A bottom-towing stabilization installation device for subsea pipelines that adapts to seabed topography

Abstract

This application discloses an adaptive seabed topography subsea pipeline stabilization installation device using a bottom-towing method, belonging to the field of marine engineering. The device includes a pipeline and a connecting cable positioned above the pipeline. Several straps connected to the connecting cable are evenly spaced along the length of the pipeline. The straps are connected to the pipeline using a "double-loop cross-wrap" method, meaning they are wrapped circumferentially around the pipeline and then cross axially to form an "X" shape constraint. A pad is placed between the straps and the pipeline, with a diamond-patterned surface. Locking devices are provided on the straps to secure them to the pipeline. The pad, positioned between the straps and the pipeline, plays a crucial protective role, completely preventing direct contact between the straps and the pipeline. This effectively prevents the straps from damaging the pipeline's anti-corrosion layer due to friction during long-term use, greatly extending the pipeline's service life, reducing maintenance costs, and ensuring the long-term stable operation of the subsea pipeline project.

Description

Technical Field

[0001] This application relates to the field of marine engineering technology, specifically to a bottom-towing stabilization installation device for subsea pipelines that is adapted to seabed topography. Background Technology

[0002] In the field of marine engineering, the laying of subsea pipelines (such as marine discharge pipes) is a key step in realizing projects such as marine resource development and sewage treatment. Currently, the mature subsea pipeline laying technologies in the industry mainly include the pipelaying vessel method, the hoisting method, and the towing method. Due to their different technical characteristics, these methods exhibit significant differences in applicable scenarios and practical applications.

[0003] While the pipelaying vessel method, as a traditional technique, can complete pipeline laying under certain conditions, it has obvious limitations: on the one hand, its offshore operations involve large-scale specialized equipment, resulting in high construction costs; on the other hand, due to equipment limitations, it cannot meet the laying requirements of large-diameter submarine pipelines, thus restricting its applicability in engineering projects.

[0004] The hoisting method involves transporting pipelines to the open sea by barge, followed by hoisting operations using crane vessels. The drawbacks of this method are the relatively short pipeline lengths that can be worked on at one time, leading to low construction efficiency. Furthermore, each pipeline section requires underwater connection, often necessitating dozens of suitable working windows to complete the entire project, resulting in significant time pressure. More importantly, it has poor resistance to wind and waves; if sudden winds or waves occur, the pipeline hoisting process cannot be stopped immediately, posing a high safety risk and severely challenging construction safety.

[0005] Pipe towing is a preferred method for pipeline laying in near-shore areas because it does not rely on pipelaying vessels and can be completed using only ordinary tugboats. It is also adaptable to various water depths, making it particularly suitable for the installation of large-diameter, thin-walled subsea pipelines. Conventional pipe towing methods are divided into bottom towing and floating towing. Bottom towing involves pulling prefabricated pipe sections from land into the water via a slipway and then directly towing them along the seabed. Because the pipeline is close to the seabed, it has a certain degree of adaptability to environmental factors such as wind, waves, and currents. Work can be interrupted if necessary with minimal time and economic losses, making it widely used in pipeline laying near the coast, in shallow waters, and on riverbeds. However, this method has its drawbacks. During towing, the pipeline will pass through seabeds with varying conditions, resulting in different levels of resistance. It is also significantly affected by seabed slope, increasing the difficulty of towing control. The floating towing method involves attaching buoys or airbags to the pipe sections at regular intervals, allowing the pipeline to float on the surface after launching. During towing, a main tugboat pulls the pipe from the head, while an auxiliary vessel applies tension at the stern, and guard vessels are positioned on both sides to prevent deviation or excessive deformation. However, the floating towing method is greatly affected by surface environmental factors such as wind, waves, and tides, and has stringent requirements for the operational window, necessitating multiple waits for suitable conditions before construction can commence.

[0006] To balance the advantages and disadvantages of bottom towing and floating towing methods, improved technologies have emerged in the industry. For example, the underwater towing device for subsea pipelines disclosed in Chinese utility model patent CN222760409U suspends the pipeline in the water by setting up buoys and counterweights (anchor chains), achieving towing off the bottom. This method falls between floating towing and bottom towing, avoiding direct contact between the pipeline and the seabed to reduce seabed resistance and towing force requirements, while also minimizing the impact of surface wind, waves, and currents. Simultaneously, the friction generated by the anchor chain in contact with the seabed maintains the stability of the pipeline during towing, and the tension applied by the stern tugboat prevents the pipeline from shifting or deforming. The device has a simple structure and is easy to use. However, in actual use, because the straps are in direct contact with the pipeline, the pipeline's anti-corrosion layer is easily worn away, affecting the pipeline's service life.

