End joint fitting for marine composite flexible pipe

Abstract

The present invention discloses an end joint fitting for a marine composite flexible pipe, comprising: an inner shell having a stepped cross-section and including first to third parallel vertical arms; an outer shell having an inverted F-shaped cross-section and including a fourth vertical arm and first to third parallel horizontal arms; the outer shell being arranged on the inner shell, defining a first cavity therebetween; a termination ring being arranged outside the third vertical arm of the inner shell, the skeleton layer, inner lining layer, compressive armor layer, insulating layer, and first wear-resistant layer of the marine composite flexible pipe terminating at the termination ring, the second wear-resistant layer and outer covering layer terminating at the bottom end of the third horizontal arm, and the end of the tensile armor layer extending into and being terminated within the cavity. The present invention, when adapted and installed with the marine composite flexible pipe in a harsh marine environment, can meet the requirements for sealing and molding polymer materials, as well as improving the pipe's fatigue resistance, thermal insulation performance, anti-static performance, corrosion resistance, leakage annulus monitoring, and optical fiber detection performance.

Description

Technical Field

[0001] The present invention relates to the technical field of marine oil and gas resource development, and in particular to an end joint fitting of a marine composite flexible pipeline. Background Art

[0002] Energy is the foundation of human life and a crucial component of modern economic development. It is also the lifeblood of national operations. The development of oil and gas energy is evolving from terrestrial oil and gas to offshore oil and gas. Oceans account for approximately 70% of Earth's total surface area. As people's lives become more refined, their high-quality needs are no longer limited to shallow-water oil and gas resources. Advances in science and technology are driving research into more complex and advanced areas, including offshore oil and gas development, and gradually into deepwater and ultra-deepwater exploration. Global offshore oil resources account for one-third of the world's total. According to statistics, global offshore oil reserves are estimated to be over 100 billion tons, of which approximately 38 billion tons are proven reserves. Energy is a constant international concern. Therefore, facing the enormous energy demands of countries around the world, the oceans, rich in oil and gas resources, are gaining increasing attention.

[0003] Marine composite flexible pipelines serve as the connecting link between offshore platforms and subsea oilfields, forming a crucial component of deep-sea oil and gas production systems. They carry out crucial tasks such as transporting oil and gas and injecting water, earning them the nickname "the lifeline of offshore oil." Compared to other flexible pipes, marine composite flexible pipelines offer advantages such as ease of installation, reusability, robustness against complex marine environments, and a wide range of applications. As living standards improve, offshore oil and gas production is increasingly being channeled into the deep sea, and flexible hoses are expected to find increasing application.

[0004] At present, the end joints of traditional marine composite flexible pipes have the following problems in practical applications:

[0005] ① Composite materials such as epoxy resin are usually poured into the cavity of traditional end joints to bond and fix the tensile armor layer steel wire of the flexible hose. However, as the service time of the equipment increases, epoxy resin may age and crack, which seriously affects its adhesion performance and easily leads to separation between the marine composite flexible pipe and the end joint, causing safety accidents.

[0006] ② Due to the positional structure of the traditional end joint cavity, the steel wire of the flexible pipe tensile armor layer needs to be bent radially outward during installation. This will cause a certain amount of residual stress at the bend, which is prone to fatigue fracture under the action of marine cyclic loads, seriously affecting the service life of the pipeline.

[0007] ③ Traditional end joints usually do not have conductive protective devices. The metal layer in the marine composite flexible pipeline is prone to accumulate charge and produce metal polarization, which seriously reduces the material strength of the metal layer and brings great risks to the operation of the marine composite flexible pipeline.

[0008] ④ The oil and gas media transported by marine composite flexible pipelines usually contain substances such as water vapor, carbon dioxide and sulfur dioxide. Some of them will penetrate from the inner lining layer into the annular space where the tensile armor layer is located, causing corrosion problems of the tensile armor layer, seriously affecting the safe operation of the marine composite flexible pipeline system.

[0009] ⑤ Since traditional end joints have no monitoring function for the temperature and pressure of the conveying medium, the recent thermal buckling phenomenon of marine composite flexible pipelines has caused great hidden dangers in the operation of marine composite flexible pipelines. Summary of the Invention

[0010] The present invention aims to address at least one of the technical problems existing in the prior art. To this end, the present invention provides an end fitting for a marine composite flexible pipeline. This fitting, when adapted and installed with the marine composite flexible pipeline in a harsh marine environment, meets the requirements for polymer material sealing and molding, as well as improving pipeline fatigue resistance, thermal insulation, antistatic properties, corrosion resistance, leakage annulus monitoring, and fiber optic detection.

