Device for installing and / or removing an optical fiber in a receiving tube of a flexible fluid transport pipe, assembly and associated method

Abstract

Device for inserting and / or removing an optical fiber in a receiving tube of a flexible fluid transport conduit, assembly and associated method. The device (2) comprises a piston (50) movable within an internal chamber (42), sealingly separating an upstream region (52) into which an insertion inlet (44) of the optical fiber (4) and a fluid discharge outlet (46) open, from a downstream region (54) into which a fluid injection inlet (48) opens. It includes a bypass (56) connecting the downstream region (54) to the insertion inlet (44) and / or to the upstream region (52), having a one-way valve (98) preventing the passage of fluid from the insertion inlet (44) and / or from the upstream region (52).The piston (50) is movable between a position for inserting the optical fiber (4), in which the discharge outlet (46) is unobstructed, and a position for removing the optical fiber (4) and / or replacing the fluid, in which the discharge outlet (46) is closed. See Figure 3 for abbreviations.

Description

Title of the invention: Device for installing and / or removing an optical fiber in a receiving tube of a flexible fluid transport pipe, assembly and associated method

[0001] The present invention relates to a device for installing and / or removing an optical fiber in a receiving tube of a flexible fluid transport conduit, the receiving tube extending along the flexible conduit between a proximal end and a distal end, the flexible conduit comprising a fluid injection tube extending longitudinally between a proximal end and a distal end, the device comprising a body intended to be connected to the distal ends of the receiving tube and the fluid injection tube, the body defining an internal chamber,

[0002] the device comprising: - an optical fiber insertion inlet opening into the internal chamber, intended to be connected to the receiving tube. - a conveying fluid outlet, connecting the internal chamber to the outside of the body, to evacuate a conveying fluid carrying an optical fiber out of the internal chamber. - a fluid injection inlet opening into the internal chamber, intended to be connected to the fluid injection tube.

[0003] The pipeline is preferably an unbonded flexible pipeline intended for the transport of hydrocarbons across a body of water, such as an ocean, a sea, a lake or a river.

[0004] Such flexible conduct is for example carried out in accordance with the normative documents published by the American Petroleum Institute (API), API 17J, 4th edition - May 2014 and API RP 17B, 5th edition - May 2014.

[0005] The pipe is generally formed of a set of concentric and superimposed layers. It is considered "unbonded" within the meaning of the present invention, provided that at least one of the pipe layers is capable of moving longitudinally relative to the adjacent layers during pipe bending. In particular, an unbonded pipe is a pipe lacking bonding materials connecting the layers forming the pipe.

[0006] The conduit is generally arranged across a body of water, between a bottom assembly, intended to collect the fluid exploited in the bottom of the body of water and a floating or fixed surface assembly, intended to collect and distribute the fluid. The surface assembly can be a semi-submersible platform, an FPSO, or another floating assembly.

[0007] Flexible pipes are often used in challenging temperature and pressure environments, sometimes being deployed in deep waters up to several thousand meters deep.

[0008] During and after its installation, the pipe is subjected to various mechanical stresses, including static and dynamic ones.

[0009] In addition, in these environments, the pressure is high and the water temperature is very low, which can lead to constraints on fluid production through the pipeline, particularly when production is stopped.

[0010] In such environments, it is very useful to equip the pipeline with sensors to check the integrity of the pipeline, the degree of stress or deformation it undergoes and / or the conditions of the fluid it contains.

[0011] In this context, optical fibers are conventionally used by being connected to a local sensor or by being deployed as a distributed sensor. This provides measurements of parameters such as the integrity of the conduit along its entire length, local temperature (DTS "Distributed Temperature Sensor"), deformation (DSS "Distributed Strain Sensor"), vibrations (DAS "Distributed Acoustic Sensor"), chemical composition (DCS "Distributed Chemical Sensor"), etc.

[0012] When used as a local or distributed sensor, the optical fiber is generally arranged in a hollow receiving tube present in the armor layers along the entire length of the flexible conduit.

[0013] In some cases, optical fiber is subjected to stresses that can damage it or even lead to its breakage. It is therefore sometimes necessary to replace it, and it is preferable to carry out this operation early, as soon as the first signs of weakness in signal transmission quality appear.

[0014] To achieve this, an efficient method is to introduce the optical fiber into a U-tube, from the proximal end of the conduit, using a conveying fluid. The U-tube comprises a first longitudinal section and a loop at the distal end of the conduit, and a second longitudinal section. The fiber passes successively through the two longitudinal sections so that these ends are accessible at the proximal end of the flexible conduit.

[0015] Such a method also allows for easy replacement of the fiber and / or the fluid surrounding it in the tube. However, the distance traveled by the fiber and its conveying fluid through the tube is equal to or greater than the length of the tube.

[0016] Conventionally, the fiber path is substantially equal to or greater than twice the length of the conduit; this technology can only be applied up to a limited pipeline length, on the order of a few kilometers, due to the use of conventional conveying fluid pressurization systems.

[0017] Indeed, the latter are limited in terms of their capacity to deliver pressure to inject the fiber into the hollow tube, as well as by the coefficient of friction existing between the fiber and the receiving tube of the latter.

[0018] To overcome this problem, it is known to use tubes extending over a length of the conduit and opening at their distal end.

