Composite material layer and method thereof

Abstract

A flexible pipe body for delivering production fluid, and a method of manufacturing a flexible pipe body, are provided. The flexible pipe body comprises: a spirally wound metal armor layer; and a composite tape layer for reducing fluid permeation of the production fluid into a pipe annulus, where the composite tape layer comprises a plurality of fibers; wherein the composite tape layer is positioned radially inward of the helically wound metal armor layer.

Description

Technical Field

[0001] The present invention relates to a flexible pipe body comprising a composite tape and a method of manufacturing the same. In particular, but not exclusively, the present invention relates to a flexible pipe body comprising a composite tape for reducing fluid permeation. Background Art

[0002] Flexible pipes can be used in particular to connect a seafloor location (which may be deep sea) to a sea level location. The pipe may have an inner diameter typically up to about 0.6 meters (e.g., the diameter may be in the range of 0.05 m to up to 0.6 m). Flexible pipes are typically formed as an assembly of a flexible pipe body and one or more end fittings. The flexible pipe body is typically formed as a combination of layered materials that form a pressure-bearing conduit. The pipe structure allows large flexures without causing bending stresses that would impair the function of the pipe during its life. The flexible pipe body is typically constructed as a combined structure comprising polymer layers and / or metal layers and / or composite material layers. For example, the flexible pipe body may include a polymer layer and a metal layer, or a polymer layer and a composite material layer, or a polymer layer, a metal layer and a composite material layer.

[0003] API Recommended Practice 17B provides guidance for the design, analysis, manufacture, testing, installation, and operation of flexible pipes and flexible pipe systems for onshore, subsea, and offshore applications. API Specification 17J, titled "Specification for Unbonded Flexible Pipe," defines the technical requirements for safe, dimensionally and functionally interchangeable flexible pipes that are designed and manufactured to uniform standards and criteria.

[0004] The flexible pipe body generally includes a fluid retaining layer (referred to as a barrier layer or liner), which is generally formed as a polymer jacket or pressure jacket. Such layers operate as the main fluid retaining layer. In order to prevent the rupture of such layers caused by the pressure of the conveying fluid, the interlocking wire layer (referred to as a pressure armor layer) is generally located radially outside the fluid retaining layer. A typical flexible pipe body includes one or more armor layers, optionally including a pressure armor layer. The main load on such layers is formed by radial forces. The pressure armor layer generally has a specific cross-sectional profile to interlock so as to be able to maintain and absorb the radial forces generated by the external or internal pressure on the pipe. Therefore, the cross-sectional profile of the winding wire that prevents the pipe from collapsing or rupturing due to pressure is sometimes referred to as a pressure-resistant profile. When the armor layer is formed by a spirally wound wire forming a hoop component, the radial force from the internal or external pressure on the pipe causes the hoop component to expand or contract, thereby applying a tensile or compressive load to the wire, respectively.

[0005] Some known examples of pressure armour layers may be provided in the form of tapes or composite tapes which are wrapped or wound around a radially inward layer. The tapes are oriented to ensure their longitudinal strength being arranged circumferentially or substantially circumferentially around the axis of the flexible pipe body. Thus, the tapes are wrapped or wound at a lay angle of 80° to 90° relative to the axis to provide a pressure armour layer formed by the tapes. In this way, the tapes form a pressure armour layer which is able to retain and absorb radial forces generated by the pressure in the pipe.

[0006] One or more tensile armour layers may be positioned radially outwardly of the pressure armour layers. The tensile armour is used to withstand tensile loads and internal pressure. The tensile armour layers are typically formed from a plurality of wires (to give the layer strength) which are positioned above the inner layer and wound helically along the length of the tube. The tensile armour layers are typically metal layers, such as formed from carbon steel. The tensile armour layers may alternatively be composite tendons of a matrix material reinforced with suitable fibres, such as glass, carbon, aramid, basalt or metal.

[0007] Flexible pipes are used to transport produced fluids such as oil and / or gas and / or water from one location to another. As used herein, "fluid" includes both liquid and gaseous substances. When produced fluids are transported through flexible pipes, fluids such as carbon dioxide and hydrogen sulfide gas, for example, can penetrate the innermost layer (e.g., internal pressure sheath) of the body of the flexible pipe. As used herein, penetration, particularly penetration of a fluid through a layer of a flexible pipe, can include both transmission of the fluid through the body of the layer and leakage of the fluid through discontinuities or gaps in the layer, as can be readily seen from the context of the accompanying description.

[0008] These fluids then accumulate in the pipe annulus, which is a layer disposed at or substantially disposed at the radially outermost portion of the flexible pipe body. This can result in a corrosive environment, particularly when associated with the presence of water in the annulus, such as during an annulus flooding event. Corrosive environments are known to cause pipe failures due to stress corrosion cracking of metal pipe layers, particularly those used within the armor layer. In addition, the accumulation of annulus fluids may result in over-pressurization and mechanical failure of the flexible pipe.

[0009] Certain examples of the present invention are intended to at least partially solve, mitigate or eliminate at least one of the problems and / or disadvantages associated with the prior art. Certain embodiments are intended to provide at least one of the advantages described below. Summary of the invention

[0010] The invention is set out in the appended claims.

[0011] According to a first aspect of the present invention, there is provided a flexible pipe body for conveying produced fluids, the flexible pipe body comprising:

[0012] a helically wound metal armor layer; and

[0013] a composite tape layer for reducing fluid penetration from the production fluid into the pipe annulus, wherein the composite tape layer comprises a plurality of fibers;

[0014] Wherein the composite tape layer is positioned radially inwardly of the helically wound metal armor layer.

[0015] By providing a composite tape layer (provided first) for reducing fluid penetration in combination with a metal armor layer (provided secondly), the flexibility of the flexible pipe body is increased without compromising hoop strength or fluid barrier properties. The helically wound metal armor layer acts as a major contributor to the hoop strength of the flexible pipe body. This allows the composite tape layer to act primarily as a shielding layer to limit fluid penetration through the flexible pipe body, i.e. from production fluids to the pipe annulus. As a result, the size of the composite tape and the lay angle of the composite tape layer can be reduced compared to typical composite pressure armor layers.

[0016] In addition, the properties of the composite tape and / or composite tape layer can be adjusted to optimize its fluid barrier properties. Either or both of the fibers and polymer matrix within the composite tape can be adjusted to reduce fluid permeation of the composite tape layer via transmission through the body of the composite tape forming the composite tape layer. For example, as described herein, the fiber density can be increased to increase the tortuosity of the composite tape layer. As a further example, the polymer matrix can be selected (particularly via transmission) from a material having low permeability, such as but not limited to PVDF, PEEK, and PEKK. In these ways, the composite tape layer provides a permeation barrier to inhibit or reduce corrosion of any metal armor layer disposed radially outward thereof.

