Protective device at joint of marine riser and flat pipe

Abstract

The invention relates to a protective device at the joint of a marine riser and a flat pipe, and belongs to the technical field of marine oil and gas engineering, the protective device comprises a riser sleeve and a protective cover, the protective cover is an arc-shaped plate, and the bottom end of the riser sleeve is fixed in the center of the outer wall of the protective cover; wherein the stand pipe sleeve is used for being arranged on the outer wall of the marine stand pipe in a sleeving mode, and the protective cover is used for being arranged above the joint of the marine stand pipe and a marine flat pipe in a covering mode. The protective cover not only can block scouring of ocean currents, slapping of waves and erosion of a seabed and reduce scouring of the ocean currents to the connecting section, but also can prevent the scouring suspension phenomenon occurring at the connecting position of the ocean vertical pipe and the ocean flat pipe, can prevent collision of ocean falling objects to the pipeline, ensures stability of the connecting position of the ocean vertical pipe and the ocean flat pipe, and improves the service life of the ocean vertical pipe and the ocean flat pipe. The device is high in environmental adaptability and is crucial to safe operation of submarine pipeline engineering, and the problem that at present, a device capable of preventing anchoring, local scouring and other influences is lacked at the joint of a marine riser and a marine flat pipe is solved.

Description

Technical Field

[0001] The invention belongs to the technical field of marine oil and gas engineering, and in particular relates to a protective device for a connection between a marine riser and a horizontal pipe. Background Art

[0002] Submarine pipelines, as the key bridge connecting wellheads and platforms, between platforms, and between platforms and land, play an irreplaceable role in the transportation of oil and gas resources. Their continuous and efficient transportation capacity and convenient management methods make them the core mode of production and transportation of marine oil and gas resources, and an indispensable component of the marine oil and gas system. However, due to the complexity and variability of the submarine environment, the connection section between the submarine riser and the horizontal pipe at the jacket faces severe challenges from multiple environmental factors, including the scouring of ocean currents, the impact of waves, and the erosion of the seabed.

[0003] These challenges may not only lead to intensified local scour, but also cause pipeline vibration, and even overhang in severe cases, thereby increasing the risk of pipeline failure. Once serious accidents such as pipeline rupture occur, it will cause huge economic losses and environmental pollution.

[0004] In conclusion, there is currently a lack of devices at the junction of the marine riser and the marine horizontal pipe that can protect against the effects of anchoring and local scouring. Summary of the invention

[0005] In view of the above problems, the purpose of the present invention is to provide a protective device for the connection between a marine riser and a marine horizontal pipe, so as to solve the problem that there is currently a lack of a device capable of protecting the connection between a marine riser and a marine horizontal pipe from the effects of anchoring and local scouring.

[0006] To achieve the above object, the present invention adopts the following technical solutions: The invention discloses a protective device for the connection between a marine riser and a horizontal pipe, which is used to be arranged at the connection between the marine riser and the horizontal pipe, and comprises a riser sleeve and a protective cover. The protective cover is an arc-shaped plate, and the bottom end of the riser sleeve is fixed at the center of the outer wall of the protective cover; Wherein, the riser sleeve is used to be sleeved on the outer wall of the marine riser; The protective cover is used to cover the upper part of the connection between the marine riser and the marine horizontal pipe.

[0007] Preferably, the protective cover is provided with a shielding plate, which is a semicircular plate and is arranged on one side of the protective cover, so that the shielding plate and the protective cover together form a cover body with a reserved gap. Wherein, the gap is used for passing the ocean flat pipe.

[0008] Preferably, the protective cover is formed by connecting a left protective cover part and a right protective cover part, the riser sleeve is formed by connecting a left riser sleeve part and a right riser sleeve part, the left riser sleeve part of the riser sleeve and the left protective cover part of the protective cover are fixedly connected to form a whole; the right riser sleeve part of the riser sleeve and the right protective cover part of the protective cover are fixedly connected to form a whole.

