A single-column moored wellhead production operation platform

Abstract

The present invention discloses a single-column moored wellhead production platform, comprising: a column body, the column body being a hollow structure; a positioning and mounting assembly arranged at the bottom of the column body; a turntable arranged outside the column body and capable of rotating around the axis of the column body, the turntable comprising a mooring connection device; an oil production platform arranged on the top of the column body and located above the turntable, the oil production platform being provided with an oil production assembly; at least one well slot in the barrel arranged inside the column body, the well slot in the barrel being able to be connected to the oil production platform. It can adapt to the economic indicators of marginal oil field exploitation.

Description

Technical Field

[0001] The invention relates to the field of marine oil and gas development, and particularly to a single-column moored wellhead production operation platform. Background Art

[0002] Many marginal oil fields have been discovered in my country's shallow waters. Marginal oil fields refer to those with low proven production (recoverable reserves of a single oil field are approximately between 100,000 tons and 2 million tons), scattered geographical locations and far away from other large oil fields, and poor economic benefits when developed using traditional development models.

[0003] A complete oilfield development requires four processes: drilling (repair)-production-storage-transportation. The current development model of traditional shallow-water oilfields in my country mainly includes the following parts: (1) single or multiple wellhead platforms; (2) production storage and offloading vessels (FPSO); (3) jackets and single-point systems for mooring FPSOs; (4) submarine pipelines connecting the wellhead platform and FPSO.

[0004] The wellhead platform is generally a jacket-type platform equipped with a Christmas tree. The FPSO is moored to a jacket by a single-point mooring system. The wellhead platform transports the crude oil mixture to the FPSO through a submarine pipeline for production and storage. At the same time, the FPSO supplies power and liquids required for life and operations to the wellhead platform through cables. Shuttle tankers regularly come to the FPSO to transport crude oil to land.

[0005] The mooring platform commonly used for mooring FPSO is a completely different type of jacket from the wellhead platform, and they cannot be used interchangeably. FPSO is moored to the mooring platform, and then connected to the wellhead platform through a submarine pipeline. In order to reserve a safe distance, it is necessary to bury expensive submarine pipelines. For oil fields with large output and dense numbers, the cost of the mooring platform, the wellhead platform and the corresponding submarine pipeline can be evenly distributed to multiple oil fields, and it has high stability and can obtain ideal economic benefits; but for marginal oil fields, it is obviously not suitable because the unit output of marginal oil fields is lower than that of dense and high-yield oil fields. For a single marginal oil field, the equipment investment may be higher than the income obtained, or only a very low income can be obtained. Due to this, the development of some marginal oil fields has been temporarily shelved.

[0006] Considering the economic requirements, two operation modes are considered for the development of marginal oil fields:

[0007] (1) The “three-in-one” development model, that is, for marginal oil and gas fields within 20 km of an already developed oil field, the oil and gas produced by the marginal oil and gas fields are transported to the developed oil field using a wellhead platform, a submarine pipeline, and a submarine cable.

[0008] (2) The “bee-style” development model, which is to develop smaller, isolated marginal oil and gas fields that are more than 20 km away from developed oil fields and cannot rely on developed oil fields, using a mobile small-scale production unit that integrates drilling (repairing), production, power, oil storage, external transportation, and living.

[0009] At present, most marginal oil fields are more than 20 km away from developed oil fields, and even submarine pipelines within 20 km in length still require high construction costs. Therefore, the "bee-style" development model is the main solution to many marginal oil fields.

[0010] This development model mainly provides a movable platform structure, so that the production, power, oil storage, external transmission, life and other operating functions can be integrated into a small production device. After the platform structure has finished extracting oil from a small oil field, it can move to another small oil field to extract oil like a bee. The "bee-style" development model can make marginal oil fields have certain economic benefits, but in order to achieve the mobility of the platform, the shape of the platform will be subject to certain restrictions, and it is difficult to configure enough space for oil storage. Generally, the full load storage cannot exceed 2,000 tons, which makes the shuttle tanker to pick up oil too frequently, thereby reducing the economic efficiency of the entire oil field development.

[0011] Another idea is to consider connecting the storage and transportation ship with the jacket under normal production conditions. The jacket is used for production, and the storage and transportation ship is used to store crude oil. It has the functions of production, power, oil storage, external transportation, and life. However, with this approach, the storage and transportation ship is subjected to a load far greater than the oil storage device configured on the original platform during production, resulting in the system's overall ability to resist wind and waves being poor. Especially when the storage and transportation ship is in a beam wave state, the lateral load is extremely large, and the violent rolling movement can easily cause the jacket or related equipment and lines to be damaged, thereby causing an accident.

