JP5951470B2 - Monitoring system for columnar structures and riser tubes - Google Patents

Description

  The present invention relates to a monitoring system for columnar structures and riser tubes.

  Offshore platforms (for oil development, scientific research, etc.), risers for excavation for suspending long pipe risers (hereinafter also referred to as “riser pipes”) below the ship, Production risers are known that are used to lift crude oil from offshore oil fields to the platform. A riser for working on such a seabed has a very long structure, and the total length of the riser can reach several thousand meters.

  In recent years, riser operations have been increasing in areas where strong currents exist. Therefore, when the vibration period of the excitation force due to the vortex generated from the riser due to the tidal current matches the natural frequency of the riser, the riser will be vortex-induced (VIV) vortex induced vibration (VIV). When the riser resonates with vibrations of about 1 to several Hz excited by vortex excitation, there is a risk of fatigue failure. Therefore, the riser is measured by measuring stress and displacement over the entire riser. It is necessary to grasp the fatigue state.

  As a method for measuring the stress and displacement of the riser, for example, a method of measuring a response of the riser to the flow of seawater by attaching a sensor such as an accelerometer or an optical fiber to the surface of the riser pipe has been proposed.

  For example, a response distribution measurement system for a riser pipe is disclosed in which an optical fiber is bonded and laid on the surface of the riser pipe in advance, the reflected light with respect to the incident light of the optical fiber is received, and the stress applied to the riser pipe is calculated. (For example, refer to Patent Document 1).

  Also, when using the riser in tidal currents, streamlined, elliptical, oval, etc. to reduce fluid resistance acting on the riser and to prevent vortex excitation caused by the vortex generated from the riser It has been proposed to install a cover (fairing) having a cross-sectional shape.

  For example, when the fairing rotates around the riser pipe, the direction of the tidal current can change in the direction of the smallest resistance, and all the same shape and size are equally spaced in the water depth direction (same installation interval) (See, for example, Patent Document 2).

JP 2012-98239 A JP 2010-7434 A

  However, in the riser pipe response distribution measurement system described in Patent Document 1, it is necessary to lay an optical fiber on the surface of the riser pipe in advance in the process of producing the riser pipe, and this is applied to an existing steel pipe riser pipe. I can't. Furthermore, since the optical fiber is connected on an offshore platform, a ship, etc., the light may be attenuated at the joint of the optical fiber and the signal may be lowered.

  In addition, since the structure of the riser pipe is very long, the mode of response of each part of the riser pipe to the seawater flow becomes a high-order vibration mode of the tenth order to the hundredth order. Therefore, in the method of measuring the response of the riser tube by attaching an accelerometer to the surface of the riser tube, a large number of measurement points are required, but only a few measurement points are provided due to difficulty in handling the measurement cable. I can't. Therefore, it is difficult to accurately measure stress, displacement, etc. over the entire riser.

  Therefore, it is desired to be able to measure stress, displacement, etc. at an arbitrary portion over the entire riser.

  The present invention has been made in view of the above problems, and provides a columnar structure and a riser pipe monitoring system capable of measuring stress, displacement, and the like at an arbitrary portion over the entire riser. With the goal.

  The first invention of the present invention for solving the above-described problems is a riser pipe formed by continuously extending a plurality of pipes in the vertical direction from the sea surface side to the sea floor side, and along the riser pipe. An elevating device that can be moved up and down, and the elevating device is arranged so as to surround the riser tube, and a gripping means that is provided in the elevating unit and temporarily holds the riser tube, A columnar structure comprising: moving means for moving the elevating part up and down along the entire length of the riser pipe.

  A second invention is a columnar structure according to the first invention, wherein the elevating unit has one or both of an accelerometer and an inclinometer, and measures the behavior of the riser tube. .

  A third invention is a columnar structure according to the first or second invention, wherein the elevating unit includes a landing base for landing and landing an underwater vehicle capable of traveling underwater.

  According to a fourth aspect of the present invention, the stress and displacement of the riser pipe are calculated based on one or more lifting and lowering apparatuses according to any one of the first to third aspects and the behavior of the riser pipe measured by the lifting and lowering apparatus. A riser monitoring system comprising: a measurement control device that records and controls movement of the lifting device; and a cable that connects the measurement control device and the lifting device.

  According to a fifth invention, in the fourth invention, a fairing that reduces fluid resistance acting on the riser pipe based on the stress and displacement calculated from the behavior of the riser pipe measured by the lifting device is provided on the riser. A monitoring system for a riser pipe, wherein one or more pipes are arranged so as to surround the pipe.

  In a sixth aspect based on the fifth aspect, the fairing is provided on the upper fairing, which is disposed so as to surround the riser pipe, and temporarily holds the riser pipe. A riser tube monitoring system comprising: gripping means for moving; and moving means for moving the upper fairing up and down along the entire length of the riser tube.

  According to the present invention, it is possible to measure stress, displacement, and the like at an arbitrary portion over the entire riser.

FIG. 1 is a schematic configuration diagram of a columnar structure and a riser pipe monitoring system according to Embodiment 1 of the present invention. FIG. 2 is a perspective view of the lifting device according to the embodiment of the present invention. FIG. 3 is a cross-sectional perspective view taken along the line XX of the lifting device shown in FIG. 2 and is a view for explaining the moving operation of the lifting device. FIG. 4 is a diagram for explaining the moving operation of the lifting device. FIG. 5 is a diagram for explaining the moving operation of the lifting device. FIG. 6 is a diagram for explaining the moving operation of the lifting device. FIG. 7 is another perspective view of the lifting device according to the first embodiment of the present invention. FIG. 8 is another perspective view of the lifting device according to the first embodiment of the present invention. 9 is a YY sectional perspective view of the lifting device shown in FIG. FIG. 10 is another configuration diagram of the monitoring system for the riser pipe according to the present embodiment. FIG. 11 is a schematic configuration diagram of a columnar structure and a riser pipe monitoring system according to Embodiment 2 of the present invention. FIG. 12 is a schematic perspective view of the lifting device according to the second embodiment of the present invention. FIG. 13 is a schematic view of an underwater vehicle according to Embodiment 2 of the present invention. FIG. 14: is a schematic block diagram of the monitoring system of the columnar structure and riser pipe | tube which concerns on Example 3 of this invention. FIG. 15 is a schematic perspective view of the fairing according to the third embodiment of the present invention, and is a view for explaining the movement operation of the fairing. FIG. 16 is a diagram for explaining the movement operation of the fairing. FIG. 17 is a diagram for explaining the movement operation of the fairing.

  Embodiments of the present invention will be described below in detail with reference to the drawings. In addition, this invention is not limited by the content described in the following Examples. In addition, constituent elements in the following embodiments described below include those that can be easily assumed by those skilled in the art, those that are substantially the same, and those in a so-called equivalent range. Furthermore, the constituent elements disclosed in the following embodiments described below can be appropriately combined.

