EP0565445A1 - Apparatus for securing a flexible line having a bend restrictor - Google Patents

Abstract

Device for securing a flexible line to a structure, including a hollow rigid member, forming part of the said structure or fixed onto the said structure, and which the flexible line passes through after having been drawn, with the aid of a hauling cable fixed to one end of the said flexible line, particularly onto the end fitting mounted on the latter for its connection to the said structure, and a bend restrictor engaged on the said flexible line and secured to fixing means capable of interacting with fixing means secured to the said hollow rigid member for fitting the bend restrictor onto the said structure. It comprises means (13) for immobilising the bend restrictor (6) on the said flexible line (4) at a distance from the said end of the latter during a first phase of hauling the flexible line, at the end of which phase the bend restrictor is brought level with the opening zone of the said hollow rigid member (3) for the purpose of fitting it, the said hollow rigid member including, at least during the said first hauling phase, a flared mouthpiece (9). <IMAGE>

Description

The present invention relates to a device for mounting a flexible line to a structure, comprising a hollow rigid member forming part of said structure or fixed on said structure, and which the flexible line crosses after having been drawn using 'a traction cable fixed to one end of said flexible line, in particular on the end fitting mounted thereon for its connection to said structure.

The present invention is particularly intended for "offshore" petroleum exploitation.

For the purposes of the invention, the term “flexible line” means flexible conduits, in particular flexible tubular conduits for conveying fluids such as hydrocarbons, composite bundles of the “bundle” type, umbilicals, or electrical cables. By structure is meant any fixed or mobile structure usable in the "off shore" field, such as a fixed rigid "jacket" structure, an oscillating structure secured to the sea floor or a floating structure such as a naval surface support. , a semi-submersible platform, a floating vertical column, anchored, connected to an oil tanker for storage / separation which is moored to it, a buoy etc.

More specifically, the invention relates to a device comprising a curvature limiter engaged on said flexible line and secured to fastening means capable of cooperating with fastening means secured to said hollow rigid member in order to embed the curvature limiter on said structure.

By curvature limiter is meant any type of device making it possible to impose on the flexible line a radius of curvature greater than a minimum radius of curvature in an area where the flexible line is subjected to bending, in particular repeated bending, risking cause its deterioration.

The curvature limiter can be of any known type, for example, consisting of rigid articulated elements called "vertebrae", or preferably in the form of a stiffener.

Known stiffeners are generally blocks molded of plastic material such as a polyurethane, of at least partially frustoconical shape, placed on the flexible line and embedded on a mounting support mounted on and / or around the flexible line. .

By embedding within the meaning of the invention means a rigid mechanical connection, at least in flexion and with respect to lateral translations, between the curvature limiter and its embedding support, that is to say a connection such that the embedding support blocks the angular displacements (curving around any axis perpendicular to the axis of the flexible line) and the transverse displacements of the curvature limiter, and consequently of the flexible line, the associated values of bending torques and support forces being fully supported by the mounting support. As a variant, said embedding may be an integral embedding, also ensuring the blocking of the axial displacements and of the effects of torsion around the longitudinal axis of the flexible pipe.

The hollow rigid member is a part of the structure or a member firmly embedded in the structure, such as a platform, to which one end of the flexible pipe is connected, said hollow rigid member having a central opening for the passage of the flexible line and constituting the last fulcrum of the flexible line on the support platform, in the manner of an hawk. Commonly, the hollow rigid member which constitutes the embedding support of the curvature limiter is an end section of a guide tube in which the flexible line is engaged, the embedding being carried out in the lower mouth zone of the end section of the guide tube.

By guide tube within the meaning of the invention is meant both a vertical tubular element (I tube) and a tubular element with progressive cant (J tube). The function of guide tube can, as a variant, be fulfilled by a trellis, or any other form of frame having an internal passage to guide the flexible line.

The technique of pulling a flexible line at one end through a guide tube secured to a structure, called the "pull-in" technique is commonly used in the "off shore" petroleum field.

This technique can be used in different configurations of operating systems of underwater oil fields and for example in a production installation comprising one or more pipes or "flow-lines" connecting the different heads of underwater wells, or other equipment arranged on the bottom, to a structure forming a surface support as described above or to a subsurface structure, located at an intermediate level between the surface and the seabed, said structure comprising various equipment and, in in particular, piping elements which must be connected by the flexible pipe to the equipment arranged on the bottom. Alternatively, the production installation may comprise, instead of equipment disposed on the bottom, a second surface support, or subsurface, to which is connected the second end of the flexible pipe which is either entirely suspended in a chain between the two supports, or partly rests on the bottom.

In a first embodiment in this type of installation, a flexible pipe is unwound from a laying vessel, a first end of the pipe being pulled by the "pull-in" technique so as to be able to connect this first end of the flexible pipe to the edge of the surface support opposite which the laying vessel is positioned.