[0011] To achieve the above object, the present invention adopts the following technical solutions:

[0012] An end joint fitting for a marine composite flexible pipe is suitable for terminating the marine composite flexible pipe and connecting it to an offshore floating platform. The end joint fitting comprises: an inner shell, which is an annular structure, and the cross section of the outer portion of the marine composite flexible pipe is in a step-like shape, including a first vertical arm, a second vertical arm, and a third vertical arm arranged in parallel along the axial direction of the marine composite flexible pipe; an outer shell, which is also an annular structure, and the cross section of the outer portion of the marine composite flexible pipe is in an inverted "F" shape, including a fourth vertical arm and a first horizontal arm, a second horizontal arm, and a third horizontal arm arranged in parallel along the radial direction of the marine composite flexible pipe, wherein the second horizontal arm, the third horizontal arm, and the fourth vertical arm are integrally connected to form a cross section of a "down"-shaped structure, and the first horizontal arm is arranged on the second horizontal arm; the outer shell is arranged Above the second vertical arm and the third vertical arm of the inner shell and fastened therewith, a first cavity is defined between the second vertical arm and the third vertical arm of the inner shell and the second horizontal arm and the third horizontal arm of the outer shell; a termination ring is arranged adjacent to the outside of the third vertical arm of the inner shell, the skeleton layer, the lining layer, the pressure armor layer, the insulation layer and the first wear-resistant layer of the marine composite flexible pipe terminate at the termination ring, the second wear-resistant layer of the marine composite flexible pipe terminates at the bottom of the third horizontal arm, the outer protective layer of the marine composite flexible pipe extends into and terminates in the second cavity defined between the second horizontal arm, the third horizontal arm and the fourth vertical arm of the outer shell, the first tensile armor layer and the second tensile armor layer ends of the marine composite flexible pipe extend into the first cavity and are terminated in the first cavity.

[0013] Preferably, radially penetrating grease injection holes are formed on the first cross arm and the second cross arm of the outer shell, and the grease injection holes are communicated with the first cavity. Epoxy resin is injected into the first cavity from the grease injection holes for potting and filling, so as to fix the first tensile armor layer and the second tensile armor layer in the first cavity.

[0014] Preferably, a first fixing hole and a second fixing hole are formed on the top and outer sides of the second vertical arm, respectively; and / or a third fixing hole is formed on the first horizontal arm and radially penetrates therethrough, and a fourth fixing hole and a fifth fixing hole are formed on the first horizontal arm and the fourth vertical arm and are connected in the axial direction.

[0015] The first horizontal arm of the outer shell and the second vertical arm of the inner shell are fixedly connected by a first fixing piece passing through the third fixing hole and the first fixing hole, and the first horizontal arm of the outer shell and the fourth vertical arm are fixedly connected by a second fixing piece passing through the fourth fixing hole and the fifth fixing hole.

[0016] Preferably, when the ends of the first tensile armor layer and the second tensile armor layer extend into the first cavity, the ends of the two are bent toward the second vertical arm of the inner shell in a U-shape and fixedly connected to the second fixing hole on the second vertical arm using a third fixing member.

[0017] Preferably, an optical fiber channel is provided in the second cross arm and the first cross arm of the outer shell, and the optical fiber channel terminates in the optical fiber end cavity in the first cross arm. The optical fiber is spirally wound and arranged between the second tensile armor layer and the outer protective layer of the marine composite flexible pipe. The optical fiber end extends into the optical fiber end cavity after passing through the optical fiber channel, and an external optical fiber monitoring device is connected thereto to perform effective real-time dynamic monitoring of the end joint accessories and the operation process of the marine composite flexible pipe; and / or, the optical fiber includes at least one optical fiber temperature sensor, at least one optical fiber voltage sensor and / or at least one optical fiber pressure sensor.

[0018] Preferably, a conductive area is installed in the outer shell, the conductive area is located at the first cross arm, the second cross arm and the third cross arm of the outer shell, and the conductive area is grounded through a wire, an insulating tape is arranged around the conductive area and has a direct electrical connection with the second tensile armor layer, and has an indirect electrical connection with the first tensile armor layer through the third fixing piece.