[0019] Such a method is suitable for longer pipe lengths. However, the tube is open at its lower end, which can lead to clogging by marine organisms or sediment. Furthermore, replacing the fiber results in its discharge into the body of water, which is undesirable. This is also the case with the replacement fluid, which flows directly into the body of water during the installation of the replacement fluid around the optical fiber.

[0020] WO2014 / 170633 describes a device for installing and removing a fiber optics in a receiving tube of a flexible fluid transport pipe which is mounted at the lower end of a flexible pipe to prevent intrusions of sediments or marine organisms into the tubes connected to the device.

[0021] However, this device still provides for the evacuation of an optical fiber or a fluid to be replaced directly into the body of water.

[0022] One object of the invention is to provide a device for installing and / or removing an optical fiber in a flexible conduit that can be used for very long lengths of conduit, while limiting discharges into the body of water, in particular during the injection of a replacement fluid and / or the replacement of an optical fiber.

[0023] To this end, according to a first object, the invention relates to a device for setting up the aforementioned type, characterized by: - a movable piston in the internal chamber, separating the internal chamber in a sealed manner into an upstream region into which the optical fiber insertion inlet and the fluid evacuation outlet open, and into a downstream region into which the fluid injection inlet opens; - a branch connecting the downstream region to the optical fiber insertion entry and / or to the upstream region, the branch having a one-way valve preventing the passage of fluid from the optical fiber insertion entry to the downstream region and / or from the upstream region to the downstream region;

[0024] the piston being movable between a position for installing the optical fiber, away from the insertion inlet, in which the fluid evacuation outlet is clear, and a position for removing the optical fiber and / or replacing the fluid, brought closer to the insertion inlet, in which the fluid evacuation outlet is blocked by the piston.

[0025] According to variants, the device for installing and / or removing an optical fiber according to the invention comprises at least one of the following features, taken individually or in any technically feasible combination: - the internal chamber extends along a body axis, the piston being movable in translation along the body axis; - the fluid discharge outlet opens transversely with respect to the body axis; - the optical fiber insertion inlet is located at one end of the internal chamber along the body axis, the fluid injection inlet being located at a second end of the internal chamber along the body axis; - the bypass includes a tube extending along the body outside the body; - the optical fiber insertion inlet includes a filter; - the branch includes an inlet fitting mounted in a branch supply orifice opening into the downstream region, the piston closing the branch supply orifice in the position of being in place, the branch supply orifice being clear of the piston in the position of being withdrawn;

[0026] The invention also relates to an assembly comprising a flexible fluid transport conduit and a device for installing and / or removing a fiber as defined above, the distal end of the receiving tube being connected to the optical fiber insertion inlet, the distal end of the fluid injection tube being connected to the fluid injection inlet.

[0027] According to other advantageous aspects of the invention, the assembly comprises one or more of the following features, taken individually or in all technically possible combinations: - the optical fiber receiving tube and the fluid injection tube extend from a proximal end of the flexible conduit to a distal end of the flexible conduit, the optical fiber installation and / or removal device being connected to the receiving tube and the fluid injection tube at the distal end of the flexible conduit; - the body is positioned axially beyond the distal end of the flexible conduit; - it includes a fiber optic loading system, connected to a proximal end of the receiving tube to deliver an optical fiber and the conveying fluid, and a fluid pumping system for fiber optic replacement or removal, connected to a proximal end of the fluid injection tube.

[0028] The invention also relates to a method for installing and / or removing an optical fiber in an assembly as defined above, the method comprising the following steps: - placement of the piston in its position for installing the optical fiber; - insertion and movement of the optical fiber in the receiving tube from the proximal end of the receiving tube to the distal end of the receiving tube by injecting the conveying fluid into the receiving tube and; - evacuation of the conveying fluid through the fluid discharge outlet.

[0029] According to other advantageous aspects of the invention, the method comprises one or more of the following steps, taken individually or in any technically feasible combination: - It includes the following steps:

[0030] + optical fiber input into the optical fiber insertion input.

[0031] + injection of a piston displacement fluid into the injection tube for move the piston from the position of insertion to the position of removal of the optical fiber and / or fluid replacement, and sealing of the fluid evacuation outlet; - It includes the following steps:

[0032] + Injection of a replacement fluid before or after the introduction of the fiber optical in the fluid injection tube preferably at a pressure lower than the upwelling pressure of the optical fiber through the receiving tube.

[0033] + passage of the replacement fluid through the bypass to the inlet insertion of the optical fiber and / or up to the upstream region and;

[0034] + return of the replacement fluid into the receiving tube from the end distal to proximal end, replacing the fluid initially present in the receiving tube, and in which optionally, when the optical fiber is present in the fluid injection tube, the replacement fluid flows up around the optical fiber without displacement of the optical fiber; - It includes the following steps:

[0035] + injection of an optical fiber removal fluid into the fluid injection tube at a pressure greater than the upwelling pressure of the optical fiber;

[0036] + passage of the withdrawal fluid through the bypass to the insertion inlet of the fiber optics and / or up to the upstream region and;

[0037] + displacement of the optical fiber along the receiving tube from the end distal to the proximal end and extraction of the optical fiber out of the receiving tube through the proximal end.

