Single-pile barrel-shaped foundation wellhead platform

Abstract

The invention discloses a single-pile bucket foundation wellhead platform which is used for offshore oilfield development and comprises a single-pile bucket foundation unit (3), a marine riser unit (2) mounted in the single-pile bucket foundation unit (3) and a wellhead supporting module (1) arranged at the top of the marine riser unit (2), and the bottom of the marine riser unit (2) is directly communicated to the bottom of the single-pile bucket foundation unit (3). A detachable sealing plug is arranged at the bottom of the marine riser unit (2), a closed bucket cabin is defined between the single-pile bucket foundation unit (3) and the marine riser unit (2), and a pressure regulating device used for pressurizing the closed bucket cabin to enable the closed bucket cabin to sink or decompressing the closed bucket cabin to enable the closed bucket cabin to float upwards is installed on the single-pile bucket foundation unit (3). The single-pile barrel-shaped foundation wellhead platform achieves efficient, economical and environment-friendly offshore oilfield development, and is particularly suitable for development of offshore marginal oilfields.

Description

Technical Field

[0001] This invention relates to the field of offshore oil facility technology, and in particular to a monopile barrel foundation wellhead platform. Background Technology

[0002] Monopile barrel foundation wellhead platforms for offshore oilfield development are an innovative marine engineering structure. They combine the stability of monopile barrel foundations with the flexibility of simple wellhead platforms, making them particularly suitable for developing marginal offshore oilfields. Utilizing the principle of negative pressure penetration, barrel foundations offer advantages such as structural stability and fatigue resistance. Compared to traditional pile foundations, they provide benefits including reduced construction and installation costs, easier transportation and installation, reusability, shorter construction time, and simpler exploration and research requirements. Currently, monopile barrel foundations are primarily used in offshore wind power and have not yet seen large-scale application in the oil industry.

[0003] In summary, how to effectively address the shortcomings in the application of monopile barrel foundations in the offshore oil sector is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0004] The purpose of this invention is to provide a monopile barrel foundation wellhead platform that enables efficient, economical, and environmentally friendly offshore oilfield development, and is particularly suitable for the development of offshore marginal oilfields.

[0005] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

[0006] A monopile barrel foundation wellhead platform for offshore oilfield development includes a monopile barrel foundation unit, a riser unit installed within the monopile barrel foundation unit, and a wellhead support module located on top of the riser unit. The bottom of the riser unit extends directly to the bottom of the monopile barrel foundation unit, and the bottom of the riser unit is equipped with a removable sealing plug. The monopile barrel foundation unit and the riser unit form a closed barrel chamber. A pressure regulating device is installed on the monopile barrel foundation unit to pressurize the closed barrel chamber to make it sink or depressurize it to make it float.

[0007] Optionally, the riser unit includes multiple risers and a riser barrel disposed on the outer periphery of all the risers. The foundation barrel and the riser barrel of the monopile barrel foundation unit are concentric. The enclosed barrel chamber is a riser ring between the foundation barrel and the riser barrel. The riser ring includes multiple independent enclosed chambers in the circumferential direction. Each chamber is connected to an independent pressure regulating device. The monopile barrel foundation wellhead platform is leveled by adjusting the pressure values ​​of the pressure regulating devices in different directions.

[0008] Optionally, the voltage regulating device includes:

[0009] An angle sensor used to detect the current angle between the axis of the monopile bucket foundation unit and the horizontal plane;

[0010] A pressure regulating unit connected to the angle sensor, used to control the negative pressure of the cabin gas on the side biased towards the acute angle to be less than the negative pressure of the cabin gas on the side biased towards the obtuse angle when the current included angle detected by the angle sensor is not a right angle.

[0011] Optionally, the pressure regulating unit includes:

[0012] Pressure sensors used to detect negative gas pressure in each of the aforementioned cabins;

[0013] A calculation unit connected to the pressure sensor, used to calculate the amount of negative gas pressure required for the axis of the single pile foundation unit to rotate to the vertical direction in each of the chambers when the current included angle detected by the angle sensor is not a right angle;

[0014] A pressure regulating valve connected to the calculation unit for pressurizing or depressurizing each of the compartments based on the negative pressure calculated by the calculation unit.