[0009] Preferably, support piles are respectively provided at the corners of the outer ends of the left protective cover part and the right protective cover part.

[0010] Preferably, a plurality of guide holes are spaced apart on the left protective cover portion, the right protective cover portion and the shielding vertical plate.

[0011] Preferably, the riser sleeve is in the shape of a truncated cone that is narrow at the top and wide at the bottom and hollow inside. A spiral strake is provided on the outer side of the riser sleeve, and the spiral strake includes a first spiral plate, a second spiral plate and a third spiral plate. The first spiral plate, the second spiral plate and the third spiral plate are gradually spiraled from high to low along the outer side surface of the riser sleeve, and are parallel to each other and evenly spaced apart on the outer side surface of the riser sleeve.

[0012] Preferably, the riser sleeve is sleeved on the outer wall of the marine riser through a buffer connector; The buffer connection piece includes a fixing belt and a fixing ring, the fixing belt is tied to the outer wall of the marine riser, and the fixing ring is connected to the fixing belt by bolts; An inner plug-in portion is fixed on the outer wall of the fixing ring, an outer plug-in portion is arranged on the inner wall of the riser sleeve, and the riser sleeve is inserted into the inner plug-in portion of the fixing ring through the outer plug-in portion to realize fixed connection between the riser sleeve and the fixing ring.

[0013] Preferably, the fixing belt is connected by a buckle to form a circle and is tied to the outer wall of the marine riser.

[0014] Preferably, the inner plug-in portion of the fixing ring comprises an upper ring and a lower ring, and the upper ring and the lower ring of the inner plug-in portion are arranged parallel to each other; The outer plug-in portion of the riser sleeve comprises a base, an upper outer ring and a lower outer ring are respectively arranged at two ends of the base, the upper outer ring and the lower outer ring are parallel to each other and have the same length, an upper inner ring and a lower inner ring are arranged in the middle of the base, the upper inner ring and the lower inner ring are parallel to each other, and the protruding lengths of the upper inner ring and the lower inner ring are respectively greater than the upper outer ring and the lower outer ring; When the riser sleeve is inserted on the inner plug-in part of the fixing ring through the outer plug-in part, the upper inner ring and the lower inner ring of the outer plug-in part of the riser sleeve are simultaneously inserted into the inner side between the upper ring and the lower ring of the inner plug-in part of the fixing ring, and the upper outer ring and the lower outer ring of the outer plug-in part of the riser sleeve are respectively sleeved on the outer side of the upper ring and the lower ring of the fixing ring.

[0015] Preferably, a spring is provided in the area enclosed by the outer wall of the fixing ring, the outer wall of the base of the outer plug-in part of the riser sleeve, and the upper and lower circles of the inner plug-in part, and the two ends of the spring are respectively fixed on the outer wall of the fixing ring and the outer wall of the base of the outer plug-in part of the riser sleeve.

[0016] Compared with the prior art, the present invention has the following beneficial effects: (I) The present invention discloses a protective device for the connection between a marine riser and a horizontal pipe, including a riser sleeve and a protective cover, wherein the protective cover is an arc-shaped plate, and the bottom end of the riser sleeve is fixed at the center of the outer wall of the protective cover; wherein the riser sleeve is arranged on the outer wall of the marine riser, and the protective cover is arranged above the connection between the marine riser and the marine horizontal pipe. The protective cover can not only block the scouring of ocean currents, the beating of waves, and the erosion of the seabed, and reduce the scouring of the connection section by ocean currents, but also protect against the scouring and suspension phenomenon that occurs at the connection between the marine riser and the marine horizontal pipe, and can protect against the collision of marine falling objects with the pipeline, thereby ensuring the stability of the connection between the submarine riser and the horizontal pipe, having strong adaptability to the environment, and being crucial to the safe operation of submarine pipeline projects, and solving the problem of the lack of a device that can protect against the effects of anchoring and local scouring at the connection between the marine riser and the marine horizontal pipe.