[0019] Preferably, an annular space detection area is installed in the outer shell, and the annular space detection area includes an annular space channel arranged at the terminal end of the outer protective layer and terminates at the annular space end cavity of the first cross arm of the outer shell. The annular space end cavity can be externally connected to an annular space detection device for detecting leaked gas.

[0020] Preferably: a first sealing ring is arranged between the end of the skeleton layer fixed by the clamping plate and the inner lining layer for sealing, and the first sealing ring is pressed by the termination ring; the end of the pressure-resistant armor layer extends into the termination ring, and the insulating layer terminates inside the termination ring, and then the second sealing ring fills the gap in the termination ring and presses the end of the pressure-resistant armor layer and the end of the insulating layer to fix and prevent leakage; a third sealing ring is arranged on the contact surface of the first tensile armor layer and the second tensile armor layer extending into the first cavity, and the third sealing ring presses the end of the second wear-resistant layer to prevent leakage of the second wear-resistant layer; a fourth sealing ring is arranged in the second cavity between the second horizontal arm, the third horizontal arm and the fourth vertical arm of the outer shell, and the outer shell presses the fourth sealing ring to form a sealed environment for the outer protective layer and compress the optical fiber.

[0021] Preferably, an "arch bridge" type contact surface is formed between the first cross arm and the second cross arm of the outer shell.

[0022] Preferably, a tungsten carbide anti-corrosion coating is applied to the contact points between the marine composite flexible pipeline and the transported medium or the possible leakage points.

[0023] The present invention has the following advantages due to the adoption of the above technical solution:

[0024] 1. When the end joint fitting provided by the present invention is connected to the marine composite flexible pipe, it avoids the fatigue problem caused by the bending and expansion of the end of the tensile armor layer due to the radial outer side of the pipe, avoids the residual stress problem caused by bending the tensile armor layer during the installation of the traditional end joint, avoids the stress concentration phenomenon at the bending point of the tensile armor layer, and improves the service life of the flexible pipe at the joint.

[0025] 2. When the end joint fitting provided by the present invention is connected to the marine composite flexible pipe, the end of the tensile armor layer extends straight into the cavity, and at the same time makes a U-shaped bend toward the side of the second vertical arm of the inner shell and uses the first fixing member to form a fixed connection with the second vertical arm of the inner shell. This not only increases the contact area between the tensile armor layer and the epoxy resin, but also avoids the failure of the tensile armor layer and the epoxy resin from separating, and also improves the tensile performance of the end joint, effectively improving the safety of the equipment during operation.

[0026] 3. The present invention arranges optical fibers in a spiral winding between the second tensile armor layer and the outer protective layer of the marine composite flexible pipe, and at the same time provides an optical fiber channel in the outer shell. The optical fibers are connected and arranged outward from the marine composite flexible pipe, and terminate in the optical fiber end cavity of the outer shell, where they are connected to an external optical fiber monitoring device. The optical fiber monitoring device can effectively and dynamically monitor the operation process of the end joint accessories and the marine composite flexible pipe in real time.

[0027] 4. The end joint fitting provided by the present invention is installed with a conductive area, an insulating tape is arranged around the conductive area and has a direct electrical connection with the second tensile armor layer, and has an indirect electrical connection with the first tensile armor layer through a third fixing piece. When the tensile armor layer accumulates too many electrons, the electrons can be released through the grounding wire to prevent the material strength from being reduced due to the electrical polarization of the material.

[0028] 5. The end joint fitting provided by the present invention is equipped with an annular space detection area. The annular space detection area is provided with an annular space channel at the terminal end of the outer protective layer and terminates at the annular space end cavity of the first cross arm of the outer shell. The leaked gas can be regularly detected through the annular space detection device.

[0029] 6. In the end joint fitting provided by the present invention, the end of the pressure-resistant armor layer extends into the termination ring, and the insulating layer terminates inside the termination ring. The second sealing ring fills the gap in the termination ring and presses the end of the pressure-resistant armor layer and the end of the insulating layer to fix them and prevent leakage. The structure composed of the termination ring, the second sealing ring, the end of the pressure-resistant armor layer and the end of the insulating layer improves the stability of the end of the pressure-resistant armor layer and further improves its sealing effect.

