Ocean oilfield wellhead floating riser wave protection device

Abstract

This utility model discloses a wave-damping device for floating risers at offshore oilfield wellheads, applicable to the field of offshore oilfield development technology. It includes multiple pontoons (3) surrounding several risers (2), and jetting mechanisms (4) installed on the side of the pontoons (3) away from the risers (2) with different spraying directions. The pontoons (3) are connected to a guide frame platform (17), and the jetting mechanisms (4) are divided into multiple spraying zones according to their location. It also includes multiple submersible pumps (8) connected to the jetting mechanisms (4) in different spraying zones. The submersible pumps (8) are located below the water surface (21), and the high-pressure water ejected by the jetting mechanisms (4) is sprayed towards the oncoming waves (23). This wave-damping device, through the combination of inflatable pontoons and jetting mechanisms, effectively reduces wave loads and protects the structural safety of the risers.

Description

Technical Field

[0001] This utility model relates to the field of offshore oilfield development technology, and in particular to a wave-prevention device for a floating riser at the wellhead of an offshore oilfield. Background Technology

[0002] In offshore oilfields, wellheads typically employ a jacket structure with a riser. For jack-up platforms, there are two common operating methods: one is to extend the derrick via a cantilever beam and align it with the riser for drilling and workover operations; the other is to slot the tail of the platform and move the derrick along a track to align it with the jacket structure and riser.

[0003] Riser operations at sea face numerous safety challenges, with environmental loads being a primary concern. The complex wind, wave, and current conditions at sea generate significant loads, especially wave forces, which constitute the largest proportion. Wave forces produce enormous dynamic inertial forces, causing the riser to vibrate and bend flexurally, severely impacting its structural strength and posing a serious threat to safe production at the wellhead. In recent years, frequent wellhead and riser rupture accidents caused by wave forces highlight the severity of this problem.

[0004] Currently, to ensure the safety of risers in harsh sea conditions, two main measures are adopted: first, using higher-strength riser materials; and second, increasing the structural dimensions of the riser. However, these measures have significant limitations. While high-strength materials can improve the riser's load-bearing capacity, they cannot reduce wave loads and are costly, hindering widespread adoption. Increasing the structural dimensions may increase wave loads, reduce the safety factor, and also increase the riser's weight, adversely affecting the buoyancy of mobile platforms during towing. Furthermore, the riser's manufacturing process is complex and expensive, further increasing oilfield development costs.

[0005] In conclusion, how to more effectively ensure the safety of risers is a problem that urgently needs to be solved by those skilled in the art. Utility Model Content

[0006] The purpose of this invention is to provide a wave protection device for a floating riser at the wellhead of an offshore oilfield. By combining an inflatable float box and a jetting mechanism, the wave load is effectively reduced, protecting the structural safety of the riser.

[0007] To solve the above-mentioned technical problems, this utility model provides the following technical solution:

[0008] A floating riser wave-damping device for offshore oilfield wellheads includes multiple pontoons surrounding several risers, and jetting mechanisms installed on the side of the pontoons away from the risers with different spraying directions. The pontoons are connected to a guide frame platform, and the jetting mechanisms are divided into multiple spraying zones according to their location. The device also includes multiple submersible pumps connected to the jetting mechanisms in different spraying zones. The submersible pumps are located below the water surface, and the high-pressure water jetted by the jetting mechanisms is directed towards the oncoming waves.

[0009] Optionally, the spraying mechanism includes multiple spray heads, and the wave-damping device further includes:

[0010] A position sensor used to detect water level height;

[0011] A height sensor used to detect the height of the center of the lowest row of nozzles;

[0012] A height adjustment mechanism connected to the position sensor and the height sensor, used to adjust the center of the jet head to be level with the water surface.

[0013] Optionally, the submersible pump is connected to the jetting mechanism via a pipeline, and the height adjustment mechanism includes a vertical rail mounted on the float, a slider that slides with the vertical rail, and a driving component that drives the slider to move along the vertical rail. The pipeline and the submersible pump are connected to the slider.

[0014] Optionally, the pipeline includes a pump inlet pipe connected to the inlet of the submersible pump, a vertical water pipe connected at one end to the outlet of the submersible pump, and a horizontal water supply pipe connected at the other end of the vertical water pipe. The horizontal water supply pipe is provided with a plurality of water inlets connected to the jet head, and the axis of the water inlets is along the horizontal direction.

