Dynamic-static transition umbilical cable and forming method therefor

Abstract

A dynamic-static transition umbilical cable, comprising a dynamic section and a static section, wherein one end of the dynamic section is connected to the static section, and a transition section is p

Description

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[0001] The present invention belongs to the field of umbilical cables, and in particular, to a dynamic-static transition umbilical cable and forming method therefor. BACKGROUND

[0002] The umbilical cable is subjected to dynamic loads and cyclic fatigue loads during operation. By calculating the strength and fatigue strength of each section of the cable, a complete umbilical cable can be divided into dynamic sections and static section, where the dynamic sections require higher strength and the static section require lower strength. However, in engineering applications of umbilical cables, to ensure safety, the entire cable is usually designed according to the strength requirements of the dynamic sections. This results in the static section having excessive strength, leading to increased production costs.

[0003] In patents No. CN210720828U and CN211351680U, to reduce production costs, the dynamic and static section are designed separately and then connected via a junction box. While this approach lowers production costs for the static section, it compromises the overall integrity of the cable at the junction box area, reduces connection strength, and increases susceptibility to external interference. Moreover, in the dynamic section, steel strands used to enhance strength lose their force-transmission effectiveness at the ends due to the absence of connections. As a result, the force is contained within the dynamic section and cannot be transferred to the static section, requiring the dynamic section to be designed with even higher strength. SUMMARY

[0004] To address the aforementioned shortcomings, the present invention proposes a dynamicstatic transition umbilical cable and a forming method therefor that ensures the integrity of the umbilical cable while enabling the cable to be formed in segments with a dynamic section and a static section.

[0005] The technical solution adopted by the present invention to solve the above problems provides a dynamic-static transition umbilical cable, comprising a dynamic section and a static section, one end of the dynamic section is connected to the static section, and the other end is connected to a floating platform. A transition section is provided between the dynamic section and the static section. The umbilical cable includes a plurality of cores arranged within an inner sheath, the cores including a steel tube. The steel tube is fixedly connected with one ferrule. Steel strands are arranged on a side of the ferrule close to the dynamic section, and a filling material is arranged on a side of the ferrule close to the static section.

[0006] Compared with existing technologies, the advantages of this invention are as follows: by utilizing the high-strength steel tube that extends through the entire umbilical cable, the section with the steel strands on the steel tube is designated as the dynamic section, while the section without the steel strands is designated as the static section. During the integration and bundling of the cores in umbilical cable, when transitioning from the static section to the dynamic section, the steel tube is converted from a structure without twisted steel strands to a structure with twisted steel strands; conversely, when transitioning from the dynamic section to the static section, the steel tube is converted from a structure with twisted steel strands to a structure without twisted steel strands. This ensures the integrity of the umbilical cable while maintaining the low cost of the static section and the high strength of the dynamic section. Furthermore, in the transition from the static section to the dynamic section, a ferrule is added in the transition section to connect the steel strands. When the dynamic section undergoes movement or bending, the deformation forces are transmitted through the steel strands to the ferrule. According to the distance between the deformation region and the ferrule, the deformation force gradually decreases from the deformation region toward the ferrule, and is finally transferred to the static section, thereby achieving continuity of load transmission. Meanwhile, without the ferrule, the ends of the steel strands are left unconnected. When bending occurs, the steel strands are prone to relative movement with the steel tube, which not only reduces their resistance to deformation but also causes friction between the steel strands and the steel tube, as well as mutual friction among the steel strands, adversely affecting long-term use.

[0007] As an improvement, the ferrule is fixedly connected to the steel tube by welding. With this improvement, the fixed connection between the ferrule and the steel tube does not require an additional connection structure, and at the same time, it can ensure the stability of the connection between the ferrule and the steel tube, thereby ensuring the stability of the ferrule in transmitting force to the static section.

