Device for suppressing vortex-induced vibration of marine riser using drilling fluid

Abstract

The present invention relates to a device for suppressing the vortex-induced vibration of a riser using drilling fluid, which includes two spoiler rods symmetrically arranged about the pipe axis of the riser and their drive assemblies; the drive assembly includes a guide cylinder and a worm gear; the guide cylinder is fixedly connected to the riser, and its water inlet end and water outlet end are sequentially arranged along the rising direction of the drilling fluid and are connected to the riser in communication, and filtering devices are provided at the water inlet end and the water outlet end; the worm gear rotates and is placed inside the guide cylinder, and a thread gap is formed between the worm gear and the inner wall of the guide cylinder, and the worm gear is fixedly connected to the spoiler rod; the rising drilling fluid drives the worm gear to rotate successively through the water inlet end, the thread gap and the water outlet end of the guide cylinder, and drives the spoiler rod to rotate synchronously, so that the tangential velocity direction of the side of the spoiler rod adjacent to the riser during rotation is opposite to the sea current direction. The device of the present invention suppresses the vortex-induced vibration by driving the spoiler rod to rotate through the drive assembly. The worm gear is placed inside the guide cylinder, so that the worm gear is not interfered by foreign objects in seawater, has strong reliability and a long service life.

Description

Technical Field

[0001] The invention relates to the technical field of marine drilling and production, and in particular to a device for suppressing vortex-induced vibration of a watertight pipe by using drilling fluid. Background Art

[0002] The Karman vortex street at the tail of the bluff body causes a periodically changing fluid force, which is applied to the structure, causing displacement, vibration and deformation response of the structure. The structural vibration response caused by the alternating vortex shedding is called vortex-induced vibration. For cylindrical cross-section structures commonly used in marine engineering, such as drilling and production pipes, it is necessary to equip them with corresponding devices to suppress vortex-induced vibration to reduce damage to the drilling and production pipes.

[0003] For example, the invention patent with application number CN201610430980.8 proposes a device and method for suppressing vortex-induced vibration of watertight pipes by utilizing the upward return energy of drilling fluid. In this method, energy is injected into the flow boundary layer of the watertight pipe through the rotation of the spoiler rods on both sides of the watertight pipe, thereby narrowing the wake area behind the watertight pipe, weakening the vortex shedding intensity, reducing the pressure difference before and after the watertight pipe, and reducing the flow lift and resistance of the ocean current on the watertight pipe, thereby suppressing vortex-induced vibration.

[0004] However, the drilling fluid in the riser is used to bring the bottom rock cuttings out of the wellhead. The drilling fluid mixed with the rock cuttings impacts the impeller, causing serious damage to the impeller. At the same time, the worm wheel and worm are easily affected by external interference, and the overall reliability performance is poor. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a device for suppressing vortex-induced vibration of the watertight pipe by using drilling fluid in view of the shortcomings of the above-mentioned prior art. When the driving component drives the flow rod to rotate, the tangential velocity direction of the side adjacent to the watertight pipe is opposite to the direction of the ocean current to suppress vortex-induced vibration. At the same time, the worm gear of the driving component is built into the guide tube. By arranging filtering devices at the water inlet and outlet ends of the guide tube, it is possible to prevent rock cuttings mixed with the drilling fluid from entering the guide tube, so that the worm gear is not disturbed by foreign matter in the seawater. The overall reliability is strong and the service life is long.

[0006] The technical solution adopted by the present invention to solve the above-mentioned technical problems is:

[0007] A device for suppressing the vortex-induced vibration of a riser using drilling fluid, comprising two spoiler rods symmetrically arranged about the pipe axis of the riser and their driving components, and the plane where the two spoiler rods are located is arranged perpendicular to the sea current direction; the driving components are integrally arranged outside the riser and include a guide cylinder and a worm gear; the guide cylinder is fixedly connected to the riser, the water inlet end and the water outlet end of the guide cylinder are arranged in sequence along the rising direction of the drilling fluid and are connected to the riser, and filtering devices are arranged at both the water inlet end and the water outlet end; the worm gear rotates and is placed inside the guide cylinder, and a thread gap is formed between the worm gear and the inner wall of the guide cylinder, and the worm gear is fixedly connected to the spoiler rod on its corresponding side; the rising drilling fluid drives the worm gear to rotate in sequence through the water inlet end, the thread gap and the water outlet end of the guide cylinder, and drives the spoiler rod to rotate synchronously, so that the tangential velocity direction of the side of the spoiler rod adjacent to the riser during rotation is opposite to the sea current direction.