The hose is then suspended "in a chain" between the laying vessel and the surface support. Then the laying vessel moves away and begins to unwind the flexible pipe on the bottom.

In a second embodiment, once the flexible pipe has been laid over practically its entire length by the laying vessel on the seabed, the second end of the flexible pipe is connected by a traction cable to the surface support then pulled on board and connected.

Usually, the connection between the end fitting of the flexible pipe and the network of pipes installed on the support structure is made above the surface of the water, at a working bridge for example. Such a device has the advantage of facilitating the connection of the flexible pipe on board the platform. On the other hand, despite the possibility of having around a bending limiter around the upper end of the flexible pipe in the form of a stiffener firmly embedded in relation to the support structure, this device presents relatively serious risks for the flexible tubular pipe, which , without protection, must cross the splash zone.

In addition, when the support structure is floating, anchored, the flexible tubular conduit, undergoes the consequences of excursion of the structure to which it must be fixed, in particular the fact that the latter, by pulling on its anchors, departs relative to the vertical of its theoretical parking location.

According to another known device, in particular when the structure is an anchored floating platform, the connection between the flexible pipe and the platform is made below the water surface, preferably in the lower part of the platform in the vicinity of Keel. The advantage of such a device is that it puts the flexible pipe relatively to the shelter, away from the zone of maximum turbulence created on the surface by the swell. It is, however, commonly considered necessary to install, at the right of the connection of the flexible line to the structure, at the lower end of the guide tube integral with the structure, a curvature limiter in the form of a stiffener, securely recessed, aimed at distributing the bending stresses and at preventing the radius of curvature printed on the flexible line from reaching a critical lower value below which the flexible line risks being rapidly put out of use. Such a device has the obvious drawback of requiring difficult and costly operations, subject to weather conditions, to make the subsea connections.

Furthermore, US-A-4 808 034 describes a device for connecting a flexible pipe to a floating structure in which an annular guide plate is joined to a stiffener mounted to play around the flexible pipe. The guide plate comprises, projecting from its front end, fastening parts cooperating with corresponding hollow parts produced at the lower end of the vertical guide tube fixed to the structure.

In this embodiment, essentially two traction phases are implemented using different lifting cables.

First of all, cables are fixed to the fixing parts projecting at the periphery of the guide plate and the assembly consisting of the guide plate secured to the stiffener and the pipe provided with its end piece is pulled upwards, the latter being in abutment on the shoulder formed by the internal edge of the guide plate. Simultaneously another lifting cable is brought in, axially disposed and fixed to the end piece.

Once the guide plate has been joined to the end of the guide tube, the other lifting cable, fixed to the end piece, is pulled, the latter as well as the flexible line, through the tube- guide, the end piece then being, in known manner, connected to the structure at, or beyond, the upper end of the guide tube.

This known device requires the use of a plurality of traction cables during different stages.

During the first phase of the installation operation of the device, it is necessary to haul several cables at the same time, balancing their respective lengths and tensions to pull on the guide plate which drives the end piece and the flexible pipe, and , in addition, to simultaneously bring the axial lifting cable with a minimum tensile force just sufficient to prevent this cable from slack.

This device is very difficult to implement, in particular in the case of flexible lines of which a certain length rests on the bottom, to ensure the traction of flexible lines of significant length and of high weight, weight to which are added the weights of the end piece, the stiffener and the guide plate. In addition, the device described in the prior document is, taking into account the configuration of the means provided for the relative positioning and the fixing of the guide plate and of the end of the guide tube, limited to an implementation with a vertical guide tube. In addition, this device has the serious drawback that the embedding of the stiffener, as it is produced by the fixing of the guide plate on the end of the guide tube, lacks solidity.

The present invention proposes to provide a device which is easier to implement than the previously known devices, and is not limited to an implementation with a vertical guide tube, while allowing efficient and reliable embedding. of the curvature limiter, in particular underwater and preferably without the intervention of divers.

The present invention essentially relates to a device for mounting a flexible line on a structure comprising a rigid hollow member, forming part of said structure or fixed on said structure, and which the flexible line crosses after having been drawn using a traction cable fixed to one end of said flexible line, preferably on the end fitting mounted on said flexible line for its connection to said structure, and a curvature limiter, engaged on said flexible line and secured to fixing means capable of cooperating with fixing means secured to said hollow rigid member for embedding the curvature limiter on said structure, characterized in that it comprises means for immobilizing the curvature limiter on said flexible line at a distance from said end thereof during a first phase of traction of the flexible line at the end of which the curvature limiter is brought to the level of the mouth of said hollow rigid member with a view to its insertion rement, said hollow rigid member comprising at least during said first phase of traction a flared mouthpiece.