[0008] As an improvement, the ferrule is provided with a plurality of connection holes arranged along a circumferential direction. Each connection hole is welded to an end portion of a corresponding one of the steel strands. The plurality of steel strands are coiled along an axial direction of the steel tube. This improvement ensures the uniformity of the force transmitted to the ferrule by the plurality of steel strands. Uneven force on the ferrule affects the stability of the force transmission.

[0009] As an improvement, the umbilical cable is provided with a plurality of steel tubes distributed around a circumferential direction of the umbilical cable. This improvement ensures uniform reinforcement of the cable strength provided by the plurality of steel tubes.

[0010] As an improvement, the ferrules on different steel tubes are arranged in a staggered manner along an axial direction of the umbilical cable. With this improvement, if the ferrules are fixedly connected in the same cross section, the cross-sectional area of that cross section will be greatly increased, making the umbilical cable more prone to damage at that cross section, and hindering the forming of the inner sheath, armor layer, and outer sheath outside the cores.

[0011] A forming method for a dynamic-static transition umbilical cable, comprising the following steps:

[0012] SI: preparing a plurality of cores of the umbilical cable, the cores including a plurality of steel tubes that are evenly distributed circumferentially outside the cores;

[0013] S2: calculating, according to service environment of the umbilical cable, lengths of a static section and a dynamic section respectively, and selecting a transition area between the static section and the dynamic section to form a transition section;

[0014] S3: selecting the steel tubes in the transition section and welding ferrules according to different distances from the static section;

[0015] S4: welding a plurality of steel strands along a circumferential direction of each of the ferrules, and twisting the steel strands along the corresponding steel tube with a stranding machine until the steel strands are twisted to a connection part between the dynamic section and a floating platform;

[0016] S5: compacting and assembling the cores in the dynamic section using an inner sheath extrusion equipment, filling gaps between the cores with a filling material, and extruding the inner sheath over outer sides of the cores to size the cores in the dynamic section;

[0017] S6: adjusting a sizing outer diameter of the inner sheath extrusion equipment according to an expanded diameter of the ferrules, filling the gaps between the cores with a filling material, extruding the inner sheath in the transition section to size the cores in the transition section;

[0018] S7: compacting and assembling the cores in the static section using the inner sheath extrusion equipment, filling the gaps between the cores with a filling material, and extruding the inner sheath over the outer sides of the cores to size the cores in the static section;

[0019] S8: passing the umbilical cable through an armor layer wire braiding equipment in the order of the static section, the transition section, and the static section, to complete forming of the armor layer of the umbilical cable;

[0020] S9: passing the umbilical cable through an outer sheath extrusion equipment in the order of the static section, the transition section, and the dynamic section, to complete forming of the outer sheath of the umbilical cable; and

[0021] S10: completing forming of the umbilical cable.

[0022] Compared with existing technologies, the advantages of this invention are as follows: by utilizing the high-strength steel tube that extends through the entire umbilical cable, the section with the steel strands on the steel tube is designated as the dynamic section, while the section without the steel strands is designated as the static section. During the integration and bundling of the cores in umbilical cable, when transitioning from the static section to the dynamic section, the steel tube is converted from a structure without twisted steel strands to a structure with twisted steel strands; conversely, when transitioning from the dynamic section to the static section, the steel tube is converted from a structure with twisted steel strands to a structure without twisted steel strands. This ensures the integrity of the umbilical cable while maintaining the low cost of the static section and the high strength of the dynamic section. Furthermore, in the transition from the static section to the dynamic section, the ferrules are added in the transition section to connect the steel strands. When the dynamic section undergoes movement or bending, the deformation forces are transmitted through the steel strands to the ferrules. According to the distance between the deformation region and the ferrules, the deformation force gradually decreases from the deformation region toward the ferrules, and is finally transferred to the static section, thereby achieving continuity of load transmission. Meanwhile, without the ferrule, the ends of the steel strands are left unconnected. When bending occurs, the steel strands are prone to relative movement with the steel tube, which not only reduces their resistance to deformation but also causes friction between the steel strands and the steel tube, as well as mutual friction among the steel strands, adversely affecting long-term use. Through the design of step S3, the increased outer diameter of the transition section caused by the ferrule structures can be evenly distributed over different cross-sections, thus reducing the increase in the outer diameter of the transition section. This facilitates the use of the umbilical cable and improves the forming of the inner sheath, armor layer, and outer sheath outside the cores.

