WO2018109373A1 - Method for manufacturing a flexible fluid transport pipe - Google Patents

Abstract

The present invention concerns a method for manufacturing a flexible pipe (11) for transporting a fluid. According to the invention, the following steps are carried out: - producing a woven base structure (23) that is tubular, or substantially tubular, in shape, according to a first weave pattern, - during the weaving of said woven base structure (23), inserting additional threads, which are attached threads relative to said first weave pattern, said additional threads forming coating supports, - said additional threads being linked to or taken into said woven base structure (23) according to a second weave pattern, optionally at regular intervals, said second weave pattern being chosen to define, for each additional thread, float areas in which said corresponding additional thread is left, by being placed externally to said woven base structure (23) in order to locally cover same, - covering the assembly (10) obtained in this way by means of a coating composition and curing said composition.

Description

 Method of manufacturing a flexible fluid transport pipe

BACKGROUND OF THE INVENTION

 Field of the invention

 The present invention relates to a method of manufacturing a flexible fluid transport pipe.

 Such a pipe finds application in particular for the transport of sea water in floating installations of energy production by conversion of the thermal energy of the seas (ETM).

Technological background

 It is known to implement flexible conduits in the marine environment for the transport of fluid, including hydrocarbons or water.

 These pipes installed at great depth must withstand very high tensions. This is particularly the case of so-called rising pipes, connecting a floating structure located on the surface to the seabed.

 The weight of these risers, of large longitudinal dimension, generates in the upper part thereof tension, including traction, very important.

 It is therefore imperative to be able to limit the weight of these pipes.

 It is also known to place at each end of each pipe, an end connection, which allows a recovery of the forces exerted on the pipe.

In its international application PCT / EP2016 / 076165, the Applicant describes a module for the transport of a fluid, comprising a woven structure forming a tubular pipe and an end connection placed at at least one end of this woven structure, this connection endpiece comprising a main body delimiting an internal channel for the passage of this fluid. The inner wall of said body delimiting said channel, or the outer wall of said body delimiting the external lateral surface of said body, being annular and having at least one shoulder defining an internal or external bearing face, for the reception of at least a ring, the anchoring of the free end of the woven structure in this connection is obtained only by friction of the faces of said free end with the surfaces of said one or more rings and said inner wall, respectively external, of said main body.

 Not only the flexible pipe of this module, formed of a woven structure, is advantageously lighter but its end fittings confer resistance to the improved tearing of the flexible pipe.

 The weaving threads of this woven structure are advantageously made of high density polyethylene (PE-HD) to ensure its mechanical strength.

 However, the Applicant has found that the implementation of this material to achieve the woven structure, made the sealing of it complex.

 Indeed, PE-HR has a very poor affinity with the coating composition so that the latter does not hold in time.

 However, the sealing of the flexible pipe is, of course, required to ensure the transport of fluid.

 There is therefore a pressing need for a method of manufacturing a flexible pipe that meets the disadvantages mentioned above.

Object of the invention

 The present invention aims to overcome the drawbacks of the prior art by proposing a method of manufacturing a flexible pipe for the transport of a fluid, simple in its design and in its operating mode, reliable and economical, ensuring in particular the sealing of this flexible pipe.

BRIEF DESCRIPTION OF THE INVENTION

 To this end, the invention relates to a method of manufacturing a flexible pipe for the transport of a fluid.

 According to the invention, the following steps are carried out:

 producing a basic woven structure having a tubular or substantially tubular shape, according to a first weave,

 inserting during the weaving of said basic woven structure, additional threads, which are threads attached to said first weave, said additional threads forming coating supports,

said additional threads being connected, regularly or otherwise, to said basic woven structure according to a second weave, said second weave is chosen to define, for each additional thread, zones of floats in which said corresponding additional thread is not bound to said basic woven structure by being placed outside of this basic woven structure, to locally cover the basic woven structure,

 covering the assembly thus obtained by means of a coating composition and hardening said composition.

 The term "wire forming a coating medium" in particular a wire whose constituent material allows, or promotes, the adhesion of the coating composition and its behavior over time.

 It is clear that the present invention is not limited to a particular type of yarn but that the term "yarn" is to be understood in its broadest sense in the textile field.

 As a purely illustrative example, the warp and weft threads used for the production of this flexible pipe are chosen from the group comprising monofilament yarns, multi-filament yarns, flat yarns, and fibers formed of fibers. together by torsion, single wire or rotor, braids twisted son, flexible stranded elements, twisted or not, such as flexible strands.