[0017] (ii) The present invention discloses a protective device for the connection between an ocean riser and a horizontal pipe. The shape of the protective cover is designed to be a saddle shape, and a plurality of diversion holes are spaced apart on the left protective cover part, the right protective cover part and the shielding vertical plate. The protective cover adopts a saddle-shaped arc surface design, and the shape of the protective cover matches the ocean current velocity gradient, so that the protective cover can more effectively withstand the impact of ocean currents from various water layers, so that ocean currents of different water levels entering the protective device can reach the connection section between the ocean riser and the ocean horizontal pipe at a uniform speed, thereby significantly reducing the risk of erosion and scouring of the pipeline connection caused by high-speed water flow.

[0018] (III) The present invention discloses a protective device for the joint between a marine riser and a horizontal pipe. The shape of the riser sleeve is designed to be a truncated cone that is narrow at the top and wide at the bottom, and hollow inside. A spiral strake is arranged on the outer side of the riser sleeve, and the spiral strake includes a first spiral plate, a second spiral plate, and a third spiral plate. The first spiral plate, the second spiral plate, and the third spiral plate gradually spiral from high to low along the outer side of the riser sleeve, and are parallel to each other and evenly spaced on the outer side of the riser sleeve. The shape of the riser sleeve is designed to be a truncated cone that is narrow at the top and wide at the bottom, and hollow inside. The shape characteristics of the spiral strake are used to change the velocity distribution of the ocean current when it passes through, so that the vortex intensity becomes uneven, and it is difficult to form a resonance phenomenon. Such a design not only enhances the stability of the pipeline system, but also improves its adaptability to complex marine environments, and effectively prevents problems such as vortex-induced oscillation and sediment scouring. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 A schematic diagram of the three-dimensional structure of the protective device at the connection between the marine riser and the horizontal pipe provided in Example 1 of the present invention; Figure 2 for Figure 1 Left view of Figure 3 for Figure 1 A top view of Figure 4 A schematic diagram of a fixing belt provided in Example 1 of the present invention being tied to a marine riser; Figure 5 This is a schematic structural diagram of the right half of the cross section of the buffer connector provided in Example 1 of the present invention.

[0020] Description of reference numerals: 100 - marine riser, 101 - marine horizontal pipe; 1- riser sleeve, 11- left riser sleeve portion, 12- right riser sleeve portion; 2- a cover body with a notch reserved, 20- a shielding plate, 21- a left protective cover part, 210- a left ear plate, 22- a right protective cover part, 220- a right ear plate, 23- a supporting pile; 3- diversion hole; 4- spiral plate, 41- first spiral plate, 42- second spiral plate, 43- third spiral plate; 51-fixing belt, 510-buckle, 511-bolt; 52-fixing ring, 521-nut; 61-upper circle, 62-lower circle; 71-upper outer ring, 72-lower outer ring; 81-upper inner circle, 82-lower inner circle; 9- Spring. DETAILED DESCRIPTION

[0021] The exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present invention and to fully convey the scope of the present invention to those skilled in the art.

[0022] In order to solve the problem that there is currently a lack of devices that can protect against anchoring and local scouring at the connection between the marine riser and the marine horizontal pipe, the present invention discloses a protective device for the connection between the marine riser and the horizontal pipe, including a riser sleeve and a protective cover, the protective cover is an arc-shaped plate, and the bottom end of the riser sleeve is fixed to the center of the outer wall of the protective cover; wherein the riser sleeve is arranged on the outer wall of the marine riser, and the protective cover is arranged above the connection between the marine riser and the marine horizontal pipe. The protective cover can not only block the scouring of the ocean current, the beating of the waves, and the erosion of the seabed, and reduce the scouring of the ocean current on the connection section, but also protect against the scouring and suspension phenomenon that occurs at the connection between the marine riser and the marine horizontal pipe, and can protect against the collision of marine falling objects on the pipeline, ensuring the stability of the connection between the submarine riser and the horizontal pipe, and has strong adaptability to the environment, which is crucial to the safe operation of the submarine pipeline project.