[0023] As an improvement, twisting of the steel strands on the steel tube is carried out simultaneously with step S5 until the steel strands (4.1.1) are twisted to the ferrule. Through this improvement, the core can be formed rapidly, reducing the handling of semi-finished materials after the steel strands are stranded onto the steel tubes and reducing the storage of the semifinished materials.

[0024] As an improvement, in step S4, before twisting the steel strands, and after welding the steel strands to the ferrule, filling a cushioning material at an end of the ferrule close to the dynamic section, the cushioning material being disposed between the steel strands and the corresponding steel tube. This improvement avoids excessive bending of the steel strands during twisting due to the distance between the connection holes and the steel tube, which could easily damage the steel strands and affect the transmission of force.

[0025] As an improvement, an end portion of the cushioning material close to the dynamic section has a conical shape. This improvement allows the steel strands to gradually reduce in diameter during the twisting process, ensuring the structural stability and stable force transmission of the steel strands. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] FIG. 1 is a schematic diagram of the overall structure of the present invention.

[0027] FIG. 2 is a schematic diagram of the core of the present invention.

[0028] FIG. 3 is a schematic diagram of a connection structure of the ferrule of the present invention.

[0029] FIG. 4 is a schematic cross-sectional view of the dynamic section of the present invention.

[0030] Reference signs are as follows: 1, dynamic section; 2, static section; 3, transition section; 4, core; 4.1, steel tube; 4.1.1, steel strand; 4.1.2, ferrule; 4.1.3, connection hole; 5, inner sheath; 6, armor layer; 7, outer sheath; 8, cushioning material. DETAILED DESCRIPTION OF EMBODIMENTS

[0031] The embodiments of the present invention will be further described below with reference to the accompanying drawings.

[0032] As shown in FIGS. 1 to 2, a dynamic-static transition umbilical cable includes a dynamic section 1 and a static section 2. One end of the dynamic section 1 is connected to the static section 2, and the other end is connected to a floating platform. A transition section 3 is arranged between the dynamic section 1 and each static section 2. The umbilical cable includes a plurality of cores 4 disposed within an inner sheath 5. The cores 4 include steel tubes 4.1, each steel tube 4.1 being fixedly connected to one ferrule 4.1.2. The ferrule 4.1.2 is provided with steel strands 4.1.1 on a side close to the dynamic section 1 and a filling material on a side close to the static section 2.

[0033] As shown in FIG. 3, the ferrule 4.1.2 is fixedly connected to the steel tube 4.1 by welding. The ferrule 4.1.2 has a plurality of connection holes 4.1.3 arranged along the circumferential direction. Each connection hole 4.1.3 is welded and fixed to an end portion of one of the steel strands 4.1.1. The plurality of steel strands 4.1.1 are coiled along the axial direction of the steel tube 4.1.

[0034] As shown in FIGS. 2 and 4, the umbilical cable is provided with a plurality of steel tubes 4.1 distributed around the circumference direction of the umbilical cable. The ferrules 4.1.2 on different steel tubes 4.1 are arranged in a staggered manner along the axial direction of the umbilical cable.

[0035] As shown in FIG. 4, the cross-sectional structure of static section 2 is similar to that of dynamic section 1, except that the structure of the steel strands 4.1.1 is different. In the static section 2, the steel strands 4.1.1 are absent and replaced with the filling material.

[0036] A forming method for a dynamic-static transition umbilical cable, including the following steps SI to S10:

[0037] In step SI, a plurality of cores 4 for the umbilical cable are prepared, the cores 4 include a plurality of steel tubes 4.1 evenly distributed circumferentially outside the cores 4;

[0038] In step S2, the lengths of the static section 2 and the dynamic section 1 are calculated respectively, based on the service environment of the umbilical cable, and a transition area between the static section 2 and the dynamic section 1 is selected to form a transition section 3.