<Riser tube monitoring system>
A monitoring system for a riser pipe having a columnar structure lifting apparatus according to Embodiment 1 of the present invention will be described with reference to the drawings. FIG. 1 is a schematic configuration diagram illustrating a columnar structure and a riser tube monitoring system according to the present embodiment. As shown in FIG. 1, the riser monitoring system 10A calculates the stress and displacement of the riser tube 11 based on the lifting device 12A provided in the columnar structure 1A and the behavior of the riser tube 11 measured by the lifting device 12A. And a measurement control device 13 that controls the movement of the lifting device 12A and a cable 14 that connects the measurement control device 13 and the lifting device 12A. The riser pipe monitoring system 10A measures the behavior of the riser pipe 11 over its entire length. The behavior (response) of the riser tube 11 refers to a response such as longitudinal vibration or lateral vibration of the riser tube 11 in an arbitrary portion. First, the columnar structure 1A including the lifting device 12A will be described.

[Columnar structure]
As shown in FIG. 1, the columnar structure 1 </ b> A is composed of a riser pipe 11 formed by continuously extending a plurality of pipes in the vertical direction from the sea surface S side to the sea bottom G side, and ascending and descending along the riser pipe 11. And a free elevating device 12A. The columnar structure 1A is used to lift offshore platforms (for oil development, scientific research, etc.), drilling risers for suspending risers from ships, and for lifting crude oil collected from offshore oil fields to offshore platforms. It can be applied to production risers used in

  The riser tube 11 has, for example, a structure in which a plurality of riser tubes 11 of 20 m to several tens of meters are connected in series, and the total length reaches several thousand meters.

  The floating body 15 floating on the ocean has the riser pipe 11 disposed in the sea S from the sea, and the tip thereof reaches the seabed G. The floating body 14 is, for example, a ship or an offshore platform. For example, in the riser pipe 11 for excavation, the seabed G is excavated at the tip portion as the riser pipe 11. A blowout preventer (BOP) 16 is disposed at the boundary between the riser pipe 11 and the seabed G.

(lift device)
FIG. 2 is a perspective view of the lifting device according to the present embodiment. As shown in FIG. 2, the elevating device 12 </ b> A includes an upper elevating unit 21 disposed so as to surround the riser tube 11, and a gripping unit 31 a that is provided in the upper elevating unit 21 and temporarily holds the riser tube 11. , 31b and moving means for moving the upper elevating part 21 up and down along the riser pipe 11 over the entire length. In addition, the lower elevating part 27 having the same shape as the upper elevating part 21 and having gripping means 33a, 33b for temporarily grasping the riser tube 11, and the upper elevating part 21 and the lower elevating part 27 can be connected to expand and contract. First expansion / contraction means 26a, 26b. Further, the upper elevating unit 21 includes an accelerometer 22, an inclinometer 23, an underwater camera 24, and a depth meter 29. The gripping means 31a, 31b, 33a, 33b, the first telescopic means 26a, 26b, the accelerometer 22, the inclinometer 23, the underwater camera 24, and the depth meter 29 are connected to the cable 14, respectively. It connects with the measurement control apparatus 13 mentioned later installed in the floating body 15 of the ocean shown in FIG. In addition, a moving means shows the 1st expansion-contraction means 26a, 26b.

  As described above, the lifting device 12A is disposed so as to surround the riser pipe 11, and includes a measuring device for measuring the behavior of the riser pipe 11 (hereinafter also referred to as “response”), and from the ocean to the seabed. It is possible to move up and down along the riser pipe up to G (section B1 shown in FIG. 1). The lifting device 12 </ b> A can move up and down along the riser tube 11 as in A <b> 1 by the moving operation of the moving means, and can measure the behavior in an arbitrary portion. The behavior (response) of the riser tube 11 refers to a response such as longitudinal vibration or lateral vibration of the riser tube 11 in an arbitrary portion.

  The shape of the upper elevating part 21 is a cylindrical shape having a hollow (hole) at the center of the donut shape, having a predetermined width from the cavity toward the outer circumferential direction, and with respect to the longitudinal direction of the riser pipe 11. It is a cylinder having a predetermined thickness. That is, the center portion of the cylindrical upper elevating part 21 is a hole, the diameter of the hole is larger than the diameter of the riser pipe 11, and the riser pipe 11 penetrates the center of the hole. Note that the shape of the upper elevating unit 21 is not limited to a cylindrical shape, and may be any shape that can be disposed so as to surround the riser tube 11, and may be, for example, a polygonal shape such as a triangular shape or a rectangular shape.

  The gripping means 31a and 31b are configured by gripping portions 25a and 25b that grip the riser tube 11, and second cylinders 32a and 32b that extend and contract the gripping portions 25a and 25b. The gripping means 31 a and 31 b are disposed in the inner hole portion of the upper elevating part 21 so as to face each other symmetrically about the riser pipe 11, and the second cylinders 32 a and 32 b are embedded in the upper elevating part 21. The shape of the grip portions 25 a and 25 b is a curved surface in which the surface contacting the riser tube 11 has the same curvature as the circumference of the riser tube 11. Accordingly, the second cylinders 32a and 32b are extended so that the gripping portions 25a and 25b grip the riser pipe 11 and temporarily fix the upper elevating portion 21. Further, the second cylinders 32a and 32b are contracted to release the temporary fixing of the upper elevating unit 21. The gripping means 31a and 31b are connected (not shown) to a measurement control device 13 (not shown) via a cable 14, and the measurement control device 13 can control the operation of the gripping means 31a and 31b. In addition, well-known cylinders, such as a hydraulic cylinder and an electric cylinder, can be used for the 2nd cylinders 32a and 32b, for example. Further, for example, a bellows type watertight cover member or a flexible cover member may be covered so as to surround the entire second cylinders 32a and 32b and prevent seawater from entering the cylinders.

  The accelerometer 22 measures acceleration due to various vibrations of the riser tube 11 at an arbitrary position. The inclinometer 23 measures the inclination angle of the riser tube 11 at an arbitrary position. The accelerometer 22 and the inclinometer 23 are not particularly limited, and known ones can be applied. The accelerometer 22 and the inclinometer 23 are installed in an arbitrary part of the upper elevating unit 21 and are connected to a measurement control device 13 to be described later via a cable 14, and measurement data is transmitted to the measurement control device 13 via the cable 14. It is supposed to be handed over. The measurement control device 13 is supplied with power for operating the accelerometer 22 and the inclinometer 23 via the cable 14 and can control the operations of the accelerometer 22 and the inclinometer 23. The installation positions of the accelerometer 22 and the inclinometer 23 are not particularly limited, and may be incorporated in the upper elevating unit 21, for example.

  The underwater camera 24 photographs the external surface of the riser tube 11 around the position where the upper elevating unit 21 is temporarily fixed. The underwater camera 24 is installed in an arbitrary portion of the upper elevating unit 21 and is connected to a measurement control device 13 (to be described later) via a cable 14 so that video data is transferred to the measurement control device 13 via the cable 14. It has become. Further, the measurement control device 13 is supplied with power for operating the underwater camera 24 via the cable 14 and can control the operation of the underwater camera 24. The underwater camera 24 is not particularly limited, and a known camera can be applied.