[0023] Embodiment 1: A protective device for the connection between a marine riser and a horizontal pipe Embodiment 1 of the present invention provides a protective device for the connection between a marine riser and a horizontal pipe, and its structure is described in detail below with reference to the accompanying drawings.

[0024] refer to Figure 1 and Figure 2 The protective device for the connection between the marine riser and the horizontal pipe is used to be arranged at the connection between the marine riser 100 and the marine horizontal pipe 101, and includes a riser sleeve 1 and a protective cover. The protective cover is an arc-shaped plate, and the bottom end of the riser sleeve 1 is fixed at the center of the outer wall of the protective cover; Wherein, the riser sleeve 1 is used to be sleeved on the outer wall of the marine riser 100; The protective cover is used to cover the upper part of the connection between the marine riser 100 and the marine horizontal pipe 101.

[0025] In order to provide effective external protection, the protection cover is disposed outside the ocean flat pipe 101 without directly contacting the pipeline of the ocean flat pipe 101 .

[0026] In order to ensure that the connection between the marine riser 100 and the marine horizontal pipe 101 is completely covered, the protective cover is equipped with a shielding vertical plate 20. The shielding vertical plate 20 is a semicircular plate and is arranged on one side of the protective cover so that the shielding vertical plate 20 and the protective cover together form a cover body 2 with a reserved gap.

[0027] The gap is used for the passage of the ocean flat pipe 101.

[0028] As a specific implementation, the protective cover is formed by connecting a left protective cover portion 21 and a right protective cover portion 22 .

[0029] Specifically, the left protective cover portion 21 and the right protective cover portion 22 each occupy 1 / 2 of the entire protective cover, and the left protective cover portion 21 and the right protective cover portion 22 are butted together to form the protective cover; The riser sleeve 1 is formed by connecting a left riser sleeve portion 11 and a right riser sleeve portion 12. Specifically, the left riser sleeve 11 and the right riser sleeve 12 each occupy 1 / 2 of the entire riser sleeve 1 , and the left riser sleeve 11 and the right riser sleeve 12 are butt-jointed to form the riser sleeve 1 .

[0030] The left riser sleeve portion 11 of the riser sleeve 1 and the left protective cover portion 21 of the protective cover are fixedly connected to form an integral body. Preferably, the left riser sleeve portion 11 and the left protective cover portion 21 are integrally formed.

[0031] The right riser sleeve portion 12 of the riser sleeve 1 and the right protective cover portion 22 of the protective cover are fixedly connected to form an integral body. Preferably, the right riser sleeve portion 12 and the right protective cover portion 22 are integrally formed.

[0032] In order to improve stability, a plurality of support piles 23 are respectively provided at the corners of the outer ends of the left protective cover part 21 and the right protective cover part 22, wherein each of the support piles 23 is used to penetrate deep into the seabed for fixation, thereby ensuring that the entire device is firmly fixed on the seabed.

[0033] Specifically, the left end of the left protective cover part 21 is configured with a left ear plate 210, and the left ear plate 210 extends outward from the left end of the left protective cover part 21 in an arc shape; the right end of the right protective cover part 22 is configured with a right ear plate 220, and the right ear plate 220 extends outward from the right end of the right protective cover part 22 in an arc shape.

[0034] Preferably, the left ear plate 210 and the right ear plate 220 are symmetrical with respect to a center line of the arc surface of the protective cover in a width direction.

[0035] Among them, the support piles 23 pass through and are inserted into the seabed to enhance the stability of the device. This design ensures that the protective device can be firmly fixed on the seabed and effectively resist the influence of ocean currents and external forces. The design of the support piles 23 enables the protective device to fit closely with the surface of the seabed, greatly improving the overall stability of the device. By closely integrating with the seabed, not only the stability of the structure is enhanced, but also the displacement caused by ocean currents or external forces is effectively prevented.