[0017] In addition, the arrangement provides improved adaptability of the flexible pipe body. In other words, the arrangement provides more options for the design and manufacture of the flexible pipe body. The layer combination provides the ability to adjust the composite tape layers according to the specific penetration requirements of the one or more production fluids contained while providing increased flexibility.

[0018] Suitably, the helically wound metal armour layer is a pressure armour layer or a tensile armour layer.

[0019] Suitably, the composite tape layer is positioned radially inwardly of and directly adjacent to the helically wound metal armour layer.

[0020] Suitably, the flexible pipe body further comprises an internal pressure sheath.The internal pressure sheath may be positioned radially inwardly or radially outwardly of the composite tape layers.

[0021] Suitably, the flexible pipe body comprises at least one sacrificial layer, the at least one sacrificial layer being radially adjacent to the composite tape. The flexible pipe body may comprise a sacrificial layer positioned radially inwardly of the composite tape. Additionally or alternatively, the flexible pipe body comprises a sacrificial layer positioned radially outwardly of the composite tape. Thus, the flexible pipe body may comprise two sacrificial layers, each sacrificial layer being radially adjacent to the composite tape, such that the composite tape is arranged between the two sacrificial layers. Thus, the composite tape may be sandwiched between two sacrificial layers.

[0022] The sacrificial layer advantageously reduces or prevents direct contact of the composite material layer with other structural layers of the pipe, thereby helping to reduce wear of the composite material layer. In addition, the contact pressure between the sacrificial layer and the metal layer (ie, metal armor layer) can further improve the shielding against fluid penetration through the flexible pipe body.

[0023] Suitably, the sacrificial layer is a polymer layer. In this way, the sacrificial layer may provide the further advantage of providing the flexible pipe body with the synergistic benefit of a tortuous path around the fibres embedded in the matrix of the composite tape and a shielding effect between the contacting surfaces of the sacrificial layer and the helically wound metal armour layer. Thus, fluid penetration into the metal armour layer is particularly limited.

[0024] Suitably, the sacrificial layer is a polymer layer comprising one or more of PEEK, PEKK, PVDF, PFA, polyurea, polyamide, polyester or polyolefins such as polyethylene or polypropylene. The sacrificial layer may also be a polymer layer comprising a filler material including a mineral additive, short fibers or a second polymeric material phase such as an elastomer or a fluoropolymer. Suitably, the second polymeric material phase comprises PTFE.

[0025] Suitably, the composite tape layer and the sacrificial layer are at least partially bonded to each other using an adhesive. Alternatively, the composite tape layer and the sacrificial layer may be at least partially bonded to each other using melt consolidation or melt bonding, using heat and / or pressure from rollers. Melt consolidation or melt bonding is bonding without an adhesive.

[0026] Suitably, the plurality of fibers in the composite tape layer are continuous fibers. That is, the continuous fibers may comprise fiber bundles or fiber filaments, or individual fibers, each of which is arranged along the length direction of the composite tape of the composite tape layer. Optionally, the fiber bundles or fiber filaments may be straight or twisted together.

[0027] Suitably, the plurality of fibres in the composite tape layer may comprise carbon fibres, glass fibres, basalt fibres, drawn polymer fibres, metal wires or any combination thereof. The fibres may be impermeable.

[0028] Suitably, the composite tapes of the composite tape layer comprise a lay angle of less than 80° relative to the pipe axis. That is, the angle relative to the longitudinal axis of the flexible pipe body at which the composite tape is wound or applied to the flexible pipe body to form the composite tape layer is less than 80°. Suitably, the composite tapes of the composite tape layer comprise a lay angle of 20° to less than 80°, more suitably 40° to less than 80°, relative to the pipe axis. Most suitably, the composite tapes of the composite tape layer comprise a lay angle of 40° to less than 60° relative to the pipe axis. By reducing the lay angle of the composite tapes, the composite tape layer becomes more flexible. The flexible pipe body comprising the composite tape layer is thereby also more flexible.

[0029] Suitably, the composite tape layer comprises a plurality of sub-layers of composite tape, for example a first composite tape layer and a second composite tape layer.

[0030] Suitably, the composite tape layer has an overlap area between adjacent tape wraps of the composite tape such that each tape wrap turn at least partially covers a laterally adjacent tape wrap turn. Typically, laterally adjacent tape wrap turns of the composite tape are provided with the same lay angle. Thus, the overlap may reduce fluid penetration through the composite tape layer by reducing or removing gaps between adjacent tape wrap turns. In particular, fluid leakage through discontinuities between laterally adjacent tape wrap turns or between radially adjacent tape wrap turn sub-layers is thereby reduced.

[0031] Suitably, the composite tape layer is consolidated with adjacent tape wrap turns and / or adjacent sub-layers of composite tape such that adjacent composite tapes are at least partially bonded together. For example, a first tape wrap turn is bonded to a laterally adjacent second tape wrap turn, wherein the first tape wrap turn partially covers the second tape wrap turn.

[0032] Suitably, the plurality of sub-layers have different lay angles from each other. That is, the first composite tape layer has a first lay angle, and the second composite tape layer has a second lay angle, wherein the first lay angle is different from the second lay angle. In other examples, the sub-layers (particularly the composite tape layers therein) may have the same lay angles from each other.

[0033] Suitably, the first composite tape layer may be wound at a first lay angle relative to the axis of the flexible pipe and the second composite tape layer may be reverse wound at a second lay angle. Optionally, the first lay angle of the wound first composite tape layer may be the same as the second lay angle of the reverse wound second composite tape layer. In this way, fluid permeation through the composite tape layer, in particular leakage through discontinuities, is reduced by removing gaps between successive wrapped turns of the composite tape layer.

[0034] Suitably, the thickness of the composite tape layer is less than 5 mm. The metal armour layer provided as one or both of the pressure armour layer and the tensile armour layer may provide the majority of the hoop strength enhancement. Advantageously, the composite layer may therefore be a thinner layer than a typical composite tape layer used to provide hoop strength. Thus, the material cost of the flexible pipe body may be reduced. Suitably, the reduction in permeation caused by the composite tape layer may allow a higher strength metal material to be used in the metal armour layer, thereby making the cross section of the wires in such layer smaller and lighter, reducing cost and pipe weight.