  The depth meter 29 measures the depth at a position where the upper elevating unit 21 is temporarily fixed. The depth meter 29 is not particularly limited and a known one can be applied. The depth meter 29 is installed in an arbitrary portion of the upper elevating unit 21 and is connected to a measurement control device 13 (to be described later) via a cable 14 so that measurement data is transferred to the measurement control device 13 via the cable 14. It has become. In addition, power for operating the depth meter 29 is supplied from the measurement control device 13 via the cable 14, and the operation of the depth meter 29 can be controlled. The installation position of the depth meter 29 is not particularly limited, and may be incorporated in the upper elevating unit 21, for example.

  In addition, although the raising / lowering apparatus 12A was equipped with the accelerometer 22, the inclinometer 23, the underwater camera 24, and the depth meter 29 in the upper raising / lowering part 21, it is not restricted to this, It is equipped with the lower raising / lowering part 27 mentioned later. It may be.

  The lower elevating unit 27 includes extendable gripping means 33 a and 33 b that temporarily hold the lower elevating unit 27 in any part of the riser pipe 11. The configuration of the lower elevating unit 27 is the same as that of the upper elevating unit 21 described above, and the configuration of the gripping means 33a and 33b is the same as that of the gripping means 31a and 31b of the upper elevating unit 21, and thus detailed description thereof is omitted.

  The first expansion / contraction means 26a and 26b, which are moving means, connect the upper elevating part 21 and the lower elevating part 27 to face each other. The first expansion / contraction means 26a is composed of a first cylinder 35a and a piston 36a. For example, the piston 36a of the first cylinder 35a is expanded and contracted by hydraulic pressure. Similarly, the first expansion / contraction means 26b includes a first cylinder 35b and a piston 36b. The first expansion / contraction means 26a, 26b are arranged symmetrically opposite to each other with the riser pipe 11 as the center, and the ends of the first expansion / contraction means 26a, 26b are on the side where the upper elevating part 21 and the lower elevating part 27 face each other. It is fixed to the surface. The first elongating means 26 a and 26 b can elevate and move the upper elevating part 21 and the lower elevating part 27 by elongating and contracting in the same direction as the longitudinal direction of the riser pipe 11. The first expansion / contraction means 26a and 26b are connected (not shown) to a measurement control device 13 (not shown) via a cable 14, and the operation of the expansion / contraction means 26a and 26b can be controlled by the measurement control device 13. As the expansion / contraction means 26a and 26b, well-known cylinders such as hydraulic cylinders and electric cylinders can be used as in the second cylinders 32a and 32b. Further, for example, a bellows type watertight cover member or a flexible cover member may be covered so as to surround the entire first expansion / contraction means 26a and 26b and prevent seawater from entering the cylinder.

  The material constituting the upper elevating part 21, the gripping means 31a, 31b, the first expansion / contraction means 26a, 26b, the lower elevating part 27 and the gripping means 33a, 33b is resistant to corrosion even when exposed to the environment at sea and in seawater. The material is not particularly limited as long as it is a material having strength against the water pressure at the seabed G.

  In the lifting device 12A, the upper lifting part 21 has gripping means 31a, 31b, the lower lifting part 27 has gripping means 33a, 33b, and the upper lifting part 21 and the lower lifting part 27 are connected as moving means. Since the first expansion / contraction means 26 a and 26 b that can be expanded and contracted are provided, the riser tube 11 can be gripped and temporarily fixed to an arbitrary portion, and can be moved up and down along the riser tube 11. In addition, since the lifting device 12A includes the accelerometer 22, the inclinometer 23, and the depth meter 29, it can measure the behavior of the riser pipe 11 at an arbitrary portion and specify the position (depth) of the measurement point. be able to. Further, since the underwater camera 24 is provided, when an abnormality is detected in the behavior of the riser tube 11, the external surface of the riser tube 11 can be observed in detail.

(Moving operation of the lifting device)
3 is a cross-sectional perspective view taken along the line XX of the lifting device shown in FIG. 3-6 is a figure explaining the movement operation | movement of a raising / lowering apparatus. The configuration of the lifting device shown in FIGS. 3 to 6 is the same as the configuration of the lifting device shown in FIG. 2 described above. Therefore, the same members as those of the lifting device shown in FIG. The description is omitted.

  As shown in FIG. 3, the upper elevating unit 21 of the elevating device 12 </ b> A is temporarily fixed to the riser pipe 11 by the gripping means 31 a and 31 b gripping the riser pipe 11 from both sides. The same applies to the lower elevating part 27. The gripping means 33a and 33b grip the riser tube 11 and are temporarily fixed. At this time, the expansion / contraction means 26a and 26b are in the most contracted state.

  Next, as shown in FIG. 4, the second cylinders 34a and 34b of the gripping means 33a and 33b of the lower elevating part 27 are contracted in the directions of C1 and C2, thereby releasing the temporary fixing of the lower elevating part 27. Thereafter, the pistons 36a and 36b of the first expansion / contraction means 26a and 26b are extended in the direction of D1 and D2 in the longitudinal direction (downward in FIG. 4) of the riser tube 11 to move the lower lift unit 27 downward.

  Next, as shown in FIG. 5, after the second cylinders 34a and 34b of the gripping means 33a and 33b of the lower elevating unit 27 are stretched in the directions of C3 and C4, the riser pipe 11 is gripped and moved downward. The lower elevating part 27 is temporarily fixed to the riser pipe 11. Thereafter, the second cylinders 32a and 32b of the gripping means 31a and 31b of the upper elevating part 21 are contracted in the directions E1 and E2 to release the temporary fixing of the upper elevating part 21. Next, the pistons 36a and 36b of the first expansion / contraction means 26a and 26b are contracted in the directions D3 and D4 to move the upper elevating part 21 downward.

  Next, as shown in FIG. 6, after the second cylinders 32 a and 32 b of the gripping means 31 a and 31 b of the upper elevating unit 21 are stretched in the directions of E3 and E4 to grip the riser pipe 11 and move downward Is temporarily fixed to the riser pipe 11. That is, as shown in the operations of FIGS. 3 to 6, the lifting device 12 </ b> A can be moved by a series of operations such as a scale insect.

  The above-described moving operation has been described with respect to the operation in which the lifting device 12A moves downward in the longitudinal direction of the riser tube 11. However, the lifting device 12A is moved to the riser tube 11 by performing the reverse operation to the above-described moving operation. Can be moved upward in the longitudinal direction. In this way, by repeating the above-described series of moving operations, the lifting device 12 </ b> A can move up and down along the entire length of the riser pipe 11.

  Thus, as described above, the lifting device 12A interlocks the gripping means 31a, 31b of the upper lifting part 21, the gripping means 33a, 33b of the lower lifting part 27, and the first expansion / contraction means 26a, 26b. The lifting device 12 </ b> A can be moved to an arbitrary position of the riser pipe 11 by performing the moving operation. Therefore, compared to a conventional device with several accelerometers, the lifting device 12A can acquire measurement data at several hundred measuring points with only one lifting device 12A. Can be measured over the entire length. Therefore, according to the lifting device 12A, it is possible to accurately measure stress, displacement, and the like over the entire riser, and to observe the outer surface of the riser tube 11 in detail. Further, since the lifting device 12A can be applied simply by attaching it to an existing steel pipe riser pipe, a new riser pipe is manufactured like a conventional riser pipe response distribution measuring system, and the riser pipe manufacturing process In this case, it is not necessary to previously lay an optical fiber on the surface of the riser tube.