[0036] In order to reduce the intensity of the water flow, preferably, the shape of the protective cover is a saddle shape, and a plurality of diversion holes 3 are spaced apart on the left protective cover portion 21 , the right protective cover portion 22 and the shielding vertical plate 20 .

[0037] Due to the large velocity gradient of the ocean current, the protective cover adopts a saddle-shaped curved surface design, and the shape of the protective cover matches the velocity gradient of the ocean current, so that the protective cover can more effectively withstand the impact of ocean currents from various water layers, so that the ocean currents at different water levels entering the protective device can reach the connection section of the ocean riser 100 and the ocean horizontal pipe 101 at a uniform speed, thereby significantly reducing the risk of erosion and scouring caused by high-speed water flow to the pipeline connection. Such a design not only improves the durability of the overall structure, but also further enhances the stability and reliability of the protective device in complex marine environments.

[0038] The design of multiple guide holes 3 can increase the outflow cross section, effectively reduce the eddy current intensity, and reduce local scouring.

[0039] In order to block the ocean current and reduce the vibration caused by the water current, the shape of the riser sleeve 1 is a truncated cone which is narrow at the top and wide at the bottom and hollow inside. A spiral plate 4 is provided on the outer side of the riser sleeve 1. The spiral plate 4 includes a first spiral plate 41, a second spiral plate 42 and a third spiral plate 43. The first spiral plate 41, the second spiral plate 42 and the third spiral plate 43 gradually spiral from high to low along the outer side surface of the riser sleeve 1, and are parallel to each other and evenly spaced on the outer side surface of the riser sleeve 1.

[0040] The shape of the riser sleeve 1 is designed to be a truncated cone with a narrow top and a wide bottom and a hollow interior. The shape characteristics of the spiral strake 4 are used to change the velocity distribution of the ocean current when it passes through, making the eddy current intensity uneven and making it difficult to form resonance. This design not only enhances the stability of the pipeline system, but also improves its adaptability to complex marine environments, effectively preventing problems such as vortex-induced oscillation and sediment scouring.

[0041] Furthermore, the riser sleeve 1 is sleeved on the outer wall of the marine riser 100 through a buffer connector; Specifically, the buffer connection member includes a fixing belt 51 and a fixing ring 52. The fixing belt 51 is tied to the outer wall of the marine riser 100; The fixing ring 52 is connected to the fixing belt 51 by bolts; specifically, the fixing belt 51 is provided with a plurality of bolts 511, the fixing ring 52 is sleeved on the fixing belt 51, and the bolts 511 on the fixing belt 51 pass through the fixing ring 52 and are respectively tightened and fixed by a plurality of nuts 521; An inner plug-in portion is fixed on the outer wall of the fixing ring 52. The shape of the riser sleeve 1 is a hollow truncated cone. An outer plug-in portion is provided on the inner wall of the riser sleeve 1. The riser sleeve 1 is inserted into the inner plug-in portion of the fixing ring 52 through the outer plug-in portion to achieve a fixed connection between the riser sleeve 1 and the fixing ring 52.

