CN210852801U - Rotary mooring and conveying system - Google Patents

Abstract

The utility model discloses a rotary mooring conveying system for oil production operation, which comprises a plurality of rotary conveying joints; each rotary transfer joint comprises: an inner conveying ring; an outer transport ring rotatable relative to the inner transport ring; a conveying structure capable of keeping conveying in the rotating process is arranged between the inner conveying ring and the outer conveying ring; an inner conveying unit connected with the inner conveying ring; an outer delivery unit connected to the outer delivery ring; wherein, the inner conveying ring of each rotary conveying joint is fixedly connected. In the field of ocean marginal oil field development, the device can be used as a conveying device which is compatible with functions of a wellhead operation platform and a mooring platform and adopts operation equipment.

Description

Rotary mooring and conveying system

Technical Field

The utility model relates to an ocean oil gas development field relates to a rotatory conveying system that moors.

Background

In shallow sea areas of our country, a number of marginal oil fields have been explored. The marginal oil fields refer to oil fields with small ascertained production (the recoverable reserves of a single oil field are about 10 ten thousand tons to 200 ten thousand tons), dispersed geographical positions and long distances from other large oil fields, and poor economic benefits for development by adopting a traditional development mode.

The development of a complete oil field needs four processes of drilling (repairing), mining, storing and transporting. The development mode of the traditional shallow water oil field in China mainly comprises the following parts: (1) single or multiple wellhead platforms; (2) production of storage offloading tankers (FPSO); (3) mooring a jacket of an FPSO and a single-point system; (4) a subsea pipeline connecting the wellhead platform with the FPSO.

The wellhead platform is generally a jacket-type platform, and carries a Christmas tree; the FPSO is moored on a jacket by a single point mooring system; the wellhead platform conveys the crude oil mixture to an FPSO (floating production storage and offloading) through a submarine pipeline for production and storage, and meanwhile, the FPSO supplies power to the wellhead platform through a cable and supplies liquid required by life and operation; shuttle tankers periodically come to the FPSO to transport the crude oil to land.

The mooring platform for mooring the FPSO commonly used at present is two types of jackets with completely different forms with a wellhead platform, and cannot be used universally, the FPSO is moored on the mooring platform and then is connected with the wellhead platform through a submarine pipeline, and the submarine pipeline with high cost needs to be buried in order to reserve a safe distance. For oil fields with large output and dense number, the manufacturing cost of the mooring platform, the wellhead platform and the correspondingly arranged submarine pipelines can be uniformly distributed to a plurality of oil fields, and the mooring platform has high stability and can obtain ideal economic benefit; but for marginal fields, it is obviously not suitable because the unit production of marginal fields is lower than that of dense high-yield fields, and for single marginal fields, the equipment investment may be higher than the obtained profit or only a very low profit can be obtained, and limited to this, the development of some marginal fields is temporarily set aside.

For economic requirements, consider marginal field development with two modes of operation:

(1) the 'three-one' development mode is that for marginal oil and gas fields within 20km of developed oil fields, the oil and gas fields produced by the marginal oil and gas fields are sent to the developed oil fields by using a wellhead platform, a submarine pipeline and a submarine cable.

(2) The 'bee type' development mode is a mode for developing a small-sized production device which integrates well drilling (repairing), production, power, oil storage, outward transportation and life and can not depend on a small and isolated small-sized marginal oil-gas field of a developed oil field beyond 20km away from the developed oil field.

Most of the marginal fields are developed over 20km from the developed field at present, and even submarine pipelines with the length within 20km still need high manufacturing cost. The "honeybee" development model is therefore the primary solution to many marginal fields.

The development mode mainly provides a movable platform structure, so that the production, power, oil storage, outward transportation, life and other operation functions can be integrated on a small production device, and the platform structure can be moved to another small oil field for oil extraction after one small oil field is extracted like bees. The 'bee type' development mode can make marginal oil field have certain economic benefits, but in order to realize the mobility of platform, the platform shape will receive certain restriction, and be difficult to dispose sufficient space and carry out the oil storage, and generally full load reserves can not exceed 2000 tons for it is too frequent to make shuttle tanker carry the number of times of oil, thereby has reduced the economic nature of whole oil field development.

The other idea is that the storage and transportation ship and the conduit frame are connected into a whole under a normal production state, the conduit frame is used for producing, and the storage and transportation ship is used for storing crude oil, so that the storage and transportation ship has production, power, oil storage, external transportation and life functions.