(Other configurations of lifting device)
Next, another configuration of the lifting device 12A will be described. FIG. 7 is a perspective view showing another configuration of the lifting device according to the present embodiment. The elevating device 12B is the same as the elevating device 12A shown in FIG. 2 except that the configurations of the upper elevating unit 21 and the lower elevating unit 27 are different and the configurations of the gripping means 31a, 31b, 33a, 33b are different. Therefore, the same members are denoted by the same reference numerals, and the description thereof is omitted.

  As shown in FIG. 7, the lifting device 12 </ b> B includes an accelerometer 22, an inclinometer 23, an underwater camera 24, and a depth meter 29. The elevating device 12A includes a concentric columnar upper elevating unit 41 disposed so as to surround the riser pipe 11, a lower elevating unit 43 disposed below the upper elevating unit 41, an upper elevating unit 41, It has 1st expansion-contraction means 26a, 26b which can be connected with the lower raising / lowering part 43 and can expand-contract.

  The shape of the upper elevating / lowering portion 41 is a cylinder surrounding the riser pipe 11, and has a hole into which the riser pipe 11 can be inserted at the center of the cylinder. The inside of the hole is in contact with the cylindrical surface of the riser tube 11. That is, the central part of the cylindrical upper elevating part 41 is a hole, the diameter of the hole is the same as the diameter of the outer periphery of the riser pipe 11, and the riser pipe 11 penetrates the hole.

  The upper elevating / lowering part 41 is a combination of fan-shaped parts divided into four at approximately 90 degrees with the riser pipe 11 as the center.

  The upper elevating part 41 is expanded and contracted in a substantially vertical direction with respect to the face of each of the four upper elevating parts 41a to 41d, and second elongating means 42a for connecting the upper elevating parts 41a, 41b, 41c, and 41d. To 42d are embedded in the upper elevating parts 41a to 41d. The second expansion / contraction means 42a and 42c and the second expansion / contraction means 42b and 42d are arranged symmetrically opposite each other with the riser tube 11 as the center.

  The inner curved surface that comes into contact with the riser pipe 11 in the holes (cavities) of the upper elevating parts 41 a to 41 d is formed to have the same curvature as the circumference of the riser pipe 11. As a result, the second elongating means 42a to 42d contract and the upper elevating parts 41a, 41b, 41c and 41d are brought into contact with each other and overlapped so that the upper elevating parts 41a to 41d are inner curved surfaces and the riser tube 11 And can be temporarily fixed to an arbitrary portion of the riser tube 11. In other words, the inner curved surfaces of the upper elevating parts 41a to 41d serve as gripping parts for the upper elevating part 41, and operate in the same manner as the gripping parts 25a and 25b of the gripping means 31a and 31b of the lifting device 12A shown in FIG. is there. Further, the second elongating means 42a to 42d are extended and the upper elevating parts 41a, 41b, 41c, 41d are moved so as to be separated and separated from each other, thereby releasing the upper elevating part 41 from being temporarily fixed. can do.

  The lower elevating part 43 has second extendable means 44 a to 44 d that can be extended and retracted similarly to the upper elevating part 41. The configuration of the lower elevating unit 43 is the same as that of the upper elevating unit 41 described above, and the configuration of the second elongating means 44a to 44d is the same as that of the second elongating means 42a to 42d of the upper elevating part 41. Is omitted.

  The second expansion / contraction means 42a to 42d and the second expansion / contraction means 44a to 44d are connected to the measurement control device 13 (not shown) by the cable 14, and the measurement control device 13 uses the second expansion / contraction means 42a to 42d and the second expansion / contraction means. The operation of the means 44a to 44d can be controlled. In addition, as for the 2nd expansion-contraction means 42a-42d and the 2nd expansion-contraction means 44a-44d, well-known cylinders, such as a hydraulic cylinder and an electric cylinder, can be used similarly to the raising / lowering apparatus 12A mentioned above, for example.

  Since the moving operation of the lifting device 12B is the same as that of the lifting device 12A described above, detailed description thereof is omitted.

  The upper elevating unit 41 and the lower elevating unit 43 of the elevating device 12B have been described as being combined with a fan shape that is divided into four at about 90 degrees with the riser tube 11 as the center, but is not limited to four divisions. What is necessary is just to be more than division.

  Therefore, the elevating device 12B moves the second elongating means 42a to 42d of the upper elevating part 41, the second elongating means 44a to 44d of the lower elevating part 43, and the first elongating means 26a and 26b in conjunction with each other. Thus, the lifting device 12B can be moved to any part of the riser tube 11. Therefore, in the lifting device 12B, the behavior of the riser pipe 11 can be measured over the entire length with only one lifting device 12B. Therefore, according to the lifting / lowering device 12B, it is possible to accurately measure stress, displacement, and the like over the entire riser, and to observe the outer surface of the riser tube 11 in detail. Moreover, since the raising / lowering apparatus 12B can be applied only by attaching to the riser pipe | tube of the existing steel pipe, it becomes possible to measure a behavior over the full length of the existing steel pipe riser.

  Next, another configuration of the lifting device 11A will be described. FIG. 8 is a perspective view showing another configuration of the lifting device according to the present embodiment. 9 is a YY sectional perspective view of the lifting device shown in FIG. The lifting device 12C is different from the lifting device 12A shown in FIG. 2 in that the lifting device 12C does not include the lower lifting part 27 and the first expansion / contraction means 26a and 26b. Further, the configuration of the lifting unit 51 of the lifting device 12C is different from the configuration of the upper lifting unit 21 of the lifting device 12A shown in FIG. 2 described above in that the internal configuration of the lifting unit 51 is different, the air pipe 17, the valve 57, and the pump 53. , 54 are the same except that the same members are denoted by the same reference numerals, and the description thereof is omitted.

  As shown in FIGS. 8 and 9, the elevating device 12 </ b> C includes a donut-shaped cylindrical elevating part 51 arranged so as to surround the riser pipe 11, and a gripping means for fixing the elevating part 51 to the riser pipe 11. 31a, 31b, the cable 14, the air pipe 17 for injecting the air 56 into the elevating part 51, the valve 57, and the pumps 52, 53 for injecting or draining the seawater 55 into the elevating part 51.

  The appearance of the elevating unit 51 is the same as that of the upper elevating unit 21 of the elevating device 12A shown in FIG. A space is formed inside the elevating part 51, and seawater 55 and air 56 can be injected into the internal space. That is, the internal space of the elevating part 51 is, for example, a ballast tank that uses seawater 55 as ballast water.

  Similarly to the lifting device 12A shown in FIG. 2 described above, an accelerometer 22, an inclinometer 23 for measuring the behavior of the riser tube 11, an underwater camera 24 and a depth meter 29 for imaging the external surface of the riser tube 11. Have The gripping means 31a, 31b, pumps 53, 54, accelerometer 22, inclinometer 23, underwater camera 24, and depth meter 29 are each connected to the cable 14, and the cable 14 is connected to the offshore floating body 15 shown in FIG. It is connected to a measurement control device 13 which will be described later.