[0015] Optionally, the enclosed tank is divided into multiple compartments by multiple vertical support plates, the extension lines of which pass through the center of the watertight tank.

[0016] Optionally, the inner wall of the water-separating bucket is connected to the outer wall of each of the water-separating pipes by a diagonal brace, the extension line of which passes through the center of the water-separating bucket and the water-separating pipe.

[0017] Optionally, the water-separating bucket and the water-separating pipe are internally connected.

[0018] Optionally, the water-proof bucket is provided with multiple partition plates, which divide the water-proof bucket into multiple water-proof areas. Each water-proof area is provided with a water-proof pipe. The centers of the water-proof pipes are distributed on the pitch circle with the center of the water-proof bucket. The support plate and the corresponding partition plate are on a straight line, and the extension lines of the support plate and the partition plate pass through the center of the base bucket.

[0019] Optionally, the water-proof pipe is connected to the partition plate by a cross brace, the cross brace is perpendicular to the partition plate, and the connection points of the partition plate and the cross braces on both sides coincide.

[0020] Optionally, the length-to-diameter ratio of the base bucket is set to 2:1, and the diameter of the base bucket is greater than or equal to 5 meters.

[0021] The beneficial effects of this invention are as follows: the riser unit is installed within a monopile foundation unit, which provides greater buoyancy and stability, helping to resist wind and waves at sea. The riser, internally housed within the monopile foundation unit, effectively reduces the environmental loads on the riser under harsh sea conditions, protecting it from the effects of wind, waves, and currents, thus effectively safeguarding its safety. The riser unit is fixed to the seabed by the monopile foundation unit, which serves as the main support structure, providing buoyancy and additional stability for the riser unit as it extends into the seabed. A wellhead support module, a small operating platform, is mounted on top of the riser unit for drilling and oil extraction.

[0022] The upper end of the riser unit passes through the wellhead support module, and the bottom of the riser unit extends directly to the bottom of the monopile foundation unit. The riser unit connects the wellhead and the seabed. Pipelines such as oil pipes and electrical wires pass through the upper end of the riser unit to the seabed, protecting the pipelines and reducing their impact from waves. The bottom of the riser unit is equipped with a removable sealing plug, which can be a concrete plug inside the pile. Specifically, before the monopile foundation unit is sunk to the seabed, a layer of concrete can be poured into the bottom of the riser unit to form an in-situ concrete plug, preventing soil and seawater from penetrating the riser unit during installation. After the monopile foundation unit's sinking construction is completed, casing is lowered using a drilling platform. The riser is drilled into the formation using a drill bit. When a concrete plug is encountered, it is broken up using the drill bit, allowing the casing to be lowered.

[0023] The monopile foundation unit and the riser unit form a closed chamber. A pressure regulating device is installed on the monopile foundation unit and is connected to the closed chamber. The pressure regulating device is used to pressurize the closed chamber to make it sink or depressurize it to make it float. The pressure regulating device enables efficient repeated insertion and removal, reducing the reliance on auxiliary pile-driving equipment such as cranes and barges. This not only reduces costs but also improves the flexibility and speed of operations. The platform can move quickly between different well locations, supporting rolling development. This is especially important for marginal oilfields with small reserves or complex geological conditions, maximizing the efficiency and economy of resource extraction. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a schematic diagram of the structure of a monopile barrel foundation wellhead platform provided in a specific embodiment of the present invention.

[0026] Figure 2 This is a schematic diagram of the overall structure of the riser unit and the monopile foundation unit.

[0027] Figure 3 This is a top view of the riser unit and the monopile bucket foundation unit;

[0028] Figure 4 This is a bottom view of a monopile bucket foundation.

