A self-repairing marine riser vortex-induced vibration suppression device

Abstract

The present application relates to the technical field of offshore drilling, and particularly relates to a self-repairing vortex-induced vibration suppression device for offshore riser, which comprises an inner sleeve 2, an outer sleeve 3 and a spoiler column 4, the inner sleeve 2 is in the shape of a truncated cone with the upper end larger than the lower end, a guide hole 20 is formed in the inner sleeve 2 along the vertical direction, and the inner sleeve 2 is sleeved outside the offshore riser 1 through the guide hole 20. The outer sleeve 3 is in the shape of a cylinder, a truncated cone hole 30 is formed in the middle of the outer sleeve 3 along the vertical direction, the truncated cone hole 30 is provided with a thread, the inner sleeve 2 is threadedly connected with the outer sleeve 3, the inner sleeve 2 is provided with a prefabricated groove 21 along the vertical direction, a one-way bearing 5 is installed between the outer sleeve 3 and the spoiler column 4, and the spoiler column 4 is externally provided with a protruding spoiler block 41. When facing the sea current, the spoiler column 4 suppresses the formation of vortex-induced vibration, and can self-reinforce the reliability of installation under the action of the sea current, avoids falling off and failure, and reduces the maintenance cost in the use process.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of offshore drilling technology, in particular to a self-repairing vortex-induced vibration suppression device for offshore riser. TECHNICAL BACKGROUND

[0002] Vortex-induced vibration is the main cause of fatigue failure of offshore riser. Due to its lock frequency resonance, it can cause large amplitude vibration of the riser, sometimes directly leading to the structural damage of the riser, causing huge losses to offshore oil exploitation. In actual engineering, in order to reduce or eliminate the influence of vortex-induced vibration and prolong the service life of offshore riser, vortex-induced vibration suppression measures are often needed.

[0003] Most of the existing vortex-induced vibration suppression devices are provided with different types of tail wings. When the sea current flows through the suppression device, the direction and speed of the sea current are changed through the tail wings to suppress the generation of vortex-induced vibration of the offshore riser. Since the offshore riser is long and in deep sea, and the surface of the offshore riser is smooth, the vortex-induced vibration suppression device will inevitably loosen and fall off when facing continuous vibration. SUMMARY

[0004] The purpose of the present application is to design a self-repairing vortex-induced vibration suppression device for offshore riser, which can self-reinforce the reliability of the connection when facing continuous vibration caused by sea current flow, and avoid falling off and failure.

[0005] The purpose of the present application is achieved by a self-repairing vortex-induced vibration suppression device for offshore riser, comprising an inner sleeve 2, an outer sleeve 3, and a spoiler column 4. The inner sleeve 2 is in the shape of a truncated cone with the upper end larger than the lower end. A guide hole 20 is formed through the inner sleeve 2 in the vertical direction. The inner sleeve 2 is sleeved outside the offshore riser 1 through the guide hole 20. The outer sleeve 3 is in the shape of a cylinder. A circular truncated cone hole 30 is formed through the cylinder in the vertical direction. The inner sleeve 2 is threadedly connected with the outer sleeve 3. The inner sleeve 2 is provided with a prefabricated groove 21 in the vertical direction. A one-way bearing 5 is arranged between the outer sleeve 3 and the spoiler column 4. The spoiler column 4 is provided with a protruding spoiler block 41 on the outside.

[0006] The spoiler block 41 is in the shape of a square, a circle, or connected to the spoiler column 4 by other means.

[0007] The one-way bearing 5 is replaced by a ratchet mechanism. The ratchet mechanism comprises a rotor 6 and a stator 7. The rotor 6 is sleeved on the outer periphery of the stator 7. The rotor 6 is provided with a ratchet tooth 61 on the inside. The stator 7 is provided with a limiting groove 71 on the outside, which is adapted to the ratchet tooth 61. The rotation direction of the threads of the outer sleeve 3 and the inner sleeve 2 is left-handed. The ratchet tooth 61 is made of elastic material.

[0008] The ratchet mechanism can be replaced by a one-way clutch capable of rotating in one direction.

[0009] The turbulence column 4 is replaced by a turbulence column 8, which is internally provided with mounting holes connected with the one-way bearing 5 and the marine riser 1, and is further provided with a flow guide hole 81, which is arranged in a counterclockwise direction and has a large left end and a small right end.

[0010] The flow guide hole 81 is circumferentially distributed around the mounting hole of the turbulence column 8.

[0011] The prefabricated groove 21 is circumferentially distributed around the axis of the inner sleeve 2.