  The air pipe 17 is for injecting air 56 into a space (ballast tank) formed inside the elevating part 51, and is connected to the measurement control device 13 installed on the floating body 15 shown in FIG. doing. The air pipe 17 is provided with a valve 57 that controls the injection of air 56. The valve 57 is connected to the cable 14, and opening and closing of the air pipe 17 is controlled by the measurement control device 13. The air pipe 17 and the cable 14 are preferably combined as one from the viewpoint of easy handling. As the air 56, it is preferable to use compressed air.

  Next, the moving operation of the lifting device 12C will be described. As shown in FIG. 9, in the elevating unit 51 of the elevating device 12 </ b> C, the grasping means 31 a and 31 b grasp the riser tube 11 and are temporarily fixed to the riser tube 11. When the elevating device 12C is moved, the gripping means 31a and 31b are released. Next, for example, when moving the lifting device 12 </ b> C downward, the pumps 53 and 54 are operated to inject the seawater 55 into the lifting portion 51. And if it moves to arbitrary parts with reference to the measurement data of the depth meter 29, the riser pipe | tube 11 will be hold | gripped with the holding means 31a and 31b, and it will fix to the riser rod 15 temporarily. When moving the elevating device 12C upward, the valve of the air pipe 17 is opened to inject the air 56 into the elevating unit 51, and the pumps 53 and 54 are operated to drain the seawater 55. After moving to an arbitrary portion of the riser tube 11 with reference to the measurement data, the riser tube 11 is gripped by the gripping means 31 a and 31 b and temporarily fixed to the riser rod 15. The gripping means 31a and 31b, the valve 57, and the pumps 53 and 54 are controlled by the measurement control device 13 described above.

  The lifting device 12 </ b> C can move up and down along the riser pipe 11 by the series of operations described above.

  In the elevating device 12 </ b> C, the seawater 55 can be moved downward by using the seawater 55 as ballast water, and can be moved upward by the drainage of the ballast water and the buoyancy of the air 56. For this reason, since the lower elevating part and the first expansion / contraction means are not required unlike the elevating apparatuses 12A and 12B described above, the configuration of the elevating apparatus 12C can be simplified. According to the lifting device 12C, the lifting device 12C can be moved to an arbitrary portion of the riser pipe 11 with a simple device. Accordingly, the lifting device 12C can measure the behavior of the riser pipe 11 over the entire length with only one lifting device 12C. Therefore, according to the lifting / lowering device 12C, it is possible to accurately measure stress, displacement, and the like over the entire riser, and to observe the outer surface of the riser tube 11 in detail. In addition, since the lifting device 12C can be applied only by being attached to the riser pipe of an existing steel pipe, the behavior can be measured over the entire length of the existing steel pipe riser.

  Next, other structural requirements (measurement control device 13 and cable 14) other than the lifting device 12A of the riser pipe monitoring system 10A will be described.

(Measurement control device)
As shown in FIG. 1, the measurement control device 13 is installed on a floating body 15 on the ocean, and is connected to the lifting device 12 </ b> A via a cable 14. The measurement control device 13 receives and records various measurement data such as behavior (response) and depth in an arbitrary portion of the riser tube 11 measured by the accelerometer 22, the inclinometer 23, and the depth meter 29 included in the lifting device 12 </ b> A. At the same time, the stress applied to any part of the riser tube 11 and the displacement of the riser tube 11 are calculated and recorded from the measurement data. Further, the image data of the external surface of the riser tube 11 photographed by the underwater camera 24 is recorded and the image is displayed on a display device (not shown).

  The measurement data of the accelerometer 22 and the inclinometer 23 arranged in the lifting device 12A of the first embodiment shown in FIG. 2 described above is data of the response of the riser pipe 11 to the flow of seawater. This response indicates, for example, a waveform (amplitude and frequency) of vibration (lateral vibration) generated in the riser tube 11. Therefore, for example, by calculating the tensile stress and the compressive stress generated in the riser tube 11 from the measurement data of the accelerometer 22 and the inclinometer 23, the stress and displacement applied to the riser tube 11 can be obtained. As a method for obtaining the stress and displacement applied to the riser tube 11, a known method can be used. Further, by integrating the stress and displacement applied to the riser tube 11, it is possible to grasp the fatigue state in an arbitrary portion of the riser tube 11.

  The measurement control device 13 is connected to the lifting / lowering device 12A via the cable 14. In the lifting / lowering device 12A, as shown in FIG. 2, the upper lifting / lowering portion 21, the lower lifting / lowering portion 27, and the first expansion / contraction means 26a are connected via the cable 14. , 26b. In the upper elevating unit 21, gripping means 31 a and 31 b, an accelerometer 22, an inclinometer 23, an underwater camera 24, and a depth meter 29 are connected via a cable 14. The lower elevating unit 27 is connected to the gripping means 33 a and 33 b via the cable 14. Accordingly, the measurement control device 13 moves the lifting device 12A via the cable 14 so that the gripping means 31a, 31b of the upper lifting part 21, the gripping means 33a, 33b of the lower lifting part 27, and the first expansion / contraction means 26a, 26b. The movement movement of can be controlled.

  When measuring the behavior (response) of the riser pipe 11 with the lifting device 12A shown in FIG. 2, the measurement control device 13 holds the riser tube 11 with the gripping means 31a, 31b, 33a, 33b of the lifting device 12A. It is temporarily fixed to an arbitrary part of the riser tube 11. Next, the accelerometer 22 and the inclinometer 23 perform measurement for a predetermined time to acquire measurement data, and the depth meter 29 acquires depth data. As the measurement time, for example, when the response frequency of the riser tube 11 is about 1 Hz, the time required to measure one point is about 2 to 3 minutes. Next, the moving means of the lifting device 12A is moved to move to the next measurement point. At this time, the distance to be moved can be arbitrarily set according to the number of points to be measured over the entire riser tube 11. Therefore, based on the set moving distance, it is possible to determine at which position (depth) of the riser tube 11 the current measurement point is from the measurement start point. After the lifting device 12A moves to the next measurement point, measurement data is acquired in the same manner as described above. By repeating this measurement, the measurement control device 13 accurately acquires the measurement data of the behavior (response) of the entire riser tube 11 by the lifting device 12A, and the stress and displacement applied to the riser tube 11 at a specific measurement point. Can be requested. As described above, if the time required for measuring one point is about 2 to 3 minutes and the time required for movement is about 5 minutes, 6 to 7 points of measurement data can be acquired in one hour. When the riser tube monitoring system 10A is operated for 20 hours a day, measurement data of about 120 to 140 points can be acquired.

(cable)
As shown in FIG. 1, the cable 14 connects the measurement control device 13 installed on the floating body 15 on the ocean and the lifting device 12A. As described above, the cable 14 is a control signal for controlling the moving operation of the lifting device 12A between the measurement control device 13 and the lifting device 12A, and the measurement measured by the accelerometer 22, the inclinometer 23, and the depth meter 29. The data signal and the video data signal photographed by the underwater camera 24 can be exchanged. In addition, it is possible to supply electric power necessary for operating the lifting device 12A. Therefore, the cable 14 is composed of a plurality of cables so that power supply and various signals can be exchanged. A known cable can be used as the cable 14.

  Therefore, since the monitoring system 10A for the riser tube has only one cable 14, there is no problem with the handling of the cable 14 as compared with the conventional method of attaching several accelerometers.