[0035] Suitably, the composite tape layer comprises a low permeability polymer matrix to minimise fluid transport through the body of the composite tape. The low permeability polymer matrix has a CO2 permeability coefficient of less than 50.00 E when tested at 100°C and 8 bar pressure in accordance with ISO 2556 and ISO 15105-1. -6 cm 3 ·(STP)·cm / cm 2 ·s·bar. Preferably, when tested under the same conditions, the CO2 permeability coefficient is less than 4.00E -7 cm 3 ·(STP)·cm / cm 2 ·s·bar, ideally less than 1.00E -9 cm 3 ·(STP)·cm / cm 2 ·s·bar.

[0036] Suitably, the permeability barrier comprises a low permeability polymer matrix comprising at least one of PFA, PEEK, PEKK, PTFE, polyketone, ethylene vinyl alcohol copolymer, polyethylene, polypropylene, PVDF or PPS.

[0037] Suitably, the composite tape layer is a high tortuosity layer due to the density of the fibres in the composite tape of the composite tape. Suitably, the density of the fibres in the composite tape is at least 50% of the cross-sectional area of ​​the composite tape. More suitably, the density of the fibres is at least 70%, even more suitably at least 80% of the cross-sectional area of ​​the composite tape. Thus, the tortuosity of the composite tape layer can be controlled by adjusting only the density of the fibres in the composite tape without hampering the hoop strength of the flexible pipe body. Thus, the density of the fibres can be adjusted to improve only the shielding effect against fluid penetration, in particular against fluid transmission through the composite tape.

[0038] As used herein, the flexible pipe body can be considered unbonded because at least one of the layers of the flexible pipe body is able to move longitudinally relative to an adjacent layer during bending or flexing of the flexible pipe body. Thus, the flexible pipe body is bendable and flexible enough to be rolled up for transportation.

[0039] Suitably, the composite tape is bonded or consolidated to one or more of the sacrificial layers. Suitably, the internal pressure sheath is bonded to the composite tape or one of the sacrificial layers.

[0040] Suitably, the flexible pipe body further comprises one or more layers arranged radially outwardly of the helically wound metal armour layer, the one or more layers being selected from:

[0041] at least one tensile armor layer;

[0042] Anti-birdcage effect belt layer;

[0043] Insulation layer;

[0044] External pressure sheath; and

[0045] External wear or abrasion layer.

[0046] The layers may be provided and arranged in any suitable manner known in the art.

[0047] According to a second aspect of the present invention there is provided a flexible riser comprising a flexible pipe body as described herein.

[0048] According to a third aspect of the present invention there is provided a method of manufacturing a flexible pipe body, the method comprising:

[0049] providing a composite tape layer for reducing fluid penetration into the armor layer; and

[0050] A metal armor layer is helically wound on the radially outer side of the composite tape layer.

[0051] By providing such a manufacturing method, an advantageous flexible pipe body as described herein is provided. Specifically, the method increases the flexibility of the design and manufacture of the flexible pipe body. The layer combination provides the ability to manufacture a flexible pipe body in which the composite tape layers are optimized according to the specific penetration requirements of the produced fluid. The penetration of the flexible pipe body is optimized without hindering the hoop strength, and allows the armor layer outside the shielding layer to be optimized. The penetration of the flexible pipe body is optimized while increasing flexibility.

[0052] Suitably, the metal armour layer is helically wound as one or both of a pressure armour layer and a tensile armour layer.

[0053] Suitably, the method further comprises extruding an internal pressure sheath.The internal pressure sheath may be positioned radially inwardly or radially outwardly of the composite tape layer.

[0054] Suitably, the method further comprises providing at least one sacrificial layer radially adjacent to the composite tape, for example between the carcass and the composite tape. The method provides a flexible pipe body comprising a sacrificial layer positioned radially inwardly of the composite tape. Additionally or alternatively, the method provides a flexible pipe body comprising a sacrificial layer positioned radially outwardly of the composite tape. That is, the flexible pipe body may comprise two sacrificial layers, each sacrificial layer being radially adjacent to the composite tape, such that the composite tape is arranged between the two sacrificial layers. Thus, the composite tape may be sandwiched between the two sacrificial layers.

[0055] Suitably, the method further comprises bonding the composite tape layer to one or more of the sacrificial layers.

[0056] Suitably, the method further comprises bonding the internal pressure sheath to the composite tape layer.

[0057] Suitably, the step of providing the composite tape layer comprises providing a plurality of sub-layers of composite tape. For example, providing a first composite tape layer and a second composite tape layer.

[0058] Suitably, the step of providing the composite tape layer comprises winding the composite tape onto the flexible pipe body at a lay angle of less than 80° relative to the pipe axis. That is, the method comprises winding the composite tape onto the flexible pipe body at an angle of less than 80° relative to the longitudinal axis of the flexible pipe body. Suitably, the method step comprises winding the composite tape of the composite tape layer at a lay angle of 20° to less than 80°, more suitably 40° to less than 80° relative to the pipe axis. Most suitably, the composite tape of the composite tape layer comprises a lay angle of 40° to less than 60° relative to the pipe axis. By reducing the angle at which the composite tape is wound onto the flexible pipe body, the composite tape layer becomes more flexible. The flexible pipe body comprising the composite tape layer is thereby also more flexible.

[0059] Suitably, the step of providing the composite tape layer comprises winding the composite tape with an overlap region between adjacent wrap turns such that each tape wrap turn at least partially covers a laterally adjacent wrap turn. The overlap may therefore reduce fluid permeation through the composite tape layer by reducing or removing gaps between adjacent tape wrap turns. In particular, fluid leakage through discontinuities between laterally adjacent tape wrap turns is thereby reduced.

[0060] Suitably, the method further comprises consolidating the composite tape layer with adjacent tape wrap turns and / or sub-layers of composite tape such that adjacent tapes are at least partially bonded together.

[0061] Unless explicitly stated otherwise, all features of the invention are considered to be combinable with each other.

[0062] Certain embodiments of the present invention provide the following advantages: A flexible pipe body having reduced infiltration of undesirable fluids and penetration of fluids into the pipe annulus can be provided. Thus, the resulting annulus environment can be milder than conventional flexible pipe bodies, which can achieve increased pipe life.