[0030] 7. In the end joint fittings provided by the present invention, a tungsten carbide anti-corrosion coating is applied to the contact points of the conveying medium or the possible leakage points. For example, the ends of the skeleton layer and the ends of the pressure-resistant armor layer can be coated with a tungsten carbide anti-corrosion coating, which is beneficial to improving the corrosion resistance of the end joints. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiment below. The accompanying drawings are for illustration purposes only and are not to be considered as limiting the present invention. Throughout the drawings, the same reference numerals are used to denote the same components. In the drawings:

[0032] Figure 1 A diagram showing a state in which an end joint fitting provided by an embodiment of the present invention is connected to a marine composite flexible pipe;

[0033] Figure 2 A schematic diagram of a partial structure of an inner shell provided in one embodiment of the present invention;

[0034] Figure 3 A schematic diagram of a partial structure of an outer shell provided in one embodiment of the present invention;

[0035] Figure 4 A schematic cross-sectional view of the end joint fitting provided by one embodiment of the present invention being connected to a marine composite flexible pipe;

[0036] Figure 5 This is a structural schematic diagram of a marine composite flexible pipeline provided by one embodiment of the present invention. DETAILED DESCRIPTION

[0037] To make the objectives, technical solutions, and advantages of the present invention more apparent, specific embodiments of the present invention are further described below with reference to the accompanying drawings. Although exemplary embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments described herein. Rather, these embodiments are provided to enable a more thorough understanding of the present invention and to fully convey the scope of the present invention to those skilled in the art.

[0038] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0039] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature identified as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "plurality" means more than two, unless otherwise specifically defined.

[0040] In the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," "connect," "fixed," etc. should be understood broadly. For example, they may refer to fixed connection, detachable connection, or integration; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0041] In the present invention, unless otherwise expressly specified or limited, when a first feature is "above" or "below" a second feature, it may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediary. Furthermore, when a first feature is "above," "above," or "above" a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is "below," "below," or "below" a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0042] In the description of this specification, the reference terms "one embodiment," "some embodiments," "example," "specific example," or "some examples" mean that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and features of different embodiments or examples without contradiction.

[0043] The end joint fitting for a marine composite flexible pipe provided by the present invention comprises: an inner shell having a step-like cross-section and including first to third vertical arms arranged in parallel; an outer shell having a cross-section shaped like an inverted "F" and including a fourth vertical arm and first to third horizontal arms arranged in parallel; the outer shell being arranged on the inner shell, and defining a first cavity therebetween; a termination ring being arranged outside the third vertical arm of the inner shell, the skeleton layer, inner lining layer, compressive armor layer, insulating layer, and first wear-resistant layer of the marine composite flexible pipe terminating at the termination ring, the second wear-resistant layer and outer covering layer terminating at the bottom end of the third horizontal arm, and the end of the tensile armor layer extending into the cavity and being terminated therein. The present invention, when adapted and installed with a marine composite flexible pipe in a harsh marine environment, can meet the requirements for sealing and molding polymer materials, and improve the pipe's fatigue resistance, thermal insulation performance, anti-static performance, corrosion resistance, leakage annulus monitoring, and optical fiber detection performance.

[0044] The end joint fitting of the marine composite flexible pipe provided by the embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

[0045] See also Figure 1 The end joint fitting of the marine composite flexible pipe provided by the present invention mainly comprises an inner shell 1 and an outer shell 2, which are suitable for terminating the marine composite flexible pipe 3 and connecting it to an offshore floating platform. The marine composite flexible pipe 3 includes, from the inside to the outside, but is not limited to, a skeleton layer 17, an inner lining layer 18, a compressive armor layer 19, an insulating layer 20, a first wear-resistant layer 21, a first tensile armor layer 22, a second wear-resistant layer 23, a second tensile armor layer 24, and an outer protective layer 25 (see FIG. 2 ). Figure 5 ).

[0046] See also Figure 2The inner shell 1 is an annular structure, and its cross-section located on the outer side of the marine composite flexible pipe 3 is stepped, including a first vertical arm 4, a second vertical arm 5 and a third vertical arm 6 arranged parallel to the axial direction of the marine composite flexible pipe 3, wherein a first threaded hole 7 is formed on the first vertical arm 4, and a first fixing hole 8 and a second fixing hole 9 are formed on the top and outer side of the second vertical arm 5 respectively.