[0029] Figure label:

[0030] 1-Wellhead support module, 2-Waterproof pipe unit, 3-Single pile foundation unit, 4-Foundation bucket, 5-Installation hole, 6-Upper sealing plate, 7-Waterproof bucket, 8-Support plate, 9-Divider plate, 10-Horizontal brace, 11-Waterproof pipe, 12-Diagonal brace, 13-Pile internal concrete plug. Detailed Implementation

[0031] The core of this invention is to provide a monopile barrel foundation wellhead platform, which enables efficient, economical and environmentally friendly offshore oilfield development, and is especially suitable for the development of offshore marginal oilfields.

[0032] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0033] Please refer to Figures 1 to 4 , Figure 1 This is a schematic diagram of the structure of a monopile barrel foundation wellhead platform provided in a specific embodiment of the present invention. Figure 2 This is a schematic diagram of the overall structure of the riser unit and the monopile foundation unit. Figure 3 This is a top view of the riser unit and the monopile bucket foundation unit; Figure 4 This is a bottom view of a monopile bucket foundation.

[0034] In one specific embodiment, the monopile barrel foundation wellhead platform provided by the present invention is used for offshore oilfield development. It includes a monopile barrel foundation unit 3, a riser unit 2 installed in the monopile barrel foundation unit 3, and a wellhead support module 1 set on the top of the riser unit 2. The bottom of the riser unit 2 extends directly to the bottom of the monopile barrel foundation unit 3. The bottom of the riser unit 2 is provided with a removable sealing plug. The monopile barrel foundation unit 3 and the riser unit 2 form a closed barrel chamber. A pressure regulating device is installed on the monopile barrel foundation unit 3 to pressurize the closed barrel chamber to make it sink or depressurize it to make it float.

[0035] In the above structure, the monopile barrel foundation wellhead platform is suitable for the development of offshore marginal oil fields, especially for applications requiring rapid movement and deployment. The monopile barrel foundation wellhead platform includes a monopile barrel foundation unit 3, a riser unit 2, a wellhead support module 1, and a pressure regulating device.

[0036] Riser unit 2 is installed within monopile foundation unit 3, and is fixed to the seabed via monopile foundation unit 3. Monopile foundation unit 3 serves as the main support structure, providing buoyancy and additional stability for the riser unit 2 as it extends into the seabed. Wellhead support module 1 is supported on top of riser unit 2. Wellhead support module 1 is a small operating platform used for drilling and oil extraction.

[0037] The upper end of the riser 11 of the riser unit 2 passes through the wellhead support module 1, and the bottom of the riser unit 2 extends directly to the bottom of the monopile bucket foundation unit 3. The riser unit 2 connects the wellhead and the seabed. Pipeline components such as oil pipes and electrical wires pass through the upper end of the riser 11 to the seabed to protect the pipelines, reduce the impact of sea waves on the pipelines, reduce the diameter or wall thickness of the riser 11, save the amount of steel used in the riser 11, and reduce costs.

[0038] The bottom of the riser unit 2 is equipped with a removable sealing plug, which can be a concrete plug 13 inside the pile. Specifically, before the monopile foundation unit 3 is sunk to the seabed, a layer of concrete can be poured into the bottom of the riser unit 2 to form the concrete plug 13 inside the pile, preventing soil and seawater from penetrating the riser unit 2 when the monopile foundation unit 3 is installed. After the monopile foundation unit 3 is sunk, a drilling platform is used for casing operation. The riser 11 is drilled into the strata using a drill bit. When a concrete plug is encountered, it is broken up using the drill bit to allow the casing to be lowered.

[0039] The monopile bucket foundation unit 3 and the water-proof pipe unit 2 form a closed bucket chamber. A pressure regulating device is installed on the monopile bucket foundation unit 3. The pressure regulating device is connected to the closed bucket chamber and is used to pressurize the closed bucket chamber to make it sink or depressurize it to make it float. The insertion and extraction of the monopile bucket foundation unit 3 are realized through the negative pressure.

