JP2016117363A - Fairing cover - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the additive's resistance of a protrusive construction which is arranged under a draft of floating equipment exhibiting a hull shape, and anchors a riser, a mooring rope or the like.SOLUTION: A riser guide 15 having a large number of guide pipes 16 is arranged under a draft of floating equipment which exhibits a hull shape along a bilge of a side shell. Fore-and-aft cover members 20C as fairings are fixed to fore-and-aft ends of the riser guide 15. Upper cover members 20U and lower cover members 20D are attached so as to cover the guide pipes 16 which vertically extend from a main body of the riser guide 15. After transferring floating-type production/storage/delivery equipment up to an installation sea area, the upper cover members 20U and the lower cover members 20D are removed by underwater work, and riser pipes are attached to the guide pipes 16, respectively.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a projecting structure for securing a riser, a mooring line, and the like provided under the draft of a floating facility having a hull shape to the hull.

  In floating production storage and loading equipment (FPSO equipment) and tension mooring platform (TLP), there are many riser pipes that connect between the sea floor and offshore facilities, and fluids such as crude oil, gas, and seawater are transported through the riser pipes. . The riser tube has flexibility and is pulled in through a guide provided on an outer plate near the keel and fixed in the horizontal direction (see Patent Document 1).

JP-T-2006-519137

  After construction, the FPSO facility is transferred offshore to a facility installation location (for example, a subsea well). However, the guide of the riser pipe increases the hull resistance because it is a structure protruding from the hull outer plate near the bilge. As a result, problems such as an increase in the size of the propulsion engine, an increase in the period required for movement, and an increase in transfer costs occur. The same problem also occurs with the chain fair leader provided under the draft to draw in the mooring lines for mooring the FPSO facility.

  An object of the present invention is to reduce the additional resistance of a protruding structure that is provided under a draft of a floating body facility that has a hull shape and is provided to hold a riser, a mooring line, or the like on the hull.

  The fairing cover of the present invention covers a protruding structure provided to hold the riser or mooring line to the hull under the draft of the floating body equipment having a hull shape, and reduces the fluid resistance in the propulsion direction by the protruding structure. It is characterized by doing.

  The fairing cover preferably includes a cover member that is removable from the protruding structure. The removable cover member preferably comprises a buoyancy body. Also, a cover member that covers the front part and the rear part of the projecting structure is permanently attached to the projecting structure, and the cover member that covers the center part of the projecting structure is removed except for the cover member that covers the front part and the rear part. It is preferable that the cover member be made possible. In addition, the removable cover member has a film structure or a panel structure, for example.

  All of the cover members may be configured integrally with the projecting structure, and the top surface and the bottom surface of the fairing cover may be configured to have openings through which the riser tubes pass corresponding to the respective guide tubes.

  The floating facility of the present invention is characterized by including any of the above fairing covers.

  ADVANTAGE OF THE INVENTION According to this invention, the additional resistance of the protrusion structure provided in order to hold a riser, a mooring line, etc. on the hull under the draft of the floating body equipment which exhibits a hull shape can be reduced.

It is a side view of the floating body type production storage loading and unloading equipment (FPSO equipment) which is a 1st embodiment. It is the elements on larger scale when a riser guide is seen from (a) stern direction, (b) side surface direction, and (c) upper direction. It is a perspective view which shows the external appearance of a riser guide. It is a perspective view which shows the external appearance of the state in which the fairing cover was attached to the riser guide. Moreover, the state which decomposed | disassembled the fairing cover is shown by FIG. It is a perspective view drawn in the state where the riser guide and guide tube in a fairing cover were seen through. It is a perspective view by which the state by which the fairing cover was decomposed | disassembled is shown. It is a perspective view which shows the structure of the fairing cover of 2nd Embodiment.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
FIG. 1 is a side view of a floating-type production storage / loading facility (FPSO facility) which is a first embodiment of a floating facility according to the present invention.

  The FPSO facility 10 according to the first embodiment has a ship shape and includes a processing facility 11 that processes hydrocarbons such as crude oil and gas. After construction, the FPSO facility 10 is self-propelled or towed, transferred to the installation sea area (water area), and moored in the sea area (water area).

  A large number of flexible riser tubes 12 (only two are shown in FIG. 1) are attached to the FPSO facility 10 moored in the installation sea area, and hydrocarbons such as crude oil and gas are treated from the sea floor to the treatment facility 11. It is pumped up and processed. The hydrocarbons processed in the processing facility 11 are stored, for example, in a tank (not shown) provided in the hull.