[0008] In the above solution, the driving component on each side includes two groups of guide cylinders and worm gears, and the two groups of guide cylinders and worm gears are respectively arranged at both ends of the spoiler rod on this side, and two worm gears are respectively fixedly connected to both ends of the spoiler rod, and the rotation directions of the two worm gears are opposite.

[0009] In the above solution, valves are arranged at both the water inlet end and the water outlet end of each guide cylinder. According to the sea current direction, the valves at the water inlet end and the water outlet end of one of the guide cylinders in the driving component on each side are controlled to open, and the valves at the water inlet end and the water outlet end of the other guide cylinder are controlled to close, so that the tangential velocity direction of the side of the spoiler rod adjacent to the riser during rotation can adapt to different sea current directions.

[0010] In the above solution, the device further includes an induction component, the induction component is arranged on the outer wall of the riser, the induction component has an induction end for inducing the sea current direction, and the induction component is respectively electrically connected to each valve to control the opening and closing of each valve.

[0011] In the above solution, the axis of the guide cylinder is arranged parallel to the riser, a water inlet pipe connected to the riser is arranged at the bottom of the guide cylinder, and a water outlet pipe connected to the riser is arranged at the top of the guide cylinder. By installing the filtering devices at both ends of the water inlet pipe and the water outlet pipe connected to the riser, the cuttings mixed in the drilling fluid can be prevented from entering the guide cylinder.

[0012] In the above solution, the water inlet pipe is an L-shaped pipe, and the water outlet pipe is a straight pipe and is horizontally arranged.

[0013] In the above solution, both the water inlet pipe and the water outlet pipe are straight pipes, the water inlet pipe is inclined downward and points to the riser, and the water outlet pipe is inclined upward and points to the riser.

[0014] In the above solution, the rotation axis of the worm gear is arranged parallel to the riser. Rotating rods are fixedly connected to both the top and bottom of the worm gear. One of the rotating rods is rotatably connected to the guide cylinder, and the other rotating rod passes through the sealing bearing on the guide cylinder and is fixedly connected to the spoiler rod.

[0015] In the above solution, two fixed disks are arranged in parallel in the guide cylinder. Through holes for the drilling fluid to flow through are formed on both fixed disks. The worm gear is arranged between the two fixed disks, and the two rotating rods are respectively rotatably connected to the two fixed disks.

[0016] In the above solution, the device further includes a fixing ring. The fixing ring is sleeved on the riser. Two mounting holes are oppositely arranged on both sides of the fixing ring. The guide cylinders on both sides of the riser are respectively fixed in the two mounting holes.

[0017] The beneficial effects of the present invention are as follows:

[0018] 1. In the present invention, the two guide cylinders are fixedly connected to the riser. The water inlet end and the water outlet end of the guide cylinder are arranged in sequence along the rising direction of the drilling fluid and are connected to the riser in communication. The worm gear rotates and is disposed inside the guide cylinder. A threaded gap is formed between the worm gear and the inner wall of the guide cylinder. The two worm gears are respectively fixedly connected to one end of the two spoiler rods. The rising drilling fluid is sequentially split from the water inlet end of the guide cylinder into the guide cylinder and returns to the riser from the water outlet end through the threaded gap between the worm gear and the guide cylinder. During the process of the drilling fluid flowing through the threaded gap, the drilling fluid drives the worm gear to rotate, thereby driving the spoiler rod to rotate synchronously. The plane where the two spoiler rods are located is placed perpendicular to the sea current direction, and the tangential velocity direction of the side of the spoiler rod adjacent to the riser during rotation is opposite to the sea current direction, injecting energy into the flow boundary layer of the riser, narrowing the wake area behind the riser, weakening the vortex shedding intensity, reducing the pressure difference between the front and back of the riser, and reducing the flow lift and resistance acting on the riser by the sea current, thereby realizing the suppression of vortex-induced vibration. At the same time, the worm gear of the driving assembly is disposed inside the guide cylinder. By arranging filtering devices at the water inlet end and the water outlet end of the guide cylinder, it is possible to prevent the cuttings mixed in the drilling fluid from entering the guide cylinder, so that the worm gear is not interfered by foreign objects in the seawater, and the overall reliability is strong and the service life is long;