[0012] Therefore, there is a need to change the existing wellhead platform structure to adapt to the economic requirements of marginal oil field development.

[0013] It should be noted that the above contents belong to the technical knowledge of the inventor and do not necessarily constitute prior art. Summary of the invention

[0014] The present invention aims to provide a production operation platform that can improve the economic indicators of marginal oil field development in view of the shortcomings of the background technology. It can improve the compactness of the layout of oil production equipment, reduce the number of facilities, and reduce the investment cost; it has good safety and stability; it also supports the integration of well repair, production, power, oil storage, external transmission, life and other functions on one platform; and supports the expansion of a sufficiently large oil storage space.

[0015] The technical solution adopted by the present invention is:

[0016] A single-column moored wellhead production operation platform, comprising:

[0017] A column body, wherein the column body is a hollow structure;

[0018] A positioning and mounting assembly disposed at the bottom of the column body;

[0019] A turntable disposed outside the column body and capable of rotating around the axis of the column body, the turntable comprising a mooring connection device;

[0020] An oil production operation platform disposed on the top of the column body and located above the turntable, wherein an oil production operation component is disposed on the oil production operation platform;

[0021] At least one inner well slot is arranged inside the column body of the column, and the inner well slot can be connected to the oil production operation platform.

[0022] Through the above technical solution, the column body is stably placed in the sea area of ​​the oil field by setting a positioning and installation assembly around the hollow column body: at the bottom of the column body. The turntable outside the column body can support the platform to realize the mooring function, such as mooring a floating production storage and offloading device (FPSO). After the floating production storage and offloading device is moored to the turntable, it can rotate around the column body together with the turntable when encountering wind and waves. The inner well slot is set inside the column body, and multiple, such as 3 to 6, can be set to support oil production operations, wherein the oil production operation assembly is set on the oil production operation platform at the top of the turntable, and the column body structure is reasonably set, and the mooring and oil production operations will not affect each other and can be carried out simultaneously. The integration of mooring and oil production operations on the production operation platform based on the same column body is realized, that is, the wellhead platform and the single-point mooring jacket in the traditional shallow water oil field development model are integrated into one, eliminating the submarine pipeline set between the mooring platform and the wellhead platform, and also reducing the number of platform jackets set. It can significantly reduce the development cost of marginal oil fields and has very high promotion value.

[0023] In a preferred implementation, the positioning and installation assembly includes a plurality of pile foundations and a conduit connecting the pile foundations and a column body.

[0024] In a preferred implementation, the positioning and installation assembly includes a pile foundation column extending downward along the bottom of the column body.

[0025] Optionally, the column body and the pile foundation body are integrally formed, that is, one end of the bottom of the column body is used as a single pile foundation, which is rammed into the seabed for fixation. The form of the positioning installation component can be selected according to different sea conditions, and can also be used in conjunction with multiple positioning methods.

[0026] In a preferred implementation, the turntable includes a turntable body and a turntable bearing, and an inner ring of the turntable bearing is fixedly connected to the column body.

[0027] The bearing selected for the turntable will preferably be a rolling bearing, in which case the outer ring of the turntable bearing is fixedly connected to the turntable body. In some cases, a sliding bearing may also be selected, in which case the bearing lubricating layer will be between the outer surface of the bearing and the inner surface of the bearing seat formed by the turntable body, and the inner surface of the bearing will be fixed to the column body by a tight fit.

[0028] In a preferred implementation, a rotating conveying assembly connected to the turntable is also included; including:

[0029] Several rotary conveying joints, the rotary conveying joints comprising:

[0030] An inner conveying ring fixedly connected to the column body;

[0031] An outer conveying ring that rotates relative to the inner conveying ring following the turntable;

[0032] A conveying structure capable of maintaining conveying during the rotation process is provided between the inner conveying ring and the outer conveying ring;

[0033] An internal conveying unit, connecting the conveying structure and the oil production operation assembly;

[0034] The external conveying unit is connected to the conveying structure.

[0035] It is further preferred that the transport unit is fixed by means of a mooring device.