[0047] See also Figure 3 The outer shell 2 is also an annular structure, and its cross-section located on the outer side of the marine composite flexible pipe 3 is in an inverted "F" shape, including a fourth vertical arm 13 and a first horizontal arm 10, a second horizontal arm 11 and a third horizontal arm 12 arranged radially and parallel to the marine composite flexible pipe 3, wherein the second horizontal arm 11, the third horizontal arm 12 and the fourth vertical arm 13 are integrally connected to form a cross-section with a "downward"-shaped structure, and the first horizontal arm 10 is arranged on the second horizontal arm 11; at the same time, a third fixing hole 14 is formed on the first horizontal arm 10 and radially penetrates therethrough, and a fourth fixing hole 16 and a fifth fixing hole 16' are formed on the first horizontal arm 10 and the fourth vertical arm 13 and are connected in the axial direction.

[0048] See also Figure 4 The outer shell 2 is arranged above the second vertical arm 5 and the third vertical arm 6 of the inner shell 1. The first horizontal arm 10 of the outer shell 2 is fixedly connected to the second vertical arm 5 of the inner shell 1 by a first fixing member 33 passing through the third fixing hole 14 and the first fixing hole 8. The first horizontal arm 10 of the outer shell 2 is fixedly connected to the fourth vertical arm 13 by a second fixing member 26 passing through the fourth fixing hole 16 and the fifth fixing hole 16'. The second vertical arm 5 and the third vertical arm 6 of the inner shell 1 and the second horizontal arm 11 and the third horizontal arm 12 of the outer shell 2 jointly define a first cavity 39; A termination ring 38 is arranged adjacent to the outer side of the third vertical arm 6 of the inner shell 1. The skeleton layer 17, the inner lining layer 18, the pressure armor layer 19, the insulation layer 20 and the first wear-resistant layer 21 of the marine composite flexible pipe 3 are terminated at the termination ring 38. The second wear-resistant layer 23 is terminated at the bottom of the third transverse arm 12. The outer protective layer 25 extends into and terminates in the second cavity defined between the second transverse arm 11, the third transverse arm 12 and the fourth vertical arm 13 of the outer shell 2. The ends of the first tensile armor layer 22 and the second tensile armor layer 24 extend into the first cavity 39 and are terminated in the first cavity 39.

[0049] In the above-mentioned embodiment, preferably, a grease injection hole 15 is formed on the first cross arm 10 and the second cross arm 11 of the outer shell, and the grease injection hole 15 is connected to the first cavity 39. Epoxy resin is injected into the first cavity 39 from the grease injection hole 15 for potting and filling, which is used to fix the first tensile armor layer 22 and the second tensile armor layer 24 in the first cavity 39, thereby improving the tensile performance of the end joint accessories.

[0050] In the above embodiment, preferably, when the ends of the first tensile armor layer 22 and the second tensile armor layer 24 of the marine composite flexible pipe 3 extend into the first cavity 39, they are bent in opposite U-shapes toward the second vertical arm 5 of the inner casing 1 and fixedly connected to the second fixing hole 9 on the second vertical arm 5 using the third fixing member 42. This arrangement not only increases the contact area between the tensile armor layer and the epoxy resin, preventing the tensile armor layer from separating from the epoxy resin and failing, but also improves the tensile performance of the end joint fittings, effectively enhancing the safety of the equipment during operation.

[0051] In the above embodiment, preferably, an optical fiber channel is provided in the second cross arm 11 and the first cross arm 10 of the outer shell 2, and the optical fiber channel terminates in the optical fiber end cavity 29 in the first cross arm 10, and the optical fiber 30 is spirally wound and arranged between the second tensile armor layer 24 and the outer protective layer 25 of the marine composite flexible pipe 3 (see Figure 5 The end of the optical fiber 30 passes through the optical fiber channel and extends into the optical fiber end cavity 29, where it is connected to an external optical fiber monitoring device to effectively and dynamically monitor the operation of the end connector and the marine composite flexible pipeline 3 in real time. Furthermore, / or alternatively, the optical fiber 30 includes at least one optical fiber temperature sensor, at least one optical fiber voltage sensor, and / or at least one optical fiber pressure sensor.