The installation operation of the flexible pipe and the connection device according to the invention comprises two phases of pulling the flexible pipe by "pull-in", these two phases being separated by an intermediate step during which the curvature limiter is immobilized on the structure. It should be noted that, according to the invention, the traction of the flexible pipe, during each of the two successive phases of traction is carried out by hauling a single and same cable which is the traction cable fixed to the end fitting flexible pipe. The device according to the invention thus has the advantage of allowing an easy installation operation, in comparison with the device described in US-A-4 808 034 which requires a set of complementary cables fixed peripherally on end pieces in projection of the guide plate mounted on the curvature limiter to perform the first phase of traction preceding the fixing of the guide plate to the lower end of the guide tube.

Another advantage of the device according to the invention is that, throughout the duration of the installation operation of the flexible pipe and, subsequently, during the operation of the installation in service, it allows, at the location critical corresponding to the upper zone of the free part of the flexible pipe which is just below the mouth of the hollow rigid member serving as a hawk, to permanently ensure a regular distribution of the bending stresses and the limitation of the radius of curvature of the flexible line with respect to the minimum value allowed. During the first phase of the pulling operation, this result is obtained thanks to the flared mouthpiece provided in the mouth area of the hollow rigid member, such as the end section of a guide tube . During the second phase of the traction operation as well as definitively, during the entire period of operation of the installation in service, this function of controlling the curvature of the flexible line is performed by the curvature limiter which was built into the structure.

The device according to the invention also has the advantage of allowing solid embedding of the curvature limiter, the positioning operation being able to be carried out easily. In particular, in an advantageous embodiment, the installation of the device is carried out without plungers by means of remote-controlled members from the surface.

In a first embodiment, the means for immobilizing the curvature limiter on the flexible line during said first traction phase are releasable from said curvature limiter after immobilization thereof. In this case, the curvature limiter is mounted on the flexible line with a radial clearance so as to allow, after release of the immobilization means of the curvature limiter, which remain axially blocked on the flexible line, a sliding of the flexible line compared to the curvature limiter.

Thus, after completion of the embedding, it is possible to implement, using the same traction cable, the second traction phase allowing the final positioning of the flexible overhead line inside the rigid hollow member until the final connection of the end fitting to the structure.

In this first embodiment, the flared mouthpiece can be permanently mounted on the hollow rigid member or is separable to allow the implementation of the mechanical members which carry out the embedding.

The embedding of the curvature limiter can be achieved by any appropriate means, in particular by assembling, using fixing members, flanges facing the curvature limiter and the hollow rigid member, or by engagement in correspondence of shapes of two complementary bearing surfaces, for example frustoconical, facing, of the curvature limiter and of the hollow rigid member or of the flared mouthpiece. The complementary bearing surfaces are preferably applied one against the other with sufficient axial force by tightening means, such as a screw-nut assembly or advantageously a clamp with corner effect.

In a second embodiment of the invention, the means for immobilizing the curvature limiter on the flexible line achieve permanent attachment of the curvature limiter on the flexible line, the embedding being effected by sliding fitting cylindrical bearing surfaces facing one another of the curvature limiter and of the hollow rigid member.

In this case, the distance between the location at which the bend limiter is immobilized on the flexible line and the end of the flexible line which must be connected to the structure, must be predetermined so that, in the embedding position of the curvature limiter, the end of the flexible line is at the level provided for its connection to the structure.

• - la figure 1 illustre schématiquement une installation pétrolière off shore dans laquelle peut être mis en oeuvre le dispositif selon l'invention,
• - les figures 2 à 4 illustrent différentes phases de mise en oeuvre d'un premier exemple de réalisation de dispositif selon l'invention, la figure 2 comportant deux zones montrées agrandies,
• - les figures 5 à 8 illustrent schématiquement différentes phases de mises en oeuvre d'un second exemple de réalisation de dispositif selon l'invention, la figure 5 comportant deux zones montrées agrandies,
• - les figures 9 et 10 illustrent schématiquement une variante de ce second exemple de réalisation,
• - la figure 11 est une vue en coupe selon XI-XI de la figure 10, et
• - les figures 12 et 13 illustrent schématiquement un autre exemple de réalisation du dispositif selon l'invention selon deux phases de mises en oeuvre, la figure 12 comportant deux zones montrées agrandies,
• - les figures 14 et 15 illustrent schématiquement encore un autre exemple de réalisation du dispositif selon l'invention et sa mise en oeuvre.

Other advantages and characteristics of the invention will appear on reading the following description of various examples of implementation given without any limitation being given with reference to the appended drawing in which:

• FIG. 1 schematically illustrates an offshore oil installation in which the device according to the invention can be used,
• FIGS. 2 to 4 illustrate different phases of implementation of a first embodiment of the device according to the invention, FIG. 2 comprising two zones shown enlarged,
• FIGS. 5 to 8 schematically illustrate different phases of implementation of a second embodiment of the device according to the invention, FIG. 5 comprising two zones shown enlarged,
• FIGS. 9 and 10 schematically illustrate a variant of this second exemplary embodiment,
• FIG. 11 is a sectional view along XI-XI of FIG. 10, and
• FIGS. 12 and 13 schematically illustrate another embodiment of the device according to the invention according to two phases of implementation, FIG. 12 comprising two zones shown enlarged,
• - Figures 14 and 15 schematically illustrate yet another embodiment of the device according to the invention and its implementation.