Thus, there is a need to adapt to the economic requirements of marginal oil field development by modifying existing wellhead platform structures.

The above description is included in the technical recognition scope of the inventors, and does not necessarily constitute the prior art.

Disclosure of Invention

Aiming at the defects existing in the background technology, the utility model aims to improve the structure of the production operation platform so as to improve the economic index of marginal oil field development, improve the compactness of the arrangement of oil extraction operation equipment, reduce the number of facilities and reduce the input cost; and has good safety and stability; the functions of well workover, production, power, oil storage, outward transportation, life and the like are integrated on one platform; the support expands a large enough oil storage space. The key point is to provide a rotary mooring transfer system applied to a wellhead platform, which can transfer fluid and energy between an FPSO moored to the wellhead platform and a production operation device.

The utility model adopts the technical proposal that:

a rotary mooring conveying system comprises a plurality of rotary conveying joints;

each rotary transfer joint comprises:

an inner conveying ring;

an outer transport ring rotatable relative to the inner transport ring;

a conveying structure capable of keeping conveying in the rotating process is arranged between the inner conveying ring and the outer conveying ring;

an inner conveying unit connected with the inner conveying ring;

an outer delivery unit connected to the outer delivery ring;

wherein, the inner conveying ring of each rotary conveying joint is fixedly connected.

In the development and adoption operation of the marginal oil field, a design is that a wellhead platform and a jacket moored by a single point are integrated, wherein the problem to be solved is that an FPSO moored on a rotary table arranged on the wellhead platform swings and rotates along with wind waves, the transportation of an oil production operation device arranged on the wellhead platform and the FPSO in the mooring process is required to be kept uninterrupted and is not influenced, and the normal operation of the operation platform is not interfered.

The rotary conveying joint is arranged, so that a solution way for eliminating conflict between oil extraction operation and mooring on a production operation platform is provided, the floating production oil storage and discharge device moored by the rotary table is driven by wind waves to drive the rotary table to rotate, at the moment, an external conveying unit such as a water conveying pipeline, an oil conveying pipeline, a power line and the like is connected to the floating production oil storage and discharge device to avoid winding and stretching, and the external and internal conveying states are kept stable in the rotary process of the rotary table through the rotary conveying joint.

As a preferred implementation manner, a plurality of the rotary conveying joints are sequentially arranged from top to bottom, and the internal conveying unit connected with the internal conveying ring of the rotary conveying joint located below passes through the internal channel formed on the internal conveying ring of the rotary conveying joint located above.

In a preferred implementation, at least one of the rotary transfer unions is a fluid transfer union.

In a preferred implementation, the conveying structure is an annular fluid groove formed between the inner conveying ring and the outer conveying ring, and the inner conveying unit includes a fluid line communicating with the annular fluid groove.

In a preferred implementation, the fluid delivered by the fluid delivery joint is selected from one or more of water, oil and gas.

As a preferred implementation, a dynamic sealing ring is arranged between the inner conveying ring and the outer conveying ring to form a sealing structure for isolating the annular fluid groove from the outside.

In a preferred implementation, at least one of the rotary conveying joints is an energy conveying joint, the conveying structure is a brush disposed between the inner conveying ring and the outer conveying ring, and the inner conveying unit includes a power line electrically connected to the brush. Or can be used for transmitting data, and the data line is used as a conveying unit.

As a preferred implementation, a dynamic sealing ring is arranged between the inner conveying ring and the outer conveying ring to form a sealing structure for isolating the annular fluid groove from the outside.

As a preferred implementation, a bearing is provided between the inner and outer transport rings.

As a preferred implementation, a turntable is also included, which connects the outer transport rings.

Drawings

The accompanying drawings, which are described herein, serve to provide a further understanding of the invention and constitute a part of this specification, and the exemplary embodiments and descriptions thereof are provided for explaining the invention without unduly limiting it. In the drawings:

fig. 1 is a schematic diagram illustrating an overall structure of an oil field production operation system according to an embodiment of the present invention.

Fig. 2 is a schematic diagram of the overall structure of the oil field production operation system according to an embodiment of the present invention, and each part is marked.

Fig. 3 is a schematic view of a partial structure of an oilfield production operation system according to an embodiment of the present invention.

Fig. 4 is a schematic partial view of the upper half of a single-column moored wellhead platform according to an embodiment of the present invention, with the turntable omitted.

Fig. 5 is a schematic cross-sectional view of a column in a single-column moored wellhead platform according to an embodiment of the present invention.