[0015] Optionally, the wave-damping device further includes:

[0016] An angle sensor used to detect the impact angle of oncoming waves;

[0017] A spray control mechanism connected to the angle sensor for controlling the activation of the spray mechanism within the spray area covering the impact angle.

[0018] Optionally, the injection control mechanism includes:

[0019] A spray area determination component for determining the spray area covering the impact angle as an effective spray area;

[0020] An orientation sensor is used to detect the spray angle of the effective spray area;

[0021] An angle control component connected to the angle sensor and the orientation sensor, used to adjust the spray angle of the effective spray area to match the impact angle.

[0022] Optionally, the injection control mechanism includes:

[0023] A pressure sensor used to detect the magnitude of the impact force of oncoming waves;

[0024] A force control component connected to the pressure sensor for adjusting the submersible pump gear according to the real-time impact force detected by the pressure sensor.

[0025] Optionally, a control switch is provided on the line between the submersible pump and the power distribution box, and the control switch is connected to the injection control mechanism.

[0026] Optionally, the plurality of the floats are connected in a circular arc shape, and the jetting mechanism is distributed 360° along the circumference of the floats.

[0027] Optionally, the spray heads of the spraying mechanism are distributed in a matrix, comprising multiple rows and columns, forming a spray net.

[0028] The beneficial effects of this utility model are as follows: The floating riser wave protection device for offshore oilfield wellheads provided by this utility model has a hollow pontoon structure. After being inflated, it floats on the water surface to resist wave impact. Multiple pontoons are connected to each other to form a stable encircling ring, surrounding several risers in the middle, forming a protective wall around the risers to block wave impact and protect them. The pontoons are installed at the locations where the risers are subjected to sea surface wave loads. Through binding and connecting devices, the wave force is transmitted to the jacket platform, while simultaneously reducing the movement of the pontoons in all directions after being subjected to wave force.

[0029] The jetting mechanism is installed on the side of the pontoon away from the riser. It is divided into multiple jetting zones based on its location, with different jetting directions in different zones and at different locations to cover waves coming from all directions. Multiple submersible pumps are connected to the jetting mechanisms in different zones. These pumps, located below the water surface, draw seawater and deliver it to the jetting mechanisms. When the submersible pumps operate, the jetting mechanisms spray high-pressure water jets at the oncoming waves, breaking them up, reducing wave force, and mitigating the impact load on the riser.

[0030] This utility model provides a floating riser wave protection device for offshore oilfield wellheads, particularly suitable for harsh sea conditions. It aims to protect the riser and thus ensure the safety of offshore oilfield production. The device consists of an inflatable pontoon installed around the riser within a jacket platform at the water surface. These pontoons are interconnected and secured to the robust jacket platform via a multi-point binding system. Extra-long piles transmit wave force to the seabed, preventing direct wave impact on the riser. An electric submersible pump and jetting mechanism are installed outside the pontoons at the water surface. High-pressure water is sprayed to break up waves, reducing the effective wave height and lessening the stress on the riser and pontoons. The combination of the pontoons and the jetting mechanism effectively reduces the wave load and dynamic response inertial force on the riser through both pontoon blocking and wave-breaking jetting, reducing riser vibration and protecting wellhead operations and drilling / workover tools. It also reduces wave impact on the riser, increases the safety factor of the riser structure, prevents riser damage and breakage, and ensures the safety of offshore oilfield production operations under harsh sea conditions. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of this utility model 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 this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 This is a general installation layout diagram of a floating riser wave-damping device for offshore oilfield wellheads provided in a specific embodiment of the present invention.

[0033] Figure 2 Plan layout of the floating riser wave protection device for offshore oilfield wellheads;

[0034] Figure 3 This is an elevation view of a single pontoon in a floating riser wave-damping device for offshore oilfield wellheads.

[0035] Figure label:

[0036] 1-Fixed rope; 2-Waterproof pipe; 3-Float box; 4-Jet mechanism; 5-Cable; 6-Windlock; 7-Power supply and distribution box; 8-Submersible pump; 9-Pump outlet pipe; 10-Pump inlet pipe; 11-Railway; 12-Pipeline; 13-Control switch; 14-Binding buckle; 15-Binding point; 16-Connecting buckle; 17-Jacket platform; 18-Derrick; 19-Cantilever beam; 20-Mobile platform; 21-Water surface; 22-Mud surface; 23-Oncoming waves. Detailed Implementation

[0037] The core of this utility model is to provide a wave protection device for a floating riser at the wellhead of an offshore oilfield. Through the combination of an inflatable float and a jetting mechanism, the wave load is effectively reduced, protecting the structural safety of the riser.