We first refer to Figure 1 where we see an offshore hydrocarbon production facility comprising a floating vertical column 1 provided with anchor lines 2 to the seabed.

Rigid guide tubes 3 are fixed along the structure of the floating column 1, inside which are engaged, for the ascent of the hydrocarbons, flexible tubular conduits 4 which may be of the type of those manufactured and sold on a large scale. length and in different diameters by the applicant company.

The flexible tubular conduits 4 are equipped, in a known manner, with a set of buoys 5 so as to determine a zone with a concavity of reverse direction oriented towards the bottom.

In the connection area of each flexible tubular pipe 4 at the lower end of the corresponding guide tube 3, there is provided a curvature limiting element 6 which will be described in more detail below.

FIG. 1 also shows schematically a vessel 7 used for laying flexible tubular conduits 4.

Referring now to Figures 2 to 4 which illustrate a first embodiment of the device according to the invention, as well as the steps of its implementation.

The curvature limiter 6 of this embodiment is produced in the form of a stiffener, in particular made of polyurethane, put in place with a radial clearance on the flexible tubular pipe 4 before the latter has been provided with its end piece. 'end 8. This radial clearance allows relative sliding between the stiffener and the flexible pipe after the embedding of the stiffener, described below.

The stiffener can be of any known type and in particular of one of the types described in patent application PCT / FR91 / 01073 of the applicant company.

On the lower end of the mouth of the guide tube 3 is mounted a mouth piece 9, in the shape of a trumpet, comprising a flange 10 for its attachment to a flange 11 at the end of the mouth of the guide tube 3 .

The stiffener 6 has a flange 12 at its front end.

An immobilization means, such as a retaining collar 13, is put in place and securely fixed on the flexible pipe 4 behind the stiffener 6 so as to immobilize the latter in position on the flexible tubular pipe during the first phase of ascent thereof, as will be described, said collar 13 being able to be separated from the stiffener 6 once the embedding has been carried out.

To raise the flexible pipe by traction, the end piece 8 is connected to the end of a traction cable 14 associated with lifting means, such as a winch mounted on the structure, such as the column 1 to which the flexible tubular pipe must be connected.

To implement the device according to the invention, a pulling force is exerted upwards on the cable 14, which causes the assembly constituted by the end piece 8, the flexible tubular pipe 4 and the stiffener 6 , held in abutment by the collar 13, until the end piece 8 after having passed through the flared mouthpiece 9 in the shape of a trumpet at the lower end of the guide tube 3, enters the latter by driving driving 4.

During this intermediate phase, illustrated in FIG. 3, the flared mouthpiece 9 provides continuous support with a determined curvature to support the flexible pipe in its critical zone so as to maintain its radius of curvature above the minimum value admitted and prevent its damage.

By continuing to pull the cable 14, the stiffener 6 reaches close to the flared mouth piece 9.

We then disassemble the mouthpiece, by disassembling the flanges 10 and 11, which then allows to assemble the flange 12 of the stiffener 6 with the flange 11 at the lower end of the guide tube 3.

This joining of the flanges achieves reliable embedding of the stiffener at the lower end of the guide tube.

After completion of the fitting, the collar 13 can be left in place on the pipe 4.

Preferably, the collar 13 is fixed in advance on the flexible line 4 in a position such that the length of flexible line between the collar and the end piece 8 is sufficient for the collar to be spaced a certain distance apart. relative to the rear end of the stiffener, when, once the pulling operation is completed, the end piece 8 is definitively connected to a connection member of the support platform such as a flange 38 (Figure 8). This arrangement, illustrated in FIG. 4, makes it possible to prevent the collar 13 from striking the stiffener 6 when, subsequently, the length of the flexible pipe 4 is caused to vary slightly as a function of the conditions of service, for example due to the internal pressure in the pipe, sliding inside the stiffener 6.

To carry out the installation under these conditions, one can, for example, proceed as follows: the flexible pipe 4 is raised to the maximum, so that the collar 13 pushing the stiffener 6 with the flange 12 against the flange 11, the embedding of the stiffener 6 is achieved by fixing the two opposite flanges for example by bolting, the end piece 8 being at a level slightly raised relative to the flange 38 to which it must be connected.

The connection between the end piece 8 and the flange 38 is then made by slightly lowering the flexible pipe 4 which slides through the stiffener 6, which makes it possible to separate the collar 13 from the stiffener.