[0012] The rotation direction of the flow guide hole 81 is the same as that of the outer sleeve 3.

[0013] Compared with the prior art, the present application has the following advantages:

[0014] 1. The reliability of the connection is self-strengthened when facing the continuous vibration caused by the sea current flow, and the failure caused by falling off is avoided.

[0015] 2. The maintenance cost during use is reduced.

[0016] 3. The service life is increased. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 is a general view of the self-repairing marine riser vortex-induced vibration suppression device

[0018] Figure 2 is a structural schematic view of the inner sleeve

[0019] Figure 3 is a structural schematic view of the outer sleeve

[0020] Figure 4 is a structural schematic view of the ratchet mechanism

[0021] Figure 5 is a sectional view of the ratchet mechanism

[0022] Figure 6 is a structural schematic view of the turbulence column 1

[0023] Reference signs: 1-marine riser, 2-inner sleeve, 20-guide hole, 21-prefabricated groove, 3-outer sleeve, 30-circular table hole, 4-turbulence column, 41-turbulence block, 5-one-way bearing, 6-rotor, 61-ratchet teeth, 7-stator, 71-limiting groove, 8-turbulence column 1, 81-flow guide hole. DETAILED DESCRIPTION

[0024] In order to make the purposes, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. The up-down and left-right directions in the drawings are the up-down and left-right directions described in the present application, so as to describe the present application. Obviously, the described embodiments are some but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application. It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other in any manner without conflict.

[0025] Embodiment one:

[0026] As Figures 1 to 3 , the self-repairing marine riser vortex-induced vibration suppression device comprises an inner sleeve 2, an outer sleeve 3 and a spoiler column 4. The inner sleeve 2 is a circular truncated cone with the size of the upper end being larger than that of the lower end. The inner sleeve 2 is provided with a guide hole 20 extending through the upper and lower ends in the vertical direction and a thread outside. The inner sleeve 2 is sleeved outside the marine riser 1 through the guide hole 20. The outer sleeve 3 is a cylindrical shape. A circular truncated cone hole 30 extending through the upper and lower ends in the vertical direction is arranged in the middle of the cylindrical shape. The outer sleeve 3 is provided with a thread inside matched with the inner sleeve 2. The outer sleeve 3 is connected with the inner sleeve 2 through the thread. The lower part of the inner sleeve 2 is provided with a prefabricated groove 21 in the vertical direction. The prefabricated groove 21 is used to ensure the smoothness of the change of the inner diameter of the inner sleeve 2 when the outer sleeve 3 is rotated. If there is no prefabricated groove 21, the size of the inner sleeve 2 is not easy to shrink when the outer sleeve 3 is tightened. A one-way bearing 5 is arranged between the outer sleeve 3 and the spoiler column 4. The spoiler column 4 is provided with a protruding spoiler block 41 outside. The shape of the spoiler block 41 can be square, circular and the like. The spoiler block 41 can also be connected to the spoiler column 4 in other ways. The purpose is to enable the spoiler column 4 to rotate when facing the sea current. When the outer surface of the spoiler column 4 is a cylinder, it cannot rotate well when facing the sea current, so it cannot well suppress the generation of marine riser vortex-induced vibration.

[0027] The prefabricated groove 21 is circumferentially distributed around the axis of the inner sleeve 2.

[0028] Embodiment two:

[0029] As Figure 4 , Figure 5As shown, the above-mentioned one-way bearing 5 can be replaced by a ratchet mechanism. The ratchet mechanism comprises a rotor 6 and a stator 7, the rotor 6 is sleeved on the outer periphery of the stator 7, and the rotor 6 can rotate around the stator 7. The rotor 6 is internally provided with a ratchet 61, and the stator 7 is externally provided with a limiting groove 71 adapted to the ratchet 61. The ratchet 61 has a certain elasticity, and the outer end of the ratchet 61 is flat and can be fitted with the limiting groove 71 to ensure the one-way rotation of the stator 7. When the inhibitor is loosened between the outer sleeve 3 and the inner sleeve 2 during the vibration process, the one-way bearing 5 or the ratchet mechanism can make the outer sleeve 3 rotate in the tightening direction under the action of the sea current. Since the flow direction of the sea current is variable, when the sea current makes the outer sleeve 3 rotate in the loosening direction, the one-way bearing 5 or the ratchet mechanism can prevent the outer sleeve 3 from loosening. Therefore, the one-way bearing 5 or the ratchet mechanism can also be replaced by other types of one-way clutches as long as it can realize the function of tightening the outer sleeve 3.