[0019] 2. In order to adapt to sea currents in different directions, each side of the driving assembly includes two groups of guide cylinders and worm gears. The two groups of guide cylinders and worm gears are respectively arranged at both ends of the spoiler rod on this side. The two worm gears are respectively fixedly connected to both ends of the spoiler rod, and the rotation directions of the two worm gears are opposite. Valves are arranged at both the water inlet end and the water outlet end of each guide cylinder. According to the sea current direction, the valves at the water inlet end and the water outlet end of one of the guide cylinders in the driving assembly on each side are controlled to open, and the valves at the water inlet end and the water outlet end of the other guide cylinder are controlled to close, so that the tangential velocity direction of the side of the spoiler rod adjacent to the riser during rotation adapts to different sea current directions. Description of the Drawings

[0020] The present invention will be further described below in conjunction with the accompanying drawings and embodiments. In the drawings:

[0021] Figure 1 is a schematic diagram of the overall structure of the device for suppressing the vortex-induced vibration of the riser using drilling fluid provided in the embodiment of the present invention;

[0022] Figure 2 is a schematic diagram of the structure of the drive assembly (at position A in Figure 1 ) of the device for suppressing the vortex-induced vibration of the riser using drilling fluid provided in the embodiment of the present invention;

[0023] Figure 3 is a schematic diagram of the structure of the fixing ring of the device for suppressing the vortex-induced vibration of the riser using drilling fluid provided in the embodiment of the present invention;

[0024] Figure 4 is a schematic diagram of the structure of the fixing plate of the device for suppressing the vortex-induced vibration of the riser using drilling fluid provided in the embodiment of the present invention;

[0025] Figure 5 is an installation schematic diagram of the water inlet pipe and the water outlet pipe of the device for suppressing the vortex-induced vibration of the riser using drilling fluid provided in another embodiment of the present invention;

[0026] Figure 6 is a schematic diagram of the rotation direction of the spoiler rod and the oncoming flow direction of the device for suppressing the vortex-induced vibration of the riser using drilling fluid provided in the embodiment of the present invention.

[0027] In the figure: 100, drill string;

[0028] 200, riser;

[0029] 300, spoiler rod;

[0030] 400, drive assembly; 410, guide cylinder; 411, water inlet pipe; 412, water outlet pipe; 413, filtering device; 414, sealing bearing; 420, worm gear; 421, thread clearance; 422, rotating rod; 423, fixing plate; 424, through hole;

[0031] 500, induction assembly; 510, inlet valve; 520, outlet valve;

[0032] 600, fixing ring; 610, mounting hole. Detailed implementation manners

[0033] In order to have a clearer understanding of the technical features, objectives, and effects of the present invention, the specific implementation manners of the present invention will now be described in detail with reference to the accompanying drawings.

[0034] As Figure 1 , Figure 2 andFigure 6 As shown in the figure, a device for suppressing the vortex-induced vibration of a riser using drilling fluid according to the present invention is used for a riser 200 with a drill string 100 built therein, and includes two spoiler rods 300 and two driving components 400. The plane where the two spoiler rods 300 are located is arranged perpendicular to the sea current direction, and when the spoiler rods 300 rotate, the tangential velocity direction of the side adjacent to the riser 200 is opposite to the sea current direction. The driving component 400 is a structure for driving the two spoiler rods 300 to rotate. The driving component 400 is integrally arranged outside the riser 200 and includes a guide cylinder 410 and a worm gear 420. The guide cylinder 410 is fixedly connected to the riser 200. The water inlet end and the water outlet end of the guide cylinder 410 are arranged in sequence along the rising direction of the drilling fluid and are connected to the riser 200, and filtering devices 413 are provided at both the water inlet end and the water outlet end. The worm gear 420 rotates and is built in the guide cylinder 410. A thread gap 421 is formed between the worm gear 420 and the inner wall of the guide cylinder 410. One end of the worm gear 420 is fixedly connected to the corresponding spoiler rod 300. The rising drilling fluid drives the worm gear 420 to rotate in sequence through the water inlet end, the thread gap 421 and the water outlet end of the guide cylinder 410, and drives the spoiler rods 300 to rotate synchronously.