[0007] Therefore, this application provides a bottom-mounted stabilization installation device for subsea pipelines that adapts to seabed topography, in order to solve the above-mentioned problems. Utility Model Content

[0008] This application provides a submarine pipeline off-bottom towing stabilization installation device that adapts to seabed topography, aiming to solve the problems mentioned in the background art, such as the direct contact between the existing straps and the pipeline, which easily wears off the pipeline's anti-corrosion layer and affects the service life of the pipeline.

[0009] To achieve the above objectives, this application provides the following technical solution: a stabilizing installation device for a submarine pipeline using an off-bottom towing method that adapts to seabed topography, comprising a pipeline and a connecting cable positioned above the pipeline. Several straps connected to the connecting cable are evenly spaced along the length of the pipeline. A counterweight, which is an anchor chain, is positioned at the bottom of each strap for pulling the pipeline down. A buoy for pulling the pipeline up is positioned above the connecting cable. By using the buoy and counterweight, the pipeline is suspended in the water, allowing it to be towed off-bottom. Off-bottom towing is between floating towing and bottom towing, avoiding direct contact with the seabed and thus requiring less towing force. It also avoids the effects of surface wind, waves, and currents on the pipeline, as is the case with floating towing. This device has a simple structure, is easy to use, and performs well.

[0010] The binding strap is connected to the pipeline using a "double-loop cross-wrap" method. This involves wrapping the strap circumferentially around the pipeline and then crossing it axially to form an "X" shape constraint. The spacing between the cross points is 1.5-2 times the pipeline diameter to enhance radial wrapping force. A pad with a diamond-patterned surface is placed between the binding strap and the pipeline. The binding strap is equipped with locking devices for securing it to the pipeline. The pad, positioned between the binding strap and the pipeline, plays a crucial protective role, completely preventing direct contact between them. This effectively prevents damage to the pipeline's anti-corrosion layer due to friction during long-term use, significantly extending the pipeline's service life, reducing maintenance costs, and ensuring the long-term stable operation of the subsea pipeline project. The pad acts as an isolation buffer layer, forming a physical barrier between the binding strap and the pipeline. When the strapping tends to shift relative to the pipeline due to the dragging force, the gasket first bears the friction force. The diamond pattern pressed on its surface further increases the friction force with the strapping and the pipeline, disperses the local stress, makes the friction force evenly distributed, and avoids concentrated wear. At the same time, its own material has good wear resistance and flexibility, which can absorb and buffer friction energy and protect the pipeline anti-corrosion layer from damage.

[0011] Preferably, the binding strap is made of high-strength polyester webbing or galvanized steel binding strap. Using high-strength polyester webbing ensures a secure connection to the pipeline while adapting to complex stress changes in the marine environment, reducing the risk of breakage due to material fatigue. Using galvanized steel binding strap ensures stable connection of the pipeline even in harsh sea conditions.

[0012] Preferably, the gasket is a neoprene rubber gasket or a polyurethane toothed gasket. Neoprene rubber gaskets effectively cushion the friction between the strap and the pipe. Polyurethane toothed gaskets, with their high hardness, high strength, and unique toothed structure, provide strong friction to prevent the strap from slipping while effectively dispersing pressure and avoiding localized stress concentration that could damage the pipe's anti-corrosion coating.

[0013] Preferably, to avoid the anchor chain being susceptible to entanglement, wear, and corrosion in the seabed environment, the anchor chain comprises a rigid section in contact with the seabed and a suspended flexible section. The anchor chain, consisting of the rigid and flexible sections, acts as a counterweight, enabling dynamic self-balancing of the suspended pipeline and greatly enhancing its stability in complex environments such as ocean currents. The rigid section, in contact with the seabed, generates friction, effectively preventing significant deviations during towing and ensuring the pipeline is towed along a predetermined trajectory. The flexible section can flexibly adjust according to changes in pipeline stress. When the pipeline is disturbed and rises or sinks, it adjusts its overall weight by changing its state (raising or lowering the rigid section), restoring the pipeline to a stable suspended state. This requires only a small towing force to move the pipeline, reducing energy consumption and equipment requirements.

[0014] Preferably, the rigid section is coated with a wear-resistant coating, such as a ceramic matrix composite material; the flexible section is coated with a corrosion-resistant alloy, such as a titanium alloy. Coating the rigid section with a ceramic matrix composite material coating significantly improves its wear resistance during frequent friction with the seabed, greatly extending the anchor chain's service life, reducing structural damage and performance degradation caused by wear, and lowering maintenance and replacement costs. The flexible section ensures that it maintains good mechanical properties and structural integrity even under harsh conditions of long-term immersion in seawater, preventing breakage or strength reduction due to corrosion, ensuring stable operation of the anchor chain in complex marine environments, effectively achieving the dynamic self-balancing function of pipeline suspension, and improving the reliability and service life of the entire installation device.