  As described above, the riser monitoring system 10A can obtain several hundred or more measurement data along the riser tube 11 over the entire length by the lifting device 12A repeating a series of moving operations of the moving means. Therefore, the behavior (response) of the entire riser tube 11 can be measured. Therefore, it is possible to accurately measure up to higher-order responses among the responses of the riser tube 11. Further, since various vibrations including vortex excitation (VIV) caused by vortex generated from the riser due to the flow of seawater can be accurately measured, it is possible to grasp the fatigue state of the riser pipe 11 in an arbitrary portion. It is possible to predict the possibility of fatigue failure in any part of the riser tube 11. Moreover, since the raising / lowering device 12A of the riser pipe monitoring system 10A can be applied only by being attached to the riser pipe of an existing steel pipe, the behavior can be measured over the entire length of the existing steel pipe riser. .

  In addition, this invention is not limited to the said Example, A various change is possible in the range which does not deviate from the meaning of invention. For example, in the present embodiment, the case where one lifting device is provided has been described. However, the present invention is not limited to this, and a plurality of lifting devices 12A may be provided. FIG. 10 is a diagram illustrating another configuration of the riser pipe monitoring system according to the present embodiment. As shown in FIG. 10, the riser pipe monitoring system 10 </ b> B includes two lifting devices 12 </ b> A <b> 1 and 12 </ b> A <b> 2 that measure the behavior (response) of the riser pipe 11. The elevating device 12A1 moves up and down like A2 up to the intermediate point from the ocean to the seabed G (section B2 shown in FIG. 10), and the elevating device 12A2 moves from the middle point from the ocean to the seabed G to the seabed G. The section up to (section B3 shown in FIG. 10) is moved up and down like A3. Moreover, the raising / lowering apparatus 12A-12C mentioned above is applicable to the monitoring system 10B of a riser pipe | tube.

  The riser pipe monitoring system 10B can simultaneously measure the behavior of the riser pipe 11 in two sections B2 and B3 by the two lifting devices 12A1 and 12A2, and therefore, compared to the riser pipe monitoring system 10A, for example, If the total number of measurement points is the same, the time for measuring the behavior of the riser pipe 11 over the entire length of the riser pipe 11 can be reduced to ½. Moreover, if it is the same measurement time, the behavior of the riser pipe | tube 11 in a twice measurement point can be measured.

  Therefore, according to the riser pipe monitoring system 10 </ b> B, approximately twice as much measurement data can be obtained, and therefore, the riser pipe 11 can be measured more accurately than the behavior of the riser pipe 11. Therefore, it is possible to more accurately measure up to higher-order responses among the responses of the riser tube 11. In addition, since various vibrations including vortex excitation (VIV) caused by vortex generated from the riser due to the flow of seawater can be measured more accurately, the fatigue state of the riser pipe 11 in any part can be grasped. Therefore, the possibility of fatigue failure in any part of the riser tube 11 can be predicted more accurately.

  A riser tube monitoring system including a columnar structure lifting apparatus according to an embodiment of the present invention will be described with reference to the drawings. In the riser pipe monitoring system according to the present embodiment, the same components as those of the riser pipe monitoring system according to the first embodiment of the present invention shown in FIG. To do.

  FIG. 11 is a schematic configuration diagram showing a riser tube monitoring system. As shown in FIG. 11, the columnar structure 1B is provided with the landing base 61 of the underwater vehicle 62 on the lifting device 12A of the columnar structure 1A according to the first embodiment shown in FIG.

  FIG. 12 is a schematic perspective view showing the lifting device according to the present embodiment. As shown in FIG. 12, the lifting device 12 </ b> D is provided with a landing base 61 on which the underwater traveling body 62 that travels underwater travels on the lifting devices 12 </ b> A to 12 </ b> C of the first embodiment described above. The landing base 61 is fixedly provided on the upper lifting part 21 of the lifting device 12D. The landing base 61 is provided with a locking portion (not shown) for fixing the underwater vehicle 62. Accordingly, the lifting device 12D can fix the underwater vehicle 62 to the landing base 61 and can move the underwater vehicle 62 simultaneously with the lifting and lowering movement of the lifting device 12D. There is no need to depart from the floating body 15. Therefore, it is not necessary to use power for moving the underwater vehicle 62 to a target position (depth). Further, since the cable 14 is connected to the landing base 61 and power can be supplied to the underwater vehicle 62 via the cable 14, the underwater vehicle 62 can be operated for a long time. . Furthermore, since the cable 14 and the underwater vehicle 62 can be connected via the landing base 61, the underwater vehicle 62 can be controlled from the measurement control device 13 of the floating body 15 on the ocean.

(Underwater vehicle)
FIG. 13 is a schematic view of the underwater vehicle according to the present embodiment. As shown in FIG. 13, the underwater vehicle 62 includes at least an illumination light 63, an underwater camera 64, a work arm 65, a propelling device 66, a rudder 67, and a sensor 68. In addition, for example, a depth meter, a gyro, and an inertial navigation device (not shown) are provided. As the underwater vehicle 62, for example, a known unmanned autonomous underwater vehicle (AUV: Autonomous Underwater Vehicle) can be used.

  In the columnar structure 1B, the behavior of the riser pipe 11 is measured, and water that is fixed to the landing base 61 is observed when an abnormality is found in the stress applied to the riser pipe 11 or the displacement of the riser pipe 11 in an arbitrary portion. When the middle traveling body 62 is started and the outer surface of the riser pipe 11 is photographed in detail by the underwater camera 64 and a defect is found, for example, if the bolts or the like of the connecting portion of the riser pipe 11 are loose, the underwater traveling body 62 The bolt can be fastened with the working arm 65.

  Therefore, according to the columnar structure 1B, since the lifting device 12D includes the landing base 61, the underwater vehicle 62 can be moved simultaneously with the lifting device 12D. Accordingly, even when an abnormal behavior of the riser pipe 11 is detected in an arbitrary portion, the underwater vehicle 62 can be quickly started to deal with the appearance surface of the riser pipe 11 in detail. Further, since the cable 14 is connected to the landing base 61 of the lifting device 12D, it is possible to always supply power for operating the underwater vehicle 62. Thereby, the work on the underwater vehicle 62 can be performed for a long time. Furthermore, since the cable 14 and the underwater vehicle 62 can be connected via the landing base 61, the underwater vehicle 62 can be controlled from the measurement control device 13 on the ocean, and control signals, measurement data signals, Various signals such as video data signals can be exchanged.

  The riser tube monitoring system 10C includes an elevating device 12D for the columnar structure 1B. Therefore, the riser pipe monitoring system 10C measures the behavior of the riser pipe 11, and is fixed to the landing base 61 when an abnormality is observed in the stress applied to the riser pipe 11 or the displacement of the riser pipe 11 at an arbitrary portion. The underwater vehicle 62 is started and the surface of the riser pipe 11 is photographed in detail by the underwater camera 64. The riser pipe monitoring system 10 </ b> C, when a defect is found on the outer surface of the riser pipe 11, is tightened with the work arm 65 of the underwater vehicle 62 if, for example, the bolt or the like of the connecting portion of the riser pipe 11 is loose. be able to. Accordingly, even when an abnormal behavior of the riser pipe 11 is detected in an arbitrary portion, the underwater vehicle 62 can be quickly started to deal with the appearance surface of the riser pipe 11 in detail.