[0036] By setting up a rotating conveying joint, a preferred method is provided to eliminate the conflict between oil production operations on the production operation platform and mooring. The floating production storage and offloading device moored with a turntable will be driven by wind and waves to rotate the turntable. At this time, external conveying units such as water pipelines, oil pipelines, power lines, etc. are connected to the floating production storage and offloading device to avoid entanglement and stretching. Therefore, a rotating conveying joint is required to maintain the stability of the external and internal conveying states during the rotation of the turntable.

[0037] In a preferred implementation, the conveying structure is used to convey fluid or electrical energy.

[0038] In a preferred implementation, the oil production operation platform includes a wellhead deck, and the oil production operation components include at least one of a Christmas tree, a manifold terminal, and a production auxiliary system.

[0039] The production support system is the equipment for traditional oilfield development operations, including but not limited to: power supply facilities, control instrument facilities, lifting facilities, fire-fighting facilities, safety facilities, and monitoring facilities.

[0040] In a preferred implementation, the oil production operation platform further includes a well repair deck disposed above the wellhead deck for carrying well repair equipment.

[0041] The well repair equipment is preferably hydraulic well repair, and can also cooperate with traditional well repair rigs to carry relevant well repair facilities, mainly providing the function of allowing the drilling (well repair) riser to penetrate into the well slot in the barrel.

[0042] In a preferred implementation, the well slot in the barrel includes a watertight pipe connected to the oil production operation platform or the oil production operation assembly;

[0043] A positioning isolation structure for supporting the watertight pipe is arranged inside the column body.

[0044] In a preferred implementation, the mooring connection device includes a rotary joint and a release device arranged on the rotary joint, the release device is used to release the connection between the rotary joint and the turntable, or the release device is used to release the connection between the release device and the rotary joint.

[0045] An oilfield production operation system, characterized by comprising:

[0046] The aforementioned single-column moored wellhead production platform;

[0047] Floating production storage and offloading units;

[0048] A mooring device connecting the floating production storage and offloading device and the mooring connection device.

[0049] As a single-column moored wellhead production platform, it cooperates with the floating production storage unit to realize oil production and storage operations. The system has the advantages of large oil storage capacity and strong wind and wave resistance. Moreover, under the premise of greatly streamlining the overall facilities and greatly reducing the investment cost, the functions are not reduced. It still has all the functions of well repair, production, power, oil storage, external transmission and life, making the development of many isolated marginal oil fields economically beneficial. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0051] Figure 1 The overall structural diagram of the oilfield production operation system in one embodiment of the present invention is depicted.

[0052] Figure 2 The overall structural diagram of an oilfield production operation system in one embodiment of the present invention is depicted, and each part is marked.

[0053] Figure 3 A partial structural schematic diagram of an oilfield production operation system in one embodiment of the present invention is depicted.

[0054] Figure 4 A partial structural schematic diagram of the upper half of a single-column moored wellhead platform in one embodiment of the present invention is depicted, with the turntable omitted in the figure.

[0055] Figure 5 A schematic diagram of a transverse section of a column body in a single-column moored wellhead platform in one embodiment of the present invention is depicted.

[0056] Figure 6 A partial structural schematic diagram of the upper half of a single-column moored wellhead platform in one embodiment of the present invention is depicted, in which part of the column body is omitted.

[0057] Figure 7 A partial cross-sectional structural schematic diagram of a portion of a single-column moored wellhead platform where a rotary conveying joint is installed is depicted in one embodiment of the present invention.

[0058] Figure 8 A schematic diagram of a single-column moored wellhead platform transfer platform and associated structures in one embodiment of the present invention is depicted.

[0059] Description of reference numerals:

[0060] 1. Floating production storage and offloading (FPSO);

[0061] 2. Column body;

[0062] 3. Position and install components;

[0063] 4. Turntable;

[0064] 5. Wellhead deck;

[0065] 6. Christmas tree;

[0066] 7. Manifold terminal;

[0067] 8. Well repairing deck;

[0068] 9. Hydraulic workover rig;

[0069] 10. Rotating conveying components;

[0070] 11. Turntable bearing;

[0071] 12. Mooring support frame;

[0072] 13. Horizontal counterweight rigid arm;

[0073] 14. Counterweight compartment;

[0074] 15. Mooring boom;

[0075] 16. Rigid delivery pipeline;

[0076] 17. Flexible jumper pipe;

[0077] 18. Pitch bearing;

[0078] 19. Roll bearing;

[0079] 20. Universal joint (one is provided at each end of each boom);