[0015] Preferably, the buoyancy of the float is adjustable, and the float is equipped with at least one valve. The buoyancy of the float is adjustable, and the amount of water injected can be controlled by the at least one valve located at the top, thereby precisely adjusting the buoyancy of the float.

[0016] Preferably, to reduce the resistance generated by the pontoon during movement: the two ends of the pontoon are conical, and streamlined guide fins are installed on the surface of the pontoon to convert lateral water flow into propulsion force, reducing the risk of deviation. The conical shape of the two ends of the pontoon effectively reduces the water resistance encountered by the pontoon during movement, improves towing efficiency, and reduces energy consumption. The streamlined guide fins installed on the surface can convert lateral water flow into propulsion force, which not only further reduces water resistance but also provides additional power for the movement of the pontoon and pipeline. At the same time, it can effectively prevent the pipeline from deviating under the action of wind, waves, and currents, enhance the stability of the pipeline during towing, and improve the safety and reliability of the entire installation operation.

[0017] Preferably, at least one of the pontoons is connected to a buoy that floats on the water surface. The buoy serves as a clear marker, providing clear location information for offshore workers and facilitating rapid positioning of the pipeline in complex marine environments. This is especially beneficial at night or in low visibility conditions, effectively preventing collisions with other vessels and ensuring operational safety and pipeline integrity.

[0018] Preferably, the system also includes a lead tugboat, which is connected to one end of the pipeline via a towing cable. The lead tugboat provides the main traction force to the pipeline, propelling it to move in a predetermined direction within the seawater.

[0019] Preferably, the system also includes a stern tugboat, which is connected to the other end of the pipeline via a towing cable. When the pipeline is subjected to strong lateral currents, appropriate tension can be applied to prevent the pipeline from shifting or deforming excessively, ensuring the stability and straightness of the pipeline during towing, improving installation accuracy, and ensuring the quality of the entire subsea pipeline laying project.

[0020] This application uses a gasket as an isolation and buffer layer to form a physical barrier between the strap and the pipe. When the strap tends to shift relative to the pipe due to dragging force, the gasket first bears the frictional force. The diamond pattern pressed on its surface further increases the friction with the strap and the pipe, dispersing local stress and making the friction force evenly distributed, avoiding concentrated wear. At the same time, its own material has good wear resistance and flexibility, which can absorb and buffer frictional energy and protect the anti-corrosion layer of the pipe from damage.

[0021] The anchor chain of this application consists of a rigid section in contact with the seabed and a suspended flexible section. The anchor chain, composed of the rigid and flexible sections, acts as a counterweight, enabling dynamic self-balancing of the pipeline's suspension and greatly enhancing its stability in complex environments such as ocean currents. The rigid section, in contact with the seabed, generates friction, effectively preventing significant deviations during towing and ensuring the pipeline is towed along a predetermined trajectory. The flexible section can flexibly adjust according to changes in pipeline stress. When the pipeline is disturbed and rises or sinks, it adjusts its overall weight by changing its own state (raising or lowering the rigid section), restoring the pipeline to a stable suspended state. Furthermore, only a small towing force is required to move the pipeline, reducing energy consumption and equipment requirements.

[0022] The pontoon of this application has conical arc-shaped ends, which can effectively reduce the water resistance encountered by the pontoon during movement, improve towing efficiency, and reduce energy consumption. The streamlined guide fins installed on the surface can convert lateral water flow into propulsion force, which not only further reduces water resistance, but also provides additional power for the movement of the pontoon and pipeline. At the same time, it can effectively prevent the pipeline from deviating under the action of wind, waves and currents, enhance the stability of the pipeline during towing, and improve the safety and reliability of the entire installation operation. Attached Figure Description

[0023] Figure 1 A schematic diagram of a subsea pipeline stabilization installation device that adapts to seabed topography and is towed off the seabed.

[0024] Figure 2 for Figure 1 Enlarged view of the middle section.

[0025] In the picture:

[0026] 1. Pipeline; 2. Connecting cable; 3. Straps; 4. Counterweight; 5. Buoy; 501. Guide fin; 6. Liner; 7. Buoy; 8. Head tugboat; 9. Towing cable; 10. Tail tugboat. Detailed Implementation

