A vortex-induced vibration suppression device for a marine riser

Abstract

The utility model belongs to the technical field of ocean energy development equipment, disclose a kind of marine riser vortex-induced vibration vibration suppression device. The marine riser vortex-induced vibration vibration suppression device includes arc sleeve, fairing, vibration suppression plate, handle and self-locking type ribbon;Arc sleeve is realized quick opening and closing by handle, it is convenient to be radially fitted and embrace in the outer wall of marine riser, self-locking type ribbon can be quickly and conveniently tied in the outer wall of marine riser, provide reliable support for vibration suppression device;Vibration suppression device can be adapted to rotate around marine riser according to the direction of ocean current, adjust posture, ensure control effect. The vibration suppression device of the utility model is simple in structure, various in installation type, convenient to operate, suitable for marine riser layout and use full life cycle installation, each vibration suppression unit is independent, can adapt to different water depth ocean current direction, vibration suppression effect is stable, can be widely applied to marine various riser and submarine cable vortex-induced vibration suppression scene.

Description

Technical Field

[0001] This utility model belongs to the field of marine resource development equipment technology, specifically a marine riser vortex-induced vibration suppression device. Background Technology

[0002] Offshore risers are key components for transporting offshore oil and gas resources. Operating in complex and variable ocean current environments, they are susceptible to vortex-induced vibrations caused by periodic fluid excitation. This vibration leads to continuous fatigue accumulation, shortening their service life and potentially causing serious safety accidents such as component fracture and oil / gas leaks. Current mainstream integrated sleeve vibration damping structures require axial insertion and fixation along the riser, while spiral rib structures need to be pre-fixed to the riser's outer wall. Both can only be installed simultaneously during the riser lowering phase, making convenient retrofitting to already operational risers impossible. Subsequent retrofitting requires extensive underwater operations, resulting in cumbersome construction, high costs, and significant challenges. Furthermore, it's difficult to flexibly retrofit at any specified depth based on the actual vortex-induced vibration conditions during the riser's service life. These methods also have poor adaptability to complex operating conditions such as inclined, near-horizontal risers, and risers with entangled materials on the outer wall, limiting their applicability. In addition, existing devices are difficult to adapt to the dynamic changes in ocean current direction. When the water flow direction deviates from the device's designed attitude, the vibration suppression effect will fluctuate greatly due to the influence of the flow field environment. The stability of the vibration suppression effect is insufficient, and it is difficult to guarantee long-term stable vibration suppression performance. Utility Model Content

[0003] The technical problem to be solved by this utility model is to provide a marine riser vortex-induced vibration damping device that is convenient and efficient to install, adaptable to multiple working conditions, reliable in vibration damping performance, and economical and practical, addressing the shortcomings of existing vibration damping devices for marine risers, such as complex assembly operations and poor compatibility with already put into production risers.

[0004] The technical solution of this utility model:

[0005] A vibration damping device for vortex-induced vibration of a marine riser includes an arc-shaped sleeve 1, a damping plate 3, a handle 4, and a self-locking cable tie 5. The weight of the vibration damping device is greater than its buoyancy in seawater. The inner diameter of the arc-shaped sleeve 1 is larger than the outer diameter of the marine riser, and it is fitted onto the marine riser. The handle 4 is fixed to the arc-shaped sleeve 1, which facilitates the installation of the arc-shaped sleeve 1 on the marine riser and allows it to rotate freely around the marine riser, so as to work with the damping plate 3 to effectively eliminate the regular shedding of vortices and suppress vortex-induced vibration. The damping plate 3 is fixed to the arc-shaped sleeve 1, and its plate surface is arranged parallel to the axis of the marine riser. The self-locking cable tie 5 is tied to the outer wall of the marine riser and is located at the lower part of the vibration damping device, providing a limiting effect for the vibration damping device and preventing it from sinking axially along the marine riser.

[0006] The marine riser vortex-induced vibration suppression device also includes a fairing 2, which consists of two plates connected at one end and open at the other end; the open end is fixed to the arc-shaped sleeve 1, and the connected end is fixed to the vibration suppression plate 3.

[0007] Multiple sets of vortex-induced vibration suppression devices for marine risers are installed on the marine risers according to the vibration suppression requirements; the height of the fairing 2 and the vibration suppression plate 3 is less than the height of the arc sleeve 1, and the upper and lower edges of the arc sleeve 1 are chamfered to form an arc shape to avoid mutual interference between the multiple sets of vortex-induced vibration suppression devices for marine risers.

