An integrated flexible riser for deep sea mining

Abstract

The application discloses an integrated flexible riser for deep-sea mining, belonging to the technical field of deep-sea mining, comprising: an integrated functional assembly, the integrated functional assembly comprising a slurry transportation central pipe, at least one communication cable unit, at least one optical fiber unit and at least one support pipe unit arranged around the slurry transportation central pipe; a bearing protection assembly, the bearing protection assembly being wrapped outside the integrated functional assembly; and a buffer fixing layer, the buffer fixing layer being filled in the gaps between the slurry transportation central pipe, the communication cable unit, the optical fiber unit and the support pipe unit, and filled in the gaps between the integrated functional assembly and the bearing protection assembly. The integrated flexible riser for deep-sea mining has the functions of conveying and guiding in one, is light in weight, easy to lay and fast to recover, thereby improving the mining efficiency and reducing the operation risk.

Description

Technical Field

[0001] This invention relates to the field of deep-sea mining technology, and in particular to an integrated flexible riser for deep-sea mining. Background Technology

[0002] The deep seabed (4000m~6000m) contains polymetallic nodules rich in manganese, nickel, cobalt, and other metals, representing immense development value. Currently, the mainstream research and development direction both domestically and internationally is pipeline-lift mining systems, which typically consist of a surface support vessel, a lift riser, and a seabed mining vehicle.

[0003] However, the existing 6000-meter-class ultra-deep-sea operation system mainly uses rigid metal risers as transport pipelines, and separately lays slurry transport pipelines and power and communication cables. This scheme has the following significant drawbacks: Deployment efficiency is low and maneuverability is poor: the rigid metal risers are extremely heavy and have a large bending radius, resulting in lengthy and complex laying and retrieval processes. Once connected, they will severely restrict the maneuverability of the surface work vessel.

[0004] High risk of system interference: Independently deployed risers and cables are prone to mutual interference, entanglement or even collision in complex and dynamic marine environments, which not only reduces mining efficiency but also brings significant operational safety hazards.

[0005] Difficulties in emergency response and evacuation: In the face of sudden sea conditions or system failures, it is impossible to quickly recover the heavy rigid riser. If the unrecovered riser is towed for transfer, there is an extremely high risk of breakage or loss of control.

[0006] In summary, the limitations of traditional solutions in terms of efficiency, safety, and flexibility are becoming increasingly apparent. Therefore, there is an urgent need for a new type of mining riser that can integrate slurry transportation, power transmission, and signal communication, while also being lightweight, highly flexible, easy to deploy, and quickly retrievable, to improve the operational efficiency and reliability of deep-sea mining systems. Summary of the Invention

[0007] The purpose of this invention is to provide an integrated flexible riser for deep-sea mining that integrates slurry transportation, power transmission and signal communication, and features lightweight, high flexibility, easy deployment and rapid recovery, thereby solving the defects of existing riser technologies such as low deployment efficiency, high interference risk and poor mobility.

[0008] To achieve the above objectives, the present invention provides an integrated deep-sea mining flexible riser, comprising: an integrated functional component, the integrated functional component including a slurry transport center pipe, and at least one communication cable unit, at least one optical fiber unit, and at least one support pipe unit arranged around the slurry transport center pipe; The protective component is wrapped around the integrated functional component. The buffer and retention layer fills the gaps between the slurry transport center pipe, communication cable unit, optical fiber unit, and support pipe unit, and also fills the gaps between the integrated functional components and the load-bearing protection components.

[0009] Preferably, the load-bearing protective component includes, from the outside to the inside, an outer sheath, a spiral armor layer, and an inner sheath; the inner sheath covers the integrated functional component, the spiral armor layer covers the inner sheath, and the outer sheath covers the spiral armor layer.

[0010] Preferably, the spiral armor layer includes a first armor sub-layer and a second armor sub-layer; the first armor sub-layer and the second armor sub-layer are respectively formed by spirally winding multiple steel wires of the same size at a 30° winding angle, and the spiral winding directions of the steel wires in the first armor sub-layer and the second armor sub-layer are opposite.

[0011] Preferably, the slurry transport center pipe is provided with a wear-resistant layer inside, and the wear-resistant layer is made of high molecular weight polyethylene.