 In known manner, one skilled in the art knows that to represent the "armor" of a fabric, the mapping process is used, which uses a grid paper, and, by definition, it is assumed that the interlinings Grid verticals include warp threads, and horizontal lines, weft threads, or fabric threads.

 If on such a grid, it is desired to show that a warp thread evolves over a weft yarn, then it is enough, by convention, to color the box placed at the intersection of the warp yarn and the yarn. frame considered. We then have a "caught".

 The absence of coloring of a box, which corresponds to a "left", symbolizes the passage of the warp thread below the corresponding weft thread.

 This carding process, which is particularly simple, thus makes it possible, by a judicious combination of grips and leashes, to represent the respective evolutions of the warp yarns and weft yarns of a woven wall or a fabric, if complicated either. they.

 The existence of a portion of additional wire free between two intersections, or two left on the armor, spaced apart from each other, defines a float zone in which this portion of additional free wire does not work and covers locally the basic woven structure. The additional wire forming a coating medium, this portion of additional free wire, placed outside the base woven structure, thus allows to locally seal the flexible pipe.

The choice of the second armor and the number of additional son advantageously allows to ensure a broad coverage of the base woven structure, difficult to seal, by these additional son forming coating medium. In various particular embodiments of this method, each having its particular advantages and susceptible to many possible technical combinations:

 each additional yarn is bonded to said basic woven structure by its intersection with a warp or weft yarn of said basic woven structure.

 This additional thread can thus be bound along its longitudinal dimension by warp or weft threads alone, or by warp and weft threads. By way of example, said additional threads being warp threads, each additional thread is bonded by its intersection with a weft thread of the basic woven structure.

 This additional wire is a warp, it advantageously has a length identical to or substantially identical to the longitudinal dimension of the woven structure.

 said additional yarns are bonded to all n weft or warp yarns of said basic woven structure, n being> 4, and even better, greater than or equal to 8.

This number n can correspond to the number of threads present in an evolution of the armor.

 This ensures a broad cover, or outer cover, the basic woven structure for sealing.

 - This coating composition is applied by a spraying process or by dipping in a bath.

 Preferably, a polymer, such as an elastomer, is used.

 said second armor is determined so that said additional threads are parallel to one another.

 during weaving, each additional yarn is at least partially plated against said woven basic structure between two leashes of said second weave.

 said tubular woven structure is made in one piece by a seamless weaving process.

 said first armor is a linen armor and said second armor is a double canvas armor.

 - Said base woven structure being made of high density polyethylene (PE-HD), said additional son are made of a material selected from nylon, polypropylene, polyester, polyamide and cotton.

For purely illustrative purposes, this basic woven structure may itself be obtained by a method of manufacturing a woven structure comprising at least one woven wall, in which the following steps are carried out: a) weaving at least a first portion of said woven structure, said first portion comprising warp threads and weft threads interwoven in the basic weave of each woven wall portion corresponding to that first portion,

 b) stopping the introduction of the weft yarns after insertion of a weft yarn associated with the positioning of at least one elongate member in said woven structure, this weft yarn being interwoven with the warp yarns of each woven wall portion according to the basic armor of said wall portion,

 c) said at least one elongated element having a main axis, introducing each elongated element between the warp son defining with said associated weft yarn, the insertion position of this elongate member in the woven structure, the main axis of said element elongated cutting the plane passing through the warp threads of each wall portion into which it is introduced

 d) holding each elongate member in position and introducing at least one new weft yarn intersecting the warp yarns of said woven structure according to said fundamental weave of each wall portion or at least one new weave, to resume fabrication of said structure woven, each elongated member being unsupported in said woven structure.

 When this woven structure has several walls, the wall portions may have the same basic armor or different armor for at least some of them.

 By the term "taken" from step d) of the process, it is clear that each elongate element introduced into the woven structure is naturally not bonded to this woven structure by the only weaving of the woven structure. Thus, and in the absence of a separate securing step of the weaving of the actual woven structure, such as a gluing of the elongated element to the warp and weft threads surrounding it, each elongate element can be removed from the woven structure.

 Of course, this operation can be more or less complicated depending on the compaction of the weft son of the desired woven structure, which may result in a more or less significant tightening of the elongated element.

 The woven walls, or webs, of the woven structure may be identical or, on the contrary, present for at least some of them, different dimensions or shapes.