  The riser pipe 12 is led from the processing equipment 11 along the ship side skin 13 to the seabed. For example, a pair of riser guides 14 and 15 for fixing the position of each riser pipe 12 is provided on the ship side. The riser guide 14 is disposed along the hull longitudinal direction above the ship side outer plate 13 and fixes a portion of each riser pipe 12 close to the processing equipment 11 to the hull. On the other hand, the riser guide 15 is disposed along the bilge near the bilge below the draft L, and fixes the riser pipe 12 hanging down into the sea to the hull.

  With reference to FIG. 2 and FIG. 3, the structure of the riser guide 15 provided under the draft L in this embodiment is demonstrated. Note that a fairing cover is not attached to the upper riser guide 14.

  2A is a view of the riser guide 15 as viewed from the stern direction of FIG. 1 along the longitudinal direction of the hull, for example. FIG. 2B is an enlarged view of the stern side end of the riser guide 15 of FIG. It is a side view. FIG. 2C is a plan view of FIG. 2B viewed from above. FIG. 3 is a perspective view of FIGS. 2B and 2C as viewed obliquely from above the stern side.

  The main body of the riser guide 15 is a structure that has a long box shape in the longitudinal direction of the hull, and protrudes outward from the ship side skin 13 near the bilge. In the riser guide 15 of the first embodiment, guide tubes 16 for guiding each riser tube 12 along the vertical direction are arranged along the longitudinal direction at a predetermined interval, for example. The guide pipe 16 is a pipe that penetrates the main body of the riser guide 15 in the vertical direction. The diameter has been expanded.

  Next, the fairing cover of the first embodiment for reducing the fluid resistance of the riser guide 15 will be described with reference to FIGS.

  4 to 6 are perspective views showing the configuration of the fairing cover 20 according to the first embodiment, and portions corresponding to those in FIG. 3 are drawn. FIG. 4 shows the appearance of the state in which the fairing cover 20 is attached to the riser guide 15, and FIG. 5 is a view in which the riser guide 15 in the fairing cover 20 is seen through. Moreover, the state which decomposed | disassembled the fairing cover 20 is shown by FIG.

  As shown in FIGS. 4 to 6, the front and rear portions (the bow side and the stern side) of the riser guide 15 are step-shaped in the front and rear portions because the shape of the riser guide 15 is a box shape, which causes an increase in resistance. Therefore, the front / rear cover member 20 </ b> C having an oblique member for alleviating the increase in resistance is provided integrally with the hull and the riser guide 15. An upper cover member 20U and a lower cover member 20D are attached to the upper and lower portions of the riser guide 15 so as to cover the guide tubes 16 projecting upward and downward from the main body of the riser guide 15, respectively.

  The upper cover member 20U and the lower cover member 20D are cover members that are removed after the FPSO facility 10 is transferred and installed, and are, for example, panel members each having an L-shaped cross section. That is, after the FPSO facility 10 is installed, the upper cover member 20U and the lower cover member 20D are removed as shown in FIG. In addition, between the upper cover member 20U and the lower cover member 20D that are attached to the riser guide 15, the side surface 15S of the riser guide 15 main body communicates to form one plane parallel to the ship-side outer plate 13. At this time, the top surface of the upper cover member 20U covers the upper opening of the guide tube 16, forms a flat surface that is the same height as the top surface of the front and rear cover member 20C, and the bottom surface of the lower cover member 20D The lower opening 16 is covered and a flat surface having the same height as the bottom surface of the front and rear cover member 20C is formed.

  In the example shown in FIG. 6, the upper cover member 20 </ b> U and the lower cover member 20 </ b> D are provided in the same number corresponding to each guide tube 16. A plate-like frame plate 21 corresponding to the cross-sectional shape of the fairing cover 20 is provided between the guide tubes 16 perpendicular to the ship side outer plate at the approximate center, and the upper cover member 20U and the lower cover are provided. The member 20D can be fixed to the frame plate 21 using a predetermined attachment method. Further, at the top of the box-type riser guide 15, an attachment member 22 for attaching the upper cover member 20 </ b> U along the outer plate is provided at an edge along the ship-side outer plate 13. A similar attachment member 22 is also provided at a portion where the lower cover member 20D is in contact with the ship side outer plate (not shown).