[0027] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0028] Example 1

[0029] This embodiment provides a subsea pipeline off-bottom towing stable installation device that adapts to seabed topography, such as... Figure 1-2 As shown, the installation device includes a pipe 1 and a connecting cable 2 positioned above the pipe 1. Several straps 3, connected to the connecting cable 2, are evenly spaced along the length of the pipe 1. The connecting cable 2 and the straps 3, evenly spaced along the length of the pipe 1, form a stable connection system that evenly distributes the external forces acting on the pipe 1 during towing, ensuring the overall stability of the pipe 1 in a suspended state. Simultaneously, the evenly spaced arrangement optimizes force distribution, preventing excessive localized stress that could lead to deformation or damage to the pipe 1. The straps 3 are connected to the pipe 1 using a "double-loop cross-wrap" method, enhancing radial wrapping force and significantly improving the reliability of the connection between the straps 3 and the pipe 1. This effectively prevents the straps 3 from loosening or falling off in complex sea conditions, further ensuring the safety and stability of the pipe 1 during off-bottom towing. The connecting cable 2 acts as a "bridge," transmitting the upward pull of the float 5 and the downward pull of the strap 3-counterweight 4 system to the pipe 1, maintaining the pipe 1 in a suspended state. The "double-loop cross-wrap" method of the strap 3 involves wrapping it around the pipe 1 twice in the circumference and then crossing it in the axial direction to form an "X" shape constraint. The distance between the cross points is 1.5-2 times the diameter of the pipe 1. This unique structure increases the contact area and friction between the strap 3 and the pipe 1, constraining the pipe 1 from both the circumferential and axial dimensions. It effectively resists torsional forces and displacements during towing, ensuring that the pipe 1 and the strap 3 are tightly connected and that the force is transmitted smoothly.

[0030] The bottom of the strap 3 is equipped with a counterweight 4 for pulling down the pipe 1, and the counterweight 4 is an anchor chain; the top of the connecting cable 2 is equipped with a float 5 for pulling up the pipe 1; by setting the float 5 and the counterweight 4, the pipe 1 is suspended in the water, so that the pipe 1 can be towed off the bottom. Off-bottom towing is between floating towing and bottom towing. It does not directly contact the seabed and is not affected by the seabed. In this way, only a small towing force is needed, and the pipe 1 is not affected by surface wind, waves and currents like in floating towing. The device has a simple structure, is easy to use, and has good effect.

[0031] The binding strap 3 is connected to the pipe 1 using a "double-loop cross-wrap" method. It wraps around the pipe 1 twice circumferentially, then crosses axially to form an "X" shape constraint. The spacing between the cross points is 1.5-2 times the diameter of the pipe 1 to enhance the radial wrapping force. A gasket 6 is placed between the binding strap 3 and the pipe 1. The surface of the gasket 6 is embossed with a diamond pattern. The binding strap 3 is equipped with locking devices for securing it to the pipe 1. The gasket 6, placed between the binding strap 3 and the pipe 1, plays a crucial protective role, completely preventing direct contact between the binding strap 3 and the pipe 1. This effectively prevents the binding strap 3 from damaging the anti-corrosion layer of the pipe 1 due to friction during long-term use, greatly extending the service life of the pipe 1, reducing maintenance costs, and ensuring the long-term stable operation of the subsea pipeline 1 project. The gasket 6 acts as an isolation buffer layer, forming a physical barrier between the binding strap 3 and the pipe 1. When the strap 3 is subjected to dragging force and has a relative displacement tendency with the pipe 1, the gasket 6 first bears the friction force. The diamond pattern pressed on its surface further increases the friction force with the strap 3 and the pipe 1, disperses the local stress, makes the friction force evenly distributed, and avoids concentrated wear. At the same time, its own material has good wear resistance and flexibility, which can absorb and buffer friction energy and protect the anti-corrosion layer of the pipe 1 from damage.

[0032] The binding strap 3 is made of high-strength polyester webbing or galvanized steel. High-strength polyester webbing offers advantages such as high strength, good wear resistance, low shrinkage, and moderate elasticity. It ensures a secure connection between the binding strap 3 and pipe 1 while adapting to complex stress changes in the marine environment, reducing the risk of breakage due to material fatigue. Its good flexibility also prevents hard scratches on the surface of pipe 1. Galvanized steel binding strap 3 provides excellent strength and rigidity, offering strong binding force to ensure stable connection of pipe 1 even in harsh sea conditions. The galvanized layer also provides excellent corrosion resistance, effectively resisting seawater erosion, extending the service life of the binding strap 3, and reducing maintenance frequency. High-strength polyester webbing, with its superior fiber structure and special twisting process, works synergistically between fibers to evenly distribute stress when subjected to tensile force, allowing it to withstand significant external forces without breaking. Its moderate elasticity also acts as a buffer when pipe 1 experiences minor displacement due to ocean currents or other factors, preventing rigid tension damage to pipe 1. The galvanized steel straps 3 rely on the high strength of the steel itself to tightly bind the pipe 1 during towing, resisting various external forces. The galvanized layer forms a dense film of basic zinc carbonate in seawater. Even if the galvanized layer is damaged locally, the steel substrate, acting as a cathode, can be protected, slowing down the corrosion rate and maintaining the structural integrity and mechanical properties of the straps 3.