[0038] The invention will be better understood upon reading the following description, given solely by way of example, and made with reference to the accompanying drawings, in which:

[0039] [Fig-1] [Fig. 1] is a view of an assembly comprising a flexible conduit connected to a device for installing and / or removing an optical fiber according to the invention;

[0040] [Fig.2] [Fig.2] is a partially cutaway perspective view of a section central to the flexible conduit;

[0041] [Fig.3] [Fig.3] is a partially cutaway perspective view of the device installation and / or removal of the [Fig.l];

[0042] [Fig.4] [Fig.4] is a schematic cross-sectional view of the mounting and / or removal of the [Fig. 1] during the installation of the optical fiber

[0043] [Fig.5] [Fig.5] is a schematic cross-sectional view of the mounting and / or removal of the [Fig.1] during optical fiber replacement or during the installation of a replacement fluid.

[0044] An assembly consisting of a first flexible conduit 10 and a device 2 for installing and / or removing an optical fiber 4 in a receiving tube 5 of the flexible conduit 10 is schematically illustrated in Figures 1 and 2.

[0045] The assembly advantageously includes a system 6 for loading the optical fiber 4, connected to the receiving tube 5 for delivering the optical fiber 4 using a conveying fluid, and a system 7 for pumping fluid for replacing or removing the optical fiber 4, connected to an injection tube 8 of the flexible conduit 10.

[0046] An example of flexible driving 10 is partially illustrated by figures 1 and 2.

[0047] The flexible conduit 10 comprises at least one section 11 including a central segment 12, and at each of the axial ends of the central segment 12, an end fitting 13.

[0048] In the example shown in [Fig.1], the flexible conduit 10 comprises several sections 11 assembled end to end by their respective ends 13.

[0049] With reference to [Fig. 2], the conduit 10 delimits a central passage 16 for the circulation of a fluid, advantageously a petroleum fluid. The central passage 16 extends along a central axis A-A', between a proximal end 14A of the conduit 10, and a distal end 14B of the conduit 10 (see [Fig. 1]).

[0050] The flexible pipe 10 is intended to be disposed through a body of water 15 in a fluid handling facility, in particular hydrocarbons.

[0051] The body of water is, for example, a sea, a lake or an ocean. The depth of the body of water at the location of the fluid handling installation is, for example, between 50 m and 4000 m.

[0052] In the example shown in [Fig.1], assembly 2 is operated while the flexible pipe 10 is immersed in the body of water 15. The fluid handling installation comprises a surface assembly, in particular a floating one, and a bottom assembly (not shown) which are generally connected to each other by the flexible pipe 10.

[0053] The flexible conduction 10 is preferably an "unbonded" conduction (designated by the English term "unbonded").

[0054] At least two adjacent layers of the flexible conduit 10 are free to move longitudinally relative to each other during bending of the conduit. Advantageously, all layers of the flexible conduit 10 are free, each, to move relative to the other.

[0055] Such conduct is described for example in the normative documents published by the American Petroleum Institute (API), API 17J, 4th edition - May 2014 and API RP 17B, 5th edition - May 2014.

[0056] Furthermore, in all that follows, the terms "outside" and "inside" are generally understood radially with respect to the central axis A-A' of the pipe, the term "outside" being understood as relatively further radially away from the axis A-A' and the term "inside" extending as relatively closer radially to the axis A-A' of the pipe.

[0057] As illustrated by [Fig.2], the conduit 10 delimits a plurality of concentric layers around the axis A-A', which extend continuously along the central section 12 to the end fittings located at the ends of the section 11.

[0058] According to the invention, the conduit 10 comprises at least a first tubular sheath 20 based on polymer material advantageously constituting a pressure sheath.

[0059] The conduit 10 further comprises at least one layer of tensile armor 24, 25 disposed externally with respect to the first sheath 20 forming a pressure sheath.

[0060] The conduit 10 may include an inner carcass 26 disposed inside the pressure sheath 20, and may also include a pressure vault 27 interposed between the pressure sheath 20 and the tensile armor layer(s) 24, 25. It preferably includes an outer sheath 30, intended for the protection of the conduit 10.

[0061] As is known, the pressure sleeve 20 is intended to hermetically seal the fluid transported in the passage 16. The pressure sleeve 20 is advantageously made of a polymer material, for example based on a polyolefin such as polyethylene or polypropylene, based on a polyamide such as PA11 or PA 12, or based on a fluorinated polymer such as polyvinylidene fluoride (PVDF).

[0062] Alternatively, the pressure sheath 20 is formed from a high-performance polymer such as a polyaryletherketone (PAEK) like polyetherketone (PEK), polyetheretherketone (PEEK), polyetheretherketoneketone (PEEKK), polyetherketoneketone (PEKK), or polyetherketoneetherketoneketone (PEKEKK), polyamide-imide (PAI), polyether-imide (PEI), polysulfone (PSU), polyphenylsulfone (PPSU), polyethersulfone (PES), polyarylsulfone (PAS), polyphenylene ether (PPE), polyphenylene sulfide (PPS), liquid crystal polymers (LCP), polyphthalamide (PPA), fluorinated derivatives such as polytetrafluoroethylene (PTFE), perfluoropolyether (PFPE), perfluoroalkoxy (PFA) or ethylene chlorotrifloroethylene (ECTFE) and / or mixtures thereof.