[0039] In step S3, the steel tubes 4.1 in the transition section 3 are selected, and ferrules 4.1.2 are welded according to different distances from the static section 2.

[0040] In step S4, a plurality of steel strands 4.1.1 are welded along a circumferential direction of each ferrule 4.1.2, and the steel strands 4.1.1 are twisted around a corresponding steel tube 4.1 using a stranding machine until the steel strands 4.1.1 are twisted to a connection part between the dynamic section 1 and a floating platform.

[0041] In step S5, the cores 4 in the dynamic section 1 are compacted and assembled through an inner sheath 5 extrusion equipment, a filling material is filled in gaps between the cores 4, and the inner sheath 5 is extruded to outer sides of the cores 4 to size the cores 4 in the dynamic section 1.

[0042] In step S6, a sizing outer diameter of the inner sheath 5 extrusion equipment is adjusted based on an expanded diameter of the ferrules 4.1.2, the filling material is filled in the gaps between the cores 4, the inner sheath 5 in the transition section 3 is extruded to size the cores 4 in the transition section 3.

[0043] In step S7, the cores 4 in the static section 2 are compacted and assembled through the inner sheath 5 extrusion equipment, the filling material is filled in the gaps between the cores 4, and the inner sheath 5 is extruded over the outer sides of the cores 4 to size the cores 4 in the static section 2.

[0044] In step S8, the umbilical cable is passed through a wire braiding equipment for an armor layer 6 in the order of the static section 2, the transition section 3, and the static section 1 to complete forming of the armor layer 6 of the umbilical cable.

[0045] In step S9, the umbilical cable is passed through an extrusion equipment for an outer sheath 7 in the order of the static section 2, the transition section 3, and the dynamic section 1 to complete forming of the outer sheath 7 of the umbilical cable.

[0046] In step S10, the forming of the umbilical cable is completed.

[0047] In step S4, the twisting of the steel strands 4.1.1 on the steel tubes 4.1 is carried out simultaneously with step S5 until the steel strands 4.1.1 are twisted to the ferrules 4.1.2.

[0048] In step S4, before twisting the steel strands 4.1.1, and after welding the steel strands 4.1.1 to the ferrules 4.1.2, a cushioning material 8 is filled at an end of the ferrules 4.1.2 close to the dynamic section 1. The cushioning material 8 is positioned between the steel strands 4.1.1 and the respective steel tubes 4.1, and an end portion of the cushioning material 8 close to the dynamic section 1 is m a conical shape.

[0049] The aforementioned filling material and cushioning material 8 are both resin materials or other plastic materials.

[0050] The above steps S5 to S7 may also be performed in the order of S7, S6, and S5 according to the requirements of the operating environment, alternatively, after completing steps S5 to S7, the umbilical cable may be reversely wound onto another take-up reel. [0051 ] The design of the present invention allows a smooth transition between the dynamic section 1 and static section 2 in the umbilical cable. This ensures the strength of dynamic section 1 while saving production costs for static section 2. In addition, by means of the combination of the ferrule 4.1.2 and the steel strands 4.1.1, the dynamic load can be transferred from the dynamic section 1 to the static section 2, thereby enhancing the load stability and resistance strength of the dynamic section 1. Moreover, since the steel strands 4.1.1 are welded to the ferrule 4.1.2, their end connections remain stable and are not prone to relative displacement caused by the bending of the dynamic section 1, which prevents friction between the steel strands 4.1.1 and the steel tube 4.1, as well as between the steel strands 4.1.1 themselves, thereby improving the service life of the umbilical cable.

[0052] The above description is merely an illustration of the preferred embodiments of the present invention and should not be construed as limiting the scope of the claims. The present invention is not limited to the embodiments described above, and specific structural variations are permissible. Any modifications made within the scope of the independent claims of the present invention shall fall within the scope of protection of the present invention.