[0040] The monopile barrel foundation wellhead platform provided by this invention enables efficient repeated insertion and extraction through a pressure regulating device, reducing reliance on auxiliary pile-driving equipment such as cranes and barges. This not only lowers costs but also improves operational flexibility and speed. The platform can move quickly between different well locations, supporting rolling development, which is particularly important for marginal oilfields with smaller reserves or complex geological conditions, maximizing resource extraction efficiency and economy. The monopile barrel foundation unit 3 provides greater buoyancy and stability, helping to resist wind and waves in the ocean. The riser 11 is built into the monopile barrel foundation unit 3, effectively reducing the environmental load on the riser 11 under harsh sea conditions, protecting it from the effects of wind, waves, and currents, and effectively ensuring its safety. The design and construction process is simplified, construction costs are lower, the platform's volume and footprint are reduced, the impact on the marine environment is minimized, and operational safety is improved.

[0041] Based on the above embodiments, the riser unit 2 includes multiple riser pipes 11 and a riser barrel 7 disposed on the outer periphery of all riser pipes 11. The foundation barrel 4 and the riser barrel 7 of the monopile barrel foundation unit 3 are concentric. The enclosed barrel chamber is a riser ring between the foundation barrel 4 and the riser barrel 7. The riser ring includes multiple independent enclosed chambers in the circumferential direction. Each chamber is connected to an independent pressure regulating device. The monopile barrel foundation wellhead platform is leveled by adjusting the pressure value of the pressure regulating device in different directions.

[0042] In practical applications, multiple riser pipes 11 are centrally symmetrically distributed, for example, four riser pipes 11 are distributed at the four corners, forming a 90° interval. This layout helps to evenly distribute environmental loads. The riser pipes 11 are concentrated in a circular area centered on the center of the base bucket 4, facilitating overall coverage through the concentric circles of the base bucket 4. That is, a riser bucket 7 is set around the outer perimeter of the riser pipe 11, wrapping around the outer perimeter of the riser pipe 11 to provide protection for the riser pipe 11 and reduce the direct impact of wind and waves on the riser pipe 11 under severe sea conditions. Through the protection of the riser bucket 7, the force of environmental load on the riser pipe 11 is effectively reduced, protecting the riser pipe 11 from the direct impact of wind, waves, and currents, reducing potential structural damage, and improving the durability and stability of the riser pipe 11.

[0043] Simultaneously, the inner side of the water-tight bucket 7 is connected to the water-tight pipe 11, and the outer side of the water-tight bucket 7 is connected to the foundation bucket 4. Through the connecting action of the water-tight bucket 7, the water-tight pipe 11 and the foundation bucket 4 are combined together to form a closed bucket structure. The water-tight ring is divided into multiple independent compartments, which are distributed along the circumference of the water-tight ring, i.e., distributed in different directions. Each compartment is equipped with an independent pressure regulating device, allowing for individual control of the negative pressure in each compartment. This design enables the wellhead platform to achieve leveling by precisely controlling the negative pressure in each compartment, ensuring the verticality of the pile body, thereby improving the stability and operational efficiency of the entire platform.

[0044] In the above embodiments, negative pressure technology is used to achieve efficient insertion, extraction and leveling of the single pile foundation unit 3, thereby reducing reliance on traditional pile driving equipment, ensuring verticality, improving operational efficiency, and enabling rapid movement and reuse of the platform, thereby reducing the overall cost of marginal oilfield development and improving development efficiency and economy.

[0045] Based on the above embodiments, the voltage regulating device includes:

[0046] An angle sensor used to detect the current angle between the axis of the single-pile bucket foundation unit 3 and the horizontal plane;

[0047] A pressure regulating unit connected to an angle sensor, used to control the negative pressure of the gas in the compartment on the side of the acute angle to be less than the negative pressure of the gas in the compartment on the side of the obtuse angle when the current included angle detected by the angle sensor is not a right angle.