[0063] The thickness of the pressure sheath 20 is for example between 5 mm and 20 mm.

[0064] With reference to [Fig.2], the internal passage 16 delimited by the pressure sheath 20 has an internal diameter DI greater than 40 mm and generally between 50 mm and 600 mm.

[0065] As illustrated by [Fig.2], when present, the frame 26 is formed from a first profiled metal strip 31, wound in a helix. The successive turns of the strip 31 are stapled to each other.

[0066] The main function of the frame 26 is to resist radial crushing forces. Radial crushing forces include, for example, the hydrostatic pressure of the body of water.

[0067] The carcass 26 is arranged inside the pressure sheath 20. It is suitable for coming into contact with the fluid circulating in the central passage 16 delimited by the pressure sheath 20.

[0068] With reference to [Fig. 1], the pressure arch 27 is intended to absorb the forces related to the pressure existing inside the pressure sheath 20. It is, for example, formed of a profiled metal wire 32 wound helically around the sheath 20. The profiled wire 32 generally has a complex geometry, in particular in the shape of a Z, T, U, K, X or I.

[0069] The metallic material forming the profiled wire 32 is selected from a carbon steel, in particular from grades of carbon steel comprising between 0.01% and 0.8% carbon. For applications in particularly corrosive environments, the metallic material is selected from austenitic or austenitic-ferritic stainless steels or from nickel-based alloys, such as duplex steels.

[0070] The pressure vault 27 is wound in a short-pitch helix around the pressure sheath 20, i.e. with a helix angle of absolute value close to 90° with respect to the central axis A-A', typically between 75° and 90°.

[0071] The flexible conduit 10 optionally includes a ferrule (not shown).

[0072] The fret, when present, is formed by a spiral winding of at least one wire advantageously of rectangular cross-section around the pressure arch 27. The superposition of several wires wound around the pressure arch 27 can advantageously replace a given total thickness of reinforcement. This increases the burst resistance of the flexible pipe 10. The winding of at least one wire is at a short pitch around the axis A-A' of the flexible pipe 10, i.e. with a helix angle of absolute value close to 90° with respect to the central axis A-A', typically between 75° and 90°.

[0073] In one embodiment of the invention, the pressure arch 27 and the fret are replaced by a pressure arch 27 of greater thickness formed from a profiled metal wire having a geometry in the shape of a T, U, K, X or I, and / or from at least one strip of aramid with high mechanical strength (Technora® or Kevlar®), and / or from at least one composite strip comprising a thermoplastic matrix in which carbon fibers or glass fibers are embedded.

[0074] The flexible conduit 10 according to the invention comprises at least one layer of armor 24, 25 formed from a helical winding of at least one elongated armor element 33.

[0075] In the example shown in [Fig.2], the flexible conduit 10 comprises a plurality of armor layers 24, 25, including an inner armor layer 24, applied to the pressure arch 27 and an outer armor layer 25 around which the outer sheath 30 is arranged. Each armor layer 24, 25 comprises longitudinal armor elements 33 wound at a long pitch around the axis A-A' of the conduit.

[0076] By "long pitch wound" it is meant that the absolute value of the helix angle is less than 60°, and is typically between 10° and 60°, in particular between 25° and 55°.

[0077] The armor elements 33 of a first layer 24 are generally wound at an opposite angle to the armor elements 33 of a second layer 25. Thus, if the winding angle of the armor elements 33 of the first layer 24 is equal to + a, a being between 10° and 60°, the winding angle of the armor elements 33 of the second layer of armor 25 arranged in contact with the first layer of armor 24 is for example equal to - a°.

[0078] The armor elements 33 are for example formed by metal wires, in particular steel wires, or by tapes of composite material, for example carbon fiber reinforced tapes.

[0079] The metallic material forming the armor elements 33 is selected from a carbon steel, in particular from grades of carbon steel comprising between 0.01% and 0.8% carbon. For applications in particularly corrosive environments, the metallic material is selected from austenitic or austenitic-ferritic stainless steels or from nickel-based alloys, such as duplex steels.

[0080] In this example, each layer of tensile armor 24, 25 advantageously rests on at least one wear-resistant strip (not shown). The wear-resistant strip is, for example, made of plastic, in particular polypropylene, polyamide, or polyvinylidene fluoride (PVDF). It has a thickness less than the thickness of each sheath.

[0081] Advantageously, a retaining tape such as a high mechanical strength aramid tape (Technora® or Kevlar®) is wrapped around the second outermost tensile armor layer 25 relative to the axis A-A', to provide mechanical support for the tensile armor layers 24, 25. Alternatively, the aramid fibers are replaced by glass fibers, basalt fibers, or carbon fibers.

[0082] The outer sheath 30 is intended to prevent fluid permeation from the outside of the flexible conduit 10 to the inside. It is advantageously made of polymer material, in particular based on a polyolefin, such as polyethylene, or based on a polyamide, such as PA11 or PA12.

[0083] The thickness of the outer sheath 30 is for example between 5 mm and 15 mm.

[0084] The optical fiber receiving tube 5 and the fluid injection tube 8 are generally arranged within layers 20 to 30 of the pipe, advantageously in the annular space between the pressure sheath 20 and the outer sheath 30.