Fig. 6 is a schematic partial structural view of the upper half of a single-column moored wellhead platform according to an embodiment of the present invention, in which some column bodies are omitted.

Fig. 7 is a schematic partial cross-sectional view of a portion of a single-column moored wellhead platform for mounting a rotary transfer joint according to an embodiment of the present invention.

Fig. 8 is a schematic diagram of a single column moored wellhead platform transfer platform and associated structures according to an embodiment of the present invention.

Description of reference numerals:

1. floating Production Storage Offloading (FPSO);

2. a column body;

3. positioning the mounting assembly;

4. a turntable;

5. a wellhead deck;

6. a Christmas tree;

7. a manifold terminal;

8. a well repair deck;

9. a hydraulic workover rig;

10. a rotary mooring transfer system member;

11. a turntable bearing;

12. mooring a support frame;

13. a horizontal counterweight rigid arm;

14. a counterweight cabin;

15. mooring the boom;

16. a rigid delivery line;

17. a flexible jumper line;

18. a pitch bearing;

19. a roll bearing;

20. universal joints (one is arranged at each of the two ends of each suspension arm);

21. a riser;

22. positioning the isolation structure;

23. an inner ring (stationary ring) of the water delivery rotary joint;

24. an outer ring (rotating ring) of the water delivery rotating joint;

25. a water delivery rotary joint sealing ring;

26. a water chamber;

27. outer ring of water delivery bearing (connecting with outer ring of rotary joint)

28. Water delivery bearing inner ring (connected with inner ring of rotary joint)

29. Export water pipeline (to FPSO);

30. an inner water pipeline (leading to a manifold terminal);

31. an inner ring (stationary ring) of the oil transportation rotary joint;

32. an outer ring (rotating ring) of the oil transportation rotating joint;

33. a seal ring of the oil transportation rotary joint;

34. an oil chamber;

35. oil delivery bearing outer ring (connected with outer ring of rotary joint)

36. Inner ring of oil delivery bearing (connected with inner ring of rotary joint)

37. An export pipeline (to the FPSO);

38. internal oil pipelines (leading to manifold terminals);

39. an inner ring (stationary ring) of a power transmission rotary joint;

40. an outer ring (rotating ring) of the power transmission rotary joint;

41. a power transmission rotary joint sealing ring;

42. an electric brush;

43. outer ring of power transmission bearing (connected with outer ring of rotary joint)

44. Inner ring of power transmission bearing (connected with inner ring of rotary joint)

45. External power transmission lines (to the FPSO);

46. internal transmission lines (leading to manifold terminals);

47. a rotary joint drive arm;

48. a drive arm support frame;

49. an inner ring (a static ring, which is rigidly fixed with the upright post) of the bearing of the turntable;

50. and a turntable bearing outer ring (a rotating ring which is rigidly fixed with the turntable).

Detailed Description

In order to more clearly explain the overall concept of the present invention, the following detailed description is given by way of example in conjunction with the accompanying drawings.

It should be noted that in the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention, however, the present invention may be practiced in other ways than those specifically described herein, and thus the scope of the present invention is not limited by the specific embodiments disclosed below.

In addition, in the description of the present invention, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "axial", "radial", "circumferential", and the like indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of description and simplicity of description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore should not be construed as limiting the present invention.

In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," and "fixed" are to be construed broadly and may, for example, be fixedly connected, detachably connected, or integrally formed; either directly or indirectly through intervening media, either internally or in any other relationship. However, the direct connection means that the two bodies are not connected to each other by the intermediate structure but connected to each other by the connecting structure to form a whole. The specific meaning of the above terms in the present invention can be understood according to specific situations by those skilled in the art.

In the present application, unless expressly stated or limited otherwise, the first feature may be directly on or directly under the second feature or indirectly via intermediate members. In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

Before describing the alternative implementations provided by the present invention with reference to the drawings, the technical idea of the present invention is first introduced.

The traditional wellhead platform for implementing oil production operation is limited by the structure, a bearing of a single-point mooring system cannot be installed, and the structure of the wellhead platform needs to be improved; likewise, existing mooring jackets are not able to act as wellheads because of the inability to deploy christmas trees. The oil extraction operation is completed, mooring and wellhead operation are indispensable, and for oil fields with large yield and dense number, the configuration of a wellhead platform and a single-point mooring jacket is feasible, the service life of the whole system is long, the cost can be uniformly distributed on a plurality of oil fields, the development cost of unit yield can reach very low, and the economic benefit is good; but for marginal oil fields, the unit yield cost of the development mode is high, and the economic requirement cannot be met.