Claims

1. A dynamic-static transition umbilical cable, characterized in that it comprises a dynamic section (1) and a static section (2), one end of the dynamic section (1) is connected to the static section (2), and the other end is connected to a floating platform, a transition section (3) is arranged between the dynamic section (1) and the static section (2), the umbilical cable comprises a plurality of cores (4) disposed within an inner sheath (5), the cores (4) comprise a steel tube (4.1), the steel tube (4.1) is fixedly connected with one ferrule (4.1.2), steel strands (4.1.1) arranged on a side of the ferrule (4.1.2) close to the dynamic section (1), and a filling material is arranged on a side of the ferrule (4.1.2) close to the static section (2).

2. The dynamic-static transition umbilical cable according to claim 1, characterized in that the ferrule (4.1.2) is fixedly connected to the steel tube (4.1) by welding.

3. The dynamic-static transition umbilical cable according to claim 2, characterized in that the ferrule (4.1.2) is provided with a plurality of connection holes (4.1.3) arranged along a circumferential direction thereof, each of the connection holes (4.1.3) is welded to an end portion of a corresponding one of the steel strands (4.1.1), and the plurality of steel strands (4.1.1) are coiled along an axial direction of the steel tube (4.1).

4. The dynamic-static transition umbilical cable according to claim 1, characterized in that the umbilical cable is provided with a plurality of steel tubes (4.1) distributed around a circumferential direction of the umbilical cable.

5. The dynamic-static transition umbilical cable according to claim 4, characterized in that the ferrules (4.1.2) on different steel tubes (4.1) are arranged in a staggered manner along an axial direction of the umbilical cable.

6. A forming method for a dynamic-static transition umbilical cable, characterized in that the method is adapted for forming the dynamic-static transition umbilical cable according to any one of claims 1-5, the method comprises the following steps:SI: preparing a plurality of cores (4) of the umbilical cable, the cores (4) including a plurality of steel tubes (4.1) that are evenly distributed circumferentially outside the cores (4);S2: calculating, according to service environment of the umbilical cable, lengths of a static section (2) and a dynamic section (1) respectively, and selecting a transition area between the static section (2) and the dynamic section (1) to form a transition section (3);S3: selecting the steel tubes (4.1) in the transition section (3) and welding ferrules (4.1.2) according to different distances from the static section (2);S4: welding a plurality of steel strands (4.1.1) along a circumferential direction of each of the ferrules (4.1.2), and twisting the steel strands (4.1.1) along the corresponding steel tube (4.1) with a stranding machine until the steel strands (4.1.1) are twisted to a connection part between the dynamic section (1) and a floating platform;S5: compacting and assembling the cores (4) in the dynamic section (1) using an inner sheath (5) extrusion equipment, filling gaps between the cores (4) with a filling material, and extruding the inner sheath (5) over outer sides of the cores (4) to size the cores (4) in the dynamic section (1);S6: adjusting a sizing outer diameter of the inner sheath (5) extrusion equipment according to an expanded diameter of the ferrules (4.1.2), filling the gaps between the cores (4) with a filling material, extruding the inner sheath (5) in the transition section (3) to size the cores (4) in the transition section (3);S7: compacting and assembling the cores (4) in the static section (2) using the inner sheath (5) extrusion equipment, filling the gaps between the cores (4) with a filling material, and extruding the inner sheath (5) over the outer sides of the cores (4) to size the cores (4) in the static section (2);S8: passing the umbilical cable through an armor layer (6) wire braiding equipment in the order of the static section (2), the transition section (3), and the static section (1), to complete forming of the armor layer (6) of the umbilical cable;S9: passing the umbilical cable through an outer sheath (7) extrusion equipment in the order of the static section (2), the transition section (3), and the dynamic section (1), to complete forming of the outer sheath (7) of the umbilical cable; andS10: completing forming of the umbilical cable.

7. The forming method for a dynamic-static transition umbilical cable according to claim 6, characterized in that, in step S4, twisting of the steel strands (4.1.1) on the steel tube (4.1) is carried out simultaneously with step S5 until the steel strands (4.1.1) are stranded to the ferrule (4.1.2).