[0063] Certain embodiments of the present invention allow for more adaptable composite tape layers to be provided in a flexible pipe body. Such composite tape layers may be more specifically tailored to the intended use of the flexible pipe. BRIEF DESCRIPTION OF THE DRAWINGS

[0064] Embodiments of the present invention are further described below with reference to the accompanying drawings, in which:

[0065] Figure 1 A flexible pipe body is illustrated;

[0066] Figure 2 illustrates a riser system;

[0067] Figure 3 illustrates a cross-sectional view of an example layer arrangement of a flexible pipe body;

[0068] Figure 4 Example composite tape layers wrapped around an internal pressure jacket are illustrated, wherein (a) is a known lay angle example, and (b) is an example lay angle according to the present invention;

[0069] Figure 5 Illustrated Figure 3 A cross-sectional view of an example arrangement of a composite tape layer, comprising a plurality of sub-layers;

[0070] Figure 6 Illustrated Figure 5 A top view of an example winding arrangement of sub-layers;

[0071] Figure 7 illustrates a cross-sectional view of an example composite tape layer including a low tortuosity fiber arrangement;

[0072] Figure 8 illustrates a cross-sectional view of an example composite tape layer including a high tortuosity fiber arrangement;

[0073] Fig. 9 illustrating a cross-sectional view of a further example layer arrangement of a flexible pipe body;

[0074] Fig.10 illustrates a cross-sectional view of another example layer arrangement of a flexible pipe body;

[0075] Fig.11 An example method of providing a flexible pipe body is illustrated;

[0076] Fig.12 Another example method of providing a flexible pipe body is illustrated; and

[0077] Fig.13 Further example methods of providing a flexible pipe body are illustrated.

[0078] In the drawings, like reference numerals refer to like parts. DETAILED DESCRIPTION

[0079] Certain terms are used in the following description for convenience only and are not limiting. The words "lower" and "upper" refer to directions in the drawings to which reference is made and are relative to the components described when assembled and installed. The words "inward", "inwardly" and "outwardly", "outwardly" refer to directions toward and away from a designated centerline or geometric center (e.g., central axis) of the described element, respectively, and the specific meaning is readily apparent from the context of the description.

[0080] Furthermore, unless otherwise stated, the use of ordinal adjectives such as "first," "second," "third," etc. merely indicates different instances of similar objects being referred to and is not intended to imply that the objects so described must be in a given order temporally, spatially, in sequence, or in any other manner.

[0081] Throughout the specification reference will be made to flexible pipe.It will be understood that a flexible pipe is an assembly of a portion of a flexible pipe body and one or more end fittings in each of which a respective end of the flexible pipe body terminates. Figure 1 1 illustrates how a flexible pipe body 100 may be formed from a combination of layered materials that form a pressure containing conduit according to one embodiment. Figure 1 Although a number of specific layers are illustrated in the drawings, it should be understood that the flexible pipe body is broadly applicable to coaxial structures including two or more layers made of a variety of possible materials. For example, the flexible pipe body can be formed of polymer layers, metal layers, composite layers, or a combination of different materials. It should also be noted that the layer thicknesses are shown only for illustrative purposes.

[0082] Although some layers of the flexible pipe body may be described as bonded or consolidated, the flexible pipe may generally be considered to be an unbonded flexible pipe. That is, unless otherwise stated, the layers of the flexible pipe body are unbonded and are thus able to move longitudinally relative to adjacent layers during bending or flexing of the flexible pipe body.

[0083] As used herein, a layer may optionally include sublayers. Multiple sublayers are combined to form a layer with a specific purpose. For example, a layer of a tape composite material may be formed from one or more sublayers.

[0084] As used herein, composite materials refer to materials formed of two or more different materials, such as materials formed of a matrix material and reinforcing fibers. In some examples, the composite material can be a composite tape layer. In other examples, the composite material can include an extruded layer. The fibers in the composite material can include any one of carbon fibers, or glass fibers, or basalt fibers, or stretched polymer fibers, or metal wires, or any combination thereof. The fibers can be long or short in order to optimize or utilize their strength in one or more directions in the composite material. Long and continuous fibers are generally considered to be oriented primarily in a specific direction in order to provide strength to the composite material in that orientation.

[0085] As used herein, tape is broadly interpreted to encompass any elongated structure of preformed cross-section that is capable of being wound in a spiral manner around an underlying structure. That is, tape refers to an elongated material provided in a wrappable or windable form so as to form a layer by winding around a radially inward layer of a flexible pipe body. In particular, a composite tape is a wrappable or windable elongated composite material used to form a composite tape layer.

[0086] As used herein, the term "lay angle" refers to the angle at which a tape or layer is applied to (i.e., wrapped around) the underlying structure of a flexible pipe body. Thus, the lay angle is an angle relative to the longitudinal axis of the flexible pipe body. A tape with a lay angle of 90° would be a tape that is wrapped around a radius of the cross-section of the flexible pipe body (perpendicular to the longitudinal axis of the pipe).

[0087] It will be appreciated that the term "radially" is used to refer to a position relative to a radius of the flexible pipe body. For example, the term "radially inward" means a position relatively closer to the center or central longitudinal axis of the flexible pipe body, and "radially outward" means a position relatively further away from the center or axis of the flexible pipe body.

[0088] Reference now Figure 1, illustrates a conventional layer arrangement of a flexible pipe body 100. In this example, the flexible pipe body 100 includes an optional innermost carcass layer 101. The carcass layer 101 provides an interlocking structure that can be used as an innermost layer to completely or partially prevent the internal pressure sheath 102 from collapsing due to pipe decompression, external pressure, and tensile armor pressure and mechanical breaking loads. The carcass layer 101 is typically a metal layer formed, for example, of stainless steel. The carcass layer 101 can also be formed of a composite material, a polymer, or other material, or a combination of materials. It should be understood that certain embodiments are suitable for "smooth hole" operations (i.e., without a carcass layer) as well as such "rough hole" applications (with a carcass layer).

[0089] The internal pressure sheath 102 acts as a fluid retaining layer and comprises a polymer layer that ensures the integrity of the internal fluid. It should be understood that this layer itself may comprise multiple sub-layers. It should be understood that when the optional carcass layer 101 is used, the internal pressure sheath 102 is generally referred to as a barrier layer by those skilled in the art. In operations without such a carcass layer 101 (so-called smooth hole operations), the internal pressure sheath 102 may be referred to as a liner.

[0090] An optional sacrificial or wear layer may also be added, either as an extruded layer or as a helically wound tape layer. The optional sacrificial or wear layer may be located radially inwardly or radially outwardly of the internal pressure sheath, or both. The sacrificial layer thereby provides a relatively smooth (compared to the outer surface of the carcass layer) surface over which the internal pressure sheath is pressed. Additionally or alternatively, the sacrificial layer thereby provides a layer of sacrificial material that can creep under pressure into the gaps between the wrapped turns of an overlying metal armor layer, particularly a pressure armor layer.