[0038] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0039] Please refer to Figures 1 to 3 , Figure 1 This is a general installation layout diagram of a floating riser wave-damping device for offshore oilfield wellheads provided in a specific embodiment of the present invention. Figure 2 Plan layout of the floating riser wave protection device for offshore oilfield wellheads; Figure 3 This is an elevation view of a single pontoon in a floating riser wave-damping device for offshore oilfield wellheads.

[0040] In one specific embodiment, the offshore oilfield wellhead floating riser wave protection device provided by this utility model includes multiple floating boxes 3 surrounding a number of risers 2, and spraying mechanisms 4 installed on the side of the floating boxes 3 away from the risers 2 with different spraying directions. The floating boxes 3 are connected to the guide frame platform 17, and the spraying mechanisms 4 are divided into multiple spraying areas according to their different locations. It also includes multiple submersible pumps 8 connected to the spraying mechanisms 4 of different spraying areas. The submersible pumps 8 are located below the water surface 21, and the high-pressure water sprayed by the spraying mechanisms 4 is sprayed towards the oncoming waves 23.

[0041] In the above structure, the jack-up offshore platform, through a lifting and preloading process, raises the mobile platform 20 to above the water surface 21, and the cantilever beam 19 extends until the derrick 18 is aligned with the wellhead above the jacket platform 17, allowing the platform to perform drilling and well repair operations. A wave-damping device is installed inside the jacket platform 17 at the water surface 21, including a pontoon 3, a jetting mechanism 4, and a submersible pump 8.

[0042] The pontoon 3 is a hollow structure filled with gas, and its buoyancy is sufficient to support its own weight and that of related equipment. After inflation, the pontoon 3 floats on the water surface 21, resisting wave impact. The pontoon 3 can be made of corrosion-resistant materials such as high-density polyethylene, and has good durability and impact resistance.

[0043] The shape of the pontoon 3 is usually cuboid or cylindrical. Multiple pontoons 3 are connected to each other. For example, the upper and lower ends or the middle part of the side wall of the pontoon 3 are provided with binding buckles 14. The binding buckles 14 of adjacent pontoons 3 are connected by connecting rods or connecting ropes to form a stable enclosure, which surrounds several water-proof pipes 2 in the middle, forming a protective wall around the water-proof pipes 2 to block the impact of waves and protect the water-proof pipes 2.

[0044] It should be noted that the smaller the interval between the floats 3, the fewer waves enter the encirclement, and the less impact on the riser 2. Preferably, several floats 3 are connected to each other around the riser 2 to form a closed loop, blocking the impact of waves on the riser 2.

[0045] The pontoon 3 is installed at the location of the riser 2 where it is subjected to wave loads. Through binding and connecting devices, it transmits wave force to the jacket platform 17, protecting the riser 2 and reducing dynamic response. Simultaneously, it reduces the movement of the pontoon 3 in all directions under wave force, ensuring that the pontoon 3 does not experience excessive displacement or swaying under wave action. The pontoon 3 can be connected to the jacket platform 17 using rigid or flexible connectors. For example, the pontoon 3 is equipped with connecting buckles 16, and the diagonal or transverse braces of the jacket platform 17 have binding points 15. The pontoon 3 and the nearby jacket platform 17 are secured with fixing ropes 1, transmitting wave force to the jacket platform 17. Multiple binding points can be used depending on the actual situation. The jacket platform 17, fixed to the seabed mud surface 22 with ultra-long piles, is very robust and suitable as a force-transmitting component.

[0046] The jetting mechanism 4 is installed on the side of the float 3 away from the riser 2. It is divided into multiple jetting zones according to its location. The jetting mechanism 4 in different zones and at different locations has different jetting directions to cover waves coming from all directions. Multiple submersible pumps 8 are connected to the jetting mechanism 4 in different jetting zones. The submersible pumps 8 are located below the water surface 21 and can draw seawater and deliver it to the jetting mechanism 4.