[0012] Preferably, the communication cable unit includes a stranded conductor made of multiple copper wires twisted together, and an insulating layer covering the outside of the stranded conductor.

[0013] Preferably, the optical fiber unit includes an optical cable, an elastomer protective layer, and a steel pipe; the optical cable is made of multiple sets of single-mode optical fibers twisted together, the elastomer protective layer covers the outside of the optical cable, and the steel pipe is sleeved on the outside of the elastomer protective layer.

[0014] Preferably, the support tube unit is a steel pipe, the steel pipe material is super duplex stainless steel, the outer diameter of the steel pipe is 60-120mm, and the wall thickness is 7-10mm.

[0015] Preferably, the communication cable unit, optical fiber unit, and support pipe unit are distributed circumferentially around the slurry transport center pipe; the communication cable unit, optical fiber unit, and support pipe unit have the same outer diameter, and the geometric center of each unit is located on a circle concentric with the slurry transport center pipe, and they are evenly arranged along the circumference; the communication cable units are spaced apart from each other.

[0016] Preferably, the deep-sea mining flexible riser is equipped with a buoyancy adjustment component, which consists of multiple buoyancy blocks continuously arranged along the flexible riser, so that the flexible riser presents a gentle wave pattern underwater.

[0017] Preferably, the buoyancy block has a cylindrical structure with an inner diameter that matches the outer diameter of the flexible riser.

[0018] The advantages and positive effects of the integrated deep-sea mining flexible riser described in this invention are: 1. Highly integrated, safe and reliable: The functions of slurry transportation, power supply, communication and structural support are integrated into a single flexible riser, which fundamentally avoids the risks of mutual interference and entanglement caused by the independent layout of multiple pipelines, and improves the overall safety and reliability of the system.

[0019] 2. Lightweight and flexible design for high operational efficiency: The composite flexible structure replaces the rigid metal pipe, significantly reducing the weight of the riser and greatly improving its bending performance. This allows the riser to be transported coiled on a drum and deployed and retrieved quickly and continuously using a tension reel, greatly improving the efficiency of offshore operations.

[0020] 3. Excellent mechanical properties: The double-layer spiral armor design ensures high axial tensile strength to meet the requirements of deep-sea operations at depths of several thousand meters, while providing excellent torsional resistance and bending flexibility, making it well adaptable to dynamic marine environments.

[0021] 4. High system stability: Through external buoyancy adjustment components, the riser can be actively shaped into a gentle wave configuration. This design reduces frictional damage caused by the riser's contact with the seabed, improving the safety of the entire system; at the same time, it effectively reduces the axial tension and bending moment of the riser, enhancing the stability of the entire mining system.

[0022] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0023] Figure 1 This is a cross-sectional view of a preferred embodiment of an integrated flexible riser for deep-sea mining according to the present invention. Figure 2 This is a schematic diagram of the load-bearing and protective component structure of a preferred embodiment of an integrated flexible riser for deep-sea mining according to the present invention; Figure 3 This is a schematic diagram of the flexible riser operation of a preferred embodiment of an integrated deep-sea mining flexible riser according to the present invention; Figure 4 This is a schematic diagram of the buoyancy block structure of a preferred embodiment of an integrated flexible riser for deep-sea mining according to the present invention.

[0024] Figure Labels 100. Flexible riser; 110. Integrated functional component; 111. Slurry transport center pipe; 1111. Wear-resistant layer; 112. Communication cable unit; 1121. Insulation layer; 113. Fiber optic unit; 1131. Elastomer protective layer; 114. Support pipe unit; 120. Load-bearing protection component; 121. Outer sheath; 122. Inner sheath; 123. Spiral armor layer; 1231. First armor sub-layer; 1232. Second armor sub-layer; 130. Buffer and retention layer; 140. Buoyancy adjustment component; 141. Buoyancy block; 1411. Lightweight buoyancy layer; 1412. Reserved bolt holes; 200. Surface working mother vessel; 300. Seabed mining vehicle. Detailed Implementation

[0025] In the description of this invention, it should be noted that the terms "upper," "lower," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product is in use. They are used only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," and "connect" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0026] In this application, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. In case of any inconsistency, the meaning set forth in this specification or derived from the content described herein shall prevail. Furthermore, the terminology used herein is for the purpose of describing embodiments of this application only and is not intended to limit the scope of this application.