[0048] In practical applications, the angle sensor detects the angle between the axis of the monopile foundation unit 3 and the horizontal plane, that is, it detects the verticality of the monopile foundation unit 3. When the angle between the axis of the monopile foundation unit 3 and the horizontal plane is not a right angle, the axis of the monopile foundation unit 3 is not perpendicular. The pressure regulating unit adjusts the negative pressure of the chamber gas in different directions. Specifically, it controls the negative pressure of the chamber gas on the side of the acute angle to be less than the negative pressure of the chamber gas on the side of the obtuse angle. As a result, the wellhead platform sinks a greater distance on the side of the acute angle and a smaller distance on the side of the obtuse angle. In other words, the axis of the monopile foundation unit 3 rotates an angle from the acute angle side to the obtuse angle side, and the platform on the acute angle side is raised a set distance relative to the obtuse angle side, thus making the axis of the monopile foundation unit 3 vertical and the wellhead platform level.

[0049] In the above embodiments, negative pressure is used to level the single pile foundation unit 3, ensuring the verticality of the single pile foundation unit 3, enhancing the stability of the platform, and achieving fast and accurate platform leveling.

[0050] Based on the above embodiments, the pressure regulating unit includes:

[0051] Pressure sensors used to detect negative gas pressure in each cabin;

[0052] A calculation unit connected to a pressure sensor, used to calculate the amount of negative gas pressure required for the axis of the single pile foundation unit 3 to rotate to the vertical direction in each chamber when the current included angle detected by the angle sensor is not a right angle;

[0053] A pressure regulating valve connected to a calculation unit to pressurize or depressurize each compartment based on the negative pressure calculated by the calculation unit.

[0054] In practical applications, the pressure regulating device includes a pressure sensor, a calculation unit, and a pressure regulating valve. The pressure sensor detects the negative pressure value of the gas in each compartment and sends the negative pressure information to the calculation unit. The calculation unit receives the negative pressure information and, based on the current angle between the axis of the monopile foundation unit 3 and the horizontal plane detected by the angle sensor, calculates the required negative pressure value for each compartment when the axis of the monopile foundation unit 3 rotates to the vertical direction (i.e., the angle between the axis of the monopile foundation unit 3 and the horizontal plane is 90°), and sends the negative pressure distribution information to the pressure regulating valve. The pressure regulating valve pressurizes or depressurizes according to the required negative pressure in each compartment calculated by the calculation unit, aligning the axis of the monopile foundation unit 3 vertically and leveling the wellhead platform, enhancing platform stability and achieving rapid and precise platform leveling.

[0055] In a preferred embodiment, the upper sealing plate 6 of the single pile foundation unit 3 is provided with a mounting hole 5, and the pressure regulating valve is installed in the mounting hole 5. Optionally, a cover plate is connected to the opening of the mounting hole 5 to protect the pressure regulating valve and reduce seawater erosion.

[0056] Furthermore, the center of the mounting hole 5 is on the pitch circle with the water-tight bucket 7 as the center. The mounting hole 5 is at the same position on the left and right sides of the corresponding compartment. The position of each pressure regulating valve for pressurizing or depressurizing the compartment is consistent. The standard for negative pressure detection and adjustment of each compartment is the same. The judgment standard is unified, the control precision is high, and the platform leveling is achieved quickly and accurately.

[0057] Based on the above embodiments, the enclosed tank is divided into multiple compartments by multiple vertical support plates 8, and the extension line of the support plate 8 passes through the center of the watertight tank 7.

[0058] In one specific embodiment, the enclosed chamber is equipped with multiple support plates 8. The support plates 8 are vertically oriented, with one side connected to the inner wall of the base tank 4 and the other side connected to the outer wall of the water-proof tank 7. The upper end of each support plate 8 is connected to the upper sealing plate 6, and the lower end is connected to the bottom surface of the base tank 4, dividing the water-proof ring into multiple compartments. Along the radial direction of the water-proof ring, i.e., through the center of the base tank 4, the water-proof ring experiences more uniform stress, reducing concentrated stress and increasing strength. It should be noted that the multiple support plates 8 can be evenly distributed, with each compartment having the same space; or they can be unevenly distributed. For example, more support plates 8 can be placed on the windward and leeward sides, resulting in smaller compartment spaces, a larger negative pressure adjustment range and greater force, and more precise control; fewer support plates 8 can be placed on the gentler surface between the windward and leeward sides, resulting in gentler negative pressure adjustment, a smaller negative pressure adjustment range and less force, and less adjustability.

