JP2016037214A - Offshore floating body structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an offshore floating body structure having an overall box shape and being excellent in the resistance performance of a lower region becoming below a water level when moving.SOLUTION: An offshore floating body structure is movable to an installation sea area and moored, fixed and operated in the installation sea area. A center part in a longitudinal direction has a rectangular parallelepiped shape. An upper deck 25 of a rear part 13 continuously disposed at the center part has the rectangular parallelepiped shape having the same width as the upper deck of the center part. A part lower than a water line when the rear part 13 moves has a streamline shape narrowing rearward.SELECTED DRAWING: Figure 4

Description

  The present invention relates to an offshore floating structure for producing and storing, for example, crude oil on the ocean.

  2. Description of the Related Art Conventionally, an offshore floating structure that is movable to an installation sea area, is moored and fixed in the installation sea area, and pumps up an oil reservoir fluid to refine and store crude oil (for example, Patent Document 1). Such an offshore floating structure has a crude oil storage tank, and various facilities such as a refining treatment facility are arranged on the upper deck, so that some are formed into a box shape as a whole. Further, in the bow and tail portion of such a box-shaped floating body, the bottom and both side walls are often cut obliquely to form an inclined surface.

JP 2001-260982 A

  As described above, it is ideal that the offshore floating structure has a box shape for functional reasons. However, it is preferable that the offshore floating structure has a certain propulsion resistance performance for moving on the ocean. It was difficult to meet.

  An object of the present invention is to provide an offshore floating structure having an overall box shape and excellent resistance performance during movement.

  The present invention is an offshore floating structure that can move to an installation sea area and is moored and fixed in the installation sea area, and has a central part in a longitudinal direction having a rectangular parallelepiped shape, and is continuously provided in the central part. The upper deck of the rear part has a rectangular shape that is the same width as the upper deck of the central part, and is characterized by exhibiting a streamline in which the lower part is narrowed toward the rear than the water line when moving the rear part .

  Preferably, the outer surface of the rear part has an upper region connected to a side wall extending vertically downward from an edge of the upper deck, a lower region connected to the bottom, and an intermediate formed between the upper region and the lower region. The inclination angle of the intermediate region is smaller than that of the upper region and the lower region. In this configuration, the intermediate region is constituted by a ruled surface, for example. In the intermediate region, a portion close to the rear end portion may be configured by a developable surface, and a portion close to the center portion may be configured by a twisted surface.

  Preferably, the upper region has an inclined surface in which the inclination angle becomes smaller toward the rear end. In this case, the upper region is constituted by a ruled surface, for example.

  The length of the central part can be freely set, for example, up to 50 to 70% of the total length of the offshore floating structure, while the width is fixed to a general-purpose size that fits the receiving size of repair docks around the world. For example, the width is set to 49 to 63 m. At the same time, the length of the front part is approximately equal to the width (about 90 to 110%), and the length of the rear part is about 120 to 140% of the width. As a result, it is possible to ensure wave-retaining properties and needle-keeping properties.

  The outer surface of the front part provided continuously in the central part is connected to the edge of the upper deck, for example, and an upper region that inclines so as to form an acute angle with respect to the upper deck, and extends vertically downward from this upper region. A lower region, and the lower region may be formed by a developable surface.

  According to the present invention, it is possible to obtain an offshore floating structure that has a box-like shape as a whole and has excellent resistance performance in a lower region that is below the water surface during movement.

It is a side view which shows the offshore floating body structure to which one Embodiment of this invention is applied. It is the perspective view which looked at the front part of the offshore floating structure from diagonally downward. It is a front view of the front part of an offshore floating structure. It is the perspective view which looked at the rear part of the offshore floating structure from diagonally downward. It is a front view of the rear part of an offshore floating structure.

Hereinafter, an offshore floating structure according to an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 schematically shows an offshore floating structure to which the present embodiment is applied. This offshore floating structure can be towed to the installation sea area or can be moved by self-propulsion, and is moored and fixed in the installation sea area. The main body 10 is divided into a front part 11, a central part 12 and a rear part 13. The overall width of the main body 10 is fixed to a general-purpose size suitable for receiving sizes of repair docks around the world, for example, 49 to 63 m. The length of the front part 11 is about 90 to 110% of the full width, and the length of the rear part 13 is about 120 to 140% of the full width. The length of the central portion 12 has a rectangular parallelepiped shape that can be freely set up to about 50 to 70% of the total length of the offshore floating structure. Reference symbol L indicates a draft line during movement, and the draft is about one third of the depth of the main body 10.