[0080] 21. Riser;

[0081] 22. Positioning isolation structure;

[0082] 23. Inner ring (stationary ring) of water transfer rotary joint;

[0083] 24. Outer ring of water transfer rotary joint (rotating ring);

[0084] 25. Sealing ring of water transfer rotary joint;

[0085] 26. Water cavity;

[0086] 27. Outer ring of water delivery bearing (connected to the outer ring of rotary joint)

[0087] 28. Inner ring of water delivery bearing (connected to the inner ring of rotary joint)

[0088] 29. External water pipeline (to FPSO);

[0089] 30. Internal water pipeline (leading to the manifold terminal);

[0090] 31. Inner ring (stationary ring) of oil transfer rotary joint;

[0091] 32. Outer ring of oil transfer rotary joint (rotating ring);

[0092] 33. Oil transfer rotary joint sealing ring;

[0093] 34. Oil cavity;

[0094] 35. Outer ring of oil transfer bearing (connected to the outer ring of rotary joint)

[0095] 36. Inner ring of oil transfer bearing (connected to the inner ring of rotary joint)

[0096] 37. External oil pipeline (to FPSO);

[0097] 38. Internal oil pipeline (leading to the manifold terminal);

[0098] 39. Inner ring (stationary ring) of power transmission rotary joint;

[0099] 40. Outer ring of power transmission rotary joint (rotating ring);

[0100] 41. Power transmission rotary joint sealing ring;

[0101] 42. Brush;

[0102] 43. Transmission bearing outer ring (connected to the outer ring of the rotary joint)

[0103] 44. Inner ring of power transmission bearing (connected to the inner ring of rotary joint)

[0104] 45. External transmission line (to FPSO);

[0105] 46. ​​Internal transmission lines (leading to manifold terminals);

[0106] 47. Rotary joint drive arm;

[0107] 48. Driving arm support frame;

[0108] 49. Inner ring of turntable bearing (stationary ring, rigidly fixed to the column);

[0109] 50. Turntable bearing outer ring (rotating ring, rigidly fixed to the turntable). DETAILED DESCRIPTION

[0110] In order to more clearly illustrate the overall concept of the present invention, a detailed description is given below in an exemplary manner in conjunction with the accompanying drawings.

[0111] It should be noted that many specific details are set forth in the following description to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the protection scope of the present invention is not limited to the specific embodiments disclosed below.

[0112] In addition, in the description of the present invention, it should be understood that the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0113] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral one; it can be directly connected, or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. However, if it is indicated as a direct connection, it means that the two connected bodies are not connected through an intermediate structure, but are only connected to form a whole through a connecting structure. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.

[0114] In the present invention, unless otherwise clearly specified and limited, the first feature "on" or "under" the second feature may be that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in an appropriate manner in any one or more embodiments or examples.

[0115] Before describing the optional implementations provided by the present invention in conjunction with the accompanying drawings, the technical concept of the present invention is first introduced.

[0116] The traditional wellhead platform used for oil production is limited by its structure and cannot be equipped with bearings of the single-point mooring system. The structure of the wellhead platform needs to be improved. Similarly, the existing mooring jacket cannot be used as a wellhead because it cannot be used to arrange a Christmas tree. To complete the oil production operation, mooring and wellhead operations are both indispensable. For oil fields with large production and dense numbers, it is feasible to configure the wellhead platform and the single-point mooring jacket at the same time. The whole system has a long service life and the cost can be evenly distributed to multiple oil fields. The development cost per unit of production can be very low, which has good economic benefits. However, for marginal oil fields, the cost per unit of production of this development model is high and cannot meet the economic requirements.

[0117] Therefore, the technical purpose that the present invention aims to achieve is: for a single isolated shallow marginal oil field, a system is used to simultaneously have all the functions of well repair, production, power, oil storage, external transmission, and life, while the number of facilities is as small as possible and the investment cost is as low as possible; and well repair can be carried out simultaneously under normal working conditions without stopping production; it can also support a sufficiently large oil storage space; it also needs to have a strong ability to resist harsh marine environment, be able to withstand sea conditions that occur once in 50 years, and not stop production under sea conditions that occur once in a year; when faced with extremely harsh sea conditions that occur once in 100 years, it can be quickly relieved.

[0118] The key to achieving the above technical objectives is to adopt a hollow column-type platform structure, and to set a mooring turntable outside the column body so as not to conflict with the oil production operations carried out on the top and inside of the column.