[0033] When using steel strapping 3, a wedge-shaped locking device is used as the locking element. The wedge-shaped locking device applies pre-tightening force through the cooperation of the wedge block and the inclined surface of the steel strapping 3, providing a strong and uniform locking force to ensure a tight connection between the steel strapping 3 and the pipe 1, effectively resisting various external impacts during towing. The stainless steel anti-loosening pin installed at the end completely prevents the wedge block from rebounding and loosening under complex working conditions such as vibration and ocean current impact, significantly improving the reliability and stability of the locking structure and avoiding pipe 1 shifting or being damaged due to loosening of the strapping 3. At the same time, the stainless steel material has good corrosion resistance and can maintain its anti-loosening function in the seawater environment for a long time, extending the service life of the locking element. During installation, the steel strapping 3 is wrapped around the pipe 1 and passed through the wedge-shaped locking device. External force pushes the wedge block to move along the inclined surface of the strapping 3, and the wedge effect of the inclined surface converts the thrust into a huge pre-tightening force on the strapping 3, so that the strapping 3 tightly wraps the pipe 1. Once the wedge block reaches the predetermined position, a stainless steel anti-loosening pin is inserted. The anti-loosening pin engages in the gap between the wedge block and the main body of the locking device, forming a mechanical limit and preventing the wedge block from moving in the opposite direction under vibration or external force. This achieves a durable and reliable locking effect, ensuring that the steel strapping 3 always maintains effective restraint on the pipeline 1.

[0034] When using synthetic fiber strapping 3, the locking mechanism employs a cam-type quick-lock buckle: the spring plate inside the cam-type quick-lock buckle automatically bites the strapping 3 when it is under force, achieving rapid locking and significantly improving installation efficiency. The dual locking mechanism (manual knob + spring clip) provides double protection in vibration environments. It allows for initial locking force application and foundation locking via the manual knob, while the spring clip automatically compensates for and strengthens the locking when the strapping 3 experiences changes in force, effectively preventing loosening and ensuring the stability of the connection between the synthetic fiber strapping 3 and the pipe 1. Simultaneously, this structure is easy to operate, facilitating rapid installation and adjustment during offshore operations, adapting to the material characteristics of the synthetic fiber strapping 3, and avoiding damage to the strapping 3 from over-tightening. In use, the synthetic fiber strapping 3 is threaded through the cam-type quick-lock buckle, and the strapping 3 is pulled to wrap around the pipe 1 with appropriate tension. At this time, the spring plate inside the buckle deforms under the tension of the strapping 3, pressing tightly against the surface of the strapping 3 to generate friction, achieving initial automatic locking. Then, tightening the manual knob further enhances the locking force on the strap 3 through mechanical transmission, fixing the buckle body in its current state. The spring clip automatically engages with the positioning groove after the knob is tightened, forming a second locking mechanism. When encountering vibration or fluctuations in the force on the strap 3, the elasticity of the spring plate automatically adjusts the gripping force according to the slight displacement of the strap 3, while the spring clip prevents the knob from loosening. The dual mechanisms work together to ensure that the buckle remains locked in complex environments.

[0035] The gasket 6 is made of neoprene rubber or polyurethane serrated gasket. Neoprene rubber gaskets possess excellent weather resistance, oil resistance, chemical corrosion resistance, and superior flexibility and elasticity, effectively buffering friction between the strap 3 and pipe 1. They can also adapt to temperature changes and chemical corrosion in seawater environments, maintaining stable protective performance over the long term. Polyurethane serrated gaskets, with their high hardness, high strength, and unique serrated structure, provide strong friction to prevent the strap 3 from slipping while effectively dispersing pressure, avoiding localized stress concentration that could damage the anti-corrosion layer of pipe 1. Furthermore, their excellent wear resistance ensures good protective performance over long-term use. Neoprene rubber gaskets utilize the special chemical bonds in their molecular structure and the high elasticity of rubber to undergo reversible elastic deformation under friction and pressure, absorbing and dispersing energy, reducing impact on pipe 1. Their chemical corrosion resistance makes them resistant to corrosion in seawater, maintaining stable physical properties. The serrated structure of the polyurethane serrated gasket is embedded between the strap 3 and pipe 1, increasing contact points and friction, making it difficult for the strap 3 to slip. The high hardness and high strength of polyurethane material make it less prone to deformation when subjected to pressure, which distributes the pressure evenly on the surface of pipe 1 and avoids excessive stress on a single point, thereby protecting the anti-corrosion layer of pipe 1.