[0027] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0028] like Figure 1As shown, the present invention discloses an integrated deep-sea mining flexible riser 100, comprising: an integrated functional component 110, which includes a slurry transport center pipe 111, and at least one communication cable unit 112, at least one optical fiber unit 113, and at least one support pipe unit 114 arranged around the slurry transport center pipe 111; a load-bearing protection component 120, which covers the outside of the integrated functional component 110; and a buffer retention layer 130, which fills all the gaps between the slurry transport center pipe 111, the communication cable unit 112, the optical fiber unit 113, and the support pipe unit 114, and also fills all the gaps between the integrated functional component 110 and the load-bearing protection component 120, so that the interior of the integrated functional component 110 and the integrated functional component 110 and the load-bearing protection component 120 form a structurally continuous whole.

[0029] The buffer retaining layer 130 is made of lightweight foam material. It constrains the deformation of the tube wall and makes the communication cable unit 112, optical fiber unit 113 and support tube unit 114 form a co-force-bearing overall structure to increase the overall stability.

[0030] The deep-sea mining flexible riser 100 provided by this invention integrates slurry transportation, power, communication and structural support functions into a single flexible riser 100, fundamentally avoiding the interference and entanglement risks caused by the independent layout of multiple pipelines, and improving the overall safety and reliability of the system.

[0031] The slurry transport center pipe 111 is made of high-strength fiber material, and an internal wear-resistant layer 1111 is provided. The wear-resistant layer is made of high molecular weight polyethylene. The wear-resistant layer 1111 is in direct contact with the slurry flowing inside, effectively reducing the erosion effect of the slurry on the slurry transport center pipe 111, and improving the stability of the transport pipeline while ensuring the transport efficiency.

[0032] The communication cable unit 112 includes a second type of copper stranded wire as the stranded conductor, which is made of multiple fine copper wires twisted together. It has excellent flexibility and resistance to bending fatigue. The stranded conductor is covered with an insulation layer 1121. The insulation layer 1121 is made of cross-linked polyethylene material with strong thermal stability and excellent insulation performance. This prevents other units from affecting the communication cable unit 112 during the transportation of slurry and ensures the safety of the communication cable unit 112 in the working state.

[0033] The optical fiber unit 113 includes an optical cable, an elastomer protective layer 1131, and a steel pipe. The optical cable is made of multiple single-mode optical fibers twisted together. The elastomer protective layer 1131 covers the outside of the optical cable, and the steel pipe is sleeved on the outside of the elastomer protective layer 1131. This arrangement enhances the resistance of the optical fiber unit 113 to external loads.

[0034] The support pipe unit 114 is a steel pipe made of super duplex stainless steel. The outer diameter of the steel pipe is 60-120mm and the wall thickness is 7-10mm. The high-strength material achieves lightweighting and thinning, reducing the bending stiffness of the steel pipe and allowing it to be bent repeatedly without permanent damage. The support pipe unit 114 provides the necessary structural support and load-bearing capacity for the riser.

[0035] Communication cable units 112, optical fiber units 113, and support pipe units 114 are distributed circumferentially around the slurry transport center pipe 111; the outer diameters of the communication cable units 112, optical fiber units 113, and support pipe units 114 are equal, and the geometric center of each unit is located on a circle concentric with the slurry transport center pipe 11, and they are evenly arranged along the circumference; the integrated deep-sea mining flexible riser 100 has multiple communication cable units 112, and the multiple communication cable units 112 are spaced apart from each other, that is, optical fiber units 113 and / or support pipe units 114 are arranged between adjacent communication cable units 112.

[0036] Specifically, each unit has the same outer diameter and is located on a circle concentric with the slurry transport center pipe 111. This design allows the units to be arranged in a regular and compact manner, minimizing the cross-sectional radius of the riser. While ensuring functional integration, it enhances the bending flexibility of the riser and facilitates winding and laying.