[0008] The marine riser vortex-induced vibration suppression device is installed in the following ways depending on the actual situation: The first installation method involves installing the self-locking cable ties 5 and the device section by section above the water surface during the lowering of the marine riser. The device is then lowered along with the marine riser, ensuring sufficient pressure between the self-locking cable ties 5 and the riser to provide vertical support for the device. This support force is the difference between the weight and buoyancy of the device. The second installation method involves installing the device above the water surface after the marine riser is in place. The third installation method involves pre-tying the self-locking cable ties 5 at the designated position on the marine riser, allowing it to sink freely under its own weight to the top of the pre-tied self-locking cable ties 5 for positioning; the second method involves pre-tied the self-locking cable ties 5 at the designated position on the marine riser, transporting the marine riser vortex-induced vibration suppression device to the top of the self-locking cable ties 5, and then using the tensioning handle 4 to install the arc-shaped sleeve 1 onto the marine riser. The marine riser vortex-induced vibration suppression device is supported on top of the self-locking cable ties 5, completing the mounting and positioning. At this time, the weight of the marine riser vortex-induced vibration suppression device is greater than its buoyancy, and the difference is balanced by the friction between the self-locking cable ties 5 and the marine riser.

[0009] The first installation method avoids underwater operations and is the most convenient, but requires accurate pre-determination of the installation location. For the subsequent installation of the marine riser vortex-induced vibration suppression device, only the latter two methods can be used. The second installation method requires that there be no other entanglements on the marine riser; otherwise, the vortex-induced vibration suppression device will have difficulty falling down on its own, and the self-locking cable ties 5 require underwater operation, slightly increasing the difficulty. The third installation method is more targeted and applicable to any complex situation, even when the marine riser is tilted close to horizontal. However, both the installation of the marine riser vortex-induced vibration suppression device and the self-locking cable ties 5 require underwater operation, making it relatively more difficult.

[0010] The inner diameter of the arc sleeve 1 is slightly larger than the outer diameter of the marine riser. Under normal conditions, the chord length between the two outer edges of the arc is less than the diameter of the marine riser. After the sleeve opening is enlarged by pulling the handles 4 on both sides outward, the arc sleeve 1 is fitted onto the marine riser. After releasing the handles 4, the arc sleeve 1 returns to the initial opening angle. After that, the arc sleeve 1 can only rotate around the marine riser. The arc sleeve 1 has sufficient strength and rigidity. Its material, shape, size and quantity are not limited. The upper and lower edges are chamfered to form an arc shape to reduce the edge friction after multiple units are installed and avoid restricting the independent rotation of each unit.

[0011] The fairing 2 has sufficient strength and rigidity, and its material, shape and size are not limited, but its height is less than that of the arc sleeve 1;

[0012] The vibration damping plate 3 can be a rigid flat plate, a corrugated plate, or a waterproof flexible fabric, and its material, shape, and size are not limited.

[0013] The handle 4 only needs to facilitate the opening of the arc sleeve 1, and there are no special requirements. Sometimes the handle 4 can be omitted and the above opening function can be accomplished in other ways.

[0014] The self-locking cable tie 5 has sufficient strength, rigidity, and ease of quick loading and unloading, and its material and construction are not limited.

[0015] The beneficial effects of this utility model are: (1) The vibration damping device is installed outside the marine riser and can rotate freely around the axis of the marine riser. Therefore, it can adaptively adjust its attitude according to the direction of the ocean current and always maintain a high efficiency of vortex vibration control; (2) The vibration damping device has a simple structure, is easy to install, and is economical and efficient; (3) The self-locking cable tie is quick to install, low in cost, reliable in force, and durable; (4) The vibration damping device can be installed and lowered synchronously with the marine riser, or it can be quickly installed at any specified depth position as needed during the service of the marine riser, and has a wide range of applicable scenarios; (5) The vibration damping device is not limited to the marine riser, but can also be used for vortex-induced vibration damping of other marine circular components such as submarine cables. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of an overall vibration damping device for marine risers caused by vortex-induced vibration.

[0017] Figure 2 This is a schematic diagram of a vibration damping unit;

[0018] Figure 3 This is a schematic diagram of a self-locking cable tie;

[0019] In the picture: 1. Arc-shaped sleeve, 2. Fairing, 3. Vibration damping plate, 4. Handle, 5. Self-locking cable tie. Detailed Implementation

[0020] The specific embodiments of this utility model are described in detail below with reference to the technical solution and accompanying drawings.

[0021] Based on theoretical analysis, experimental verification, or simulation calculation results, determine the size, quantity, installation location, and appropriate specifications of self-locking cable ties for the vibration damping device.

[0022] Installation Method 1: Applicable to the marine riser lowering construction phase, allowing for operation entirely above the water surface without underwater construction. During the marine riser lowering process, self-locking cable ties 5 are first secured to the pre-installed section of the marine riser above the water surface, followed by the assembly of the marine riser vortex-induced vibration suppression device. The marine riser vortex-induced vibration suppression device includes an arc-shaped sleeve 1, a fairing 2, a damping plate 3, and a handle 4. By pulling the arc-shaped sleeve 1 with the handle 4 to enlarge the opening, it is radially fitted onto the upper part of the self-locking cable ties 5 on the marine riser. Releasing the handle 4 allows the arc-shaped sleeve 1 to return to its original position, completing the installation of a single marine riser vortex-induced vibration suppression device. For ease of installation, the length of a single arc-shaped sleeve 1 should not be too long or too short, ideally within the range of 0.5-2m. Multiple marine riser vortex-induced vibration suppression devices can be grouped together. After completing the installation of multiple groups of marine riser vortex-induced vibration suppression devices segment by segment using this method, they can be lowered along with the marine riser. Installation Method 1 requires no underwater operation and is the most convenient method, but the installation location must be determined in advance.