[0036] To prevent the anchor chain from being easily entangled, worn, and corroded in the seabed environment, the anchor chain consists of a rigid section in contact with the seabed and a suspended flexible section. The anchor chain, composed of the rigid and flexible sections, acts as a counterweight 4, enabling the dynamic self-balancing of the suspended pipeline 1 and greatly enhancing its stability in complex environments such as ocean currents. The rigid section, in contact with the seabed, generates friction, effectively preventing significant deviations of the pipeline 1 during towing and ensuring it is towed along a predetermined trajectory. The flexible section can flexibly adjust according to changes in the force applied to the pipeline 1. When the pipeline 1 is disturbed and rises or sinks, it adjusts its overall weight by changing its own state (raising or lowering the rigid section), restoring the pipeline 1 to a stable suspended state. This requires only a small towing force to move the pipeline 1, reducing energy consumption and equipment requirements. When the pipeline 1 is in a stable suspended state, part of the weight of the rigid section is supported by the seabed, while the flexible section maintains the connection between the pipeline 1 and the rigid section and adapts to certain positional changes. If Pipeline 1 is disturbed and begins to float, the flexible section will pull more of the rigid section away from the seabed, increasing the overall weight of Pipeline 1. Based on the balance between gravity and buoyancy, this forces Pipeline 1 to sink and return to its original position. Conversely, when Pipeline 1 sinks, the flexible section will place the rigid section back onto the seabed, reducing the overall weight of Pipeline 1 and causing it to float back to its original position. During towing, the friction between the rigid section and the seabed provides lateral resistance to Pipeline 1, resisting the lateral forces of ocean currents, preventing Pipeline 1 from deviating, and ensuring the stability of the towing direction.

[0037] The rigid section employs a wear-resistant coating, such as ceramic matrix composites. Ceramic matrix composites possess characteristics such as high hardness, high wear resistance, high temperature resistance, and good chemical stability. Coating the rigid section of the anchor chain with a ceramic matrix composite coating significantly improves its wear resistance during frequent friction with the seabed, greatly extending the anchor chain's service life, reducing structural damage and performance degradation caused by wear, lowering maintenance and replacement costs, and ensuring that the anchor chain effectively maintains the stability of the pipeline and achieves dynamic self-balancing during long-term seabed operations. The high hardness of the ceramic matrix composite allows it to withstand the scraping of sharp objects such as seabed sand and gravel. During friction, the ceramic particles on the coating surface, with their hardness advantage, resist wear and reduce the loss of the rigid section's main material. Its good chemical stability prevents corrosion of the rigid section's metal material by seawater and seabed chemicals, maintaining the anchor chain's mechanical properties and structural integrity. Even in special environments such as high-temperature hydrothermal vent areas on the seabed, the high-temperature resistance of the ceramic matrix composite ensures the coating's stable performance, continuously providing effective protection for the rigid section.

[0038] The flexible section utilizes corrosion-resistant alloys, such as titanium alloys. Titanium alloys possess excellent corrosion resistance, exhibiting virtually no corrosion in seawater, while also possessing high strength and good toughness. Applying them to the flexible section of the anchor chain ensures that it maintains good mechanical properties and structural integrity even under harsh conditions of long-term immersion in seawater, preventing breakage or strength reduction due to corrosion. This guarantees stable operation of the anchor chain in complex marine environments, effectively achieving the dynamic self-balancing function of pipe 1's suspension, and improving the reliability and service life of the entire installation device. A dense and stable oxide film forms on the surface of the titanium alloy. This oxide film has extremely strong corrosion resistance in seawater, preventing seawater and its dissolved oxygen, chloride ions, and other corrosive substances from chemically reacting with the titanium alloy matrix, thus preventing metal corrosion. Its high strength allows the flexible section to withstand the tensile forces generated by changes in buoyancy and ocean currents in pipe 1, while its good toughness ensures that the flexible section is not prone to brittle fracture during frequent bending and stretching deformations, maintaining effective connection and adjustment between the rigid section and pipe 1.