Stopping the weave to introduce one or more elongated elements into the woven structure is therefore identified with respect to the weft yarn directly associated with the position of the elongated element (s) in the woven structure. This means that this weft yarn is one of the threads of the woven structure surrounding the elongated element (s). Of course, steps b) to d) are repeated each time one or several new elongated elements whose position or positions are associated with another weft yarn of the woven structure, are to be introduced into this woven structure. These operations therefore require to determine in advance what is the weft thread, or what are the weft son, of the woven structure associated with the positioning of one or more elongated elements in this structure. A follow-up of the guiding and the introduction of these weft yarns in each lane of the loom is also necessary to trigger the stopping of the weaving. Nevertheless, such a method allows a very precise positioning, since close to the wire, of an elongated element in the woven structure without mechanically weakening the latter.

 The elongate member has a major axis extending along its longitudinal dimension and, by way of example, the elongate member is a solid wire, a wire, an insert, a stiffening rod, a tube, a tube provided with at least one transverse sealing membrane, a tube whose internal wall is threaded and combinations of these elements.

 Advantageously, this elongated element is of circular or ovoid cross section.

 Two sealing membranes placed in a tube can define a sealed housing to protect the external object placed in the tube, for example water.

 Furthermore, an elongated element in the form of a tube can receive an external object.

 When in addition, at least a portion of the inner wall of this tube is threaded, this external object can advantageously be locked in position. Such an external object may then be an insert, a fastener or a measuring device for example.

 Advantageously, this external object may then comprise at least one friction zone, grooved, threaded or otherwise, on at least a portion of its connection zone intended to be in contact with the inner wall of the tube, this friction zone allowing to avoid the extraction of this external object under the effect of the fluid pressure.

 Preferably, this elongated element is separable so that, passing right through the woven structure, it is possible, for example, to separate two walls of this woven structure connected by such an elongate element from each other.

 For example, these elongated elements are tubes allowing passage through the woven structure, fasteners for fixing stiffening bars to stiffen the woven structure to resist crushing.

These elongated elements can serve as a support for the attachment of measuring tools, such as probes. The present invention also relates to the use of the flexible pipe obtained by the manufacturing method as described above for the transport of water, for example, in a plant for the production of energy by conversion of the thermal energy of the sea.

BRIEF DESCRIPTION OF THE DRAWINGS

 Other advantages, aims and particular features of the present invention will emerge from the description which follows, made for an explanatory and non-limiting purpose, with reference to the appended drawings, in which:

 - Figure 1 shows schematically a fluid transport assembly according to a particular embodiment of the present invention;

 - Figure 2 is a partial view in cross section of the flexible pipe of FIG. 1, this flexible pipe having been obtained by the manufacturing method according to a particular embodiment of the present invention;

 FIG. 3 is a perspective view of a floating plant for the production of energy by conversion of thermal energy of the sea (ETM) equipped with a handling unit according to an embodiment of the present invention;

 - Figure 4 shows schematically a partial view in section of the floating installation of FIG. 3;

 - Figure 5 schematically shows a partial view and from above the floating installation of FIG. 3 showing the draft system and the central well;

DETAILED DESCRIPTION OF THE EMBODIMENT OF THE INVENTION

 First, we note that the figures are not scaled.

 Figures 1 and 2 show an example of a fluid transport assembly 10 implementing a flexible tubular conduit 1 1 obtained by the manufacturing method of the invention.

 This fluid transport assembly 10 is here used to transport water but could also be used for transporting gaseous fluids such as air.

 This transport assembly 10 thus comprises a flexible tubular conduit 1 1 and a ballast 12 placed at its lower end.

 This flexible tubular conduit 11 is made of a sealed woven structure. The woven structure is advantageously made in one piece to enhance its mechanical strength.

More specifically, this sealed woven structure comprises a base woven structure 23 having a tubular shape to which is bonded a wall 24 placed outside of this woven base structure 23 surrounding the latter all the way around. This wall 24 is formed by additional threads reported, which are here warp threads which were inserted during weaving of the base structure 23 being regularly bonded thereto along its longitudinal axis. These additional yarns which form coating substrates, carry the cured coating composition to render through the flexible pipe tight.

 At each end of this hose 1 1 flexible is placed an assembly flange 13, 14.