[0119] Combination Figure 1 and Figure 2 , depicting an oilfield production operation system based on a single-column moored wellhead production operation platform. The system mainly includes a floating production storage and offloading device 1, a single-column moored wellhead production operation platform and an above-water soft rigid arm single-point mooring system. Among them, the floating production storage and offloading device can be implemented as a production storage tanker, which can be transformed from an old tanker. According to the actual needs of the oil field, a tanker of appropriate size is selected, and necessary production facilities, generator sets, mooring support frames, and external transmission modules are added.

[0120] refer to Figure 3 The single-column moored wellhead production operation platform mainly includes a column 2, a positioning and installation component 3, a turntable 4, a wellhead deck 5, a Christmas tree 6, a manifold terminal 7, a well repair deck 8, a hydraulic well repair rig 9, a rotating conveying component 10 and a turntable bearing 11.

[0121] The diameter of the column is about 2 to 6 meters, and it can be driven into the seabed by a pile hammer and has a certain depth. The hollow inside can be arranged in an array of well slots to arrange drilling risers or production risers. There are three conduits at the bottom of the column distributed at 120 degrees, and the outer end of each conduit is fixed to the seabed through pile foundation piling.

[0122] The wellhead deck is set on the top of the column body. A Christmas tree is set on the top of each riser at the wellhead deck. Each Christmas tree converges to the manifold terminal on the wellhead deck. A workover deck is set above the wellhead deck, and a hydraulic workover rig is arranged. A turntable is set below the wellhead deck. The turntable is connected to the column body through a turntable bearing and can rotate around the column body in a horizontal plane. A rotating transmission component joint is set above the turntable, for example, including a transmission rotating joint for transmitting oil, electricity, and water respectively. The manifold and the stationary part of the rotating joint are connected by oil pipes, water pipes and cables.

[0123] The soft rigid arm mooring system includes a mooring support frame 12, a horizontal counterweight rigid arm 13, a counterweight cabin 14, a boom 15, a rigid conveying pipeline 16, a flexible jumper pipeline 17 (which can be used to convey fluid and energy), a pitch bearing 18, a roll bearing 19 and a universal joint 20.

[0124] Specifically, the soft rigid arm single-point mooring system consists of an onboard support frame, two booms and a horizontal counterweight rigid arm. One end of the counterweight rigid arm is connected to the turntable of the single-column platform, and a detachable universal joint is provided in between, so that the counterweight rigid arm can be rotated arbitrarily relative to the turntable (that is, rotate around the horizontal axis, vertical axis and center axis), and can be quickly released and reconnected; two counterweight cabins are provided at the other end of the counterweight rigid arm, inside which counterweights can be added; the top of the counterweight cabin is connected to the boom through a universal head; the top of the boom is connected to the onboard support frame through a universal head.

[0125] like Figure 4 As shown, the watertight pipe 21 is located in the hollow structure of the column body 2, forming the well slot in the tube. The number and arrangement of the watertight pipes 21 can be determined according to the pipe diameter and the needs of the oil field. The watertight pipe can be inserted into the riser. The riser includes a production riser and a water injection riser. The production riser pumps the crude oil mixture from the seabed to the oil tree 6 on the wellhead deck 5, and the water injection riser pumps water from the upper oil tree 6 into the seabed oil well. The manifold terminal 7 on the wellhead deck 5 is used to gather the lines of all the oil trees 6. In addition to the oil and water pipelines leading to the oil trees 6, there are also cables, and these oil, water and electricity ultimately need to be connected to the FPSO.

[0126] The interaction between the single-pillar moored wellhead production platform and the FPSO is divided into two parts:

[0127] One part is the single-column moored wellhead production platform, which provides mooring positioning for FPSO and serves as the mooring anchor of FPSO. It transmits the mooring force through the soft rigid arm mooring and allows FPSO to rotate around the column under the action of wind, waves and currents. Figure 8As shown, 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 counterweight arm 13 of the soft arm, so the FPSO and the soft arm can drive the turntable 4 to rotate around the column 2. In addition, the pitch bearing 18 and the roll bearing 19 can release the pitch and roll rotation of the horizontal counterweight arm 13, so the horizontal counterweight arm 13 can roll and pitch freely under the drive of the FPSO, and there is no constraint on the FPSO, thereby supporting a large load, thereby allowing large tonnage storage. On the other hand, the mooring support frame is rigidly fixed to the FPSO, and the boom 15 is suspended on the mooring support frame 12 and connected to the lowered counterweight cabin 14. When the FPSO undergoes longitudinal movement, the boom 15 will tilt to increase the work of the counterweight cabin 14, and the pulling force of the counterweight cabin 14 on the boom 15 will produce a horizontal component, and this force component is opposite to the direction of the hull movement as a restoring force, pulling the FPSO back to the equilibrium position. In addition, a quick release device can be provided at the universal joint 20, so that when extreme weather exceeding the design (such as sea conditions that occur once in a hundred years) arrives, quick release can be performed. The quick release device is a common safety measure in the field, and can be automatically released by load changes. As an alternative implementation method, the quick release device can also be provided at the mooring connection.

[0128] The other part is to keep the oil, water and electricity transported when the FPSO rotates relative to the column. This part is mainly completed by the rotating conveying assembly 10. In order to prevent the rotating conveying and oil production operations from interfering with each other, each rotating conveying joint in the rotating conveying assembly is set to a hollow form, and the position of the rotating conveying assembly is set below the wellhead deck. Figure 6 and 7In the implementation shown, the rotating conveying components are water supply joints, oil supply joints and power supply joints from top to bottom. The inner and outer rings (23, 24, 31, 32, 39, 40) of the rotating joints are respectively connected to the inner and outer rings (27, 28, 35, 36, 43, 44) of the bearings. 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 rings 24 (water), 32 (oil), 40 (electricity) of the rotating joint to rotate together, while the inner rings 23 (water), 31 (oil), 39 (electricity) of the rotating joint are rigidly connected to the column body and remain stationary. An annular cavity 26, 34 is formed between the outer ring 24 (water), 32 (oil) of the rotary joint and the inner ring 23 (water), 31 (oil) of the rotary joint. One end of the cavity 26, 34 is connected to the pipeline 29, 37 leading to the FPSO, and the other end is connected to the pipeline 30, 38 leading to the platform manifold. The edges of the cavities 26, 34 are respectively provided with dynamic sealing rings 25, 33 on the contact surfaces of the inner and outer rings. The sealing rings are made of rubber materials with corrosion resistance, high temperature resistance, wear resistance, high elasticity and other characteristics, such as silicone rubber, fluororubber, ethylene propylene rubber, and acrylic rubber. When the pressure in the cavity 26, 34 is relatively high, the contact surfaces of the inner and outer rings of the rotary joint can ensure rotational friction while ensuring sealing. The inner ring 39 and the outer ring 40 of the power transmission rotary joint are respectively connected with brushes 42. The brushes are in a ring shape. When the rotary joint rotates, the two ends of the brushes are always in contact to ensure circuit connectivity. The contact surface between the inner ring 39 and the outer ring 40 of the power transmission rotary joint is also provided with a sealing ring 41.

[0129] In addition, there is an annular cavity in the contact surface between the inner ring and the outer ring for conveying fluids such as water and oil. The cavity is provided with a dynamic sealing ring at the intersection of the two rings to ensure that the fluid in the cavity does not leak during rotation; the cavity has a channel outlet on the inner and outer ring sides respectively; there is also a groove on the contact surface between the inner ring and the column body, forming a channel from bottom to top, which allows the liquid below the rotary joint or the pipe or cable at the outlet of the static part of the electric rotary joint to pass through and lead to the manifold on the wellhead deck.

[0130] When the oil field is operating normally, the FPSO can only rotate around the platform under the positioning of the single point of the soft rigid arm, and has limited longitudinal, pitch and roll movements. FPSO provides power and personnel life. Electricity and water reach the platform manifold through the rotary joint, and then enter the oil well through the oil tree and riser; at the same time, the collected crude oil mixture enters the platform manifold through the oil tree and riser, and then reaches the FPSO for production through the rotary joint, and the produced crude oil is stored in the FPSO, waiting for the shuttle tanker to pick up the oil regularly. When well repair is needed, there is no need to stop production. It is only necessary to pause the oil tree for well repair, take out the production or water injection riser, replace it with a drilling riser, and repair the well with the well repair rig 9. After the well repair is completed, it is replaced with a production riser for production.

[0131] In addition, as an implementation method that can be implemented based on the above solution:

[0132] The number of decks above the single-column moored wellhead production operation platform is not limited to the wellhead deck and the well repair deck, and other decks required for production operations may also be added, such as the manifold deck, water injection deck, boarding deck, etc.