  A riser tube monitoring system including a columnar structure lifting apparatus according to an embodiment of the present invention will be described with reference to the drawings. In the riser pipe monitoring system according to the present embodiment, the same components as those of the riser pipe monitoring system according to the first embodiment of the present invention shown in FIG. To do.

  FIG. 14 is a schematic configuration diagram showing a riser tube monitoring system. As illustrated in FIG. 14, the columnar structure 1 </ b> C includes the fairing 70 in addition to the columnar structure 1 </ b> A according to the first embodiment illustrated in FIG. 1 described above.

  15 to 17 are schematic perspective views of the fairing according to the present embodiment, and are diagrams for explaining the movement operation of the fairing. As shown in FIG. 14, the columnar structure 1 </ b> C includes a riser pipe 1, an elevating device 12 </ b> A, a fairing 70, and a cable 76. Furthermore, the lifting device 12A may be provided with the landing base 61 shown in FIG. 11 described above.

  In the columnar structure 1C, one or more fairings 70 that reduce fluid resistance acting on the riser pipe are arranged so as to surround the riser pipe. For example, when there are a plurality of portions with large stresses and displacements calculated from the measurement data measured by the lifting device 12A, a plurality of fairings 70 are arranged. By installing the fairing 70 around the riser tube 11, it is possible to reduce fluid resistance acting on the riser tube 11 and to suppress vortex excitation (VIV) due to vortices generated from the riser tube 11.

(Fairing)
As shown in FIG. 14, the fairing 70 can be moved up and down like the A4 along the riser pipe 11 by a moving operation, and can be moved and fixed to any part of the riser pipe 11. The fairing 70 is configured to be able to rotate around the riser pipe 11, and changes its direction in the direction in which the resistance becomes the smallest with respect to the flow direction of the seawater, thereby reducing the fluid resistance acting on the riser pipe 11. be able to.

  As shown in FIG. 15, the fairing 70 is a cover (fairing) having a streamlined cross-sectional shape surrounding the riser pipe 11. The fairing 70 is an upper fairing 71 disposed so as to surround the riser tube 11, a lower fairing 72, and a first telescopic means that can be expanded and contracted by connecting the upper fairing 71 and the lower fairing 72. 75a, 75b. The gripping means includes upper fairings 71a and 71b and second expansion / contraction means 73a and 73b. In addition, a moving means shows the 1st expansion-contraction means 75a and 75b.

  The fairing 70 includes upper fairings 71a and 71b and second expansion / contraction means 73a and 73b, lower fairings 72a and 72b, second expansion / contraction means 74a and 74b, first expansion / contraction means 75a and 75b, and a depth meter 29. And a cable 76. The second expansion / contraction means 73a, 73b, 74a, 74b, the first expansion / contraction means 75a, 75b, and the depth meter 29 are each connected to a cable 76 (not shown), and the cable 76 is a floating body on the ocean shown in FIG. 15 is connected (not shown) to the measurement control device 13 installed at 15. The fairing 70 is provided with, for example, a bearing mechanism (not shown) so that the periphery of the riser pipe 11 can be rotated. A known fairing rotation mechanism can be applied as the rotation mechanism.

  As for the shape of the upper fairing 71, the cross-sectional shape in a substantially vertical direction with respect to the longitudinal direction of the riser tube 11 is streamlined. The upper fairing 71 is divided into two fairings 71 a and 71 b so that a substantially semicircular portion 71 a and a substantially isosceles triangular portion 71 b are opposed to each other with the riser tube 11 as a center.

  The upper fairing 71 expands and contracts in a substantially vertical direction with respect to the surface where the two upper fairings 71a and 71b are opposed to each other, and second expansion and contraction means 73a and 73b that connect the upper fairings 71a and 71b are the upper fairing. It is embedded in 71a and 71b. The second expansion / contraction means 73a, 73b are arranged symmetrically opposite to each other with the riser tube 11 as the center.

  The inner curved surface in contact with the riser pipe 11 in the hole (hollow) portion of the upper fairing 71 is formed to have the same curvature as the circumference of the riser pipe 11. That is, since it is the same as the upper raising / lowering part 41 of the raising / lowering apparatus 12B of Example 1 of FIG. 7 mentioned above, detailed description is abbreviate | omitted. As a result, the second expansion / contraction means 73a, 73d contract and the upper fairings 71a, 71b are brought into contact with each other and overlapped so that the upper fairings 71a, 71b grip the riser tube 11 with the inner curved surface. It can be fixed to any part of the riser tube 11. Therefore, the inner curved surfaces of the upper fairings 71a and 71b are the gripping portions of the upper fairing 71, and operate in the same manner as the gripping portions 25a and 25b of the gripping means 31a and 31b of the lifting device 12A shown in FIG.

  The second expansion / contraction means 73a and 73b are connected to the measurement control device 13 by a cable 76 (not shown), and the measurement control device 13 can control the operation of the second expansion / contraction means 73a and 73b. Since the configuration and operation of the second expansion / contraction means are the same as those of the second expansion / contraction means of the elevating device 12B of the first embodiment shown in FIG. 7 described above, detailed description thereof is omitted.

  The shape of the upper fairing 71 is not limited to the streamlined cross-sectional shape, and may be any shape that can reduce the fluid resistance acting on the riser tube 11, for example, an oval or oval cross-sectional shape. Or a shape similar to a known fairing.

  Similarly to the upper fairing 71, the lower fairing 72 has second extendable means 74a and 74b that can be extended and contracted. The configuration of the lower fairing 72 is the same as that of the upper fairing 71 described above, and the configuration of the second expansion / contraction means 74a and 74b is the same as that of the second expansion / contraction means 73a and 73b of the upper fairing 71. Is omitted.

  In addition, although the upper fairing 71 and the lower fairing 72 of the fairing 70 have been described as being divided into two with the riser pipe 11 as a center, the present invention is not limited to this and may be divided into two or more.

  The first expansion / contraction means 75a and 75b, which are moving means, connect the upper fairing 71 and the lower fairing 72 to face each other. The first expansion / contraction means 75a and 75b are arranged symmetrically opposite to each other with the riser tube 11 as a center. The first expansion / contraction means 75 a and 75 b are embedded in the upper fairing 71. The first expansion / contraction means 75a, 75b are arranged so as to divide the upper fairing 71 and the lower fairing 72 into upper and lower parts, and the upper fairing 71, The lower fairing 72 can be moved. The first expansion / contraction means 75a and 75b are connected to the measurement control device 13 by a cable 76 (not shown), and the measurement control device 13 can control the operation of the expansion / contraction means 75a and 75b. Since the configuration and operation of the first expansion / contraction means are the same as those of the first expansion / contraction means of the lifting device 12B of the first embodiment shown in FIG. 7 described above, detailed description thereof is omitted.

  Since the depth meter 29 is the same as the depth meter 29 of the first embodiment described above, detailed description thereof is omitted. The depth meter 29 is configured to pass measurement data obtained via the cable 76 to the measurement control device 13, but the cable 76 is eliminated and a rechargeable battery for operating the depth meter 29 is incorporated. Measurement data and control can be performed in a wireless manner.