So the utility model aims at realizing the technical purpose that: adopt hollow column platform structure, set up the mooring turret that can not conflict with the oil recovery operation that the top and the inside of stand carried on in the outside of stand cylinder.

With reference to fig. 1 and 2, an oilfield production operation system based on a single-column moored wellhead production operation platform is depicted. The system mainly comprises a floating production oil storage and discharge device 1, a single-upright-column mooring type wellhead production operation platform and an overwater soft rigid arm single-point mooring system. The floating production oil storage and discharge device can be a production oil storage wheel and can be formed by reforming an old oil wheel, the oil wheel with a proper size is selected according to the actual requirement of an oil field, and necessary production facilities, a generator set, a mooring support frame and an output module are added.

Referring to fig. 3, the single-column mooring type wellhead production operation platform mainly comprises a column 2, a positioning and mounting assembly 3, a rotary table 4, a wellhead deck 5, a christmas tree 6, a manifold terminal 7, a workover deck 8, a hydraulic workover rig 9, a rotary mooring conveying system 10 and a rotary table bearing 11.

Wherein, the interaction between single-column mooring type wellhead production operation platform and FPSO divides into two parts:

one part is that single-upright-column mooring type well mouth production operation platform provides mooring positioning for FPSO, as the mooring anchor point of FPSO, transfers mooring force through soft rigid arm mooring, and lets FPSO rotate around the upright column body under the action of the wave current. As shown in fig. 8, the inner ring 49 of the turntable bearing is fixed to the column body 2, the outer ring 50 of the turntable bearing is fixed to the turntable 4, and the turntable 4 is connected to the horizontal counter-weight rigid arm 13 of the flexible rigid arm, so that the turntable 4 can be driven by the FPSO and the flexible rigid arm to rotate around the column body 2. In addition, the pitch bearing 18 and the roll bearing 19 can release the pitch and roll rotations of the horizontal counter weight rigid arm 13, so that the horizontal counter weight rigid arm 13 can freely roll and pitch under the drive of the FPSO and has no constraint on the FPSO, thereby supporting the bearing of a large load, and allowing the provision of large tonnage storage. On the other hand, the mooring support frame is rigidly fixed with the FPSO, the suspension arm 15 is suspended on the mooring support frame 12 and connected with the lowered counterweight cabin 14, when the FPSO is in surging motion, the suspension arm 15 can be inclined so as to improve the counterweight cabin 14 to do work, and the tension of the counterweight cabin 14 on the suspension arm 15 can generate a horizontal component, and the component of the force is opposite to the movement direction of the ship body and used as a restoring force to pull the FPSO back to a balance position. In addition, a quick release device may be provided at the universal joint 20, and when extreme weather (such as a hundred year sea) exceeding the design comes, the quick release may be performed. The quick release device is a common safety measure in the field, and can automatically realize release through load change. As an alternative realization, a quick release device may also be provided at the mooring connection.

The other part is that the FPSO keeps the transportation of oil, water and electricity when rotating relative to the column body. This is accomplished in part primarily by means of the rotary mooring transfer system 10. In order to prevent the rotary conveying and the oil production operation from interfering with each other, each rotary conveying joint in the rotary mooring conveying system is arranged to be in a hollow form, and the position of the rotary mooring conveying system is arranged below a wellhead deck. In the implementation shown in fig. 6 and 7, the rotary mooring conveyance system is, from top to bottom, a water transfer connection S1, an oil transfer connection S2 and an electricity transfer connection S3. The inner and outer rings (23, 24, 31, 32, 39, 40) of the rotary joint are connected with the inner and outer rings (27, 28, 35, 36, 43, 44) of the bearing respectively. When the turntable 4 rotates, with the help of the bearings (27, 28, 35, 36, 43, 44), the driving arm bracket 48 and the driving arm 47 connected to the turntable drive the outer swivel rings 24 (water), 32 (oil), 40 (electricity) to rotate together, while the inner swivel rings 23 (water), 31 (oil), 39 (electricity) are rigidly connected to the column body and remain stationary. An annular cavity 26, 34 is formed between the rotary joint outer ring 24 (water), 32 (oil) and the rotary joint inner ring 23 (water), 31 (oil), respectively, and the cavity 26, 34 is connected at one end to a pipeline 29, 37 leading to the FPSO and at the other end to a pipeline 30, 38 leading to the platform manifold. The edges of the cavities 26 and 34 are respectively provided with dynamic sealing rings 25 and 33 on the contact surfaces of the inner ring and the outer ring, the sealing rings are made of rubber materials with the characteristics of corrosion resistance, high temperature resistance, wear resistance, high elasticity and the like, such as silicon rubber, fluororubber, ethylene propylene rubber and acrylate rubber, and when the pressure of the cavities 26 and 34 is high, the rotary friction of the contact surfaces of the inner ring and the outer ring of the rotary joint can be ensured, but the sealing can be ensured. The inner ring 39 and the outer ring 40 of the power transmission rotary joint are respectively connected with an electric brush 42, the electric brushes are annular, and when the rotary joint rotates, two ends of each electric brush are always in contact, so that the circuit is ensured to be communicated. The contact surface between the inner ring 39 and the outer ring 40 of the power transmission swivel is also provided with a sealing ring 41.