[0091] The optional pressure armour layer 103 is disposed radially outside the internal pressure sheath 102. The pressure armour layer 103 is a structural layer that increases the resistance of the flexible pipe to internal and external pressures and mechanical breaking loads. That is, the pressure armour layer 103 bears radial loads. The pressure armour layer 103 specifically provides hoop strength to the flexible pipe body 100.

[0092] The pressure armor layer 103 also structurally supports the inner pressure sheath 102. Figure 4 (a), the pressure armour layer 103 is formed by an interlocking construction of wires wound at a lay angle α relative to the flexible pipe body axis AA. The lay angle α is typically close to 90°. In this way, the laterally adjacent interlocking wires provide a rigid pressure armour layer 103 that provides maximum hoop strength for the entire flexible pipe body 100.

[0093] As shown, the flexible pipe body 100 includes sub-layers including a first tensile armor layer 105 and a second tensile armor layer 106. Each tensile armor layer is used to withstand tensile loads and internal pressures and is wound around the pipe body at angles that are optimized to achieve the desired tensile and pressure bearing balance. For example, when pressure armor wires are not used in the design (and the tensile armor must withstand both compression and tension), the lay angle of the tensile armor wires can be about + / -55°, however, when radially inward pressure armor is incorporated at a lay angle close to 90° and the tensile armor layer is primarily intended to withstand tensile loads, their lay angle can be much lower, such as as low as 27° to 30°. Each tensile armor layer is formed of a plurality of wires (to give the layer strength) that are located above the inner layer and are spirally wound along the length of the pipe. The tensile armor layers are typically wound in pairs in opposite directions. The tensile armor layer is typically a metal layer formed, for example, of carbon steel.

[0094] The flexible pipe body 100 shown also includes optional tape layers 104 provided radially outwardly of the tensile armour layers 105, 106 which help to contain underlying layers and to provide a degree of protection against abrasion between adjacent layers.

[0095] The flexible pipe body 100 also typically includes an optional insulating layer 107 and an outer jacket 108, which includes a polymer layer for protecting the pipe from penetration, corrosion, abrasion and mechanical damage by seawater and other external environments. Additional layers (not shown) may also be added radially outside the outer jacket 108 to provide additional wear / abrasion protection for the pipe and prevent damage to the outer jacket 108.

[0096] Each flexible pipe 100 includes at least one portion (sometimes referred to as a section or segment of the flexible pipe body 100) and an end fitting located at at least one end of the flexible pipe. The end fitting provides a mechanical device that forms a transition between the flexible pipe body and the connector. For example, Figure 1 The different pipe layers shown terminate in end fittings so that loads are transferred between the flexible pipe body and the connector.

[0097] Reference now Figure 2 , shows a known riser assembly 200 suitable for transporting produced fluids such as oil and / or gas and / or water from a seafloor location 201 to a floating facility. Figure 2 In the embodiment, the seafloor location 201 includes a seafloor flow line. The flexible flow line 205 includes a flexible pipe 203 that is fully or partially resting on or buried below the seafloor 204 and is used for static applications. The floating facility can be composed of a platform and / or a buoy or a floating structure such as a mobile station. Figure 2The vessel 200 shown provides a riser assembly 200 in the form of a flexible riser, ie a flexible pipe 203 connecting the vessel to a seabed facility. The flexible pipe 203 may be located in a section of a flexible pipe body having connecting end fittings.

[0098] It should be understood that there are different types of risers, as is well known to those skilled in the art. Embodiments may be used with any type of riser, such as a freely suspended riser (free catenary riser), a riser constrained to some extent (buoy, chain), a fully constrained riser or enclosed in a tube (I-tube or J-tube). Figure 2 It is also illustrated how portions of the flexible pipe body may be used as flow lines 205 or jumpers.

[0099] Reference now Figure 3 , shows an example layer arrangement of a flexible pipe body 300 in cross section. In this example, the flexible pipe body 300 includes an internal pressure sheath 302. The internal pressure sheath 302 defines a flexible pipe bore. In some examples, a carcass layer (not shown) may be disposed radially inwardly of the internal pressure sheath 302 to define the pipe bore.

[0100] Tape layers (not numbered), tensile armour layers 305, 306 and an outer jacket 308 are provided in a radially outer portion of the flexible pipe body 300. Figure 1 These layers are described and therefore will not be described again for the sake of brevity.Although not illustrated, one or more insulating layers and / or abrasion resistant layers may also be included in the flexible pipe body 300 as is known in the art.

[0101] In the example shown, the flexible pipe body 300 in this example comprises a pressure armour layer 303. The pressure armour layer 303 is a helically wound pressure layer.

[0102] The pressure armour layer 303 comprises pressure armour wires. These pressure armour wires are wrapped or wound around composite tape layers 310 to form the pressure armour layer 303. Continuous pressure armour wires are wrapped around composite tape layers 310 to provide an overlap region between laterally adjacent wire windings.

[0103] The pressure armor layer 303 has an interlocking construction. Each pressure armor wire includes axially opposed edges 303a, 303b that include interengaging features as known in the art. In this manner, laterally adjacent wires of the pressure armor layer 303 are wound and interlocked in the region of the overlapping edges 303a, 303b. In this manner, the pressure armor layer 303 primarily provides hoop strength to the flexible pipe body 300.

[0104] The pressure armour layer 303 is arranged radially outside the inner pressure sheath 302 .

[0105] The flexible pipe body 300 comprises a composite tape 310 positioned radially inwardly of the pressure armour layer 303. In the example shown, the composite tape 310 is provided between the internal pressure sheath 302 and the pressure armour layer 303. The internal pressure sheath 302 is positioned radially inwardly of the composite tape.

[0106] It will be appreciated that for flexible pipe designs where interlocking pressure armour is not required so that the tensile armour layer provides both pressure reinforcement and tensile reinforcement to the pipe, then Figure 3 The pressure armour layer 303 shown in FIG. 3 may be omitted.

[0107] Additional references Figure 4 (b), the composite tape layer 310 is formed of a composite tape wrapped around the internal pressure jacket 302. The composite tape layer 310 is configured to reduce fluid penetration therethrough. In the example shown, the composite tape layer 310 includes a lay angle β relative to the axis BB of the flexible pipe body 300. In the example shown, the lay angle β relative to the axis BB of the flexible pipe body 300 is 40°. Therefore, the reduced lay angle β can result in a reduced minimum bending radius of the composite tape layer (without the risk of damage, delamination or rupture of the composite tape). Therefore, a lower minimum bending radius can provide greater flexibility to the flexible pipe body.