[0047] A power distribution box is installed near the derrick 18 of the cantilever beam 19 of the mobile platform 20. A cable 5 connects to the power distribution box 7 of the wave-damping device. The power distribution box 7 is located on the floating box 3. Each submersible pump 8 is electrically connected to the power distribution box 7, providing power to the submersible pumps 8. In harsh working conditions, the mobile platform 20's electrical system provides stable and reliable power. When the submersible pumps 8 are operating, the jetting mechanism 4 sprays high-pressure water jets at the oncoming waves 23, breaking up the waves, reducing wave force, and mitigating the impact load on the riser 2.

[0048] The floating riser wave protection device for offshore oilfield wellheads provided by this utility model is particularly suitable for harsh sea conditions, aiming to protect the riser 2 and thus ensure the safety of offshore oilfield production. The device consists of an inflatable pontoon 3 installed around the riser 2 within the jacket platform 17 at the water surface 21. These pontoons 3 are interconnected and secured to the robust jacket platform 17 via a multi-point binding system. Extra-long piles are used to transfer wave force to the seabed, thereby preventing waves from directly impacting the riser 2. An electric submersible pump and jetting mechanism 4 are installed at the water surface 21 outside the pontoons 3 to spray high-pressure water to break up waves, reduce the effective wave height, and alleviate the stress on the riser 2 and pontoons 3. The combination of the float box 3 and the jetting mechanism 4 effectively reduces the wave load and dynamic response inertial force on the riser 2 through two methods: blocking by the float box 3 and breaking waves by jetting. This reduces the vibration of the riser 2 and protects the safety of wellhead operations and drilling and workover tools. It also reduces the impact of waves on the riser 2, improves the safety factor of the riser 2's structural strength, avoids damage and breakage of the riser 2, and ensures the safety of offshore oilfield production operations under harsh sea conditions.

[0049] Based on the above specific embodiments, the spray mechanism 4 includes multiple spray heads, and the wave-blocking device further includes:

[0050] A position sensor used to detect the height of the water surface 21;

[0051] A height sensor used to detect the height of the center of the lowest row of nozzles;

[0052] A height adjustment mechanism connected to a position sensor and a height sensor, used to adjust the center of the jet head to be flush with the water surface 21.

[0053] In one specific embodiment, the jetting mechanism 4 includes multiple jet heads, which are installed at the outer water surface 21 of the pontoon 3. Depending on the shape and size of the pontoon 3 and the wind force in the sea area, the jet heads can be arranged in various ways. For example, multiple jet heads can be arranged in a horizontal row along the pontoon 3 with equal heights, or they can be distributed in a matrix, including multiple rows and columns, forming a jetting network. Regardless of the arrangement of the jet heads, it is necessary to ensure effective jetting of waves arriving from all directions.

[0054] The position sensor is used to detect the height of the water surface 21 and can be installed at a suitable location, such as the top or side of the float box 3, where the position of the water surface 21 can be sensed. It can be implemented in various ways, such as infrared reflection or float-type level sensing. Infrared reflection position sensors utilize infrared transmitting and receiving devices to determine the position of the water surface 21 based on the strength and angle of infrared reflection; float-type level sensors use a float that rises and falls with changes in the water surface 21, driving connected mechanical or electrical components to output corresponding electrical signals, reflecting changes in the water surface 21's height.

[0055] A height sensor is used to detect the height of the center of the lowest row of nozzles. It can be installed near the bottom of the float 3, close to the lowest row of nozzles. The height sensor monitors the relative position of the nozzle center and the water surface 21 in real time, providing a basis for the adjustment mechanism. The height sensor can be of the proximity switch type, laser rangefinder type, etc. The proximity switch type height sensor determines the height by sensing a metal object or other conductive material near the nozzle center; the laser rangefinder type height sensor accurately calculates the height of the nozzle center from the water surface 21 by emitting a laser beam and receiving the reflected light, measuring the round-trip time or phase difference of the laser beam.

[0056] The height adjustment mechanism is connected to the position sensor and the height sensor. It is used to automatically adjust the center of the jet head to be flush with the water surface 21 based on the signals detected by the sensors, so that the jet mechanism 4 can break the waves in the best working condition and improve the overall performance and effect of the wave-breaking device.

[0057] Based on the above specific embodiments, the submersible pump 8 and the jetting mechanism 4 are connected by a pipeline 12. The height adjustment mechanism includes a vertical rail 11 installed on the float box 3, a slider that slides with the vertical rail 11, and a driving component that drives the slider to move along the vertical rail 11. The pipeline 12 and the submersible pump 8 are connected to the slider.