[0042] Specifically, the fixing belt 51 is connected to form a circle through a buckle 510 and tied to the outer wall of the marine riser 100. As a specific implementation method for inserting the riser sleeve 1 into the inner plug-in portion of the fixing ring 52 through the outer plug-in portion, the inner plug-in portion of the fixing ring 52 includes an upper ring 61 and a lower ring 62, and the upper ring 61 and the lower ring 62 of the inner plug-in portion are arranged parallel to each other; The outer plug-in portion of the riser sleeve 1 includes a base 70, and an upper outer ring 71 and a lower outer ring 72 are respectively provided at both ends of the base 70, and the upper outer ring 71 and the lower outer ring 72 are parallel to each other and have the same length. An upper inner ring 81 and a lower inner ring 82 are provided in the middle of the base 70, and the upper inner ring 81 and the lower inner ring 82 are parallel to each other, and the protruding lengths of the upper inner ring 81 and the lower inner ring 82 are respectively greater than the upper outer ring 71 and the lower outer ring 72. When the riser sleeve 1 is inserted into the inner plug-in portion of the fixing ring 52 through the outer plug-in portion, the upper inner ring 81 and the lower inner ring 82 of the outer plug-in portion of the riser sleeve 1 are simultaneously inserted into the inner side between the upper ring 61 and the lower ring 62 of the inner plug-in portion of the fixing ring 52, and the upper outer ring 71 and the lower outer ring 72 of the outer plug-in portion of the riser sleeve 1 are respectively sleeved on the outer sides of the upper ring 61 and the lower ring 62 of the fixing ring 52.

[0043] In order to cushion the influence of external impact force and enhance stability, a spring 9 is provided in the area enclosed by the outer wall of the fixing ring 52, the outer wall of the base 70 of the outer plug-in part of the riser sleeve 1, and the upper ring 61 and the lower ring 62 of the inner plug-in part. The two ends of the spring 9 are respectively fixed on the outer wall of the fixing ring 52 and the outer wall of the base 70 of the outer plug-in part of the riser sleeve 1.

[0044] When the marine riser 100 shakes, the spring 9 inside the buffer connector will stretch or contract to generate elastic force, and at the same time, the outer plug-in portion of the riser sleeve 1 and the inner plug-in portion of the fixing ring 52 will be relatively displaced. The generated friction force can offset part or even all of the energy of the pipeline shaking, thereby achieving the effect of maintaining the stability of the marine riser 100.

[0045] Specifically, the outer plug-in part of the riser sleeve 1 and the inner plug-in part of the fixing ring 52 are made of two different damping materials, and the friction force is generated by their mutual movement. When the marine riser 100 vibrates, it will drive the mutual movement between the sleeves, and the vibration is suppressed by the generated friction force.

[0046] Specifically, the protective device at the connection between the marine riser and the horizontal pipe, namely the riser sleeve 1 and the cover body 2 with a reserved gap, is made of fiberglass, which has excellent impact resistance and can effectively protect the pipeline when hit by falling objects in the ocean.

[0047] Specifically, the support piles 23 are made of steel structure, which provides sufficient strength to fix the entire protective device.

[0048] Specifically, the first spiral plate 41, the second spiral plate 42 and the third spiral plate 43 of the spiral column plate 4 are made of polyurethane elastomer, polyethylene, fiberglass and the like.

[0049] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A protective device for the connection between a marine riser and a horizontal pipe, used for being arranged at the connection between a marine riser (100) and a marine horizontal pipe (101), characterized in that: It includes a riser sleeve (1) and a protective cover, The protective cover is an arc-shaped plate, and the bottom end of the riser sleeve (1) is fixed at the center of the outer wall of the protective cover; Wherein, the riser sleeve (1) is used to be sleeved on the outer wall of the marine riser (100); The protective cover is used to cover the upper part of the connection between the marine riser (100) and the marine horizontal pipe (101).

2. The protective device according to claim 1, characterized in that: The protective cover is provided with a shielding vertical plate (20). The shielding upright plate (20) is a semicircular plate, and is arranged on one side of the protective cover, so that the shielding upright plate (20) and the protective cover together form a cover body (2) with a reserved notch. The notch is used for passing the ocean flat pipe (101).

3. The protective device according to claim 2, characterized in that: The protective cover is formed by connecting a left protective cover part (21) and a right protective cover part (22). The riser sleeve (1) is formed by butting a left riser sleeve portion (11) and a right riser sleeve portion (12). The left riser sleeve portion (11) of the riser sleeve (1) and the left protective cover portion (21) of the protective cover are fixedly connected to form an integral body; The right standpipe sleeve portion (12) of the standpipe sleeve (1) and the right protective cover portion (22) of the protective cover are fixedly connected to form an integral body.