As a variant, it is possible to mount the collar 13 secured, in a separable manner, with the stiffener 6, by mechanical connection members capable of being broken so as to allow relative sliding between the stiffener and the flexible pipe once the embedding produced, the collar 13 preferably being fixed in front of the stiffener 6.

To this end, different modes of execution are possible.

Thus, it is possible to connect the collar to the stiffener by members such as cables capable of being cut, in particular by plungers.

As a variant, it is possible to provide means that can be controlled remotely to achieve this separation or else to produce between the collar and the stiffener a separable connection under the effect of a pull on the flexible tubular pipe after completion of the embedding, of the type for example of the connections which will be described later in relation to the exemplary embodiments of FIGS. 5 to 11.

It is found, by examining the drawing, that the guide tube 3 used in the illustrated embodiment is of the "J tube" type, that is to say a progressive cant tube. Thus, it is understood that the invention is in no way limited to implementation with a vertical guide tube of the "I tube" type.

Referring now to Figures 5 to 8 which illustrate a second embodiment of the device according to the invention.

In this embodiment, the mouthpiece 15 in the shape of a trumpet is, unlike that of the previous embodiment, permanently mounted at the lower end of the guide tube 3.

The stiffener 16 is provided with a fixing flange 17 capable of coming to bear on an end flange 18 provided at the end of the mouthpiece 15.

In this embodiment, the stiffener 16 and the flange 17 are integral with a male frustoconical part 19 which is constituted by a rigid structure, for example made of sheet steel, with clearance surrounding the flexible pipe 4, and the surface of which external, continuous or discontinuous, constitutes a mounting surface, of generally frustoconical shape, which corresponds to that of the female frustoconical recess 20 of the mouthpiece 15. Preferably, the facing surfaces of the frustoconical parts, respectively male and female, 19 and 20 form regulated and axisymmetric geometric surfaces. Advantageously, these surfaces are in the form of cones of revolution of the same angle.

The mouthpiece 15 comprises a plurality of pawls 21, pushed by springs 22, and capable of sliding in housings 23 arranged radially in a same plane perpendicular to the axis of the central cylindrical passage that presents the part 15 and in which flexible pipe 4 must be housed.

For the engagement of the pawls 21, a groove 24 is provided in the external surface of a front part which extends the male frustoconical part 19 and which constitutes a rigid structure integral with this male frustoconical part 19. This front part has a passage central, for example cylindrical, inside which the flexible pipe 4 is disposed, and an outer surface, of general shape, for example cylindrical, such that it can take place inside the upper part of the part d '' mouth 15.

The front end of the front part secured to the male frustoconical part 19 comprises an element 39 made so that it can be fixedly fixed on the flexible pipe 4. Between the clamping element 39 and the groove 24, the front part integral with the tapered male part 19 has a rupture zone 25 which has a limited determined value of resistance to the axial tensile force, so as to be able to be broken when the cable 14 exerts a traction greater than the resistance limit value. The rupture zone 25 can be produced according to any known principle, for example by a cy sleeve lindrique of reduced thickness, a cylindrical sleeve comprising a plurality of holes of a certain diameter, or a groove, or even plurality of longitudinal studs forming a cylindrical cage.

To achieve engagement and immobilization in the mouthpiece 15 of the assembly constituted by the stiffener 16, the flange 17 and the male frustoconical part 19, as will be explained below, a pull is exerted towards the top, as illustrated in FIGS. 5 and 6, on the traction cable 14 going up the flexible tubular conduit 4 via its end tip 8, said assembly thus being simultaneously driven, thanks to the clamping element 39 securely fixed on the pipe 4.

At a time of movement, the end fitting 8 having penetrated into the mouthpiece 15 the flexible pipe 4 is guided in the female frustoconical bearing which, like the mouthpiece 9 of the previous embodiment, allows it to maintain its radius curvature above the minimum allowable value.

In the rest of the movement, the frusto-conical part 19 at the front of the stiffener 16 reaches the level of the female frusto-conical part 20 of the mouth piece 15. Simultaneously, the pawls 21 engage in the groove 24 immobilizing the stiffener relative to the guide tube. The pawls can have an asymmetrical profile allowing, in combination with the profile of the groove 24, automatic engagement in the upward pulling direction, and blocking of the device in the opposite direction. In the embodiment illustrated in FIGS. 5 to 8, the pawls 21 ensure the immobilization of the stiffener 16 temporarily, prior to its embedding, so that the realization of the embedding is made easier. Advantageously, the width of the groove 24 in the direction of the axis of the flexible pipe is slightly greater than that of the pawls 21, the resulting longitudinal play making it possible to secure the embedding in an easier and more solid manner. The flanges 17 and 18 are then facing each other, at the start of contact or at a very short distance, without however being tightened.