[0108] The composite tape layer 310 includes a composite tape wrapped or wound around the internal pressure jacket 302 to form the composite tape layer 310. Successive wrapped turns of the composite tape are wrapped or wound around the composite tape layer 310 to provide an overlap area between laterally adjacent wire windings.

[0109] The composite tape layer 310 includes an overlap region between laterally adjacent tape wrap turns. In this manner, a first tape wrap turn overlaps a laterally adjacent second tape wrap turn. Each tape wrap turn at least partially covers a laterally adjacent second tape wrap turn. Thus, the overlap can reduce fluid permeation through the composite tape layer by reducing or eliminating gaps between adjacent tape wrap turns that would otherwise provide leakage paths.

[0110] The composite tape layer 310 includes a plurality of long fibers. The plurality of long fibers in the composite tape of the composite tape layer 310 are continuous fibers, such as those disclosed herein.

[0111] The continuous fibers are arranged along the length direction of the composite tape. That is, the continuous fibers are arranged longitudinally within the composite tape. In the case where the composite tape is wrapped around the internal pressure jacket 302, the continuous fibers of the composite material have a lay angle that is substantially the same as the lay angle β of the composite tape layer 310.

[0112] Reference now Figure 5 and Figure 6 , showing Figure 3 310. The composite tape layer 310 includes a first sub-layer 310a of composite tape and a second sub-layer 310b of composite tape. The first sub-layer 310a is disposed radially outward of the second sub-layer 310b.

[0113] In the example shown, the first sub-layer 310a is consolidated with the second sub-layer 310b. In this manner, the sub-layers are substantially bonded together to form a single composite tape layer 310. Thus, the sub-layers collectively function as a composite tape layer 310 to reduce fluid penetration within the flexible pipe body 300, as described herein.

[0114] The composite tape of each of the first sublayer 310a and the second sublayer 310b has the properties of the composite tape as described herein. One or more properties of the composite tape of the first sublayer 310a may be different from one or more corresponding properties of the second sublayer 310b.

[0115] The first sub-layer 310a is wound at a first lay angle β1 relative to the axis of the flexible pipe body 300. The second sub-layer 310b is counter-wound at a second lay angle β2 relative to the axis of the flexible pipe body 300. In this manner, fluid permeation through the composite tape layers 310 is reduced by removing gaps or discontinuities between consecutive wrap turns of the composite tape sub-layers 310a, 310b that could otherwise provide leak paths.

[0116] In use, the flexible pipe body 300 including the above-described example composite tape layer 310 may be provided with suitable connectors to enable the flexible pipe body to form a flexible pipe for conveying production fluids, such as reference Figure 2 By providing as reference Figure 3 The described layer arrangement may provide a flexible pipe body having reduced undesirable fluid penetration into the pipe annulus.

[0117] Advantageously, by forming the composite tape 310 from two (or more) sub-layers 310a, 310b, more options are provided for the design and manufacture of the flexible pipe body 300. The consolidation of the sub-layers provides the ability to tailor the composite tape 310 to the specific permeation requirements of the production fluid contained within the flexible pipe body 300. For example, a first sub-layer may preferentially block permeation, i.e., transmission, of a first production fluid, and a second sub-layer may preferentially block permeation, i.e., transmission, of a second production fluid.

[0118] Reference now Figure 7, shows a schematic example of a composite tape layer 710 where the fiber density provides a low tortuosity layer. The fibers 712 of the composite tape layer 710 are impermeable such that penetration of the fluid occurs by permeating the matrix 714 in which the fibers 712 are embedded.

[0119] In the example shown, the fiber density of the composite tape 710 is substantially less than 50%. That is, the composite tape 710 has a low fiber density. In general, the low fiber density can be the result of using bundles with relatively large gaps between fiber bundles, in which the matrix material is primarily or solely present. Therefore, when a fluid permeates through the composite tape 710 via a relatively short tortuosity path, there is a low tortuosity. The fiber density is low enough that the composite tape 710 will withstand fluid penetration, particularly transmission, so that the flexible pipe body including the composite tape 710 will exceed the technical requirements of a safety pipe.

[0120] Reference now Figure 8 , shows a schematic example of a composite tape layer 810 where the fiber density provides a high tortuosity layer. The composite tape layer is composed of a polymer matrix 814 and composite fibers 812 to provide sufficient fiber density so that fluid penetration occurs via a relatively long tortuous path 819.

[0121] In the example shown, the fiber density of the composite tape layer 810 is substantially greater than 50%. Thus, when tested in accordance with ISO 2556 and ISO 15105-1 at 100°C and 8 bar pressure, the CO2 permeability coefficient is less than 50.00E-6 cm 3 ·(STP)·cm / cm 2 ·s·bar. The composite tape layer 810 thereby significantly reduces fluid penetration into the flexible pipe annulus. Thus, the likelihood of stress corrosion cracking and sulfide stress cracking is reduced.

[0122] Reference now Fig. 9 , shows another example layer arrangement of a flexible pipe body 900. This layer arrangement is similar to reference 900 except that the flexible pipe body 900 includes a sacrificial layer 912 radially adjacent to the composite tape layer 910. Figure 3 The arrangements described are essentially the same.

[0123] Also provided are tape layers, tensile armor layers 905, 906, and an outer jacket 908. These layers are substantially as described herein with reference to Figure 1 described, and therefore will not be described again for the sake of brevity.

[0124] In the example shown, the sacrificial layer 912 is disposed radially outward of the composite tape layers 910 .

[0125] Composite tape 910 is bonded to sacrificial layer 912. In the example shown, composite tape 910 and sacrificial layer 912 are at least partially bonded to each other using an adhesive. Alternatively, composite tape and sacrificial layer can be at least partially bonded to each other using melt consolidation or melt bonding, using heat and / or pressure from rollers. Melt consolidation or melt bonding is bonding without an adhesive.

[0126] The sacrificial layer 912 is thus located between the pressure armour layer 903 and the composite tape 910. This therefore prevents direct contact between the composite tape 910 and the pressure armour layer 903. The sacrificial layer 912 will protect the composite tape 910 from damage caused by contact with the pressure armour layer 903. The use of the sacrificial layer 912 prevents local strain. The use of the sacrificial layer 912 prevents the composite tape 910 from being affected by gaps within the pressure armour layer 903.

[0127] Reference now Fig.10 , shows another example layer arrangement of a flexible pipe body 1000. This layer arrangement is similar to reference 1 except that the flexible pipe body 1000 includes two sacrificial layers radially adjacent to the composite tape layer 1010. Fig. 9 The arrangements described are essentially the same.

[0128] Also provided are tape layers, tensile armor layers 1005, 1006, and an outer jacket 1008. These layers are substantially as described herein with reference Figure 1 described, and therefore will not be described again for the sake of brevity.

