Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
  • F16L11/00—Hoses, i.e. flexible pipes
  • F16L11/04—Hoses, i.e. flexible pipes made of rubber or flexible plastics
  • F16L11/08—Hoses, i.e. flexible pipes made of rubber or flexible plastics with reinforcements embedded in the wall
  • F16L11/081—Hoses, i.e. flexible pipes made of rubber or flexible plastics with reinforcements embedded in the wall comprising one or more layers of a helically wound cord or wire
  • F16L11/083—Hoses, i.e. flexible pipes made of rubber or flexible plastics with reinforcements embedded in the wall comprising one or more layers of a helically wound cord or wire three or more layers

Definitions

• the present invention relates to a method of manufacturing a flexible tubular conduit and to a flexible tubular conduit obtained according to said method.
• Flexible tubular conduits for the transport of hydrocarbons usually comprise an internal sealing sheath made of a polymer material defining a flow path, within which hydrocarbon or sludge is able to flow.
• the inner sealing sheath is covered, on the one hand, with a pressure vault made of short-pitch-wound wires so as to be able to withstand the radial stresses caused by the circulation of the fluid inside the casing.
• the layer of tensile armor is generally covered with an outer sealing sheath intended to prevent the penetration of water through the layers of armor and the pressure vault.
• the flexible tubular conduits are provided, inside the inner pressure sheath, a metal carcass made of a staple metal strip wound helically at short pitch at an angle close to 90 ° relative to the longitudinal axis of the flexible tubular pipe.
• a flexible tubular pipe is called, in English: "rough-boron”.
• a fluoropolymer sheath is extruded coaxially on a metal carcass. It comes to support after its extrusion on the metal carcass. Its inner wall thus marries the asperities of the metal carcass, because the polymer is still in the viscous state before being completely cooled. Then, the sealing sheath and supported by the metal carcass, is successively covered with layers of armor son helically wound.
• the present invention proposes, according to a first object, a method of manufacturing a flexible tubular pipe intended for the transport of hydrocarbons, said method being of the type comprising the following steps: a) a thermoplastic fluoropolymer capable of being shaped in the molten state; b) forming said fluoropolymer in the molten state to obtain a tight tubular sheath having an inner wall; and, c) helically wrapping armor threads around said sealed tubular sheath to form a set of layers of armor yarns; and, in step b), said inner wall is released.
• the cooling of the inner wall and its transition to the solid state is uniformly and uniformly distributed over the entire cylindrical surface of the inner wall.
• no crack initiation or residual stresses appear in the inner wall of the tubular sheath.
• the service life of the tubular sheath within the service line is increased.
• the absence of metal carcass is not detrimental to the inner tubular sheath, even though the flexible tubular pipe is installed at great depth and carries hot hydrocarbons.
• Flexible tubular conduits without a metal carcass are well known.
• a pressure-armor wire is wound in a short-pitch helix around said sealed tubular sheath to form a pressure-resistant layer capable of withstanding the pressure.
• This pressure layer on the inner wall of which abuts the outer wall of the tubular sealed sheath, allows in particular to take over the internal and external radial stresses due to the pressure of the hydrocarbon inside the tubular sheath waterproof and hydrostatic pressure exerted by the external environment.
• an anti-creep layer is provided between the internal sealing sheath 12 and the pressure layer 14 to limit the creep of the fluoropolymer in the gaps formed by the contiguous turns of the pressure vault.
• a plurality of tensile armor wires are wound in a long pitch helix around said pressure layer to form at least one tensile strength layer.
• the tensile armor wires are intended to take up the tensile forces exerted on the flexible tubular pipe as well as partially or completely the internal pressure exerted by the hydrocarbon circulating inside the tubular sealed sheath. These tensile forces are naturally exerted when the flexible tubular pipe is suspended from the surface of the marine environment and reaches the bottom located at the plumb. And they are all the more important as the depth of water is great.
• the method also comprises a further step, in which a metal layer is formed around said outer sealing sheath, for example a metal carcass, a pressure vault or even tensile armor.