[0058] In one specific embodiment, the submersible pump 8 is installed below the water surface 21, and the submersible pump 8 is connected to the jetting mechanism 4 via a pipe 12. The high-pressure water delivered by the submersible pump 8 is ejected from the jetting head at a specific angle and speed, forming a powerful water jet that breaks up the waves. The submersible pump 8, the pipe 12, and the jetting head are made of corrosion-resistant materials, enabling them to operate stably in seawater for extended periods.

[0059] The height adjustment mechanism includes a vertical track 11, a slider, and a drive component. The vertical track 11 is mounted on the float box 3, and the slider slides along the vertical track 11. The surface of the track 11 is smooth and highly precise to ensure that the slider can slide smoothly along the track 11. To reduce friction, a groove or roller matching the vertical track 11 can be provided on the slider to achieve smooth up and down movement. The length of the track 11 is determined according to the height adjustment range of the spray head.

[0060] The drive component can consist of a drive motor, a transmission device, or a winch 6. Based on the signals from the position sensor and the height sensor, as well as the preset control logic, the drive motor drives the transmission device to move the slider along the vertical track 11, thereby achieving precise adjustment of the nozzle height.

[0061] Specifically, the winch 6 is fixed to the top or side of the pontoon 3. The submersible pump 8, the jetting mechanism 4 and related connecting pipes are pulled by the traction rope of the winch 6. The height of the jetting mechanism 4 is adjusted according to different drafts using the track 11 on the pontoon 3.

[0062] The nozzle, pipe 12, and submersible pump 8 are fixedly connected to the slider, which can be done by bolts or other fasteners. The nozzle, pipe 12, and submersible pump 8 move up and down along the vertical track 11 as a whole, so as to adjust the height of the nozzle. Alternatively, the submersible pump 8 can be fixed at a specific position on the float 3, and the submersible pump 8 is connected to the pipe 12 through a telescopic hose. The pipe 12 and the nozzle move with the slider, reducing the load weight on the drive components.

[0063] The control system of the height adjustment mechanism receives signals from the sensors in real time, performs rapid and accurate calculations and judgments, and controls the direction, speed and angle of the drive components to ensure that the center of the jet head is always flush with the water surface 21.

[0064] Based on the above specific embodiments, the pipeline 12 includes a pump inlet pipe 10 connected to the inlet of the submersible pump 8, a vertical water pipe connected at one end to the outlet of the submersible pump 8, and a horizontal water supply pipe connected at the other end of the vertical water pipe. The horizontal water supply pipe is provided with multiple water inlets connected to the jet head, and the axis of the water inlets is along the horizontal direction.

[0065] In one specific embodiment, the pump inlet pipe 10 is connected to the inlet of the submersible pump 8 via a flange or other reliable connection method, and the connection is well sealed to prevent seawater from seeping in or high-pressure water from leaking.

[0066] One end of the vertical water pipe is connected to the outlet of the submersible pump 8. It can be fixed by means of threaded connection, welding or clamp, etc., to ensure the firmness and sealing of the connection.

[0067] The horizontal water supply pipe connects to the other end of the vertical water pipe. Multiple nozzles on the horizontal water supply pipe connect to the jet heads, distributing high-pressure water to each nozzle. The length of the horizontal water supply pipe can be determined based on the length of the set spray area. The same horizontal water supply pipe is connected to a submersible pump 8, and the jet heads connected to the horizontal water supply pipe move and are controlled synchronously. The axis of the nozzles is horizontal, ensuring that the sprayed water effectively impacts the waves. Each nozzle is equipped with a control valve, which can be opened or closed according to the direction and intensity of the waves, achieving precise breaking of waves from different directions.

[0068] Based on the above specific embodiments, the wave-damping device also includes:

[0069] An angle sensor used to detect the impact angle of oncoming waves 23;

[0070] A spray control mechanism connected to an angle sensor, used to control the activation of the spray mechanism 4 within the spray area covering the impact angle.

[0071] In one specific embodiment, the jet head sprays in all directions to ensure effective breaking of waves from different directions.

[0072] An angle sensor is installed on the wave-facing side of the float 3, which can capture changes in wave direction in a timely manner, accurately sense the direction of the incoming wave, monitor the impact angle of the oncoming wave 23 in real time, and convert this information into an electrical signal to be transmitted to the jet control mechanism.