8. The forming method for a dynamic-static transition umbilical cable according to claim 6, characterized in that, in step S4, before twisting the steel strands (4.1.1), and after welding the steel strands (4.1.1) to the ferrule (4.1.2), filling a cushioning material (8) at an end of the ferrule (4.1.2) close to the dynamic section (1), and the cushioning material (8) is disposed between the steel strands (4.1.4) and the corresponding steel tube (4.1).

9. The forming method for a dynamic-static transition umbilical cable according to claim 8, characterized in that an end portion of the cushioning material (8) close to the dynamic section (1) has a conical shape.INTERNATIONAL SEARCH REPORT International application No. PCT / CN2024 / 085192A. CLASSIFICATION OF SUBJECT MATTER H01B 7 / 20(2006.01)i; H01B 7 / 24(2006.01)i; H01B 7 / 22(2006.01)i; H01B 7 / 18(2006.01)i; H01B 7 / 04(2006.0l)i; H01B 7 / 00(2006.01)i; H01B 13 / 00(2006.01)i; H01B 13 / 26(2006.01)i; H01B 13 / 22(2006.0l)i According to International Patent Classification (IPC) or to both national classification and IPC B. FIELDS SEARCHED Minimum documentation searched (classification system followed by classification symbols) IPC: H01B7, H01B13 Documentation searched other than minimum documentation to the extent that such documents are included in the fields searched Electronic data base consulted during the international search (name of data base and, where practicable, search terms used) CNTXT, ENTXTC, ENTXT, VEN, CJFD, ISI_Web of Science: M WB, W, 3W, S dynamic, static, com er+. transit+, umbilical, cable, float+, wire?, sheath, lantern, ring, pipe C. DOCUMENTS CONSIDERED TO BE RELEVANT Category* Citation of document, with indication, where appropriate, of the relevant passages Relevant to claim No. X WO 2022011897 Al (ZHONGTIAN TECHNOLOGY SUBMARINE CABLE CO., LTD.) 20 January 2022 (2022-01-20) description, paragraphs 26-45, and figures 1-3 1-9 PX A CN 116682604 A (NINGBO ORIENT WIRES &CABLES CO., LTD.) 01 September 2023 (2023-09-01) description, paragraphs 5-25 US 6472614 Bl (COFLEXIP) 29 October 2002 (2002-10-29) entire description 1-9 1-9 A CN 111292889 A (ZHONGTIAN TECHNOLOGY SUBMARINE CABLES CO., LTD. et al.) 16 June 2020 (2020-06-16) entire description 1-9 A CN 205911038 U (ZHONGTIAN TECHNOLOGY SUBMARINE CABLES CO., LTD.) 25 January 2017 (2017-01-25) entire description 1-9 | | Further documents are listed in the continuation of Box C. | J | See patent family annex. * Special categories of cited documents: “T” later document published after the international filing date or priority “A” document defining the general state of the art which is not considered date and not in conflict with the application but cited to understand the to be of particular- relevance principle or theory underlying the invention “D” document cited by the applicant in the international application -‘X” document of particular relevance; the claimed invention cannot be “E" earlier application or patent but published on or after the international considered novel or cannot be considered to involve an inventive step filing date when the document is taken alone “L" document which may throw doubts on priority claim(s) or which is “Y” document of particular relevance; the claimed invention cannot be cited to establish the publication date of another citation or other considered to involve an inventive step when the document is special reason (as specified) combined with one or more other such documents, such combination “O” document referring to an oral disclosure, use, exhibition or other being obvious to a person skilled in the ait means document member of the same patent family “P” document published prior to the international filing date but later than the priority date claimed Date of the actual completion of the international search 23 June 2024 Date of mailing of the international search report 28 June 2024 Name and mailing address of the ISA / CN China National Intellectual Property Administration (ISA / CN) China No. 6, Xitucheng Road, Jimenqiao, Haidian District, Beijing 100088 Authorized officer Telephone No.

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