(Fairing movement)
Since the movement operation of the fairing 70 is basically the same as that of the lifting device 12A of the first embodiment shown in FIGS. 3 to 7 described above, detailed description thereof is omitted. As shown in FIGS. 16 and 17, the cylinders of the second expansion / contraction means 74a and 74b of the lower fairing 72 are extended in the direction F1 to release the grip of the riser tube 11, and then the first expansion / contraction means 75a and 75b are used. The pistons 76a and 76b of this cylinder are extended in the directions of G1 and G2, and the lower fairing 72 is moved downward. Next, as shown in FIG. 17, the second expansion / contraction means 74a and 74b of the lower fairing 72 are contracted in the direction F2, and the riser tube 11 is temporarily gripped. Next, the cylinders of the second expansion / contraction means 73a, 73b of the upper fairing 71 are extended in the direction F3 to release the grip of the riser pipe 11, and then the pistons 76a, 76b of the cylinders of the first expansion / contraction means 75a, 75b. Is reduced in the directions of G3 and G4, and the upper fairing 71 is moved downward. Next, the cylinder of the second expansion / contraction means of the upper fairing 71 is contracted to temporarily grip the riser tube. The fairing 70 can be moved to an arbitrary position by repeating a series of operations such as the above series of measuring insects. At this time, the distance moved by one movement operation can be arbitrarily set depending on the length of the first expansion / contraction means 75a and 75b. The position (depth) of the fairing 70 is calculated based on the measurement data of the depth meter 29 and the moving distance once, and the fairing 70 is fixed when the fairing 70 moves to the target position of the riser tube 11.

  In the columnar structure 1 </ b> C, the behavior of the riser tube 11 is measured by the lifting device 12 </ b> A, and the stress applied to the riser tube 11 and the displacement of the riser tube 11 are large in any part, for example, the acceleration is large or the vibration is large. Identify the part. Thereafter, for example, the fairing 70 can be moved and arranged in a specified portion where the vibration of the riser pipe 11 is large. Thus, according to the columnar structure 1 </ b> C, after specifying a portion where the vibration of the riser tube 11 is large, the fairing 70 that reduces the fluid resistance acting on the riser tube 11 is moved to the specified portion and arranged. Therefore, the vibration of the riser tube 11 can be reduced at an arbitrary portion. Thereby, accumulation of fatigue of the riser pipe 11 in an arbitrary portion can be suppressed, and the possibility of fatigue failure of the riser pipe 11 can be reduced.

  The riser tube monitoring system 10D includes an elevating device 12A for the columnar structure 1C. Accordingly, the riser pipe monitoring system 10D measures the behavior of the riser pipe 11 by the lifting device 12A, and a portion where the stress applied to the riser pipe 11 and the displacement of the riser pipe 11 are large in an arbitrary portion, for example, acceleration is large. Alternatively, a portion where vibration is large is specified. Thereafter, the riser tube monitoring system 10 </ b> D can be arranged by moving the fairing 70 to the specified portion of the riser tube 11 where the vibration is large, for example. Thereby, the vibration of the riser pipe 11 can be reduced in an arbitrary portion.

  Moreover, although the said Example demonstrated the case where the columnar structure 1A based on Example 1 shown in FIG. 1 mentioned above was provided with the fairing 70, it is not limited to this, The columnar structure 1C is The columnar structure 1B according to the second embodiment shown in FIG. 11 described above may be provided with a fairing 70.

1A, 1B, 1C Columnar structure 10A, 10B, 10C, 10D Riser tube monitoring system 11 Riser tube 12, 12A, 12A1, 12A2, 12B, 12C, 12D Lifting device 13 Measurement control device 14 Cable 15 Floating body 16 Ejection prevention device (BOP)
17 Air pipe 21, 41, 41a, 41b, 41c, 41d Upper lift part 22 Accelerometer 23 Inclinometer 24 Underwater camera 25a, 25b, 28a, 28b Grip part 26a, 26b First telescopic means 27, 43, 43a, 43b, 43c, 43d Lower elevating part 29 Depth meter 31a, 31b, 33a, 33b Grasping means 32a, 32b, 34a, 34b Second cylinder 35a, 35b First cylinder 36a, 36b Piston 42a, 42b, 42c, 42d, 44a, 44b, 44c, 44d 2nd expansion-contraction means 51 Elevating part 53, 54 Pump 55 Seawater 56 Air 57 Valve 61 Departure base 62 Underwater vehicle 63 Illumination light 64 Underwater camera 65 Work arm 66 Propeller 67 Rudder 68 Sensor 70 Fairing 71, 71a 71b Upper fairing 72 72a, 72b lower fairing 73a, 73b, 74a, 74b second stretchable means 75a, 75b first elastic means 76 cable G seabed S Sea

Claims (7)

A riser pipe formed by continuously extending a plurality of pipes in the vertical direction from the sea surface side to the sea floor side;
A lifting device that can be lifted and lowered along the riser pipe,
The lifting device, said disposed so as to surround the periphery of the riser tube, the lifting unit Ru provided with a landing base for landing the underwater vehicle capable of cruising underwater,
A gripping means provided in the elevating unit for temporarily gripping the riser pipe;
Moving means for moving the elevating part up and down freely along the entire length of the riser pipe;
A columnar structure characterized by comprising: In claim 1,
The elevating unit has one or both of an accelerometer and an inclinometer, and measures the behavior of the riser tube. One or more lifting devices according to claim 1 or 2 ,
A measurement control device that calculates and records the stress and displacement of the riser tube based on the behavior of the riser tube measured by the lifting device, and controls the movement of the lifting device;
A cable connecting the measurement control device and the lifting device;
A riser tube monitoring system characterized by comprising: In claim 3 ,
Based on the stress and displacement calculated from the behavior of the riser pipe measured by the lifting device, one or more fairings that reduce the fluid resistance acting on the riser pipe are arranged so as to surround the riser pipe. Riser tube monitoring system characterized by that. From the sea surface side to the sea floor side, it can freely move up and down along a riser pipe formed by continuously extending a plurality of pipes in the vertical direction, and an elevating part arranged so as to surround the riser pipe, One or more lifting devices provided in a lifting unit, the gripping unit temporarily gripping the riser tube, and a moving unit that moves the lifting unit up and down freely along the entire length of the riser tube; ,
A measurement control device that calculates and records the stress and displacement of the riser tube based on the behavior of the riser tube measured by the lifting device, and controls the movement of the lifting device;
A cable connecting the measurement control device and the lifting device;
Have
Based on the stress and displacement calculated from the behavior of the riser pipe measured by the lifting device, one or more fairings that reduce the fluid resistance acting on the riser pipe are arranged so as to surround the riser pipe. Riser tube monitoring system characterized by that. In claim 5,
Any one of the elevating devices includes one or both of an accelerometer and an inclinometer, and measures the behavior of the riser tube. In claim 4 any one of claims 6,
The fairing is an upper fairing arranged to surround the riser tube;
A gripping means provided on the upper fairing for temporarily gripping the riser tube;
Moving means for moving the upper fairing up and down along the entire length of the riser tube;
A riser tube monitoring system characterized by comprising:

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