  The production equipment 21 provided on the upper deck 25 of the central portion 12 includes oil treatment equipment, gas treatment equipment, water treatment equipment, power generation equipment, and the like. A companion gas combustion device 22 is provided in front of the production facility 21, and a crane 23 is provided around the production facility 21. Residential area facilities 24 are provided on the upper deck 25 of the rear portion 13.

  FIG. 2 is a perspective view of the front portion 11 as viewed obliquely from below, and FIG. 3 is a front view of the front portion 11. The front portion 11 is provided continuously with the central portion 12, and the outer surface thereof is partitioned into an upper region 31, a lower region 32, and a bottom portion 33. The upper region 31 is connected to the edge of the upper deck 25 and is inclined with respect to the upper deck 25 so as to form an acute angle. The lower region 32 extends vertically downward from the upper region 31. As is understood from FIG. 3, the lower region 32 is formed by only a line segment extending in the vertical direction except for the bilge portion 34, and the horizontal plane shape forms a curve whose width becomes narrower as it approaches the front end portion. That is, the lower region 32 is constituted by a developable surface and can be developed on a plane. The bottom 33 is a plane. 2 and 3, reference numerals F1 to F4 indicate outlines at positions corresponding to each other.

  The cross-sectional shape of the central part 12 is substantially rectangular, and the side wall of the central part 12 is a flat plate except for the bilge part 34 (see FIG. 3). That is, both side walls of the central portion 12 are substantially parallel flat plates, and a storage tank for crude oil or the like is formed in the central portion 12.

  FIG. 4 is a perspective view of the rear portion 13 as viewed obliquely from below, and FIG. 5 is a front view of the rear portion 13. The rear part 13 is provided continuously to the central part 12, and the upper deck 25 has the same width as the central part 12. Ideally, the upper deck 25 of the rear part 13 is rectangular when viewed from above. However, actually, the planar shape of the rear portion 13 is a rectangular shape including a case where a corner is chamfered or rounded. In addition, the rear portion 13 exhibits a streamline shape in which a lower portion is narrowed toward the rear side of the waterline L (see FIG. 1) during movement. The outer surface of the rear portion 13 is divided into a side wall 42, an upper region 43, an intermediate region 44, a lower region 45, and a bottom 46. 4 and 5, reference numerals A0 to A2 indicate outlines at positions corresponding to each other.

  The side wall 42 extends vertically downward from the edge of the upper deck 25. The upper region 43 is connected to the side wall 42 and is a torsion surface having an inclined surface whose inclination angle becomes smaller as approaching the rear end portion, as indicated by outlines A0 to A2 in FIG. That is, the upper region 43 becomes a ruled surface (developable surface or twisted surface, or a combination thereof) that can be configured only by line segments. On the other hand, the lower region 45 is connected to the bottom portion 46, and the connection portion with the bottom portion 46, that is, the bilge portion 47 is a three-dimensional curved surface close to an arc, but other than the bilge portion 47 is a ruled surface.

  The intermediate region 44 is formed between the upper region 43 and the lower region 45, the upper edge of the intermediate region 44 is connected to the upper region 43, and the lower edge of the intermediate region 44 is connected to the lower region 45. The inclination angle of the intermediate region 44 is smaller than that of the upper region 43 and the lower region 45. Further, the intermediate region 44 is configured by a developable surface in a portion close to the rear end portion (between and near the reference symbols A1 to A2 in FIG. 5), and is closer to the central portion 12 (than the reference symbol A2 in FIG. 5). The front) is constituted by a twisted surface. That is, the intermediate region 44 is represented as a line segment trajectory and is constituted by a ruled surface.

  The corner 51, which is the boundary between the upper region 43 and the intermediate region 44, is bent into a convex shape as shown in FIG. On the other hand, the corner 52, which is the boundary between the intermediate region 44 and the lower region 45, is bent in a concave shape as shown in FIG.