By continuing to pull at the end of the flexible tubular pipe, as shown in FIG. 7, the rupture zone 25 is torn off, the flexible tubular pipe 4 being able to slide inside the guide tube 3 up to its final position of connection with the support platform, the end piece 8 being connected to the connection member, such as the flange 38, secured to the platform (Figure 8).

To achieve the embedding, there is provided according to the invention, in the case of the variant illustrated by Figures 5 to 8, a clamp 26 comprising two jaws articulated around the mouthpiece 15, capable of coming to cap the flanges facing 17 and 18, the peripheral profile of the flanges and the peripheral profile of the jaws, being suitable for, when applying the collar to the flanges, causing by corner effect an axial movement of the flanges towards one another. 'other so as to bring in tight contact the frustoconical parts 19 and 20 respectively integral with the stiffener and the mouthpiece. Preferably, at least one of the flanges and the corresponding part of the collar 26 have a ramp-shaped peripheral profile making it possible to obtain, by virtue of a relatively small clamping force on the collar, a sufficient axial compressive force between the parts tapered male and female 19 and 20 so as to achieve a solid embedding. The collar 26 may be a member independent of the other elements of the device, or it may be carried by the assembly constituted by the stiffener 16 and the male frustoconical part 19, or also, as illustrated in the advantageous variant of FIGS. 5 to 8, it can be supported by the mouthpiece 15.

There is thus provided between the stiffener and the embedding support constituted by the mouthpiece at the lower end of the guide tube, a very effective embedding thanks to the conical interlocking effect between the frustoconical bearing surfaces 19 and 20 complementary .

It should be noted that the clamping function from the outside performed by the collar 26 essentially has the effect of ensuring the resumption of the relatively weak axial forces, and not of ensuring resistance to the bending moments applied by the pipe. flexible tubular and transmitted by the stiffener 16. These bending moments which are, in practice very important, are directly taken up by cooperation in correspondence of shapes, at the level of the conical fitting of the bearings 19 and 20.

The operation of closing the jaws of the clamp 26, which makes it possible, as described above, to ensure both clamping and locking, achieving the final embedding of the embedding surfaces 19 and 20, can be made as soon as the pawls 21 are in place in the groove 24, or alternatively, once the flexible pipe 4 is put in place and the end piece 8 connected to the platform.

In the alternative embodiment illustrated in FIGS. 9 to 11, there is provision, for clamping from the outside, in the frustoconical part 19 integral with the stiffener, a groove 27 capable of receiving clamping punches 28 capable of sliding radially in a guide flange 29 mounted on the mouth piece 15. The various punches 28 are capable of being moved radially so as to engage in the groove 27 under the action of a rotary ring 30 provided with ramp-shaped surfaces 31, the rotation of the ring around the axis of the frustoconical part 20 causing the pushers 32 to radially driving the clamping punches.

The ring can be rotated by any suitable means, in particular by pulls, jacks, spur gears or tangent screws, or even by means remotely controlled from the surface. The location of the clamping punches in the female frustoconical part is determined so that, as in the previous embodiment, the cooperation of the ramp-shaped surfaces of the groove 27 and the punches 28 which act like keys clamping causes by corner effect, a final axial movement of approaching the frustoconical facing surfaces respectively secured to the stiffener and the mouthpiece to achieve an exact and solid fitting in correspondence of shapes of the corresponding parts.

Ratchets (not shown), in cooperation with the groove 24, provide the retaining function beforehand, in the same way as in the previous embodiment.

In the embodiment of Figures 12 and 13, a mouthpiece 33 is permanently fixed to a cylindrical tube 40 forming the lower end of the guide tube 3. The stiffener 6 is secured by its end flange 12 with the rear end flange 34 of a cylindrical part 35 whose outside diameter corresponds with a slight clearance to the inside diameter of the tube 40 in order to form a fitting in correspondence of shapes inside the tube 40.

The part 35 in the form of a cylindrical cuff has a conical end portion 36 and is preferably produced in two rigid half-shells comprising clamping means 37 on the flexible tubular pipe 4.

The part 35 is thus firmly fixed on the pipe 4 and ensures, in a non-releasable manner, the immobilization of the stiffener on the latter at a determined distance from the end piece 8.

It has just been mentioned that, as a result of the traction exerted on the flexible pipe, the cuff 35 integral with the stiffener realizes an embedding in correspondence of shapes with the cylindrical tube 40 forming the lower end of the guide tube 3.

However, it should be noted that, given the tolerances on the diameter of manufacture of the flexible tubular pipe and the nature of the means of tightening the two half-shells of the sleeve 35 on the flexible tubular pipe, it is unlikely that the assembled cuff has both a perfectly circular cross section and a precisely predictable circumscribed diameter.

In addition, the tube 40 constituting the end of the guide tube 3 has its own manufacturing tolerances and may have been locally deformed, in particular by welding or various manipulations.