[0073] The jet control mechanism activates the jetting mechanism 4 within the jetting area covering the wave impact angle, based on the wave impact angle detected by the angle sensor. This ensures that the high-pressure water jets are precisely aimed at the direction of the wave, thereby more effectively breaking up the wave and reducing the impact force of the wave on the riser 2 and the float 3. The jet control mechanism is equipped with a control circuit and logic judgment module, which can quickly process the signals from the angle sensor and issue commands accordingly to precisely activate the corresponding jetting heads, achieving efficient wave resistance.

[0074] In this embodiment, the spray control mechanism can accurately determine the effective spray area based on the impact angle of the waves and activate the corresponding spray heads for spraying. This precise spraying method can maximize spraying efficiency, ensuring that the sprayed high-pressure water can directly act on the front of the waves, effectively breaking up the waves and reducing the impact force of the waves on the riser 2 and the float 3.

[0075] Based on the above specific embodiments, the injection control mechanism includes:

[0076] A spray area determination component is used to determine the effective spray area by identifying the spray area that covers the impact angle.

[0077] An orientation sensor used to detect the spray angle of the effective spray area;

[0078] An angle control component connected to an angle sensor and an orientation sensor, used to adjust the spray angle of the effective spray area to match the impact angle.

[0079] In one specific embodiment, the jet area determination component calculates and determines which jet areas are valid jet areas based on the wave impact angle detected by the angle sensor. This component includes a signal processing unit and a region mapping module, capable of quickly analyzing wave impact angle data and mapping it to the corresponding jet areas.

[0080] An orientation sensor is installed on the spray mechanism 4 to detect the spray angle of the effective spray area in real time, ensuring that the spray angle matches the wave impact angle.

[0081] The angle control component is connected to angle and azimuth sensors to adjust the spray angle of the effective spray area in real time, ensuring it aligns with the wave impact angle. The spray angle of the spray area is achieved by adjusting the angle of the spray head, ensuring that the spray mechanism 4 is always in optimal working condition, providing continuous and effective protection even in harsh sea conditions with frequently changing wave direction and intensity. This component includes a controller and an actuator. The controller calculates the required adjustment angle based on sensor data and precisely adjusts the spray head angle via an actuator such as a servo motor or hydraulic cylinder.

[0082] In this embodiment, the spray angle of the jet head can be precisely adjusted according to the impact angle of the wave to ensure that the jet water can directly and accurately act on the front of the wave, effectively breaking the wave and thus effectively weakening the energy and impact force of the wave.

[0083] Based on the above specific embodiments, the injection control mechanism includes:

[0084] A pressure sensor used to detect the magnitude of the impact force of oncoming waves 23;

[0085] A force control component connected to a pressure sensor to adjust the 8 gears of the submersible pump based on the real-time impact force detected by the pressure sensor.

[0086] In one specific embodiment, a pressure sensor is installed on the wave-facing side of the float 3 to capture changes in wave impact force in a timely manner, monitor the magnitude of wave impact force in real time, and convert the impact force signal into an electrical signal.

[0087] The force control component is connected to a pressure sensor and automatically adjusts the operating level of the submersible pump 8 based on the real-time detected impact force. The force control component typically includes a controller and an actuator. The controller calculates the required output power of the submersible pump 8 based on the pressure sensor signal and adjusts the speed or flow rate of the submersible pump 8 via an actuator such as a frequency converter or servo motor, thereby changing the spray intensity of the jetting mechanism 4. By rationally controlling the operating level of the submersible pump 8, the high-pressure water output by the submersible pump 8 can be fully utilized, improving energy efficiency and reducing the operating cost of the device.

[0088] In this embodiment, the injection control mechanism precisely adjusts the operating gear of the submersible pump 8 according to the wave impact force, and adjusts the injection intensity in a timely manner, effectively reducing the impact force of waves on the riser 2 and the pontoon 3, reducing the risk of equipment damage, and improving the safety and reliability of offshore oilfield production operations.

[0089] Based on the above specific embodiments, a control switch 13 is provided on the line between the submersible pump 8 and the power supply and distribution box 7, and the control switch 13 is electrically connected to the injection control mechanism.

[0090] The submersible pump 8 is installed inside the float box 3 and connected to the nozzle via pipe 12. The power cord of the submersible pump 8 is connected to the power distribution box 7, which contains a control switch 13 for controlling the start and stop of the submersible pump 8. The control switch 13 is electrically connected to the jet control mechanism, enabling precise control of the submersible pump 8. The jet control mechanism adjusts the opening state and operating level of the nozzle based on the impact force and angle of the waves, thereby changing the jet intensity and angle of the jet mechanism 4.