[0085] Preferably, the optical fiber receiving tube 5 and the fluid injection tube 8 are wound with a long pitch outside the pressure sheath, in particular within a layer of armor 24, 25, replacing one or more armor elements 33.

[0086] With reference to [Fig. 1], the receiving tube 5 thus extends axially preferably over the entire length of the conduit and beyond the ends 14A, 14B thereof, between a proximal end 34A, configured to be detachably connected to the optical fiber loading system 6 4 and a distal end 34B connected to the placement and removal device 2.

[0087] The fluid injection tube 8 also extends axially, preferably along the entire length of the pipe and beyond its ends 14A, 14B, between a proximal end 36A, configured to be detachably connected to the optical fiber 4 replacement or removal fluid pumping system 7 and a distal end 36B connected to the installation and removal device 2.

[0088] The optical fiber installation and / or removal device 2 is illustrated in Figures 1 and 3.

[0089] In the example illustrated by [Fig.1], the device 2 extends axially beyond the distal end 34B of the flexible conduit 10, being connected to the flexible conduit 10 exclusively by the receiving tube 5 and by the injection tube 8.

[0090] As illustrated by [Fig.3], the device 2 comprises a body 40 forming a housing connected to the flexible conduit 10 near its distal end 14B. It defines an internal chamber 42, into which the receiving tube 5 and the injection tube 8 open.

[0091] The device 2 further includes an optical fiber insertion inlet 44 opening into the internal chamber 42, connected to the receiving tube 5 and a conveying fluid outlet 46, connecting the internal chamber 42 to the outside of the body 40.

[0092] The device 2 also includes a fluid injection inlet 48 connected to the fluid injection tube 8 and a piston 50 movable in the internal chamber 42, between a first position for placing the optical fiber (visible on [Fig.4]) and a second position for removing the optical fiber and / or replacing the fluid (visible on [Fig.5]), the piston 50 delimiting, in the internal chamber 42, an upstream region 52 and a downstream region 54.

[0093] The device 2 also includes a branch 56 connecting the downstream region 54 to the upstream region 52. It includes, provided in the body 40, an orifice 58 for supplying the branch 56, opening into the downstream region 54, and an orifice 60 for discharging the branch 56, opening into the upstream region 52.

[0094] The body 40 is hollow and extends along a body axis B-B'. In the example of [Fig. 3], the body 40 is advantageously cylindrical. It is advantageously formed of several parts assembled together. For example, the body 40 comprises a hollow region and a cover removably mounted on the hollow region.

[0095] The body 40 thus comprises a proximal transverse wall 66 and a peripheral wall 68, formed in this example by the hollow region. It comprises a distal transverse wall 70, formed in this example by the lid.

[0096] The internal chamber 42 is delimited axially, on either side of the body 40, respectively by the proximal transverse wall 66 and by the distal transverse wall 70. It is delimited laterally by the peripheral wall 68. It advantageously has a generally cylindrical shape through which the piston 50 is mounted to slide.

[0097] The optical fiber insertion entry 44 extends through the proximal transverse wall 66. It includes a through passage 71, opening here into the internal chamber 42 through a cup 72, a fiber inlet fitting 74 mounted projecting outwards on the proximal side of the through passage 71 and a filter 76 mounted projecting in the cup on the distal side of the through passage 71.

[0098] The through passage 71 and the basin 72 extend here parallel to the axis of body B-B' by connecting the exterior of body 40 to the upstream region 52 of the internal chamber 42.

[0099] The bowl 72 has a cross-section with a greater area than that of the passage 71. It defines with the passage 71 a proximal shoulder 78 on which the filter 76 rests.

[0100] The cup 72 has a cross-section with an area less than that of the upstream region 52 of the internal chamber 42. Thus, the proximal transverse wall 66 defines, around the cup 72, a proximal stop surface 82 of the piston 50.

[0101] The fiber inlet fitting 74 is connected to the distal end 34B of the receiving tube 5. It is configured to accommodate the passage of the optical fiber 4 surrounded by the conveying fluid.

[0102] The filter 76 includes a transverse filter wall 84. The filter wall 84 forms an axial stop for the optical fiber 4, which is prevented from passing through the filter wall 84 and entering the internal chamber 42, while accommodating the passage of fluid, in particular conveying fluid for the optical fiber 4, and preventing the passage of sediments or marine organisms.

[0103] The conveying fluid outlet 46 includes at least one through hole 86 provided transversely through the peripheral wall 68, to connect the upstream region 52 of the internal chamber 42 to the outside of the body 40.

[0104] The fluid injection inlet 48 includes a through passage 88 formed through the distal wall 70 and a fluid inlet fitting 90 mounted projecting outwards from the distal side of the through passage 88.

[0105] The through passage 88 extends here parallel to the axis of body B-B' by connecting the downstream region 54 of the internal chamber 42 to the outside of the body 40.

[0106] The fluid inlet fitting 90 is connected to the distal end 36B of the injection tube 8. It is configured to accommodate the passage of lower pressure replacement fluid and / or higher pressure optical fiber 4 removal fluid, typically at least twice the pressure required for the insertion of the optical fiber 4 into the receiving tube 5.

[0107] The pressure used for the insertion of the optical fiber 4 is for example greater than 5 bars and in particular between 5 bars and 300 bars, in particular between 10 bars and 200 bars.