[0059] The support plate 8 can be a single piece, dividing the compartment into independent spaces. The negative pressure of the entire enclosed tank can be adjusted by individually controlling the negative pressure of each compartment, making adjustment more convenient. In this case, the support plate 8 is welded to the base tank 4 and the watertight tank 7, ensuring good sealing. Alternatively, the support plate 8 can be a supporting rib, connecting the compartments, allowing the negative pressure of the entire enclosed tank to be adjusted according to its orientation.

[0060] Based on the above embodiments, the inner wall of the water-separating bucket 7 and the outer wall of each water-separating pipe 11 are connected by a diagonal brace 12, and the extension line of the diagonal brace 12 passes through the center of the water-separating bucket 7 and the water-separating pipe 11.

[0061] In one specific embodiment, the diagonal brace 12 connects the water-tight bucket 7 and the water-tight pipe 11, thereby connecting the water-tight pipe 11 and the base bucket 4. The diagonal brace 12 can be a vertical solid plate, providing strong support and stable support from top to bottom; or it can be multiple horizontal diagonal ribs spaced apart along the height of the base bucket 4, saving materials and reducing costs. Optionally, the spacing between adjacent diagonal ribs is equal, so that the water-tight bucket 7 and the water-tight pipe 11 are subjected to uniform vertical force, improving stability.

[0062] Since the connection stability is weakest when the water-tight pipe 11 is furthest from the center of the water-tight container 7, the diagonal brace 12 is placed at the furthest point from the center of the water-tight pipe 11 to the center of the water-tight container 7, that is, at the intersection of the line connecting the centers of the water-tight container 7 and the water-tight pipe 11 with the water-tight pipe 11. This position is the closest to the water-tight pipe 11 and the water-tight container 7, thus shortening the length of the diagonal brace 12 and reinforcing the water-tight pipe 11. The diagonal brace 12 is along the diameter direction of the water-tight pipe 11 and is consistent with the direction of the tangential force, making the connection point less likely to break.

[0063] Under extreme conditions, the diagonal brace 12 approaches zero, and the water-tight pipe 11 is internally connected to the water-tight bucket 7, resulting in a larger connection area and a stronger connection. This eliminates the need for the diagonal brace 12, simplifying the structure.

[0064] Based on the above embodiments, the water-proof bucket 7 is provided with multiple partition plates 9, which divide the water-proof bucket 7 into multiple water-proof areas. Each water-proof area is provided with a water-proof pipe 11, and the center of the water-proof pipe 11 is distributed on the pitch circle with the center of the water-proof bucket 7. The support plate 8 and the corresponding partition plate 9 are on a straight line.

[0065] In one specific embodiment, the water-proof pipes 11 are placed in separate water-proof areas to reduce mutual interference between them. Multiple water-proof pipes 11 have the same radius and can be housed in a single water-proof container 7, minimizing the radius of the container. The dispersed yet concentrated arrangement of the water-proof pipes 11 facilitates connection and enhances their stability and durability.

[0066] Based on the above embodiments, the extension lines of the support plate 8 and the partition plate 9 pass through the center of the base barrel 4, and the partition plates 9 on the opposite side are connected. Thus, the support plate 8 and the partition plate 9 penetrate the diameter of the base barrel 4, providing a large support range and continuous support force, thereby enhancing the overall stability and ensuring the strength and rigidity of the water-proof pipe 11.

[0067] Based on the above embodiments, the water-proof pipe 11 and the partition plate 9 are connected by a cross brace 10, the cross brace 10 is perpendicular to the partition plate 9, and the connection points of the partition plate 9 and the cross braces 10 on both sides coincide.

[0068] In one specific embodiment, the cross brace 10 connects the partition plate 9 and the water-proof pipe 11, increasing the number of connection points of the water-proof pipe 11, providing additional support, and enhancing the strength and rigidity of the water-proof pipe 11.