[0035] When the device works, the rising drilling fluid is shunted into the guide cylinder 410 from the water inlet end of the guide cylinder 410 in sequence, and returns to the riser 200 from the water outlet end through the thread gap 421 between the worm gear 420 and the guide cylinder 410. During the process of the drilling fluid flowing through the thread gap 421, the drilling fluid pushes the worm gear 420 to rotate, thereby driving the spoiler rods 300 to rotate synchronously. The plane where the two spoiler rods 300 are located is placed perpendicular to the sea current direction, and when the spoiler rods 300 rotate, the tangential velocity direction of the side adjacent to the riser 200 is opposite to the sea current direction, injecting energy into the flow boundary layer of the riser 200, narrowing the wake area behind the riser 200, weakening the vortex shedding intensity, reducing the pressure difference between the front and rear of the riser 200, and reducing the flow lift and drag acting on the riser 200 by the sea current, thereby realizing the suppression of vortex-induced vibration. The above structure for driving the spoiler rods 300 to rotate is not arranged inside the riser 200 and is not affected by the cuttings mixed in the drilling fluid. At the same time, the worm gear 420 is built in the guide cylinder 410. By arranging filtering devices 413 at the water inlet end and the water outlet end of the guide cylinder 410, the cuttings mixed in the drilling fluid can be prevented from entering the guide cylinder 410, so that the worm gear 420 is not interfered by foreign objects in the seawater. The overall reliability is strong and the service life is long.

[0036] It should be noted that the riser 200 is one of the core components of offshore oil drilling. It constructs the transmission channel between the drilling platform and the seabed wellhead, and plays important roles such as isolating seawater, guiding drill pipes and tubular strings, circulating drilling fluid and completion fluid, and compensating for the lifting movement of the drilling floating body. The drilling fluid in the annulus of the riser 200 moves from bottom to top. In order to enable the drilling fluid to smoothly carry the formation cuttings out of the wellhead, the platform mud pump often pumps in drilling fluid with a sufficiently high pressure. The embodiment of the present invention precisely utilizes the above-mentioned high-pressure drilling fluid to achieve the structure for suppressing vortex-induced vibration.

[0037] For further optimization, in order to adapt to ocean currents in different directions, each side of the driving assembly 400 includes two sets of guide cylinders 410 and worm gears 420. The two sets of guide cylinders 410 and worm gears 420 are respectively arranged at both ends of the spoiler rod on this side. Among them, the two worm gears 420 are respectively fixedly connected to both ends of the spoiler rod, and the rotation directions of the two worm gears 420 are opposite. Valves (the inlet valve 510 and the outlet valve 520 shown respectively) are arranged at the inlet end and the outlet end of each guide cylinder 410. According to the ocean current direction, the valves at the inlet end and the outlet end of one of the guide cylinders 410 in each side of the driving assembly 400 are opened, and the valves at the inlet end and the outlet end of the other guide cylinder 410 are closed, so that the tangential velocity direction of the side adjacent to the riser 200 when the spoiler rod rotates adapts to different ocean current directions. Figure 1 As shown, in the direction of the figure, when the ocean current flows from the left to the riser 200, the valves at the inlet end and the outlet end of the two lower guide cylinders 410 are opened, and the valves at the inlet end and the outlet end of the two upper guide cylinders 410 are closed; on the contrary, when the ocean current flows from the right to the riser, the valves at the inlet end and the outlet end of the two lower guide cylinders 410 are closed, and the valves at the inlet end and the outlet end of the two upper guide cylinders 410 are opened, so as to adapt to ocean currents in different directions. It can be understood that when the ocean current flows to the riser from the other two directions, the two spoiler rods 300 can directly suppress the vortex-induced vibration generated in the riser, and there is no need for the spoiler rods 300 to rotate.