[0129] In the example shown, the first sacrificial layer 1012a is disposed radially outwardly of the composite tape 1010 , and the second sacrificial layer 1012b is disposed radially inwardly of the composite tape 1010 .

[0130] In this example, the flexible pipe body 1000 comprises an internal pressure sheath 1002. The internal pressure sheath 1002 defines a flexible pipe bore. Optionally, a carcass layer (not shown) may be provided radially inwardly of the internal pressure sheath 1002 to define the pipe bore.

[0131] In addition, this example includes a pressure armor layer 1003, a composite tape layer 1010, and a first sacrificial layer 1012a located between the composite tape layer and the pressure armor layer, as described above in Fig. 9 Described in .

[0132] The second sacrificial layer 1012b is disposed radially adjacent to the composite tape layer 1010. Specifically, the second sacrificial layer 1012b is disposed radially inwardly of the composite tape layer 1010. The two sacrificial layers protect the composite tape layer 1010 from damage from the pressure armor layer 1003 and from the internal pressure jacket 1002. The two sacrificial layers can also each provide a shielding effect that acts as a further anti-permeation feature to fluids from the produced fluid. The two sacrificial layers can be applied as extrudates, or as spirally wound tapes of a suitable polymer material, either consolidated or unconsolidated.

[0133] Reference now Fig.11 , shows a flow chart illustrating a method 1100 of manufacturing a flexible pipe body, such as those described herein. The method may be performed using any suitable operating options, such as mechanically or manually winding the layers.

[0134] The first step 1120 includes providing a composite tape layer for a flexible pipe body, the composite tape layer for reducing fluid penetration through the flexible pipe body. The composite tape layer thus reduces fluid penetration from production fluids conveyed within the bore of the inner pressure jacket to the pressure armor layer.

[0135] The composite tape layer is wound on the flexible pipe body. The composite tape layer is wound on the flexible pipe body at a lay angle of less than 80° relative to the axis of the flexible pipe body. In this way, the structure of the composite tape layer will be flexible. The composite tape layer will also have fewer gaps between layers to effectively reduce fluid penetration through the layers, especially through leaks, and into the pipe annulus.

[0136] Optionally, the composite tape layer may be provided on the flexible pipe body as a plurality of sub-layers overlapping each other.In this way, the first sub-layer and the second sub-layer are wound on the flexible pipe body in sequence.

[0137] The second step 1140 includes helically winding a metal armor layer radially outside the composite tape layer. In this manner, the method provides a metal armor layer to primarily provide hoop strength to the flexible pipe body.

[0138] Reference now Fig.12 , a flow chart illustrating another method 1200 of manufacturing a flexible pipe body is shown. This method is similar to the reference method except that a sacrificial layer is additionally provided. Fig.11 The method 1100 described is substantially the same. The method may be performed using any suitable operating options, such as mechanically or manually winding the layers.

[0139] The first step 1210 comprises providing an internal pressure sheath for the flexible pipe body. Suitably, the internal pressure sheath is formed by an extrusion process known in the art.

[0140] The second step 1215 includes providing a sacrificial layer radially adjacent to the composite tape. The sacrificial layer prevents direct contact between the composite tape and the internal pressure jacket. Damage to the internal pressure jacket that may be caused by such contact or by heat applied during the manufacturing consolidation process of the composite tape is prevented. The sacrificial layer also has some shielding properties, which further reduces penetration through the flexible pipe body.

[0141] The third step 1220 includes providing a composite tape layer. The composite tape is configured to reduce fluid penetration into a pressure armor layer of a flexible pipe, as described herein.

[0142] Composite tape can be as reference Fig.11 The method is described as winding as mentioned in the first step 1120. By providing the composite tape layer after the sacrificial layer, the method ensures that the composite tape layer is radially adjacent to the sacrificial layer.

[0143] The fourth step 1230 includes providing a second sacrificial layer. The second sacrificial layer is disposed radially adjacent to the composite tape layer, in this case radially outward of the composite tape layer. The second sacrificial layer protects the composite tape layer from any damage and strain that may be caused by the composite layer in contact with the metal armor layer. The second sacrificial layer may also help reduce fluid permeation through the flexible pipe body.

[0144] The fifth step 1240 includes helically winding a metal armor layer radially outside the composite tape layer. In this manner, the method provides a metal armor layer to primarily provide hoop strength to the flexible pipe body.

[0145] Reference now Fig.13 , a flow chart illustrating another method 1300 of manufacturing a flexible pipe body is shown. This method is similar to the reference method except that certain layers of the flexible pipe body are additionally bonded to radially adjacent layers. Fig.12 The method 1200 described is substantially the same.

[0146] Thus, a first step 1310 comprises providing an internal pressure sheath of the flexible tube. Optionally, the internal pressure sheath is provided on a carcass layer (not shown).

[0147] The second step 1315 includes providing a sacrificial layer radially adjacent to the composite tape layer, such as in Fig.12 The corresponding step 1240 of the method is described.

[0148] The third step 1318 includes bonding the sacrificial layer to the internal pressure jacket. In the example shown, the internal pressure jacket and the sacrificial layer are at least partially bonded to each other using an adhesive. Alternatively, the composite tape layer and the sacrificial layer can be at least partially bonded to each other using melt consolidation or melt bonding, using heat and / or pressure from rollers. Melt consolidation or melt bonding is bonding without an adhesive.

[0149] A fourth step 1320 comprises providing a composite tape layer. This may be wound onto a flexible pipe body as described with reference to the above method.

[0150] A fifth step 1328 includes bonding the composite tape layer to the sacrificial layer.

[0151] The sixth step 1330 includes providing a second sacrificial layer radially adjacent to the composite tape layer, such as in Fig.12 The corresponding step 1280 of the method is described.

[0152] The seventh step 1338 includes bonding the composite tape to the second sacrificial layer. This provides additional permeation resistance and protects the composite tape from damage caused by contact with the pressure armor layer.

[0153] An eighth step 1340 includes helically winding a metal armor layer radially outside the composite tape layer. In this manner, the method provides a metal armor to at least partially provide hoop strength to the flexible pipe body.

[0154] It will be apparent to those skilled in the art that the features described with respect to any of the above embodiments may be applied interchangeably between the different embodiments.The above embodiments are examples for illustrating the various features of the present invention.