[0037] The communication cable units 112 are spaced apart from each other, and an optical fiber unit 113 and / or a support tube unit 114 are provided between any adjacent cable units 112. This isolation layout avoids the local temperature rise caused by the concentrated arrangement of multiple cables, effectively prevents the mechanical properties of the insulation layer and buffer retaining layer from deteriorating due to heat accumulation, and ensures the safety and service life of the riser under long-term operation.

[0038] The deep-sea mining flexible riser 100 provided by this invention adopts a composite flexible structure, replacing the traditional rigid metal pipe, which significantly reduces the weight of the riser and significantly improves its bending performance. This allows the riser to be transported by coiling on a drum and to be deployed and retrieved quickly and continuously using a tension reel, greatly improving the efficiency of offshore operations.

[0039] like Figure 2 As shown, the load-bearing protective component 120 includes, from the outside to the inside, an outer sheath 121, a spiral armor layer 123, and an inner sheath 122. The inner sheath 122 covers the integrated functional component 110, the spiral armor layer 123 covers the inner sheath 122, and the outer sheath 121 covers the spiral armor layer 123. The spiral armor layer 123 is in direct contact with the inner sheath 122, and is externally wrapped by the outer sheath 121, ensuring the stability and safety of the deep-sea mining flexible riser 100.

[0040] The inner sheath 122 and the outer sheath 121 are made of thermoplastic polyurethane material, which has good tensile strength and wear resistance. It can effectively cope with the high tension, salt spray corrosion and temperature changes that the riser is subjected to in the deep sea, thus extending the service life of the flexible riser.

[0041] The spiral armor layer 123 includes a first armor sub-layer 1231 and a second armor sub-layer 1232. Both the first and second armor sub-layers are formed by spirally winding multiple steel wires of the same size at a 30° angle, with the spiral winding directions of the wires in the first and second armor sub-layers 1231 and 1232 being opposite. The spiral armor layer 123 improves the overall tensile strength of the flexible riser 100 in deep-sea mining, and the axial tensile force exerted on the flexible riser 100 by the external environment is primarily borne by the spiral armor layer 123. The fact that the winding angles of the steel wires in the first and second armor sub-layers 1231 are the same but the spiral directions are opposite cancels out the torsional coupling effect. In the field of deep-sea mining, the riser mainly bears axial tension and internal pressure. To achieve a balance between high axial strength, high compressive strength, and flexibility, a 30° winding angle is chosen.

[0042] The deep-sea mining flexible riser 100 provided by this invention adopts a double-layer spiral armor layer 123 design, which ensures high axial tensile strength to meet the requirements of deep-sea operations at depths of several thousand meters, while providing excellent torsional resistance and bending flexibility, and can adapt well to dynamic marine environments.

[0043] like Figures 3-4 As shown, the deep-sea mining flexible riser 100 also includes a buoyancy adjustment component 140, which is composed of multiple buoyancy blocks 141 continuously arranged along the flexible riser 100, so that the flexible riser 100 presents a gentle wave pattern underwater.

[0044] The buoyancy block 141 has a cylindrical structure with an inner diameter that matches the outer diameter of the flexible riser 100. The buoyancy block 141 is fixed to the flexible riser 100 by bolts and pre-drilled bolt holes 1412 to prevent radial sliding of the buoyancy block 141 on the flexible riser 100. The buoyancy block 141 is provided with a lightweight buoyancy layer 1411, which is made of low-absorption foamed polyethylene material to provide buoyancy for the buoyancy block 141.

[0045] The flexible riser 100 for deep-sea mining provided by this invention has an external buoyancy adjustment component 140, which enables the riser to form a gentle wave-like configuration. This configuration reduces frictional damage caused by the riser's contact with the seabed, improving the safety of the entire system; at the same time, it effectively reduces the axial tension and bending moment of the riser, enhancing the stability of the entire mining system.

[0046] The pipeline lifting mining system using the integrated deep-sea mining flexible riser 100 provided by the present invention includes: a surface work mother vessel 200, a flexible riser 100, and a seabed mining vehicle 300.