[0091] Specifically, a nozzle within the spray area is connected to a submersible pump 8. Depending on the wave direction under severe sea conditions, one or more submersible pumps 8 can be activated to spray and break up the oncoming waves 23, reducing the effective wave height and wave force. When the wave impact force decreases, the control switch 13 automatically lowers the operating level of the submersible pump 8 or stops the submersible pump 8, ensuring that the high-pressure water output by the submersible pump 8 can be fully utilized, improving energy efficiency and reducing the operating cost of the device.

[0092] Based on the above specific embodiments, multiple float boxes 3 are connected in a circular arc shape, and the injection mechanism 4 is distributed 360° along the circumference of the float box 3.

[0093] In one specific embodiment, multiple pontoons 3 are connected end-to-end in a circular or annular shape, surrounding the riser 2 to form a closed protective ring. The jet nozzles are arranged at intervals along the circumference of the pontoons 3, with the distance between the nozzles optimized based on the radius of the spray cone's base circle to ensure that the jet stream effectively covers the wave propagation direction. The jetting mechanism 4 is distributed 360° along the circumference of the pontoons 3, enabling all-around wave breaking and effectively reducing the impact force of the waves on the riser 2.

[0094] Of course, depending on the location and distribution of the riser pipe 2, the floats 3 can also be arranged into other suitable shapes, such as four floats 3 forming a rectangular protective ring, which is easy to connect.

[0095] Based on the above specific embodiments, the spray heads of the spray mechanism 4 are distributed in a matrix, including multiple rows and columns, forming a spray net.

[0096] In one specific embodiment, the jet heads are arranged in a matrix pattern, specifically in multiple rows and columns, forming a jet network. This design increases the number of rows of jet heads, thereby increasing the jet height and effectively expanding the jet range. This ensures that the jet water flow can uniformly cover the direction of wave propagation, enhancing the wave-breaking effect.

[0097] The floating riser wave shielding device at the wellhead of offshore oilfields uses a closed loop of combined inflatable floats 3 to block wave forces and a jetting mechanism 4 to break up waves, thereby reducing wave loads. The specific usage steps are as follows:

[0098] Step 1: When encountering severe sea conditions during drilling and workover operations on the mobile platform 20, retrieve this device. Inflate the pontoon 3 to bring it into working condition. Install the submersible pump 8, jetting mechanism 4, fixed winch 6, and track 11. Manually or using the winch 6 and other driving components, pull the device to the sea surface around the riser 2 inside the jacket platform 17.

[0099] Step 2: Use connecting buckles 16 to connect the floats 3 around the riser 2 to form a closed loop structure, blocking waves and protecting the riser 2. Secure each float 3 to the diagonal or horizontal bracing of the adjacent jacket platform 17 with fixing ropes 1 to ensure that wave force can be transmitted to the jacket platform 17 through the binding system.

[0100] Step 3: Install a power distribution box near the derrick 18 of the cantilever beam 19 of the mobile platform 20, and connect the power distribution box 7 on the floating box 3 and the circuits of each submersible pump 8 with cable 5.

[0101] Step 4: Based on the draft of the pontoon 3, adjust the vertical position of the jetting mechanism 4 using the winch 6 to achieve the best wave-breaking effect. Depending on the wave direction, activate one or more submersible pumps 8 in different directions to spray the waves in the opposite direction of propagation, thereby significantly reducing the effective wave height and decreasing the wave force acting on the pontoon 3.

[0102] Step 5: After being sprayed head-on by the spraying mechanism 4, the wave force is greatly reduced, and combined with the float box 3 and the binding system, the wave force is transferred to the jacket platform 17. Therefore, the wave force acting on the riser 2 is greatly reduced, achieving the expected protection purpose.

[0103] Step 6: When the adverse sea conditions end or drilling and repair operations are completed and relocation is required, disconnect the relevant circuits and loosen the connecting buckles 16 between the pontoons 3. Use the winch 6 of the mobile platform 20 or a small crane to lift the pontoons 3 and the jetting mechanism 4 back to the platform.

[0104] Step 7: Remove the spray mechanism 4 from the float 3. After checking that there is no damage, classify and store the device in designated locations for future use.