• a metal layer is formed around said outer sealing sheath, for example a metal carcass, a pressure vault or even tensile armor.
• the present invention relates to a flexible tubular pipe intended for the transport of hydrocarbons, said flexible tubular pipe comprising, on the one hand, a tubular tubular sheath formed of a thermoplastic fluoropolymer and having an inner wall, and on the other hand a set of layers of armor wires wound helically around said sealed tubular sheath.
• Said internal wall of said sealed tubular sheath is advantageously free.
• said thermoplastic fluoropolymer used has, preferably, a melting point greater than 300 ° C, or even greater than 310 ° C.
• said thermoplastic fluoropolymer is perfluoroalkoxy.
• said inner wall has a smooth inner surface. It is then devoid of roughness and crack initiation.
• FIG. 1 is a schematic perspective view of a cutaway flexible tubular pipe obtained by the method according to the invention.
• - Figure 2 is a flowchart of the different steps of the method according to the invention.
• the flexible tubular conduit 10 comprises, from the inside to the outside, an internal sealing sheath 12, a pressure layer or vault 14, two layers 16, 18 of tensile armor and a sealing sheath external 20.
• the internal sealing sheath 12 is an extruded fluoropolymer sheath whose function is the confinement of the hydrocarbon flowing inside the pipe 10 against its inner wall 21.
• the manufacturing process of the fluoropolymer sheath 12 is described in greater detail in the following description.
• Perfluoroalkyloxy is preferably used as a polymeric material to form the sealing sheath 12. This material, in addition to good performance. in terms of mechanical characteristics and resistance to chemical agents, the advantage of being easily extruded through the extruders commonly used to form the sealing sheaths.
• the pressure vault 14 also referred to here as the pressure layer, it is formed of a metal wire wound with a short pitch in contiguous turns at an angle close to 90 ° with respect to the longitudinal axis of the flexible tubular conduit, around the internal sealing sheath 12. It thus makes it possible to take up the radial forces related to the pressure of the fluid circulating at the inside the pipe 10 and those related to the hydrostatic pressure exerted by the surrounding environment.
• traction armor 16, 18 they have the function of taking up the tensile forces which are exerted longitudinally on the flexible tubular pipe 10, especially when it is suspended between the bottom and the surface of the marine medium, as well as the internal pressure of the hydrocarbon circulating inside the internal sealing sheath 12.
• These armor plies 16, 18 are constituted respectively of two pluralities of metal weave wires helically wound to not long, in the opposite direction and at an angle of between 20 ° and 55 ° relative to the longitudinal axis of the flexible tubular conduit, around the pressure vault 14. They are, in Figure 1, crossed so as to balance the recovery of torsional forces.
• the pressure layer 14 and the tensile armor layers 16, 18 constitute a set of layers of armor wires forming reinforcing layers.
• the external protective sealing sheath 20 made of polymeric material is extruded around the armor plies 16, 18.
• the invention could also be applied to pipes that do not include an external sealing sheath.
• other layers such as a retaining layer or an anti-wear layer not shown, because optional, can come to cover the traction armor plies 16, 18 or intercalated between them.
• the holding layer comprises at least one helically wrapped ribbon with a short pitch around the traction armor plies 16, 18. It makes it possible to contain these traction armor plies 16, 18 and to prevent their swelling.
• the anti-wear layer comprises at least one helically wrapped ribbon with a short pitch around the traction armor ply 16 in order to avoid a phenomenon of frictional wear between the traction armor plies 16, 18.
• an external reinforcing metal layer such as a metal carcass, a pressure vault or a tensile armor layer is wound around the external sealing sheath of the protection 20 to effectively protect it from external damage.
• a thermoplastic fluoropolymer for example perfluoroalkoxy in the form of granules or in pulverulent form.
• This polymer has all the advantages of polytetrafluoroethylene in terms of melting point since it is close to 327 ° C., the melting point of perfluoroalkoxy being approximately 307 ° C., and also in mechanical terms since its modulus of elasticity is close to 600 MPa. Moreover, it also has excellent chemical inertness. On the other hand, it is easily extrudable unlike polytetrafluoroethylene.