[0038] As Figure 6 shown

[0039] For further optimization, in order to facilitate the control of the opening and closing of the above valves, the device further includes an induction assembly 500. The induction assembly 500 is arranged on the outer wall of the riser 200. The induction assembly 500 has an induction end for inducing the direction of the ocean current. The induction assembly 500 is electrically connected to each valve respectively to control the opening and closing of each valve. In this embodiment, the induction assembly 500 includes a controller and two induction plates. The two induction plates are arranged on both sides of the plane where the two spoiler rods 300 are located and are fixed on the riser 200. The two induction plates are used to measure the flow velocity of the ocean current. The controller receives the flow velocity of the ocean current and compares it with a preset value. The controller is electrically connected to the valve and controls the opening and closing of the valve according to the comparison result. Of course, in other embodiments, induction plates for inducing the impact force of the ocean current, etc. can also be used to achieve the above functions, and the embodiments of the present invention do not limit this.

[0040] For further optimization, in order to realize the connection between the guide cylinder 410 and the riser 200, the axis of the guide cylinder 410 is arranged parallel to the riser 200. The bottom of the guide cylinder 410 is provided with a water inlet pipe 411 connected to the riser 200, and the top of the guide cylinder 410 is provided with a water outlet pipe 412 connected to the riser 200. At the same time, by installing a filtering device 413 at one end of the water inlet pipe 411 and the water outlet pipe 412 connected to the riser 200, the cuttings mixed in the drilling fluid can be prevented from entering the guide cylinder 410. In this embodiment, the filtering device 413 adopts a sieve mesh. The sieve mesh is arranged along the direction of the water flow in the riser 200, and the sieve mesh can be cleaned as the water in the riser 200 flows.

[0041] For further optimization, in this embodiment, the water inlet pipe 411 is an L-shaped pipe, and the water outlet pipe 412 is a straight pipe and is horizontally arranged. In order to facilitate the diversion of the drilling fluid in the riser 200 into the guide cylinder 410, in another embodiment, both the water inlet pipe 411 and the water outlet pipe 412 are straight pipes. The water inlet pipe 411 is inclined downward and points to the riser 200, and the water outlet pipe 412 is inclined upward and points to the riser 200, reducing the energy loss when the drilling fluid enters and exits the guide cylinder 410, as Figure 5 shown.

[0042] For further optimization, the rotation axis of the worm gear 420 is arranged parallel to the riser 200. Both the top and bottom of the worm gear 420 are fixedly connected with a rotating rod 422. One of the rotating rods 422 is rotationally connected to the guide cylinder 410, and the other rotating rod 422 passes through the sealing bearing 414 on the guide cylinder 410 and is fixedly connected to the spoiler rod 300.

[0043] For further optimization, in order to achieve the rotation of the worm gear 420 relative to the flow guide cylinder 410, two fixed disks 423 are arranged in parallel in the flow guide cylinder 410. Through holes 424 for the circulation of drilling fluid are formed in both of the two fixed disks 423. The worm gear 420 is arranged between the two fixed disks 423, and two rotating rods 422 are respectively rotatably connected to the two fixed disks 423.

[0044] For further optimization, in order to facilitate the fixation of the flow guide cylinder 410, this embodiment further includes a fixing ring 600. The fixing ring 600 is sleeved on the riser 200. Two mounting holes 610 are oppositely arranged on the fixing ring 600, and the flow guide cylinder 410 is fixed in the mounting holes 610. Wherein, the fixing ring 600 includes two semi-ring structures arranged oppositely, and the two semi-ring structures are detachably connected. The two mounting holes 610 are respectively formed on the two semi-ring structures.

[0045] The various embodiments in this specification are described in a progressive manner. The key point of each embodiment is to illustrate the differences from other embodiments. For the same or similar parts among the various embodiments, reference can be made to each other.

[0046] The embodiments of the present invention have been described above in conjunction with the accompanying drawings. However, the present invention is not limited to the above specific embodiments. The above specific embodiments are merely illustrative rather than restrictive. Under the inspiration of the present invention, those of ordinary skill in the art can also make many forms without departing from the spirit and scope protected by the present invention and the claims. All of these fall within the protection scope of the present invention.