[0105] This wave-damping device, through the combination of an inflatable float 3 and a jetting mechanism 4, effectively reduces wave loads and protects the structural safety of the riser 2. The device boasts advantages such as being detachable, easy to install and store, low cost, and environmentally friendly, making it suitable for offshore oilfield operations in harsh sea conditions.

[0106] 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.

[0107] The above provides a detailed description of the floating riser wave-damping device for offshore oilfield wellheads provided by this utility model. Specific examples have been used to illustrate the principles and implementation methods of this utility model. The descriptions of the embodiments above are merely for the purpose of helping to understand the method and core ideas of this utility model. It should be noted that those skilled in the art can make various improvements and modifications to this utility model without departing from its principles, and these improvements and modifications also fall within the protection scope of the claims of this utility model. Therefore, this utility model 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 wave-damping device for a floating riser at the wellhead of an offshore oilfield, characterized in that, It includes multiple pontoons (3) surrounding several water-proof pipes (2), and spraying mechanisms (4) installed on the side of the pontoons (3) away from the water-proof pipes (2) with different spraying directions. The pontoons (3) are connected to the guide frame platform (17). According to their different orientations, the spraying mechanisms (4) are divided into multiple spraying areas. It also includes multiple submersible pumps (8) connected to the spraying mechanisms (4) in different spraying areas. The submersible pumps (8) are located below the water surface (21). The high-pressure water sprayed by the spraying mechanisms (4) is sprayed towards the oncoming waves (23).

2. The offshore oilfield wellhead floating riser wave-damping device according to claim 1, characterized in that, The spraying mechanism (4) includes multiple spray heads, and the wave-blocking device further includes: A position sensor used to detect the height of the water surface (21); A height sensor used to detect the height of the center of the lowest row of nozzles; A height adjustment mechanism connected to the position sensor and the height sensor for adjusting the center of the jet head to be level with the water surface (21).

3. The offshore oilfield wellhead floating riser wave-damping device according to claim 2, characterized in that, The submersible pump (8) is connected to the jetting mechanism (4) via a pipeline (12). The height adjustment mechanism includes a vertical rail (11) mounted on the float (3), a slider that slides with the vertical rail (11), and a driving component that drives the slider to move along the vertical rail (11). The pipeline (12) and the submersible pump (8) are connected to the slider.

4. The offshore oilfield wellhead floating riser wave-damping device according to claim 3, characterized in that, The pipeline (12) includes a pump inlet pipe (10) connected to the inlet of the submersible pump (8), a vertical water pipe connected to the outlet of the submersible pump (8) at one end, and a horizontal water supply pipe connected to the other end of the vertical water pipe. The horizontal water supply pipe is provided with multiple water inlets connected to the jet head, and the axis of the water inlets is along the horizontal direction.

5. The offshore oilfield wellhead floating riser wave-damping device according to claim 1, characterized in that, The wave-damping device also includes: An angle sensor used to detect the impact angle of oncoming waves (23); A spray control mechanism connected to the angle sensor for controlling the opening of the spray mechanism (4) within the spray area covering the impact angle.

6. The offshore oilfield wellhead floating riser wave-damping device according to claim 5, characterized in that, The injection control mechanism includes: A spray area determination component for determining the spray area covering the impact angle as an effective spray area; An orientation sensor is used to detect the spray angle of the effective spray area; An angle control component connected to the angle sensor and the orientation sensor, used to adjust the spray angle of the effective spray area to match the impact angle.

7. The offshore oilfield wellhead floating riser wave-damping device according to claim 5, characterized in that, The injection control mechanism includes: A pressure sensor used to detect the magnitude of the impact force of oncoming waves (23); A force control component connected to the pressure sensor for adjusting the gear of the submersible pump (8) based on the real-time impact force detected by the pressure sensor.

8. The offshore oilfield wellhead floating riser wave-damping device according to claim 5, characterized in that, The control switch (13) on the line between the submersible pump (8) and the power distribution box (7) is connected to the injection control mechanism.

9. The offshore oilfield wellhead floating riser wave-damping device according to claim 1, characterized in that, Multiple floats (3) are connected in a circular arc shape, and the jetting mechanism (4) is distributed 360° along the circumference of the floats (3).

10. The offshore oilfield wellhead floating riser wave-damping device according to claim 9, characterized in that, The spray heads of the spray mechanism (4) are distributed in a matrix, consisting of multiple rows and columns, forming a spray net.

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