[0108] The supply port 58 of the branch 56 is provided transversely through the peripheral wall 68. It is through and opens into the downstream region 54.

[0109] The discharge orifice 60 of the bypass 56 is provided axially through the proximal transverse wall 66, parallel to the through passage 71 and the basin 72. It is through and opens into the upstream region 52, next to the basin 72, being separated from the basin 72 by the proximal stop surface 82.

[0110] The branch 56 includes an inlet fitting 92, mounted in the supply port 58, and an outlet fitting 94 mounted in the discharge port 60. It includes, mounted in series between the inlet fitting 92 and the outlet fitting 94, a U-tube 96 and a one-way valve 98.

[0111] The U-tube 96 extends here axially along the peripheral wall 68, between the inlet fitting 92 and the one-way valve 98. The U-region 100 of the U-tube 96 protrudes axially beyond the proximal transverse wall 66.

[0112] The one-way valve 98 is for example formed of a non-return valve allowing the passage of fluid only in the direction from the inlet fitting 92 connected to the downstream region 54 to the outlet fitting 94 connected to the upstream region 52.

[0113] It extends here axially, parallel to the fiber inlet fitting 74.

[0114] The piston 50 here includes a peripheral sleeve 102 for sealing support on the peripheral wall 68, advantageously at least one peripheral sealing seal 104A, 104B carried by the sleeve 102.

[0115] In this example, it comprises a central transverse wall 106 closing the center of the sleeve 102 and a central proximal stop 108 configured to abut against the proximal stop surface 82.

[0116] In this example, the sleeve 102 extends around the body axis B-B'. Here it houses at least two seals 104A, 104B arranged respectively along its proximal and distal edges.

[0117] The proximal central stop 108 projects towards the proximal transverse wall 66 at the center of the central wall 106. It delimits with the sleeve 102 and the central wall 106 an annular space 110 extending opposite the filter wall 84 and the discharge orifice 60.

[0118] The piston 50 is mounted to slide along the body axis B-B' in the internal chamber 42, between the optical fiber 4 insertion position visible in [Fig.4], and the optical fiber 4 removal position and / or fluid replacement position visible in [Fig.5].

[0119] With reference to [Fig. 4], in the optical fiber 4 insertion position, the piston 50 is moved away from the insertion inlet 44 and towards the fluid injection inlet 48. It is positioned against the distal transverse wall 70 and is at axial distance of the proximal transverse wall 66, in particular of the proximal buttress surface 82.

[0120] In this position, the peripheral sleeve 102 is axially offset towards the distal transverse wall 70 relative to the fluid discharge outlet 46. The upstream region 52 has a maximum volume, while the downstream region 54 has a minimum or zero volume.

[0121] The supply port 58 of the bypass 56 is closed by the peripheral sleeve 102 of the piston 50.

[0122] Each through hole 86 of the fluid evacuation outlet 46 is clear, allowing the conveying fluid to be evacuated from the upstream region 52 to the outside.

[0123] With reference to figures 3 and 5, in the position of optical fiber 4 withdrawal and / or fluid replacement, the piston 50 is brought closer to the insertion inlet 44 and is moved away from the fluid injection inlet 48. It is positioned against the proximal transverse wall 66, in particular by contact of the proximal central stop 108 with the proximal stop surface 82. It is at an axial distance from the distal transverse wall 70.

[0124] In this position, the peripheral sleeve 102 is axially offset towards the proximal transverse wall 66 relative to the fluid discharge outlet 46. The downstream region 54 has a maximum volume, while the upstream region 52 has a minimum or zero volume.

[0125] Each through hole 46 is sealed, preventing the evacuation of conveying fluid from the upstream region 52 to the outside and the intrusion of fluid from the body of water 15 into the upstream region 52.

[0126] The supply port 58 of the bypass 56 is clear of the peripheral sleeve 102 of the piston 50.

[0127] A method for placing an optical fiber 4 in a receiving tube 5 of a flexible conduit 10 equipped with a placement and / or removal device 2 according to the invention will now be described.

[0128] Initially, preferably before the flexible pipe 10 is placed in the body of water 15, the placement and / or removal device 2 is connected to the flexible pipe 10.

[0129] The distal end 34B of the receiving tube 5 is connected to the optical fiber insertion inlet 44. Similarly, the distal end 36B of the injection tube 8 is connected to the fluid injection inlet 48.

[0130] Then, the flexible pipe 10 carrying the installation and / or removal device 2 was lowered into the body of water 15.

[0131] When the optical fiber 4 is to be placed in the receiving tube 5, the optical fiber 4 loading system 6, for example of the type marketed by Plumettaz SA, is connected to the proximal end 34A of the receiving tube 5.

[0132] Similarly, the fluid pumping system 7 for replacing or removing the optical fiber 4 is connected to the proximal end 36A of the injection tube 8.

[0133] Conveying fluid is then injected from the loading system 6, through the receiving tube 5, the optical fiber insertion inlet 44 to the proximal region 52 of the internal chamber 42. The conveying fluid exerts pressure on the piston 50, which moves into its optical fiber 4 placement position, as described above with reference to [Fig.4].

[0134] The conveying fluid includes, for example, water, a hydrocarbon, an oil, an alcohol or mixtures thereof.