As an extended alternative implementation, a signal transmission joint of similar construction to the power transmission joint may also be employed, with wires and brushes for transmitting electrical signals.

In addition, an annular cavity is arranged in the contact surface of the inner ring and the outer ring for conveying fluid such as water, oil and the like, and a dynamic sealing ring is arranged at the joint surface of the two rings in the cavity, so that the fluid in the cavity is prevented from leaking when the cavity rotates; the cavity is provided with a channel outlet at the inner ring side and the outer ring side respectively; the contact surface of the inner ring and the upright post body is also provided with a groove to form a bottom-up channel, and the channel is used for a pipeline or a cable of an outlet of a static part of a liquid or electric rotary joint below the rotary joint to pass through and lead to a manifold on a wellhead deck.

When the oil field normally works, the FPSO can only rotate around the platform and do limited surging, pitching and rolling motions under the positioning of the single point of the soft rigid arm. Power and personnel life are provided on the FPSO, electricity and water are passed through the swivel to the platform manifold and into the oil well through the christmas tree and riser; meanwhile, the collected crude oil mixture enters a platform manifold through a production tree and a riser, then reaches the FPSO through a rotary joint for production, and the produced crude oil is stored in the FPSO to wait for a shuttle tanker to periodically lift the crude oil. When the well is required to be repaired, production does not need to be stopped, the Christmas tree required to be repaired is only needed to be suspended, the production or water injection vertical pipe is taken out and replaced by the drilling vertical pipe, the well is repaired through the workover rig 9, and after the well is repaired, the production or water injection vertical pipe is replaced by the production vertical pipe for production.

In addition, as a matched setting, the diameter of the upright post cylinder is about 2-6 meters, the upright post cylinder can be driven into the seabed through a pile driving hammer and has a certain depth, and the inner part is hollow and can be arrayed with a cylindrical inner well slot to arrange a drilling riser or a production riser. The bottom of the upright post is provided with 3 guide pipes which are distributed at 120 degrees, and the outer end of each guide pipe is fixed on the seabed through pile foundation piling.

The well head deck sets up in the top of stand cylinder, and every riser top is equipped with the production tree in well head deck department, and every production tree assembles the manifold terminal on the well head deck. A workover deck is arranged above the wellhead deck, and a hydraulic workover rig is arranged. The revolving stage is established to well head deck below, and this revolving stage passes through the revolving stage bearing with the stand cylinder and is connected, can wind stand cylinder in the horizontal plane internal rotation, and the revolving stage top sets up rotatory mooring conveying system and connects, for example including the transmission rotary joint who carries oil, electricity, water respectively. The manifold is connected to the stationary part of the swivel by means of oil pipes, water pipes and electric cables.

The soft steel arm mooring system comprises a mooring support frame 12, a horizontal counterweight steel arm 13, a counterweight cabin 14, a boom arm 15, a rigid transfer line 16, a flexible crossover line 17 (which can be used to transfer fluid and energy), a pitch bearing 18, a roll bearing 19 and a universal joint 20.

Specifically, the soft rigid arm single-point mooring system consists of a ship support frame, two suspension arms and a horizontal counterweight rigid arm, wherein one end of the counterweight rigid arm is connected with a turntable of the single-column platform, and a detachable universal joint is arranged between the counterweight rigid arm and the turntable, so that the counterweight rigid arm can rotate randomly relative to the turntable (namely rotate around a horizontal shaft, a vertical shaft and a central shaft) and can be detached and connected back and forth quickly; two counterweight cabins are arranged at the other end of the counterweight rigid arm, and a counterweight can be added inside the counterweight rigid arm; the upper part of the counterweight cabin is connected with the suspension arm through a universal head; the upper part of the suspension arm is connected with a support frame on the ship through a universal head.