Claims

1. A device for suppressing the vortex-induced vibration of a riser using drilling fluid, comprising two spoiler rods symmetrically arranged about the axis of the riser and their driving components, and the plane where the two spoiler rods are located is arranged perpendicular to the direction of the ocean current; characterized in that, The driving assembly is integrally arranged outside the riser pipe and includes a flow guide cylinder and a worm gear; the flow guide cylinder is fixedly connected to the riser pipe, the water inlet end and the water outlet end of the flow guide cylinder are arranged in sequence along the rising direction of the drilling fluid and are communicated with the riser pipe, and filtering devices are arranged at both the water inlet end and the water outlet end; the worm gear is rotatably arranged inside the flow guide cylinder, a threaded gap is formed between the worm gear and the inner wall of the flow guide cylinder, and the worm gear is fixedly connected to the spoiler rod on its corresponding side; the rising drilling fluid drives the worm gear to rotate successively through the water inlet end, the threaded gap and the water outlet end of the flow guide cylinder, and drives the spoiler rod to rotate synchronously, so that the tangential velocity direction of the spoiler rod adjacent to the riser pipe during rotation is opposite to the sea current direction. The driving assembly on each side includes two sets of flow guide cylinders and worm gears, and the two sets of flow guide cylinders and worm gears are respectively arranged at both ends of the spoiler rod on this side. Among them, the two worm gears are respectively fixedly connected to both ends of the spoiler rod, and the rotation directions of the two worm gears are opposite. Valves are arranged at both the water inlet end and the water outlet end of each flow guide cylinder. According to the sea current direction, the valves at the water inlet end and the water outlet end of one of the flow guide cylinders in the driving assembly on each side are controlled to open, and the valves at the water inlet end and the water outlet end of the other flow guide cylinder are controlled to close, so that the tangential velocity direction of the spoiler rod adjacent to the riser pipe during rotation can adapt to different sea current directions. The device further includes an induction assembly. The induction assembly is arranged on the outer wall of the riser pipe. The induction assembly has an induction end for inducing the sea current direction, and the induction assembly is electrically connected to each valve respectively to control the opening and closing of each valve. The axis of the flow guide cylinder is arranged parallel to the riser pipe. A water inlet pipe communicated with the riser pipe is arranged at the bottom of the flow guide cylinder, and a water outlet pipe communicated with the riser pipe is arranged at the top of the flow guide cylinder. By installing the filtering devices at both ends of the water inlet pipe and the water outlet pipe communicated with the riser pipe, the cuttings mixed in the drilling fluid can be prevented from entering the flow guide cylinder.

2. The device for suppressing the vortex-induced vibration of a riser using drilling fluid according to claim 1, characterized in that, The water inlet pipe is an L-shaped pipe, and the water outlet pipe is a straight pipe and is arranged horizontally.

3. The device for suppressing the vortex-induced vibration of a riser using drilling fluid according to claim 1, characterized in that, Both the water inlet pipe and the water outlet pipe are straight pipes. The water inlet pipe inclines downward and points to the riser pipe, and the water outlet pipe inclines upward and points to the riser pipe.

4. The device for suppressing the vortex-induced vibration of a riser using drilling fluid according to claim 1, characterized in that, The rotation axis of the worm gear is arranged parallel to the riser pipe. Rotating rods are fixedly connected to both the top and the bottom of the worm gear. One of the rotating rods is rotatably connected to the flow guide cylinder, and the other rotating rod passes through the sealing bearing on the flow guide cylinder and is fixedly connected to the spoiler rod.

5. The device for suppressing the vortex-induced vibration of a riser using drilling fluid according to claim 4, characterized in that, Two fixed disks are arranged in parallel inside the flow guide cylinder. Through holes for the drilling fluid to flow through are formed on both fixed disks. The worm gear is arranged between the two fixed disks, and the two rotating rods are respectively rotatably connected to the two fixed disks.

6. The device for suppressing the vortex-induced vibration of a riser using drilling fluid according to claim 1, characterized in that, The device further includes a fixing ring. The fixing ring is sleeved on the riser pipe. Two mounting holes are arranged oppositely on both sides of the fixing ring, and the flow guide cylinders on both sides of the riser pipe are respectively fixed in the two mounting holes.

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