[0135] The optical fiber 4 is then introduced into the receiving tube 5 from the proximal end 34A of the receiving tube 5 to the distal end 34B of the receiving tube 5, by injecting the conveying fluid into the receiving tube 5.

[0136] With the conveying fluid outlet 46 cleared by the piston 50, the conveying fluid is evacuated through the filter wall 84 in the upstream region 52, then out of the body 40 through the hole or each hole passing through 86.

[0137] When the optical fiber 4 reaches the distal end 34B of the receiving tube 5, it enters the body 40 through the optical fiber insertion inlet 44, up to the filter 76, where it butts against the filter wall 84.

[0138] Next, the conveying fluid injection is stopped. A piston displacement fluid 50 is then injected from the pumping system 7 into the injection tube 8. This fluid reaches the downstream region 54 of the internal chamber 42 through the fluid injection inlet 48. It exerts pressure on the piston 50 to move it from the position of insertion to the position of retraction of the optical fiber and / or fluid replacement. The sleeve 102 then covers the holes passing through 86. Thus, the fluid discharge outlet 46 is sealed, as seen in [Fig. 5].

[0139] The displacement fluid includes, for example, water, a hydrocarbon, an oil, an alcohol or mixtures thereof.

[0140] When the fluid present around the optical fiber needs to be replaced, a replacement fluid is injected into the injection tube 8 at a pressure lower than the upwell pressure of the optical fiber 4 through the receiving tube 5.

[0141] The pressure used for the replacement of the fluid is for example greater than 5 bars and in particular between 5 bars and 300 bars, in particular between 10 bars and 200 bars.

[0142] The replacement fluid reaches the downstream region 54 and is discharged through the supply port 58 of the bypass 56. It then travels through the U-tube 96, then passes through the one-way valve 98 and enters the upstream region 52 through the discharge port 60 of the bypass 56. It then passes through the filter wall 84 of the filter 76.

[0143] It then rises around the optical fiber 4 in the receiving tube 5 in replacement of the fluid initially present around the optical fiber 4, without displacement of the optical fiber 4, given that its pressure is lower than a rise pressure of the optical fiber through the receiving tube 5.

[0144] On the contrary, when the optical fiber 4 has to be removed from the receiving tube 5, for example because it has been damaged, a removal fluid is injected into the injection tube 8 at a pressure greater than the uplift pressure of the optical fiber 4 through the receiving tube 5.

[0145] The pressure used for replacing optical fiber 4 is, for example, greater than 10 bars and in particular between 10 bars and 600 bars, in particular between 20 bars and 400 bars.

[0146] As described previously, the removal fluid reaches the downstream region 54 and is discharged through the supply port 58 of the bypass 56. It then travels through the U-tube 96, then passes through the one-way valve 98 and enters the upstream region 52 through the discharge port 60 of the bypass 56. It then passes through the filter wall 84 of the filter 76.

[0147] The optical fiber 4 then moves under the effect of the pressure of the retraction fluid along the receiving tube 5 from the distal end 34B to the proximal end 34A and is extracted out of the receiving tube 5 through the proximal end 34A.

[0148] A new operation to load another optical fiber 4 can then be carried out, as described above.

[0149] The method according to the invention, implemented using the installation and / or removal device 2 as described above, is suitable for long conduit lengths, since it does not require loading an optical fiber 4 into a U-tube.

[0150] The receiving tube 5 connected to the device 2 remains open only when the optical fiber 4 is in place (advantageously being equipped with a filter 76), which prevents it from being blocked by marine organisms or sediments.

[0151] Furthermore, the replacement of the optical fiber 4 does not lead to its discharge into the body of water 15, since the optical fiber 4 is brought up through the receiving tube 5, under the effect of a pressure of the removal fluid introduced via the injection tube 8 and redirected into the receiving tube 5 via the bypass 56. This is also the case for the replacement fluid when it is placed around the optical fiber 4 which pushes the replaced fluid upwards, without discharge into the body of water 15.

[0152] Thus, the installation and / or removal device 2 is easily connectable to a flexible conduit 10, even when it has a significant length, to allow the installation of optical fibers 4 while limiting splicing and connection operations, and while limiting discharges into the body of water 15 in particular during the injection of a replacement fluid and / or the replacement of optical fibers 4.

[0153] In one embodiment, the replacement fluid is injected into the fluid injection tube 8 and through the receiving tube 5 before the optical fiber 4 is introduced into the receiving tube 5. In this way, the risk of damage to the optical fiber 4 during its insertion is limited.