[0069] The cross brace 10 is perpendicular to the partition plate 9. The cross brace 10 is beyond the diameter of the water-proof pipe 11. The connection distance between the water-proof pipe 11 and the partition plate 9 is the shortest. The length of the cross brace 10 is shortened, and the relative torque is larger. The water-proof pipe 11 and the partition plate 9 are not easily twisted or deformed.

[0070] The connection point of the partition plate 9 coincides with that of the horizontal braces 10 on both sides, that is, the line connecting the centers of the water-proof pipes 11 on both sides is perpendicular to the partition plate 9. The horizontal braces 10 are supported by both the horizontal braces 10 on the opposite side and the partition plate 9, thus strengthening the support. The partition plate 9 can be connected to the horizontal braces 10 on both sides at the same time, simplifying the connection process.

[0071] Based on the above embodiments, the length-to-diameter ratio of the base bucket 4 is set to 2:1, and the diameter of the base bucket 4 is greater than or equal to 5 meters.

[0072] In practical applications, the length-to-diameter ratio refers to the ratio of the length to the diameter of the monopile bucket foundation unit 3. The length of the monopile bucket foundation unit 3 is twice its diameter, and the bucket diameter is not less than 5 meters. In this case, the length of the monopile bucket foundation unit 3 is not less than 10 meters. This increased length-to-diameter ratio compared to existing technologies increases the length of the monopile bucket foundation unit 3 submerged in the seabed, providing sufficient buoyancy and stability for the platform, while also providing ample space for internal support structures and equipment. It also increases the buoyancy and bending resistance of the monopile bucket foundation unit 3, contributing to improved platform stability.

[0073] The present invention also provides a construction method for a monopile barrel foundation wellhead platform that penetrates any of the above-mentioned features, comprising:

[0074] The monopile barrel foundation wellhead platform is lowered into the water, allowing the monopile barrel foundation unit 3 to sink to the seabed by its own weight;

[0075] Simultaneously, the pressure of multiple pressure regulating valves is adjusted to release the pressure inside the sealed tank so that it can continue to sink;

[0076] Adjust the pressure of the pressure regulating valves to level the wellhead platform of the single-pile barrel foundation.

[0077] Specifically, the processing and manufacturing of a simple wellhead platform for a movable monopile barrel foundation is completed on land, and the prefabrication and installation of the pressure regulating valve are completed; a layer of concrete is poured into the bottom of the riser unit 2 to form the concrete plug 13 inside the existing pile.

[0078] The movable monopile barrel foundation simple wellhead and pressure regulating valve were transported to the designated construction sea area.

[0079] The crane vessel lowered the movable monopile barrel foundation simple wellhead platform into the water, allowing the monopile barrel foundation unit 3 to sink to the seabed under its own weight.

[0080] After the self-weight sinking stops, the pressure regulating valve opens simultaneously. By adjusting the pressure of the pressure regulating valve, the internal pressure of the foundation tank 4 is released, and the foundation tank 4 continues to sink due to negative pressure.

[0081] After the movable monopile barrel foundation simple wellhead sinks to the predetermined depth under negative pressure, the pressure of the pressure regulating valve is adjusted to level the simple wellhead platform of the jacket-type monopile barrel foundation to ensure the verticality of the pile.

[0082] After the single pile driving construction is completed, the casing is lowered using a drilling platform. The drill bit is used to drill the riser 11 into the formation. When a concrete block is encountered, it is broken by relying on the drill bit to achieve casing lowering.

[0083] After the operation in this sea area is completed, the pressure regulating valve is adjusted at the same time. Through the negative pressure action, the foundation barrel 4 is efficiently pulled out and moved to the next sea area. This cycle is repeated to realize the rolling development of the mobile monopile barrel foundation simple wellhead platform between multiple marginal oil fields.