• melt index characterized by its MFR, an acronym for "Melt Flow Rate" in the English language, measured under an applied load of 5 kg and at a temperature of 372 ° C., is for example between 0.5 and 15 g / 10 min, preferably between 1.5 and 3 g / 10 min.
• This fluoropolymer is supplied in the form of granules or in pulverulent form and is loaded into an extruder to be shaped according to a step b).
• the extruder comprises upstream a storage hopper of the fluoropolymer and downstream an extrusion head of a tubular sheath.
• the storage hopper and the extrusion head are connected to each other by means of an endless screw equipped with heating means so as, on the one hand, to bring the fluoropolymer from a solid state to a melted state, and secondly to drag it, through the extrusion head in the molten state.
• the extrusion head has an annular chamber through which the fluoropolymer in the molten state flows axially so as to form a cylindrical sheet having a thickness of between 0.5 and 2 cm, for example, at the end of the lips. of the extruder and having a diameter of between 5.08 cm (2 ") and 50.8 cm (20"), preferably between 7.62 cm (3 ") and 15.24 cm (6").
• the extrusion head is equipped with sonotrodes for generating high-power sound or ultrasonic waves so as to vibrate certain parts in direct contact with the molten polymer, especially those located near the outlet of the head.
• extrusion where the molten polymer is the most viscous These amplitude vibrations of the order of 1 micrometer to 0.01 millimeter and frequency of between 5 kilohertz and 200 kilohertz have the effect of facilitating the flow of the polymer by reducing the coefficient of friction at the metal-polymer interface. .
• the cylindrical sheet is extruded at low speed because the fluoropolymer in the molten state is sensitive to the shearing phenomenon of the material at the outlet of the extrusion head.
• additives such as boron nitride eliminates this undesirable effect.
• the cylindrical sheet is driven towards a cooling system such as a calibrator, preferably a vacuum calibrator in order firstly to fix the outside diameter of the tube to the desired dimensions and secondly to cool the sheet in a controlled manner.
• a cooling system such as a calibrator, preferably a vacuum calibrator in order firstly to fix the outside diameter of the tube to the desired dimensions and secondly to cool the sheet in a controlled manner.
• the calibrator consists of a set of tooling parts machined to the shape of the profile of the cylindrical sheet of revolution and thermoregulated.
• the calibrator is of the bushing type, with rings or rings or with a dry socket. Channels are machined in the thickness of the wall of the calibrator and allow the circulation of a refrigerant fluid, for example water. Therefore, they ensure the cooling of the cylindrical sheet of revolution, or circular symmetry.
• the internal surface of the calibrator on which slides the outer surface of the cylindrical sheet has several holes pierced.
• a third step c is wound helically around this rigid tubular sheath rigid all the layers of armor son as mentioned above, by means of a spiraleuse and a armeuse successively.
• the sealed tubular sheath and covered with the set of layers of armor son is again driven through an extruder, according to a fourth step d), to come to apply a protective sheath sealed in a polymeric material which n is not necessarily a fluoropolymer.
• the flexible tubular pipe obtained according to the method described above is also an object of the invention.

Landscapes

• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Rigid Pipes And Flexible Pipes (AREA)
• Extrusion Moulding Of Plastics Or The Like (AREA)
• Laminated Bodies (AREA)

Priority Applications (4)

Applications Claiming Priority (2)

Publications (1)

Family

ID=50231420

Family Applications (1)

Country Status (6)

Cited By (1)

Families Citing this family (5)

Citations (3)

Family Cites Families (3)

• 2013
  • 2013-12-27 FR FR1363636A patent/FR3016019B1/fr active Active
• 2014
  • 2014-12-26 GB GB1610694.0A patent/GB2535944B/en active Active
  • 2014-12-26 WO PCT/FR2014/053566 patent/WO2015097422A1/fr active Application Filing
  • 2014-12-26 CN CN201480076461.5A patent/CN106030178B/zh active Active
  • 2014-12-26 BR BR112016014988-2A patent/BR112016014988B1/pt active IP Right Grant
• 2016
  • 2016-06-23 DK DKPA201670453A patent/DK201670453A1/en not_active Application Discontinuation

Patent Citations (4)

Also Published As

Similar Documents

Legal Events