Claims

1. Demands Device (2) for inserting and / or removing an optical fiber (4) in a receiving tube (5) of a flexible fluid transport conduit (10), the receiving tube (2) extending along the flexible conduit (10) between a proximal end (34A) and a distal end (34B), the flexible conduit (10) comprising a fluid injection tube (8) extending longitudinally between a proximal end (36A) and a distal end (36B), the device (2) comprising a body (40) for connection to the distal ends of the receiving tube (5) and the fluid injection tube (8), the body (40) defining an internal chamber (42), the device (2) comprising: - an optical fiber insertion inlet (44) opening into the internal chamber (42), intended to be connected to the receiving tube (5); - a conveying fluid outlet (46), connecting the internal chamber (42) to the outside of the body (40), to evacuate a conveying fluid carrying an optical fiber (4) out of the internal chamber (42); - a fluid injection inlet (48) opening into the internal chamber (42), intended to be connected to the fluid injection tube (8); characterized by: - a movable piston (50) in the internal chamber (42), separating the internal chamber (42) in a sealed manner into an upstream region (52) into which the optical fiber (44) insertion inlet and the fluid discharge outlet (46) open, and into a downstream region (54) into which the fluid injection inlet (48) opens; - a branch (56) connecting the downstream region (54) to the optical fiber insertion inlet (44) and / or to the upstream region (52), the branch (56) having a one-way valve (98) preventing the passage of fluid from the optical fiber insertion inlet (44) to the downstream region (54) and / or from the upstream region (52) to the downstream region (54); the piston (50) being movable between a position for the installation of the optical fiber (4), away from the insertion inlet (44), in which the fluid discharge outlet (46) is clear, and a position for the removal of the optical fiber (4) and / or for the replacement of the fluid, closer to the insertion inlet (44), in which the fluid discharge outlet (46) is closed by the piston (50).

2. Device (2) according to claim 1, in which the internal chamber (42) extends along a body axis (B-B'), the piston (50) being movable in translation along the body axis (B-B').

3. Device (2) according to claim 2, wherein the fluid discharge outlet (46) opens transversely with respect to the body axis (B-B').

4. Device (2) according to claims 2 or 3, wherein the optical fiber insertion inlet (44) is located at a first end of the internal chamber (42) along the body axis (B-B'), the fluid injection inlet (48) being located at a second end of the internal chamber (42) along the body axis (B-B').

5. Device (2) according to any one of the preceding claims, wherein the bypass (56) comprises a tube (96) extending along the body (40) outside the body (40).

6. Device (2) according to any one of the preceding claims, wherein the insertion inlet (44) of the optical fiber (4) includes a filter (76).

7. Device (2) according to any one of the preceding claims, wherein the bypass (56) has an inlet fitting (90) mounted in a bypass supply orifice (58) opening into the downstream region (54), the piston (50) closing the bypass supply orifice (58) in the set position, the bypass supply orifice (58) being clear of the piston (50) in the retracted position.

8. Assembly comprising a flexible fluid transport conduit (10) and a device (2) for installing and / or removing an optical fiber (4) according to any one of the preceding claims, the distal end (34B) of the receiving tube (5) being connected to the insertion inlet (44) of the optical fiber (4), the distal end (36B) of the fluid injection tube (8) being connected to the fluid injection inlet (48).

9. Assembly according to claim 8, wherein the optical fiber (4) receiving tube (5) and the fluid injection tube (8) extend from a proximal end (14A) of the flexible conduit (10) to a distal end (14B) of the flexible conduit (10), the optical fiber (4) installation and / or removal device (2) being connected to the receiving tube (5) and the fluid injection tube (8) at the distal end (14B) of the flexible conduit (10).

10. Assembly according to claim 9, wherein the body (40) is positioned axially beyond the distal end (14B) of the flexible conduit (10).

11. Assembly according to any one of claims 8 to 10 comprising a system (6) for loading an optical fiber (4), connected to a proximal end (34A) of the receiving tube (5) for delivering an optical fiber (4) and conveying fluid, and a system (7) for pumping fluid for replacing or removing optical fiber (4), connected to a proximal end (36B) of the fluid injection tube (8).

12. A method for installing and / or removing an optical fiber (4) in an assembly according to any one of claims 8 to 11, the method comprising the following steps: - placing the piston (50) in its optical fiber installation position (4); - introducing and moving the optical fiber (4) in the receiving tube (5) from the proximal end (34A) of the receiving tube (5) to the distal end (34B) of the receiving tube (5) by injecting the conveying fluid into the receiving tube (5); and - evacuating the conveying fluid through the fluid discharge outlet (46).

13. A method according to claim 12, comprising the following steps: - inserting the optical fiber (4) into the optical fiber insertion inlet (44); - injecting a piston displacement fluid (50) into the injection tube to move the piston (50) from the optical fiber insertion position to the optical fiber retraction position (4) and / or fluid replacement, and sealing of the fluid discharge outlet (46).

14. A method according to claim 13, comprising the following steps: - injection of a replacement fluid before or after the introduction of the optical fiber (4) into the fluid injection tube (8) preferably at a pressure lower than the upstroke pressure of the optical fiber (4) through the receiving tube (5); - passage of the replacement fluid through the bypass (56) to the insertion inlet (44) of the optical fiber (4) and / or to the upstream region (52) and; - the replacement fluid is drawn up into the receiving tube (5) from the distal end (34A) to the proximal end (34A), replacing the fluid initially present in the receiving tube (5), and optionally, when the optical fiber (4) is present in the fluid injection tube (8), the replacement fluid rises around the optical fiber (4) without displacement of the optical fiber (4).

15. A method according to claim 13 or 14, comprising the following steps: - injection of an optical fiber retraction fluid (4) into the fluid injection tube (8) at a pressure greater than the optical fiber retraction pressure (4) - passage of the withdrawal fluid through the bypass (56) to the insertion inlet (44) of the optical fiber (4) and / or to the upstream region (52) and; - displacement of the optical fiber (4) along the receiving tube (5) from the distal end (34B) to the proximal end (34A) and extraction of the optical fiber (4) out of the receiving tube (5) through the proximal end (34A).

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