[0133] The structure of the positioning and installation assembly at the bottom of the column body is not limited to the form of three diagonal braces at an angle of 120 degrees. Other forms can be selected according to the actual seabed conditions and structural design, such as frame support, single-side diagonal brace, diagonal lock fixation, etc. The support legs are fixed to the seabed not limited to pile connection, but also suction anchors. The column body can also be directly used as a single pile foundation and rammed into the seabed.

[0134] The number of rotary conveying joints is not limited to 3, and channels can be increased according to the actual needs of the oil field. The types are not limited to oil, water, and electricity rotary joints, and gas rotary joints, multi-functional auxiliary rotary joints, etc. can also be added.

[0135] The well repairing method is not limited to the hydraulic workover rig, and a derrick can also be installed above the workover deck and a traditional workover rig can be used.

[0136] The quick release device of the soft rigid arm system is not limited to being arranged at the connection between the horizontal counterweight rigid arm and the turntable, but can also be arranged at the connection between the boom and the counterweight rigid arm.

[0137] In addition, although the solution of the present invention is proposed for the development of marginal oil fields, the present invention does not limit the application environment of the solution. Under the conditions of economy and equipment safety and stability, the solution of the present invention can also be implemented in non-marginal oil fields to form a "platform network" in a multi-platform manner.

Claims

1. A single-column moored wellhead production operation platform, characterized in that: include: The column body is a hollow structure, and the hollow interior can be arranged with well slots in an array to arrange drilling risers or production risers; A wellhead deck is arranged on the top of the column body, and a Christmas tree is arranged on the top of each riser at the wellhead deck, and each Christmas tree converges to a manifold terminal on the wellhead deck; A positioning and mounting assembly disposed at the bottom of the column body; The positioning and installation assembly places the column body firmly in the sea area of ​​the oil field; A turntable disposed outside the column body and capable of rotating around the axis of the column body, the turntable comprising a mooring connection device; An oil production operation platform disposed on the top of the column body and located above the turntable, wherein an oil production operation component is disposed on the oil production operation platform; At least one well slot is provided inside the column body of the column, and the well slot can be connected to the oil production platform; A soft rigid arm mooring system, the soft rigid arm mooring system comprising a mooring support frame, a horizontal counterweight rigid arm, a counterweight cabin, a boom, a rigid conveying pipeline, a flexible jumper pipeline, a pitch bearing, a roll bearing and a universal joint; The rotary conveying assembly connected to the turntable comprises: a plurality of rotary conveying joints, wherein the rotary conveying joints comprise: An inner conveying ring fixedly connected to the column body; An outer conveying ring that rotates relative to the inner conveying ring following the turntable; A conveying structure capable of maintaining conveying during the rotation process is provided between the inner conveying ring and the outer conveying ring; An internal conveying unit, connecting the conveying structure and the oil production operation assembly; The external conveying unit is connected to the conveying structure.

2. The single-column moored wellhead production platform according to claim 1, characterized in that: The positioning and installation assembly includes a plurality of pile foundations and a guide tube connecting the pile foundations and a column body.

3. The single-column moored wellhead production platform according to claim 1, characterized in that: The positioning and installation assembly comprises a pile foundation column extending downward along the bottom of the column body.

4. The single-column moored wellhead production platform according to claim 1, characterized in that: The turntable comprises a turntable body and a turntable bearing, and an inner ring of the turntable bearing is fixedly connected to the column body.

5. The single-column moored wellhead production platform according to claim 1, characterized in that: The oil production operation platform also includes a well repair deck arranged above the wellhead deck for carrying well repair equipment.

6. The single-column moored wellhead production platform according to claim 1, characterized in that: The well slot in the barrel includes a water-proof pipe connected to the oil production operation platform or the oil production operation assembly; A positioning isolation structure for supporting the watertight pipe is arranged inside the column body.

7. The single-column moored wellhead production platform according to claim 1, characterized in that: The mooring connection device comprises a rotary joint and a release device arranged on the rotary joint, wherein the release device is used to release the connection between the rotary joint and the turntable, or the release device is used to release the connection between the release device and the rotary joint.

8. An oilfield production operation system, characterized in that: include: The single-column moored wellhead production operation platform according to any one of claims 1 to 7; Floating production storage and offloading units; A mooring device connecting the floating production storage and offloading device and the mooring connection device.

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