Therefore, in practice, a certain clearance is provided between the outside diameter of the cuff 35 and the inside diameter of the lower cylindrical part 40 of the guide tube. This produces, between the assembly constituted by the stiffener 6 and the cuff 35 immobilized on the flexible pipe 4, on the one hand, and, on the other hand, the mounting support constituted by the cylindrical tube 40 with the part flared mouth 33, not an integral, but partial recess, of the recess type by cylindrical fitting as described above. Such embedding blocks the effects of bending and the effects of radial support, while allowing relative axial sliding between the two assemblies, thus having the advantage that variations in length of the flexible tubular conduit as a function of variations in internal pressure. in the pipe are freely absorbed.

In cases where this device is likely to be affected by harmful effects of permanently matting, it is possible to interpose an intermediate layer of buffer material capable of absorbing shocks in the annular space between the sleeve 35 and the tube 40 .

We now refer to Figures 14 and 15.

As in the embodiment illustrated in Figures 9 to 11, the stiffener 16 constitutes the rear part of an assembly which has an axial central passage for the flexible pipe 4 and which comprises a rigid male frustoconical part 19, as well as 'a front part whose front end comprises an element 39 which can be fixedly fixed in the manner of a collar on the pipe 4 and thus constituting a means for immobilizing said assembly integral with the stiffener 16. Between the frustoconical part 19 and the clamping element 39, the front part has a rupture zone 25 as described above. In the embodiment of FIGS. 14 and 15, the outer surface of the frustoconical part 19 comprises an annular hollow part 41 whose contour has, in its front part, a conical bearing 42.

By pulling from the support platform, the pulling cable 14, the end of which is connected to the end fitting 8 of the pipe 4 and which passes through the central opening which the mouthpiece 15 is integral with the platform 1 in the vicinity of its lower part, the flexible pipe 4 and the integral assembly of the stiffener 16 are brought up, which remains immobilized on the flexible pipe, during the first phase of the traction operation, by means of the clamping element 39.

The mouthpiece 15, which may constitute the lower part of a guide tube 3, comprises a female frustoconical part 20 defining a conical internal surface which is in correspondence of shapes with the external surface enveloped by the male frustoconical part 19. A plurality of latches or dogs 43, for example three in number, are arranged inside housings 44 where they are guided so as to be able to be movable in translation along radial axes relative to the longitudinal axis of the part frustoconical 20. Springs 45 push the latches 43 towards the center. The front part, directed towards the axis of the latches has, in a meridian plane passing through said longitudinal axis of the device, a wedge-shaped outer contour 46.

At rest, the latches 43, pushed by the springs 45, partially exit from the housings 44, and their front end is projecting inside the internal surface of the female frustoconical part 20, as it appears in the left half of Figure 15 A.

The traction operation being continued, the male frusto-conical part 19 penetrates inside the female frusto-conical part 20 and comes into contact with the front part 46 of the latches 43, at the conical surface 47 of the male frusto-conical part 19 which is located just in front of the hollow part 41. The zone concerned of the front part 46 (dashed line on the right half of FIG. 15A) has a cam profile such that the latches 43 are pushed back inside. housings 44 by compressing the springs 45, so as to release the internal surface of the female frustoconical part 20 (line in solid line on the right half of FIG. 15A). When the frustoconical parts, male and female 19 and 20 respectively, come to bear one on the other at the end of the first phase of the traction operation, the latches 43 are then opposite the hollow part 41 in which they enter under the action of the springs 45, to find themselves again in the extended position as illustrated in the left half of Figure 15A. The active zone of the front part 46 of the latches 43, which is the anterior zone on the top side of the conical shapes 19 and 20, has a cam profile such as the latches 43, penetrating inside the hollow part 41, bear on the conical bearing 42. The radial penetration of the latches 43 which act in the manner of clamping keys, thus determines by corner effect an axial clamping force allowing a solid embedding of the tapered male part 19 integral with the stiffener 16 in the female frustoconical part 20.

It is understood that, in this embodiment, the latches 43 fill, both and successively, in cooperation with the hollow part 41 and the conical bearing 42, on the one hand the provisional retaining function of the stiffener provided, for example , by the pawls 21 engaging in the groove 24 in the case of the variant of FIGS. 5 to 8, or of the variant of FIGS. 9 to 11, and, on the other hand, the tightening function of the embedding members which was produced by the collar 26 with the flanges 17 and 18 in the case of the variant of FIGS. 5 to 8, and by the punches 28 penetrating into the groove 27 in the case of the variant of FIGS. 9 to 11.