[0039] The buoyancy of the float 5 is adjustable, and at least one valve is installed on the float 5. Specifically, a DN1000 steel pipe sealed on both sides is used as the float 5. The length of a single steel pipe is 5m, and the buoyancy is approximately 4t. The steel pipe is directly tied to the connecting cable 2 using slings. Two valves are installed at the top of the steel pipe. The valves are used to fill the float 5 with water after the pipe 1 is connected, to retrieve the float 5, and to control the amount of water filled into the float 5 to control its buoyancy. The buoyancy of the float 5 is adjustable, and the amount of water filled is controlled by at least one valve at the top, thereby precisely adjusting the buoyancy of the float 5. This feature allows the device to flexibly change the buoyancy of the float 5 according to factors such as the actual weight of the pipe 1, ocean currents, and seawater density, ensuring that the pipe 1 is always in a stable suspended state, improving the adaptability of the device to different operating environments. After the pipe 1 is connected, water can be filled into the float 5 through the valves to reduce its buoyancy, making it easier to retrieve the float 5, reducing device costs, and improving resource utilization. When buoyancy of pontoon 5 needs to be increased, the valve is closed, filling the pontoon 5 with air. The density difference between air and seawater generates upward buoyancy. When buoyancy needs to be decreased, the valve is opened, allowing seawater to enter the pontoon 5. As the amount of water increases, the overall weight of the pontoon 5 increases, and the buoyancy decreases accordingly. After the pipeline 1 is connected, the valve is opened, allowing a large amount of seawater to flood into the pontoon 5. When the buoyancy is less than the weight of the pontoon 5 itself, it sinks, facilitating recovery. In this way, the buoyancy of pontoon 5 can be adjusted precisely and at any time according to actual operational needs, ensuring the suspension stability of pipeline 1 and the smooth progress of subsequent operations.

[0040] To reduce the resistance generated by the pontoon 5 during movement: the two ends of the pontoon 5 are conical, and streamlined guide fins 501 are installed on the surface of the pontoon 5 to convert lateral water flow into propulsion, reducing the risk of drift. The conical shape of the two ends of the pontoon 5 effectively reduces the water resistance encountered by the pontoon 5 during movement, improves towing efficiency, and reduces energy consumption. The streamlined guide fins 501 installed on the surface can convert lateral water flow into propulsion, which not only further reduces water resistance, but also provides additional power for the movement of the pontoon 5 and the pipe 1. At the same time, it can effectively prevent the pipe 1 from drifting under the action of wind, waves, and currents, enhance the stability of the pipe 1 during towing, and improve the safety and reliability of the entire installation operation. The conical design of the two ends conforms to the principles of fluid mechanics, allowing the water flow to separate more smoothly when flowing through the pontoon 5, reducing turbulence and vortices in the water flow, and reducing pressure drag. The special shape and installation angle of the streamlined guide fin 501 can guide the lateral water flow in a specific direction. According to the principle of action and reaction, the water flow generates a reaction force on the guide fin 501. This reaction force is decomposed into a propulsive force consistent with the towing direction and a lateral force that resists the deviation of the pipe 1. The propulsive force assists the tugboat in dragging the float 5 and the pipe 1, while the lateral force maintains the stability of the pipe 1 and reduces the risk of deviation.

[0041] At least one buoy 5 is connected to a buoy 7, which floats on the water surface. The buoy 7 serves as a prominent marker, providing clear location information for offshore workers and facilitating rapid positioning of the pipeline 1 in complex marine environments, especially at night or in low visibility conditions. This effectively prevents collisions with other vessels, ensuring operational safety and the integrity of the pipeline 1. It also allows construction personnel to monitor and adjust the entire installation process in real time. The buoy 7 floats on the water surface by its own buoyancy and is connected to the underwater buoy 5 and pipeline 1 via a connecting device. Its conspicuous color, shape, and potential luminous or audible warning devices enable it to be spotted by workers and passing vessels from a distance. By observing the position of the buoy 7, workers can visually determine the approximate underwater location of the pipeline 1 and adjust parameters such as towing speed and direction as needed to ensure smooth installation. It also serves as a warning to surrounding vessels, preventing accidental collisions.

[0042] It also includes a lead tugboat 8, which is connected to one end of the pipeline 1 via a towing cable 9. The lead tugboat 8 provides the main traction force to the pipeline 1, propelling the pipeline 1 to move in the seawater in a predetermined direction.

[0043] It also includes a tail tugboat 10, which is connected to the other end of the pipeline 1 via a towing cable 9. When the pipeline 1 is subjected to strong lateral currents, appropriate tension can be applied to prevent the pipeline 1 from shifting or deforming excessively, ensuring the stability and straightness of the pipeline 1 during towing, improving installation accuracy, and ensuring the quality of the entire subsea pipeline laying project.

[0044] The lead tugboat 8 starts its engine, generating strong traction, which is transmitted to the pipeline 1 via the tow cable 9, overcoming the resistance of the pipeline 1 in the water and moving it forward. The tail tugboat 10 monitors the force and attitude of the pipeline 1 in real time. When the lateral current exerts a force on the pipeline 1, causing the pipeline 1 to deviate or deform, the tail tugboat 10 adjusts its own position and the tension of the tow cable 9 to generate a pulling force opposite to the lateral current force, balancing the lateral force and maintaining the straightness of the pipeline 1. This ensures that the pipeline 1 can still be stably towed to the predetermined location for installation even in complex ocean current environments.