[0155] Throughout the detailed description and claims of this specification, the words "comprise" and "contain" and their variations mean "including but not limited to", and they are not intended to (and do not) exclude other parts, additives, components, wholes or steps. Throughout the detailed description and claims of this specification, the singular encompasses the plural unless the context otherwise requires. Specifically, where the indefinite article is used, the specification should be understood to contemplate both the plural and the singular unless the context otherwise requires. It should also be understood that throughout this specification, language expressed in the general form of "X for Y" (where Y is some action, activity or step, and X is some means for performing the action, activity or step) covers means X that are specifically (but not exclusively) adjusted or arranged to perform Y.

[0156] Unless otherwise expressly stated, each feature disclosed in this specification may be replaced by an alternative feature used for the same, equivalent or similar purpose. Therefore, unless otherwise expressly stated, each feature disclosed is only an example of a general series of equivalent or similar features.

[0157] The features, structures, entities, characteristics, compounds, chemical moieties or groups described in conjunction with a particular aspect, embodiment or example of the invention should be understood to be applicable to any other aspect, embodiment or example described herein, unless incompatible therewith. All features disclosed in this specification (including any attached claims, abstract and drawings) and / or all steps of any method or process so disclosed may be combined in any combination, except that at least some of such features and / or steps are mutually exclusive combinations. The present invention is not limited to the details of any foregoing embodiments. The present invention extends to any novel feature structure or any novel combination of the features disclosed in this specification (including any attached claims, abstract and drawings), or to any novel step or any novel combination of the steps of any method or process so disclosed.

[0158] The reader's attention is directed to all papers and documents filed in connection with this patent application concurrently with or before this specification and which disclose public inspection of the present specification, and the contents of all these papers and documents are incorporated herein by reference.

Claims

1. A flexible pipe body for conveying produced fluid, the flexible pipe body comprising: A spirally wound metal armor layer; and a composite tape layer, the composite tape layer being used to reduce fluid penetration of the produced fluid into the pipe annulus, wherein the composite tape layer comprises a plurality of fibers; Wherein the composite tape layer is positioned radially inwardly of the helically wound metal armour layer.

2. The flexible pipe body of claim 1 further comprising an internal pressure sheath, wherein the internal pressure sheath is positioned radially inwardly of the composite tape layers.

3. The flexible pipe body of claim 1 further comprising an internal pressure sheath, wherein the internal pressure sheath is positioned radially outwardly of the composite tape layers.

4. The flexible pipe body according to any one of claims 1 to 3, wherein the flexible pipe body comprises at least one sacrificial layer radially adjacent the composite tape layer.

5. The flexible pipe body of claim 4, wherein the flexible pipe body comprises two sacrificial layers, each sacrificial layer being radially adjacent to the composite tape layer such that the composite tape layer is arranged between the two sacrificial layers.

6. A flexible pipe body as claimed in any preceding claim, wherein the plurality of fibres in the composite tape layers are continuous fibres.

7. The flexible pipe body of claim 6, wherein the continuous fibres are aligned along the length of the composite tape.

8. A flexible pipe body according to any preceding claim, wherein the plurality of fibres in the composite tape layers comprise carbon fibres, glass fibres, basalt fibres, drawn polymer fibres, metal wires or any combination thereof.

9. A flexible pipe body as claimed in any preceding claim wherein the composite tapes of the composite tape layer comprise a lay angle of less than 80° relative to the axis of the flexible pipe body.

10. The flexible pipe body according to any preceding claim, wherein the layer of composite tape comprises a plurality of sub-layers of composite tape.

11. The flexible pipe body according to any preceding claim, wherein the composite tape layer comprises an overlap region between adjacent composite tape wrap turns such that each composite tape wrap turn at least partially covers a laterally adjacent composite tape wrap turn.

12. The flexible pipe body of claim 11, wherein the composite tape layer is consolidated with adjacent composite tape wrap turns and / or sub-layers of composite tape such that the adjacent tapes are at least partially bonded together.

13. The flexible pipe body according to any one of claims 10 to 12, wherein the plurality of sub-layers comprise different lay angles to each other.

14. The flexible pipe body according to any preceding claim, wherein the thickness of the composite tape layers is less than 5mm.

15. A flexible pipe body according to any preceding claim, wherein the composite tape layer comprises a low permeability polymer matrix having a CO2 permeability coefficient of less than 50.00E-6 cm 3 ·(STP)·cm / cm 2 ·s·bar.

16. A flexible pipe body as claimed in any preceding claim, wherein the composite tape layer is a high tortuosity layer due to a fibre density in the composite tapes being at least 50% of the cross-sectional area of ​​the composite tapes.

17. A flexible pipe body as claimed in any preceding claim, wherein the composite tape layers are bonded to one or more of the sacrificial layers.

18. A flexible pipe body as claimed in any one of claims 2 to 17, wherein the internal pressure sheath is bonded to one of the composite tape layers or the sacrificial layer.

19. A flexible pipe body according to any preceding claim, wherein the pipe further comprises one or more layers arranged radially outwardly of the helically wound metal armour layer, the one or more layers being selected from: at least one tensile armor layer; Anti-birdcage effect belt layer; Insulation layer; External pressure sheath; and External wear or abrasion layer.

20. A flexible riser comprising a flexible pipe body according to any preceding claim.

21. A method of manufacturing a flexible pipe body, the method comprising: providing a composite tape layer for reducing fluid penetration into a metal armor layer; as well as The metal armor layer is spirally wound on the radially outer side of the composite tape layer.

22. The method of claim 21 further comprising the step of extruding an internal pressure sheath, wherein the internal pressure sheath is positioned radially inwardly of the composite tape layers.

23. A method according to claim 21 or 22, further comprising the step of providing at least one sacrificial layer radially adjacent to the composite tape layer.

24. The method of claim 23, further comprising the step of bonding the composite tape layer to one or more of the sacrificial layers.

25. A method according to any one of claims 22 to 24, further comprising the step of bonding the internal pressure sheath to the composite tape layer.

26. A method according to any one of claims 21 to 25, wherein providing the layer of composite tape comprises providing a plurality of sub-layers of composite tape.

27. A method according to any one of claims 21 to 26, wherein providing the composite tape layer comprises winding the composite tape onto the flexible pipe body at a lay angle of less than 80° relative to the pipe axis.

28. The method of any one of claims 21 to 27, wherein providing the composite tape layer comprises winding the composite tape with an overlap area between laterally adjacent composite tape wrap turns, such that each composite tape wrap turn at least partially covers the laterally adjacent composite tape wrap turns.

29. The method of claim 28, further comprising the step of consolidating the composite tape layer with laterally adjacent composite tape wrap turns and / or sub-layers of composite tape using heat and / or pressure such that the adjacent tapes are at least partially bonded together.

Images