[0023] Installation Method Two: Applicable to scenarios where the marine riser is already installed and then added later. After the marine riser is installed, the self-locking cable ties 5 are first secured at the designated installation section of the marine riser using underwater equipment. Above the water surface, the vortex-induced vibration damping device for the marine riser is assembled. The opening of the arc-shaped sleeve 1 is enlarged by tensioning the handle 4, and it is then radially fitted onto the section of the marine riser above the water surface before being released and reset. Utilizing the characteristic that the gravity of the vortex-induced vibration damping device is greater than the buoyancy of seawater, it is allowed to sink freely along the marine riser to the top of the self-locking cable ties 5, where the self-locking cable ties 5 provide axial restraint, preventing it from moving downwards along the axial direction of the marine riser. Installation Method Two requires underwater operation only for the self-locking cable ties 5, making the construction slightly more difficult than the first installation method. It is necessary to ensure that there are no obstructions on the outer wall of the marine riser that could hinder the device's descent.

[0024] Installation Method 3: Suitable for complex working conditions such as inclined risers, external entanglements, and near-horizontal states, and can also be used for post-installation on already operational marine risers. First, use underwater equipment to secure the self-locking cable ties 5 at the designated installation section of the marine riser. Then, transport the pre-assembled marine riser vortex-induced vibration suppression device to the upper position of the self-locking cable ties 5. Underwater, use handle 4 to stretch the arc-shaped sleeve 1 to enlarge the opening, radially fitting it to the designated position on the marine riser, and then release it to reset it. This allows the marine riser vortex-induced vibration suppression device to rest against the top of the self-locking cable ties 5, with the self-locking cable ties 5 providing axial restraint. Installation Method 3 is highly targeted and adaptable to various complex working conditions. The entire process is underwater, making it the most challenging method to implement.

[0025] Working process: When the ocean current acts on the fairing 2, the fairing 2 generates torque under the thrust of the water flow, driving the marine riser vortex-induced vibration suppression device to rotate around the marine riser, achieving adaptive attitude adjustment. When vortex-induced vibration occurs in the marine riser, the marine riser vortex-induced vibration suppression device oscillates or rotates synchronously with the marine riser in the transverse direction, which increases the added mass force of the overall structure, weakens the regular vortex shedding, reduces vortex-induced force, and thus significantly suppresses the vibration amplitude of the marine riser, achieving a vibration reduction effect. Each group of marine riser vortex-induced vibration suppression devices is independent of each other and can adaptively adjust its attitude according to the ocean current direction at different water depths without interfering with each other. At the same time, the self-locking cable ties 5 effectively prevent the arc-shaped sleeve 1 from sinking and sliding over, ensuring that the marine riser vortex-induced vibration suppression device is always in the preset working position. The marine riser vortex-induced vibration suppression device has a simple structure, is easy to install, and can be flexibly arranged, and can be widely used in various marine riser and submarine cable vortex-induced vibration suppression scenarios.

[0026] The above description is merely a preferred embodiment of this utility model and should not be considered as any limitation thereof. Any equivalent changes, modifications, or improvements made by those skilled in the art to the above embodiments when utilizing the technical solution of this utility model should be considered as falling within the protection scope of this utility model.

Claims

1. A device for suppressing vortex-induced vibration of a marine riser, characterized in that, The marine riser vortex-induced vibration suppression device includes an arc sleeve (1), a vibration damping plate (3), a handle (4), and a self-locking cable tie (5). The weight of the marine riser vortex-induced vibration suppression device is greater than its buoyancy in seawater. The inner diameter of the arc sleeve (1) is greater than the outer diameter of the marine riser, and it is fitted onto the marine riser. The handle (4) is fixed on the arc sleeve (1) to facilitate the installation of the arc sleeve (1) on the marine riser and free rotation around the marine riser. The vibration damping plate (3) is fixed to the arc sleeve (1), and its plate surface is arranged parallel to the axis of the marine riser. The self-locking cable tie (5) is tied to the outer wall of the marine riser and is located at the lower part of the marine riser vortex-induced vibration suppression device.

2. The vortex-induced vibration suppression device for marine risers according to claim 1, characterized in that, The marine riser vortex-induced vibration suppression device also includes a fairing (2), which is composed of two plates. The two plates are connected at one end and open at the other end. One open end is fixed to the arc-shaped sleeve (1), and the connected end is fixed to the vibration suppression plate (3).

3. The vortex-induced vibration suppression device for marine risers according to claim 2, characterized in that, The vibration damping plate (3) is a rigid flat plate, a corrugated plate, or a waterproof flexible fabric.

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