[0030] Embodiment three:

[0031] Because Figure 1 The vortex-induced vibration suppression device shown has a great relationship with the vortex-induced vibration suppression efficiency of the vortex shedding column 4, more accurately, the vortex-induced vibration suppression of the vortex shedding block 41 and the tightening degree of the outer sleeve 3. The greater the longitudinal cross-sectional area of the vortex shedding block 41, the greater the tightening degree of the outer sleeve 3 when facing the same flow rate of the sea current. However, a large area of the vortex shedding block 41 will bring negative problems such as an increase in the quality of the device and a decrease in the reliability of the vortex shedding block.

[0032] As Figure 6 As shown, the vortex shedding column one 8 is internally provided with a mounting hole connected with the one-way bearing 5 and the marine riser 1. In addition, the vortex shedding column one 8 is also provided with a flow guide hole 81, which is arranged in the interior of the vortex shedding column one 8 in the counterclockwise direction, and the left end of the flow guide hole 81 has a large diameter and the right end has a small diameter. The two ends of the flow guide hole 81 are communicated with the outside, and a greater pressure is generated in the process of the sea current flowing from the large port to the small port of the flow guide hole 81, which is used to compensate for the defect that the vortex shedding column 4 needs a large size to tighten the outer sleeve 3. In addition, the exterior of the vortex shedding column one 8 can also be additionally provided with a vortex shedding block 41 to enhance its function.

[0033] The flow guide hole 81 is uniformly distributed along the mounting hole of the vortex shedding column one 8, so that the entire device reaches a balanced state.

[0034] The one-way bearing 5 in this embodiment can be replaced by the ratchet mechanism in embodiment two, or it can be replaced by a common bearing. When a common bearing is used, the rotation direction of the flow guide hole 81 needs to be the same as the rotation direction of the threads of the outer sleeve 3.

[0035] Now with the first embodiment to explain the use of the method, use by rotating the spoiler column 4 with the inner sleeve 2 and the marine riser 1 fixed connection. Assume that the spoiler column 1 clockwise rotation makes the outer sleeve 3 is tightened, clockwise rotation unscrewing. When facing the current spoiler column 4 clockwise rotation, tighten the outer sleeve 3, the inner wall of the inner sleeve 2 under the action of the outer sleeve 3 shrink tight marine riser 1, can avoid the whole device facing the current caused by the vibration of the marine riser from the sea off failure. When facing the current spoiler column 4 counterclockwise rotation, the outer ring of one-way bearing 5 rotation, the inner ring is fixed, will not make 3 outer sleeve 3 unscrew.

Claims

1. A self-repairing marine riser VIV suppression device, comprising an inner sleeve (2), an outer sleeve (3) and a turbulence column (8), the inner sleeve (2) is a truncated cone with the upper end larger than the lower end, the inner sleeve (2) is provided with a guide hole (20) extending vertically through the upper and lower ends, the inner sleeve (2) is sleeved outside the marine riser (1) through the guide hole (20), the outer sleeve (3) is a cylindrical shape, a truncated cone hole (30) extending vertically through the upper and lower ends is provided in the middle of the outer sleeve (3), the truncated cone hole (30) is provided with a left-handed thread, the inner sleeve (2) is connected with the outer sleeve (3) through the left-handed thread, the lower part of the inner sleeve (2) is provided with four prefabricated grooves (21) uniformly distributed in the circumferential direction, a one-way bearing (5) is provided between the outer sleeve (3) and the turbulence column (8), the one-way bearing (5) prevents counterclockwise rotation, the outer surface of the turbulence column (8) is provided with square protruding turbulence blocks (41), the turbulence column (8) is provided with a mounting hole connected with the one-way bearing (5) and the marine riser (1), the turbulence column (8) is further provided with a flow guide hole (81), the flow guide hole (81) is arranged in the counterclockwise direction, the two ends of the flow guide hole (81) are communicated with the outside world, the left end has a large diameter and the right end has a small diameter, the flow guide hole (81) is uniformly distributed in the circumferential direction of the mounting hole of the turbulence column (8), the rotation direction of the flow guide hole (81) is the same as the rotation direction of the thread of the outer sleeve (3), and the flow guide hole (81) and the prefabricated groove (21) are four.

2. The self-repairing marine riser VIV suppression device according to claim 1, wherein the one-way bearing (5) is replaced by a ratchet mechanism, the ratchet mechanism comprises a rotor (6) and a stator (7), the rotor (6) is sleeved on the outer periphery of the stator (7), the rotor (6) is provided with a ratchet (61) inside, the stator (7) is provided with a limiting groove (71) outside which is matched with the ratchet (61), and the ratchet (61) is made of elastic material.

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