[0052] In the above embodiment, preferably, a conductive area 43 is installed in the outer shell 2. The conductive area 43 is located at the first cross arm 10, the second cross arm 11, and the third cross arm 12 of the outer shell 2. The conductive area 43 is grounded via a wire 32. An insulating tape 31 is arranged around the conductive area 43 and is directly electrically connected to the second tensile armor layer 24. It is indirectly electrically connected to the first tensile armor layer 22 via a third fixing member 42. Through the above arrangement, when the first tensile armor layer 22 and / or the second tensile armor layer 24 accumulate excessive electrons, the electrons can be released via the wire 32, thereby preventing the material from being polarized and causing a decrease in material strength.

[0053] In the above embodiment, preferably, an annular space detection area 27 is installed in the outer shell 2. The annular space detection area 27 includes an annular space channel arranged at the terminal end of the outer protective layer 25, and terminates at the annular space end cavity of the first cross arm 10 of the outer shell 2. The annular space end cavity can be externally connected to an annular space detection device, thereby detecting leaked gas.

[0054] In the above embodiment, preferably, a first sealing ring 35 is arranged between the end of the skeleton layer 17 fixed by the clamping plate 44 and the inner lining layer 18 for sealing, and the first sealing ring 35 is pressed by the termination ring 38; the end of the pressure-resistant armor layer 19 extends into the termination ring 38, and the insulating layer 20 terminates inside the termination ring 38, and then the second sealing ring 36 fills the gap of the termination ring 38 and presses the end of the pressure-resistant armor layer 19 and the end of the insulating layer 20 to fix and prevent leakage; a third sealing ring 37 is arranged on the contact surface of the first tensile armor layer 22 and the second tensile armor layer 24 extending into the first cavity 39, and the third sealing ring 37 presses the end of the second wear-resistant layer 23 to prevent the second wear-resistant layer 23 from leaking; a fourth sealing ring 28 is arranged in the second cavity between the second horizontal arm 11, the third horizontal arm 12 and the fourth vertical arm 13 of the outer shell 2, and the outer shell 2 presses the fourth sealing ring 28 to form a sealed environment for the outer protective layer 25 and compress the optical fiber 30.

[0055] In the above-mentioned embodiment, preferably, an "arch bridge" type contact surface is formed between the first cross arm 10 and the second cross arm 11 of the outer shell 2. After the radial displacement of the first cross arm 10 and the second cross arm 11 constrained by the second fixing member 26, the "arch bridge" type contact surface can provide a certain tensile strength for the end joint accessories.

[0056] In the above embodiment, preferably, a tungsten carbide anti-corrosion coating is applied to the contact points between the marine composite flexible pipe 3 and the conveying medium or the possible leakage points. For example, a tungsten carbide anti-corrosion coating can be applied to the ends 40 of the skeleton layer and the ends 41 of the pressure-resistant armor layer, which is beneficial to improving the corrosion resistance of the end joint accessories.

[0057] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. An end joint fitting for a marine composite flexible pipe, suitable for terminating a marine composite flexible pipe and connecting it to an offshore floating platform, characterized in that: The end fittings include: The inner casing is an annular structure, the cross section of which is located outside the marine composite flexible pipe and is stepped, and includes a first vertical arm, a second vertical arm and a third vertical arm arranged in parallel along the axial direction of the marine composite flexible pipe; The outer shell is also an annular structure, and its cross section at the outer side of the marine composite flexible pipe is similar to an inverted "F" shape, including a fourth vertical arm and a first horizontal arm, a second horizontal arm and a third horizontal arm arranged in parallel along the radial direction of the marine composite flexible pipe, wherein the second horizontal arm, the third horizontal arm and the fourth vertical arm are integrally connected to form a cross section similar to an "F" structure, and the first horizontal arm is arranged on the second horizontal arm; The outer shell is arranged above the second vertical arm and the third vertical arm of the inner shell and is fastened thereto, and a first cavity is defined between the second vertical arm and the third vertical arm of the inner shell and the second horizontal arm and the third horizontal arm of the outer shell; a termination ring is arranged adjacent to the outside of the third vertical arm of the inner shell, and the skeleton layer, lining layer, pressure armor layer, insulation layer and first wear-resistant layer of the marine composite flexible pipe terminate at the termination ring, and the second wear-resistant layer of the marine composite flexible pipe terminates at the bottom of the third horizontal arm, and the outer protective layer of the marine composite flexible pipe extends into and terminates in the second cavity defined between the second horizontal arm, the third horizontal arm and the fourth vertical arm of the outer shell, and the ends of the first tensile armor layer and the second tensile armor layer of the marine composite flexible pipe extend into the first cavity and are terminated in the first cavity.