  The upper cover member 20U and the lower cover member 20D are attached to the riser guide 15 or the ship side skin 13 by, for example, lashing with bolts, ropes or wire wires, or local welding. After installing the FPSO facility 10, an underwater worker Removed. In this embodiment, since the panel which comprises the upper cover member 20U and the lower cover member 20D is comprised, for example with a steel board etc., the removal operation | work in water from its own weight becomes difficult. Therefore, in the present embodiment, as shown by the broken lines in FIG. 6, buoyancy bodies (voids) 23 are provided in the upper cover member 20U and the lower cover member 20D, so that the upper cover member 20U and the lower cover member 20D are underwater. For example, it is configured to have neutral buoyancy.

  The buoyancy body 23 is provided at a position corresponding to a void in the fairing cover 20 when the upper cover member 20U and the lower cover member 20D are attached to the riser guide 15. That is, it arrange | positions in the space between the adjacent guide pipe | tubes 16 like FIG.

  In the description of the present embodiment, the upper cover member 20U and the lower cover member 20D are described as steel panel members. However, both members or one of them is not a panel member but a steel plate or the like. The underwater weight is lighter than that of the panel member, and the canvas (membrane member) may have a good workability. In this case, the canvas fabric is attached to the attachment member 22 and the shape as a fairing cover is a frame plate. 21 is held.

  As described above, according to the present embodiment, when the FPSO equipment is transferred, the riser guide and the guide tube are covered by the fairing cover, so that the fluid resistance is lowered and the transfer efficiency is improved. Further, after the transfer and after the installation of the FPSO facility 10, the fairing cover can be easily removed by an underwater worker. Further, since the front and rear cover members are fixed, the number of cover members to be removed after installation is reduced, and the working time is shortened.

  Next, the structure of the fairing cover 25 of 2nd Embodiment is demonstrated with reference to FIG. FIG. 7 is a perspective view corresponding to FIG. 4 of the first embodiment.

  In the second embodiment, the fairing cover 25 and the riser guide 15 (projecting structure) are integrally configured. The external appearance of the fairing cover 25 of the second embodiment is substantially the same as the external appearance of FIG. 4, but the top surface 25T and the bottom surface 25B have openings 16A through which the riser pipes penetrate in correspondence with the guide pipes 16, respectively. 16B is provided. At the time of transfer, for example, a lid-like cover member is fitted in each of the openings 16A and 16B. After the FPSO facility 10 is installed, only these lid-like cover members are removed, but a slight increase in resistance is allowed. Thus, it is possible to eliminate the lid-like cover member.

  As described above, the same effects as those of the first embodiment can be obtained in the configuration of the second embodiment. In the second embodiment, for example, only the lid-like cover member needs to be removed, so that the work amount of the underwater worker is further reduced.

  In this embodiment, the riser guide of the floating production storage and loading (FPSO) facility has been described as an example. However, the present invention provides a projecting structure for anchoring the mooring line to the hull, such as a chain fair leader. Can also be applied, and can also be applied to floating body equipment that exhibits a hull shape other than FPSO, such as floating body storage and shipping (FSO) equipment.

10 Floating production storage and shipping equipment (FPSO equipment)
11 Processing equipment 12 Riser pipe 13 Ship side skin 15 Riser guide (under draft L)
15S riser guide side wall 16 guide tube 16A, 16B opening 20, 25 fairing cover 20C front / rear cover member 20D lower cover member 20U upper cover member 21 frame plate 22 mounting member 23 buoyancy body (void)
L draft

Claims (7)

  A fairing characterized by covering a projecting structure provided to hold a riser or mooring line to the hull under the draft of a floating body facility having a hull shape, and reducing fluid resistance in the propulsion direction by the projecting structure cover.   The fairing cover according to claim 1, further comprising a cover member that is removable from the protruding structure.   The fairing cover according to claim 2, wherein the removable cover member includes a buoyancy body.   A cover that covers a central portion of the projecting structure except for a cover member that is permanently attached to the projecting structure and covers the front and rear portions of the projecting structure. The fairing cover according to any one of claims 2 and 3, wherein a member is constituted by the removable cover member.   The fairing cover according to any one of claims 2 to 4, wherein the removable cover member has a film structure or a panel structure.   All of the cover members are integrally formed on the projecting structure, and the top surface and the bottom surface of the fairing cover are provided with openings through which the riser tubes pass corresponding to the respective guide tubes. The fairing cover according to 1.   A floating facility comprising the fairing cover according to claim 1.

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