[0047] The surface work vessel 200 is connected to the flexible riser 100, which is directly connected to the seabed mining vehicle 300. The surface work vessel 200 can move while the system is operating, which greatly increases the working range of the mining vehicle and improves mining efficiency. Because the flexible riser 100 is a composite flexible structure, compared with traditional rigid metal pipes, the riser weight is greatly reduced and the bending performance is significantly improved. This allows the riser to be transported by winding it on a drum and to be deployed and retrieved quickly and continuously using a tension reel, which greatly improves the efficiency of offshore operations.

[0048] Therefore, the integrated deep-sea mining flexible riser 100 described in this invention integrates slurry transportation, power, communication, and structural support functions into a single flexible riser 100, avoiding the interference and entanglement risks associated with independent deployment of multiple pipelines. The use of a composite flexible structure replaces rigid metal pipes, significantly reducing riser weight and improving bending performance. The flexible riser 100 can be transported coiled on a reel and deployed and retrieved quickly and continuously using a tension reel. The outer layer is equipped with a double-layer spiral armor layer 123, ensuring high axial tensile strength to meet the requirements of deep-sea operations at depths of several thousand meters while providing excellent torsional resistance and bending flexibility. This solves the shortcomings of existing technologies, such as low riser deployment efficiency, high interference risk, and poor mobility.

[0049] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. An integrated flexible riser for deep-sea mining, characterized in that, include: The integrated functional components include a slurry transport center pipe, and at least one communication cable unit, at least one optical fiber unit, and at least one support pipe unit arranged around the slurry transport center pipe. The protective component is wrapped around the integrated functional component. The buffer and retention layer fills the gaps between the slurry transport center pipe, communication cable unit, optical fiber unit, and support pipe unit, and also fills the gaps between the integrated functional components and the load-bearing protection components.

2. The integrated flexible riser for deep-sea mining according to claim 1, characterized in that: The load-bearing protective component includes, from the outside to the inside, an outer sheath, a spiral armor layer, and an inner sheath; the inner sheath covers the integrated functional component, the spiral armor layer covers the inner sheath, and the outer sheath covers the spiral armor layer.

3. The integrated flexible riser for deep-sea mining according to claim 2, characterized in that: The spiral armor layer includes a first armor sub-layer and a second armor sub-layer; the first armor sub-layer and the second armor sub-layer are respectively formed by spirally winding multiple steel wires of the same size at a 30° winding angle, and the spiral winding directions of the steel wires in the first armor sub-layer and the second armor sub-layer are opposite.

4. The integrated flexible riser for deep-sea mining according to claim 1, characterized in that: The slurry transport center pipe is equipped with a wear-resistant layer, which is made of high molecular weight polyethylene.

5. The integrated flexible riser for deep-sea mining according to claim 1, characterized in that: The communication cable unit includes a stranded conductor made of multiple copper wires twisted together, and an insulating layer covering the outside of the stranded conductor.

6. The integrated flexible riser for deep-sea mining according to claim 1, characterized in that: The optical fiber unit includes an optical cable, an elastomer protective layer, and a steel pipe; the optical cable is made of multiple sets of single-mode optical fibers twisted together, the elastomer protective layer covers the outside of the optical cable, and the steel pipe is sleeved on the outside of the elastomer protective layer.

7. An integrated flexible riser for deep-sea mining according to claim 6, characterized in that: The support tube unit is a steel pipe made of super duplex stainless steel with an outer diameter of 60-120mm and a wall thickness of 7-10mm.

8. The integrated flexible riser for deep-sea mining according to claim 1, characterized in that: The communication cable unit, optical fiber unit, and support pipe unit are distributed around the circumference of the slurry transport center pipe; the outer diameters of the communication cable unit, optical fiber unit, and support pipe unit are equal, and the geometric center of each unit is located on a circle concentric with the slurry transport center pipe, and they are evenly arranged along the circumference; the communication cable units are spaced apart from each other.

9. An integrated flexible riser for deep-sea mining according to claim 1, characterized in that, The deep-sea mining flexible riser is equipped with a buoyancy adjustment component, which consists of multiple buoyancy blocks continuously arranged along the flexible riser, so that the flexible riser presents a gentle wave pattern underwater.

10. An integrated flexible riser for deep-sea mining according to claim 9, characterized in that: The buoyancy block has a cylindrical structure with an inner diameter that matches the outer diameter of the flexible riser.

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