The device is then permanently locked in the embedding position thus produced. Acette end, it is possible to use various known mechanical means allowing, independently of the action of the springs 45, to irreversibly block the latches 43 against the conical bearing 42 facing. In the case illustrated in FIG. 15, bolts 48 are used which are directed along the same radial axis of the housings 44 as the latches 43, and which are pushed into abutment against the rear face of the latches 43 by screwing in nuts 49 integral with the housings 44. The bolting of the bolts 48 can be carried out, for example, by a remote-controlled underwater robot such as a ROV (Remote Operated Vehicle). Alternatively, the latches 43 can be locked by fingers, similar to the clamping punches 28 illustrated in FIGS. 10 and 11, and which are pushed under the effect of the rotation of a rotary ring having shaped surfaces of ramps similar to the ramps 31 of the ring 30. Alternatively, it is possible to use a rotary ring having surfaces in the form of ramps which constitute a cylindrical or conical surface around the longitudinal axis of the frustoconical part 20, and not inscribed in a radial plane, in this case, the ramps can act, always by wedge effect, on a lateral face of the rear part of the latches having a suitable angle slope. It is also possible to produce such devices which are entirely remote-controlled from the surface, for example by using hydraulic drive members.

When the fitting of the connection device is made, and the locking done, it is possible to undertake the second phase of the pulling operation. By resuming traction on the cable 14, one begins by causing the rupture of the zone 25, which makes it possible to release the flexible pipe 4 relative to the assembly integral with the stiffener 6 which remains permanently embedded on the mounting support 15 , the clamping element 39 remaining fixed on the pipe. We can then complete the raising operation of the flexible pipe until the connection of the nozzle 8 with the member 38, such as a flange, on board the platform.

It is possible, without departing from the scope of the invention, to install the embedding device of the stiffener in the upper part of the support platform to which the flexible pipe is connected, above sea level, and not not, as described above, in the submerged position in the vicinity of the lower part of the platform. In this case, the length of the end section of the flexible pipe between its end end piece and the embedding device of the stiffener is relatively reduced, but the end piece remains separated from the embedding area.

Although the invention has been described in connection with a particular embodiment, it is of course obvious that it is in no way limited thereto and that any desirable modifications may be made to it without departing from its scope or of his mind.

Claims (12)

1 - Device for mounting a flexible line on a structure, comprising a rigid hollow member, forming part of said structure or fixed on said structure, and which the flexible line crosses after being pulled using a traction cable fixed to one end of said flexible line, in particular on the end fitting mounted thereon for its connection to said structure, and a curvature limiter engaged on said flexible line and secured to fixing means capable of cooperating with fixing means secured to said hollow rigid member for embedding the curvature limiter on said structure, characterized in that it comprises means (13, 35, 39) for immobilizing the curvature limiter (6, 16) on said flexible line (4) at a distance from said end of the latter during a first phase of traction of the flexible line at the end of which the curvature limiter is brought to the level of the mouth of said hollow rigid member (3.40) in v eu of its embedding, said hollow rigid member comprising at least during said first phase of traction a flared mouthpiece (9,15,33). 2 - Device according to claim 1, characterized in that the means (13, 39) for immobilizing the curvature limiter on the flexible line during said first traction phase are axially blocked on the flexible line and are releasable from said curvature limiter after immobilization thereof. 3 - Device according to claim 2, characterized in that said releasable immobilization means comprise a member such as a collar (13) immobilized axially on the flexible line behind the curvature limiter (6), said curvature limiter pressing against said collar during said first traction phase. 4 - Device according to claim 2, characterized in that said releasable immobilization means (39) are integral with the curvature limiter (16) during said first traction phase and are connected to it by a rupture zone (25) having a limited determined value of resistance to axial tensile force. 5 - Device according to any one of claims 2 to 4, characterized in that the curvature limiter is mounted on the flexible line so as to allow, after release of the immobilization means (13, 39) of the curvature limiter , a sliding of the flexible line relative to the latter. 6 - Device according to any one of claims 1 to 5, characterized in that the flared mouthpiece (9) is separable after completion of the fitting. 7 - Device according to any one of claims 1 to 5, characterized in that the flared mouthpiece (15,33) is permanently fixed to the hollow rigid member. 8 - Device according to any one of claims 6 and 7, characterized in that the embedding of the curvature limiter is produced by engagement in correspondence of bearing shapes (19,47,35; 20,40) facing each other respectively of the curvature limiter and of said hollow rigid member. 9 - Device according to claim 8, characterized in that it comprises clamping means (26; 27.28; 43.41) for applying said bearing surfaces in mutual support. 10 - Device according to claim 9, characterized in that it comprises retaining means (21,24) for immobilizing the curvature limiter (16) relative to the hollow rigid member before implementation of the clamping means (26,27,28). 11 - Device according to any one of claims 8 to 10, characterized in that said bearing surfaces (19,47; 20) are frustoconical and produced respectively on the curvature limiter and the flared mouthpiece. 12 - Device according to any one of claims 9 and 10, characterized in that said bearing surfaces are cylindrical. 13. Device according to claim 8, characterized in that said bearing surfaces (35,40) are cylindrical and have a radial clearance allowing axial sliding between them.

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