[0045] When the buoyancy of the pontoon 5 equals the weight of the pipe 1, the pipe 1 can achieve a stable suspended state. However, this equilibrium is a static equilibrium, and even slight external disturbances can disrupt it, causing the pipe 1 to either float or sink, making it highly uncontrollable. Therefore, the counterweight 4 uses an anchor chain, which consists of a rigid section and a flexible section. The rigid section contacts the seabed, and the seabed supports the weight of this part of the anchor chain. When the pipe 1 is disturbed and floats, the anchor chain on the seabed is pulled up, increasing the overall weight of the pipe 1 and forcing it to sink. When the pipe 1 is disturbed and sinks, the anchor chain is placed back on the seabed for support, reducing the overall weight of the pipe 1 and forcing it to float. This achieves dynamic self-balancing of the pipe 1's suspension. Secondly, the counterweight 4 uses an anchor chain. The rigid section contacts the seabed, while the flexible section achieves dynamic self-balancing of the pipeline suspension. The rigid section has friction with the seabed, which allows the pipeline 1 to maintain stability during towing under the action of ocean currents and prevents large deviations. The friction of the anchor chain that partially contacts the seabed is also not large (compared to the entire anchor chain contacting the seabed), so it can be dragged with a small towing force.

[0046] All components of the device have undergone anti-corrosion treatment.

[0047] It should be noted that many of the standard parts used in this application are available on the market, while non-standard parts can be specially customized. The connection method used in this application is also a very common method in the mechanical field, and will not be described in detail here.

[0048] The above description is merely a preferred embodiment of this application, but the scope of protection of this application is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in this application, based on the technical solution and concept of this application, should be included within the scope of protection of this application.

Claims

1. A subsea pipeline stabilization and installation device adapted to seabed topography using a bottom-towing method, comprising a pipeline (1) and a connecting cable (2) disposed above the pipeline (1), characterized in that: The pipe (1) is provided with several straps (3) that are connected to the connecting cable (2) at equal intervals along its length. The bottom of the straps (3) is provided with a counterweight (4) for pulling down the pipe (1). The counterweight (4) is an anchor chain. The top of the connecting cable (2) is provided with a float (5) for pulling up the pipe (1). The binding strap (3) is connected to the pipe (1) in a "double-loop cross-wrap" manner, that is, after wrapping around the pipe (1) circumferentially for 2 loops, it crosses in the axial direction to form an "X" shaped constraint. The distance between the cross points is 1.5-2 times the diameter of the pipe 1 to enhance the radial wrapping force. A pad (6) is provided between the strap (3) and the pipe (1). The surface of the pad (6) is pressed with a diamond pattern. A locking member is provided on the strap (3) for fixing the strap (3) to the pipe (1).

2. A self-adapting seabed topography seabed pipeline off-bottom tow method stabilising installation according to claim 1, characterised in that: The strap (3) is made of high-strength polyester webbing or galvanized steel strap.

3. A self-adapting seabed topography seabed pipeline off-bottom tow method stabilizing installation apparatus according to claim 1, characterized in that: The liner (6) is made of neoprene rubber or polyurethane toothed pad.

4. A self-adapting seabed topography seabed pipeline off-bottom tow method stabilizing installation apparatus according to claim 1, characterized in that: The anchor chain consists of a rigid section in contact with the seabed and a flexible section suspended in the air.

5. A self-adapting seabed topography seabed pipeline off-bottom tow method stabilising installation according to claim 4, characterised in that: The rigid section is coated with a wear-resistant coating, such as a ceramic matrix composite material; The flexible segment is made of a corrosion-resistant alloy, such as titanium alloy.

6. A self-adapting seabed topography seabed pipeline off-bottom tow method stabilizing installation apparatus according to claim 1, characterized in that: The buoyancy of the float (5) is adjustable, and the float (5) is provided with at least one valve.

7. The adaptive seabed topography-based stabilization and installation device for submarine pipelines using the off-bottom towing method according to claim 1, characterized in that: The two ends of the float (5) are conical arc-shaped, and the surface of the float (5) is equipped with streamlined guide fins (501), which can convert the lateral water flow into propulsion and reduce the risk of drift.

8. A self-adapting seabed topography seabed pipeline off-bottom tow method stabilizing installation apparatus according to claim 1, characterized in that: At least one of the pontoons (5) is connected to a buoy (7), which floats on the water surface.

9. A self-adapting seabed topography seabed pipeline off-bottom tow method stabilizing installation apparatus according to any one of claims 1-8, characterized in that: It also includes a lead tugboat (8), which is connected to one end of the pipeline (1) via a towing cable (9).

10. A self-adapting seabed topography seabed pipeline off-bottom tow method stabilising installation according to claim 9, characterised in that: It also includes a tail tug (10), which is connected to the other end of the pipe (1) via the towing cable (9).

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