2. The end fitting according to claim 1, wherein: Grease injection holes are formed on the first cross arm and the second cross arm of the outer shell and are connected to the first cavity. Epoxy resin is injected into the first cavity from the grease injection holes for potting and filling, so as to fix the first tensile armor layer and the second tensile armor layer in the first cavity.

3. The end fitting according to claim 1, wherein: A first fixing hole and a second fixing hole are formed on the top and outer sides of the second vertical arm, respectively; and / or a third fixing hole is formed on the first horizontal arm and passes through in the radial direction, and a fourth fixing hole and a fifth fixing hole are formed on the first horizontal arm and the fourth vertical arm and are connected in the axial direction; The first horizontal arm of the outer shell and the second vertical arm of the inner shell are fixedly connected by a first fixing piece passing through the third fixing hole and the first fixing hole, and the first horizontal arm of the outer shell and the fourth vertical arm are fixedly connected by a second fixing piece passing through the fourth fixing hole and the fifth fixing hole.

4. The end fitting according to claim 3, wherein: When the ends of the first tensile armor layer and the second tensile armor layer extend into the first cavity, the ends of the two are bent toward the second vertical arm of the inner shell in a U-shape and fixedly connected to the second fixing hole on the second vertical arm using a third fixing piece.

5. The end fitting according to claim 1, wherein: An optical fiber channel is provided in the second cross arm and the first cross arm of the outer shell, and the optical fiber channel terminates in the optical fiber end cavity in the first cross arm. The optical fiber is spirally wound and arranged between the second tensile armor layer and the outer protective layer of the marine composite flexible pipe. The optical fiber end extends into the optical fiber end cavity after passing through the optical fiber channel and is externally connected to an optical fiber monitoring device to perform effective real-time dynamic monitoring of the operation process of the end joint fitting and the marine composite flexible pipe; and / or, The optical fiber includes at least one optical fiber temperature sensor, at least one optical fiber voltage sensor and / or at least one optical fiber pressure sensor.

6. The end fitting according to claim 4, wherein: A conductive area is installed in the outer shell, and the conductive area is located at the first cross arm, the second cross arm and the third cross arm of the outer shell, and the conductive area is grounded through a wire. An insulating tape is arranged around the conductive area and has a direct electrical connection with the second tensile armor layer, and has an indirect electrical connection with the first tensile armor layer through the third fixing member.

7. The end fitting according to claim 1, wherein: An annular space detection area is installed in the outer shell. The annular space detection area includes an annular space channel arranged at the terminal end of the outer protective layer and terminates at the annular space end cavity of the first cross arm of the outer shell. The annular space end cavity can be externally connected to an annular space detection device for detecting leaked gas.

8. The end fitting according to claim 5, wherein: A first sealing ring is arranged between the end of the skeleton layer fixed by the clamping plate and the inner lining layer for sealing, and the first sealing ring is pressed by the termination ring; the end of the pressure-resistant armor layer extends into the termination ring, and the insulating layer terminates inside the termination ring, and then the second sealing ring fills the gap of the termination ring and presses the end of the pressure-resistant armor layer and the end of the insulating layer to fix and prevent leakage; a third sealing ring is arranged on the contact surface of the first tensile armor layer and the second tensile armor layer extending into the first cavity, and the third sealing ring presses the end of the second wear-resistant layer to prevent leakage of the second wear-resistant layer; a fourth sealing ring is arranged in the second cavity between the second horizontal arm, the third horizontal arm and the fourth vertical arm of the outer shell, and the outer shell presses the fourth sealing ring to form a sealed environment for the outer protective layer and compress the optical fiber.

9. The end fitting according to any one of claims 1 to 8, characterized in that An "arch bridge" type contact surface is formed between the first transverse arm and the second transverse arm of the outer shell.

10. The end fitting according to any one of claims 1 to 8, characterized in that A tungsten carbide anti-corrosion coating is applied to the contact points between the marine composite flexible pipeline and the transported medium or to the possible leakage points.

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