 The assembly flange 13 connected to the upper end of the woven structure 1 1 is intended for assembling the transport assembly 10 to a thermal power station 15, at sea, while its opposite end is assembled by the flange. 14 to the ballast 12.

 This hose 1 1 is intended for the transport of cold deep water to supply the thermal power station 15, which exploits, for illustrative purposes, in an intertropical oceanic zone, the temperature difference between the surface water much greater than 20 ° C. and deep waters about 4 ° C, to produce electricity.

 The woven structure 1 1 here has a length of 1100 m having an outside diameter, for example, slightly less than four meters while the assembly flanges 13, 14 integral with its ends, have an outside diameter greater than four meters. . The flexible pipe 1 1 typically weighs several tens of tons.

 It is stored in a storage unit (not shown) while being flattened, this storage unit being placed on a floating structure 16 forming part of the thermal power station 15.

 This floating structure 16 comprises a central well 17, or moon pool, whose opening diameter is here greater than the diameter D of the each assembly flange 13, 14 and ballast 12 to allow their passage for immersion.

 It also comprises a system for pulling the flexible pipe 11 comprising first and second sets of attracting devices 18 arranged vertically, said first and second assemblies being movable between a clamping position, in which they are placed at least partly in position. above the well 17 to tighten this flexible pipe 1 1 and ensure its displacement, and at least a second so-called inactive position, in which they are set back from said well 17 in particular to release the passage to the flanges 13, 14 to and out of this central well.

Each set comprises two superimposed attracting devices 18, these attracting devices 18 being arranged to provide a tangential drive of the flexible pipe 11. Such a configuration of the pulling system advantageously makes it possible to apply a constant and symmetrical force to the two walls of the tubular woven structure.

 This handling unit further includes a crane 19 for operating the fluid transport assembly, which crane 19 is configured to support the at least partially immersed fluid transport assembly 10 when said first and second assemblies are in their inactive position. . This crane 19 is mounted on the deck of the floating structure 16.

 The attractors 18 of each set being mounted vertically on a structure 20, 21 separate support, the pulling system comprises, for each support structure, two linear actuators 22, such as cylinders, to move the corresponding support structure 20, 21 between clamping positions and inactive.

 Preferably, all these linear actuators must be in the retracted position when the duct pulling system 1 1 flexible is not in operation to protect the cylinder rods.

Claims

1. Process for manufacturing a flexible pipe for the transport of a fluid, characterized in that the following steps are carried out:  producing a basic woven structure having a tubular or substantially tubular shape, according to a first weave,  inserting during the weaving of said basic woven structure, additional threads, which are threads attached to said first weave, said additional threads forming coating supports,  said additional threads being connected, regularly or otherwise, to said basic woven structure according to a second weave, said second weave is chosen to define, for each additional thread, zones of floats in which said corresponding additional thread is not bound to said basic woven structure being placed externally thereto for locally covering the basic woven structure, covering the assembly thus obtained by means of a coating composition and hardening said composition.  2. Method according to claim 1, characterized in that each additional wire is bonded to said basic woven structure by its intersection with a warp or weft of said basic woven structure.  3. Method according to claim 1 or 2, characterized in that said additional son being warp son, each additional wire is bonded by its intersection with a weft yarn of the basic woven structure.  4. Method according to one of claims 2 to 3, characterized in that said additional son are bonded all n weft son or warp of said basic woven structure, n being> 4, and even better, greater or equal at 8.  5. Method according to any one of claims 1 to 4, characterized in that said coating composition is applied by a spraying process or by dipping in a bath.  6. Method according to claim 5, characterized in that implements a polymer.  7. Method according to any one of claims 1 to 6, characterized in that said second armor is determined so that said additional son are parallel to each other. 8. Method according to any one of claims 1 to 7, characterized in that during weaving, at least partially each additional wire plate against said woven base structure between two left of said second weave. 9. Method according to any one of claims 1 to 8, characterized in that said tubular woven structure is made in one piece by a seamless weaving process.  10. A method according to any one of claims 1 to 9, characterized in that said first armor is a linen armor and said second armor is a double canvas armor.  1 1. Method according to any one of claims 1 to 10, characterized in that said basic woven structure being made of high density polyethylene (PE-HD), said additional threads are made of a material selected from nylon, polypropylene, polyester, polyamide and cotton.  12. Use of the flexible pipe obtained by the manufacturing method according to any one of claims 1 to 1 1 for the transport of water, for example in a plant for the production of energy by conversion of the thermal energy of the seas. .