As shown in fig. 4, located within the hollow structure of the column body 2 is a riser 21, forming an in-barrel well. The number and arrangement of risers 21 can be determined by the diameter of the pipe and the requirements of the oil field, into which risers can extend, the risers comprising production risers which pump the crude oil mixture from the seabed to the production tree 6 on the wellhead deck 5 and water injection risers which drive water into the subsea well from the production tree 6 above. Manifold terminals 7 on the wellhead deck 5 are used to aggregate all the lines of the christmas tree 6, in addition to the oil and water lines leading to the christmas tree 6, and also the electrical cables, which ultimately need to be connected to the FPSO.

Further, as an implementation that can be implemented based on the foregoing embodiment:

the number of decks above the single-column mooring type wellhead production operation platform is not limited to wellhead decks and workover decks, and decks required by other production operations, such as manifold decks, water injection decks, boarding decks and the like, can be added.

The structure of the positioning and mounting assembly at the bottom of the column body of the upright column is not limited to a form that 3 inclined struts form an angle of 120 degrees, and other forms can be selected according to the practical condition and structural design of the seabed, such as frame support, unilateral inclined struts, inclined pulling lock and the like. The support legs are not limited to a piling connection, and suction anchors may also be used for the fixation to the seabed. The upright column body can also be directly used as a single pile foundation to be tamped into the seabed.

The number of the rotary conveying joints is not limited to 3, passages can be added according to the actual needs of oil fields, the types are not limited to oil, water and electric rotary joints, and a cyclone joint, a multifunctional auxiliary rotary joint and the like can be added.

The workover mode is not limited to hydraulic workover rig, and a derrick can be installed above a workover deck by adopting a traditional workover rig.

The quick release device of the soft rigid arm system is not limited to be arranged at the joint between the horizontal counterweight rigid arm and the rotary table, and can also be arranged at the joint between the suspension arm and the counterweight rigid arm.

Furthermore, although the utility model discloses a scheme is to marginal oil field development proposition, the utility model discloses do not restrict the application environment of scheme, under the condition that accords with economic nature and equip the safety and stability, the utility model discloses a scheme also can be implemented in non-marginal oil field to many platforms mode constitutes "platform network".

Claims (9)

1. A rotary mooring transfer system is characterized by comprising a plurality of rotary transfer joints;

each rotary transfer joint comprises:

an inner conveying ring;

an outer transport ring rotatable relative to the inner transport ring;

a conveying structure capable of keeping conveying in the rotating process is arranged between the inner conveying ring and the outer conveying ring;

an inner conveying unit connected with the inner conveying ring;

an outer delivery unit connected to the outer delivery ring;

wherein, the inner conveying ring of each rotary conveying joint is fixedly connected.

2. The rotary mooring transfer system of claim 1, wherein a plurality of the rotary transfer joints are arranged in series from top to bottom, and the inner transfer unit connected to the inner transfer ring of the rotary transfer joint located below passes through an inner passage opened in the inner transfer ring of the rotary transfer joint located above.

3. A rotary mooring transfer system as claimed in claim 1 or 2, wherein at least one of the rotary transfer joints is a fluid transfer joint.

4. The rotary mooring transfer system of claim 3, wherein the transfer structure is an annular fluid groove formed between the inner and outer transfer rings, the inner transfer unit comprising a fluid line in communication with the annular fluid groove.

5. The rotary mooring transfer system of claim 4, wherein the fluid transfer joint transfers a fluid selected from one or more of water, oil, and gas.

6. A rotary mooring transfer system as claimed in claim 4 or 5, wherein a dynamic seal is provided between the inner transfer ring and the outer transfer ring to form a seal isolating the annular fluid groove from the outside.

7. The rotary mooring transfer system of claim 1, wherein at least one of the rotary transfer joints is an energy transfer joint, the transfer structure is a brush disposed between the inner transfer ring and the outer transfer ring, and the inner transfer unit includes a power line electrically connected to the brush, or

At least one rotary conveying joint is a data conveying joint, the conveying structure is an electric brush arranged between the inner conveying ring and the outer conveying ring, and the inner conveying unit comprises a data wire electrically connected with the electric brush.

8. The rotary mooring transfer system of claim 1, wherein a bearing is disposed between the inner transfer ring and the outer transfer ring.

9. The rotary mooring transfer system of claim 1, further comprising a turntable connecting each outer transfer ring.

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