969D0 (en) * 2002-05-14 2002-06-19 Fred Olsen Renewables Ltd Off shore base
NO20032730L (en) * 2003-06-16 2004-12-17 Aker Kvaerner Technology As Device for use in interconnecting large structures
SG120186A1 (en) * 2004-09-07 2006-03-28 Offshore Technology Dev Pte Lt Improved jackup oil rig and similar platforms
US7527450B2 (en) * 2005-02-04 2009-05-05 Rri Holdings, Inc. Selectably operable field mateable pin assembly
SG177019A1 (en) * 2010-06-09 2012-01-30 Keppel Offshore & Marine Technology Ct Pte Ltd Movable brace frame for self-installing platform
US8807875B2 (en) 2010-10-21 2014-08-19 Conocophillips Company Ice worthy jack-up drilling unit with conical piled monopod and sockets
GB2502463B (en) * 2011-01-14 2016-04-20 Glosten Solutions Inc Installation method for water-submersible platforms and installation vessel
EP2753765B1 (en) * 2012-02-03 2015-11-18 Vallourec Deutschland GmbH Foundation structure of an offshore plant, in particular an offshore wind turbine, which foundation structure is to be installed at a low noise level, and installation method therefor
WO2014113386A2 (en) * 2013-01-21 2014-07-24 Conocophillips Company Jack-up drilling unit with tension legs
KR102263254B1 (en) * 2014-11-27 2021-06-11 그래비플로트 에이에스 Sea bed terminal for offshore activities
US10060220B2 (en) 2015-03-31 2018-08-28 Fluor Technologies Corporation Subsea protection system
AR109872A1 (en) * 2016-10-27 2019-01-30 Gravifloat As PORT PLANT AND METHOD TO FUND A FLOATING BODY ON A PORT PLANT
NL2020037B1 (en) * 2017-12-07 2019-06-19 Ihc Holland Ie Bv A coupling system, an assembly of a vessel and a coupling system, and an assembly of a coupling system, jacket pile and foundation pile

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US3412564A (en) * 1967-02-21 1968-11-26 Pike Corp Of America Sub-sea working and drilling apparatus
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FR2320450A1 (en) * 1975-08-04 1977-03-04 Lynes Inc INFLATABLE FIXING DEVICE FOR ELEMENTS THAT SNAP INTO ONE ANOTHER
GB2071740A (en) * 1980-02-22 1981-09-23 Mitsui Shipbuilding Eng Method of assembling and testing a vertically movable marine working platform having groundable support frames
EP0042540A2 (en) * 1980-06-20 1981-12-30 Giunio Guido Santi Method of making, assembling and positioning an artificial island in the sea, and an island made, assembled and positioned by this method

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US2430014A (en) * 1945-09-12 1947-11-04 Hillman A Hansen Submersible exploration barge
US3412564A (en) * 1967-02-21 1968-11-26 Pike Corp Of America Sub-sea working and drilling apparatus
FR2320450A1 (en) * 1975-08-04 1977-03-04 Lynes Inc INFLATABLE FIXING DEVICE FOR ELEMENTS THAT SNAP INTO ONE ANOTHER
DE2609823B1 (en) * 1976-03-10 1976-12-16 Hochtief Ag Hoch Tiefbauten DEVICE AND METHOD FOR PLACING A DRILLING AND PRODUCTION PLATFORM ON THE SUBSTRUCTURE OF AN OFFSHORE DRILLING RIG
GB2071740A (en) * 1980-02-22 1981-09-23 Mitsui Shipbuilding Eng Method of assembling and testing a vertically movable marine working platform having groundable support frames
EP0042540A2 (en) * 1980-06-20 1981-12-30 Giunio Guido Santi Method of making, assembling and positioning an artificial island in the sea, and an island made, assembled and positioned by this method

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0580513A1 (en) * 1992-07-23 1994-01-26 Bouygues Apparatus and method for making an off-shore foundation on vertical piles, more specifically a bridge-pier foundation
FR2694030A1 (en) * 1992-07-23 1994-01-28 Bouygues Sa Device and method for making a foundation on vertical piles at sea, including the foundation of a bridge pile.
FR2996892A1 (en) * 2012-10-16 2014-04-18 Technip France DAMPING ASSEMBLY FOR AT LEAST PARTLY INSTALLED INSTALLATION IN A WATER EXTEND, ASSOCIATED INSTALLATION AND METHOD
WO2014060363A1 (en) * 2012-10-16 2014-04-24 Technip France Shock-absorbing assembly for an apparatus at least partially submerged in a body of water, and related apparatus and method
US9708033B2 (en) 2012-10-16 2017-07-18 Technip France Shock-absorbing assembly for an apparatus at least partially submerged in a body of water, and related apparatus and method

Also Published As

Publication number Publication date
BR8606289A (en) 1987-10-06
NO174355C (en) 1994-04-20
NO865113D0 (en) 1986-12-17
NO174355B (en) 1994-01-10
NO865113L (en) 1987-06-22
JPS62215710A (en) 1987-09-22
US4762442A (en) 1988-08-09
EP0228955B1 (en) 1990-04-18
DK612086D0 (en) 1986-12-18
FI87477C (en) 1993-01-11
FR2592075B1 (en) 1988-06-24
FI87477B (en) 1992-09-30
FR2592075A1 (en) 1987-06-26
FI865160A0 (en) 1986-12-17
JPH051846B2 (en) 1993-01-11
FI865160A (en) 1987-06-20
DK612086A (en) 1987-06-20
DK165760B (en) 1993-01-11
CA1264229A (en) 1990-01-09
DK165760C (en) 1993-06-14

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