4. The protection device according to claim 3, characterized in that: Support piles (23) are respectively provided at the corners of the outer ends of the left protective cover portion (21) and the right protective cover portion (22).

5. The protection device according to claim 4, characterized in that: A plurality of air guide holes (3) are spaced apart and distributed on the left protective cover portion (21), the right protective cover portion (22) and the shielding upright plate (20).

6. The protection device according to claim 1, characterized in that: The riser sleeve (1) is in the shape of a truncated cone which is narrow at the top and wide at the bottom and hollow inside. A spiral strake (4) is arranged on the outer side of the riser sleeve (1). The spiral strake (4) comprises a first spiral plate (41), a second spiral plate (42) and a third spiral plate (43). The first spiral plate (41), the second spiral plate (42) and the third spiral plate (43) are gradually spiraled from high to low along the outer side surface of the riser sleeve (1), and are parallel to each other and evenly spaced apart on the outer side surface of the riser sleeve (1).

7. The protection device according to claim 1, characterized in that: The riser sleeve (1) is sleeved on the outer wall of the marine riser (100) via a buffer connector; The buffer connection piece comprises a fixing belt (51) and a fixing ring (52). The fixing belt (51) is tied to the outer wall of the marine riser (100), and the fixing ring (52) is connected to the fixing belt (51) by bolts; An inner plug-in portion is fixed on the outer wall of the fixing ring (52), and an outer plug-in portion is provided on the inner wall of the riser sleeve (1). The riser sleeve (1) is inserted into the inner plug-in portion of the fixing ring (52) via the outer plug-in portion, thereby achieving a fixed connection between the riser sleeve (1) and the fixing ring (52).

8. The protection device according to claim 7, characterized in that: The fixing belt (51) is connected by a buckle (510) to form a circle, and is tied to the outer wall of the marine riser (100).

9. The protection device according to claim 7, characterized in that: The inner plug-in portion of the fixing ring (52) comprises an upper ring (61) and a lower ring (62), and the upper ring (61) and the lower ring (62) of the inner plug-in portion are arranged parallel to each other; The outer plug-in portion of the riser sleeve (1) comprises a base (70), and an upper outer ring (71) and a lower outer ring (72) are respectively arranged at two ends of the base (70), and the upper outer ring (71) and the lower outer ring (72) are parallel to each other and have the same length. An upper inner ring (81) and a lower inner ring (82) are arranged in the middle of the base (70), and the upper inner ring (81) and the lower inner ring (82) are parallel to each other, and the upper inner ring (81) and the lower inner ring (82) have a greater extension length than the upper outer ring (71) and the lower outer ring (72), respectively. When the riser sleeve (1) is inserted into the inner plug-in portion of the fixing ring (52) through the outer plug-in portion, the upper inner ring (81) and the lower inner ring (82) of the outer plug-in portion of the riser sleeve (1) are simultaneously inserted into the inner side between the upper ring (61) and the lower ring (62) of the inner plug-in portion of the fixing ring (52), and the upper outer ring (71) and the lower outer ring (72) of the outer plug-in portion of the riser sleeve (1) are respectively sleeved on the outer sides of the upper ring (61) and the lower ring (62) of the fixing ring (52).

10. The protective device for the connection between the marine riser and the horizontal pipe according to claim 9, characterized in that: A spring (9) is provided in the area enclosed by the outer wall of the fixing ring (52), the outer wall of the base (70) of the outer plug-in portion of the riser sleeve (1), and the upper ring (61) and the lower ring (62) of the inner plug-in portion. The two ends of the spring (9) are respectively fixed on the outer wall of the fixing ring (52) and the outer wall of the base (70) of the outer plug-in portion of the riser sleeve (1).

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