[0084] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0085] The monopile barrel foundation wellhead platform provided by this invention has been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the embodiments above are merely for the purpose of helping to understand the method and core ideas of this invention. It should be noted that those skilled in the art can make various improvements and modifications to this invention without departing from its principles, and these improvements and modifications also fall within the protection scope of the claims of this invention. Therefore, this invention is not limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A monopile barrel foundation wellhead platform for offshore oilfield development, characterized in that, The system includes a single-pile bucket foundation unit (3), a water-proof pipe unit (2) installed inside the single-pile bucket foundation unit (3), and a wellhead support module (1) set on the top of the water-proof pipe unit (2). The bottom of the water-proof pipe unit (2) extends directly to the bottom of the single-pile bucket foundation unit (3). The bottom of the water-proof pipe unit (2) is provided with a detachable sealing plug. The single-pile bucket foundation unit (3) and the water-proof pipe unit (2) form a closed bucket chamber. The single-pile bucket foundation unit (3) is equipped with a pressure regulating device for pressurizing the closed bucket chamber to make it sink or depressurizing it to make it float.

2. The monopile barrel foundation wellhead platform according to claim 1, characterized in that, The riser unit (2) includes multiple risers (11) and a riser barrel (7) disposed on the outer periphery of all the risers (11). The foundation barrel (4) of the monopile barrel foundation unit (3) and the riser barrel (7) are concentric. The enclosed barrel chamber is a water-proof ring between the foundation barrel (4) and the riser barrel (7). The circumferential direction of the riser ring includes multiple independent enclosed chambers. Each chamber is connected to an independent pressure regulating device. The monopile barrel foundation wellhead platform is leveled by adjusting the pressure value of the pressure regulating device in different directions.

3. The monopile barrel foundation wellhead platform according to claim 2, characterized in that, The voltage regulating device includes: An angle sensor used to detect the current angle between the axis of the single-pile bucket foundation unit (3) and the horizontal plane; A pressure regulating unit connected to the angle sensor, used to control the negative pressure of the cabin gas on the side biased towards the acute angle to be less than the negative pressure of the cabin gas on the side biased towards the obtuse angle when the current included angle detected by the angle sensor is not a right angle.

4. The monopile barrel foundation wellhead platform according to claim 3, characterized in that, The pressure regulating unit includes: Pressure sensors used to detect negative gas pressure in each of the aforementioned cabins; A calculation unit connected to the pressure sensor, used to calculate the amount of negative gas pressure required for the axis of the single pile foundation unit (3) to rotate to the vertical direction in each of the chambers when the current included angle detected by the angle sensor is not a right angle; A pressure regulating valve connected to the calculation unit for pressurizing or depressurizing each of the compartments based on the negative pressure calculated by the calculation unit.

5. The monopile barrel foundation wellhead platform according to claim 2, characterized in that, The enclosed tank is divided into multiple compartments by multiple vertical support plates (8), and the extension line of the support plate (8) passes through the center of the water-proof tank (7).

6. The monopile barrel foundation wellhead platform according to claim 5, characterized in that, The inner wall of the water-separating bucket (7) is connected to the outer wall of each water-separating pipe (11) by a diagonal brace (12), the extension line of which passes through the center of the water-separating bucket (7) and the water-separating pipe (11).

7. The monopile barrel foundation wellhead platform according to claim 6, characterized in that, The water-separating bucket (7) and the water-separating pipe (11) are internally connected.

8. The monopile barrel foundation wellhead platform according to claim 7, characterized in that, The water-proof bucket (7) is provided with multiple partition plates (9), which divide the water-proof bucket (7) into multiple water-proof areas. Each water-proof area is provided with a water-proof pipe (11). The center of the water-proof pipe (11) is distributed on the pitch circle with the center of the water-proof bucket (7). The support plate (8) and the corresponding partition plate (9) are on a straight line. The extension lines of the support plate (8) and the partition plate (9) pass through the center of the base bucket (4).

9. The monopile barrel foundation wellhead platform according to claim 8, characterized in that, The water-proof pipe (11) is connected to the partition plate (9) by a cross brace (10). The cross brace (10) is perpendicular to the partition plate (9), and the connection point of the partition plate (9) coincides with the connection point of the cross brace (10) on both sides.

10. The monopile barrel foundation wellhead platform according to any one of claims 2-9, characterized in that, The length-to-diameter ratio of the base bucket (4) is set to 2:1, and the diameter of the base bucket (4) is greater than or equal to 5 meters.

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