  As described above, in the present embodiment, the front portion 11 is configured by a flat bottom portion 33 except for the bilge portion 34, the lower region 32 of the side wall is configured as a developable surface, and the width becomes narrower toward the front end portion. ing. That is, the shape of the front portion 11 is simple, the construction cost can be suppressed, and the resistance during movement can be reduced. Furthermore, since the upper region 31 has a flare shape, the area of the upper deck 25 will be expanded, and not only will it be possible to secure space for placing production equipment, storage equipment, mooring equipment, etc. It is possible to improve the wave survivability.

  About the center part 12, it occupies about 50 to 70% of the full length (waterline length) of the main body 10, and can be made longer than a general ship. When the central portion 12 is made long in this way, the construction as an offshore floating structure is simplified as a whole, so that construction is facilitated. Moreover, since the part where both side walls are parallel becomes long, the space for installing piping etc., such as a riser pipe | tube etc. which connects an oil well etc. of a seabed and storage equipment can be increased.

  The rear portion 13 has a shape close to a hull shape below the waterline L during movement. Therefore, the resistance at the time of movement can be reduced as compared with the offshore floating structure having a box shape. By reducing the resistance, the propulsion device can be reduced in size, and thus the engine room can be made smaller, so that the storage space can be expanded by this amount. Further, since the fuel consumption during movement can be suppressed, the environmental load can be reduced and the movement cost can be reduced. Furthermore, according to the shape of the rear part 13, even if the offshore floating structure is a towed type or a self-propelled type, the needle-holding property is improved.

  Further, the upper deck 25 of the rear portion 13 has the same width as that of the central portion 12, and the upper deck 25 is expanded to the maximum width as compared with the conventional offshore floating structure whose width is reduced toward the stern end. . On the upper deck 25, production equipment 21, residential area equipment 24, mooring equipment, lifesaving equipment, helicopter boarding / exiting equipment, etc. are arranged. Therefore, it is preferable to isolate it from storage facilities such as dangerous oil. Since the rear part 13 away from the storage facility provided in the central part 12 is a highly safe place, by securing a large area of the upper deck 25 of the rear part 13, the residential area equipment 24, helicopter boarding / exiting equipment, lifesaving It becomes easy to arrange equipment or the like in the rear portion 13.

  In the upper region 43 of the rear portion 13, the rear end portion is inclined as indicated by reference numeral A 0, and the inclination angle becomes larger as the center portion 12 is approached. Such an inclination of the upper region 43 improves the wave resistance against waves during mooring and fixing. That is, the water line when mooring is fixed (during operation) is above the time of movement, for example, near the lower end of the line segment indicated by reference numeral A0, but the upper region 43 is inclined, so that the main body 10 is pitched or The slamming impact can be reduced even when it moves up and down. Moreover, since the upper area | region 43 inclines, since there exists an effect which enlarges the water surface area at the time of operation | movement, the inclination of an offshore floating body structure can be suppressed and stability can be improved.

  Further, as shown in FIG. 5, the corner 52 between the intermediate region 44 and the lower region 45 of the rear portion 13 approaches the water line L (see FIG. 1) as it approaches the rear end. That is, the space below the intermediate region 44 is larger toward the rear end. Therefore, the hull posture trim during movement can be used as the stern trim, and the degree of submersion of the propeller can be sufficiently secured.

  Further, in the rear portion 13, the upper region 43, the intermediate region 44, the lower region 45, and the bottom portion 46, except for the bilge portion 47, are configured by flat surfaces or ruled surfaces (expandable surfaces or twisted surfaces, and combinations thereof). ing. Therefore, the shape of the rear portion 13 is simple, and the construction cost can be suppressed.

DESCRIPTION OF SYMBOLS 11 Front part 12 Center part 13 Back part 25 Upper deck 42 Side wall 43 Upper area | region 44 Middle area | region 45 Lower area | region

Claims (10)

An offshore floating structure that can move to the installation sea area and is moored and fixed in the installation sea area.
The central part in the longitudinal direction has a rectangular parallelepiped shape, and the upper part of the rear part provided continuously to the central part has a rectangular shape having a width equal to that of the upper part of the central part. An offshore floating structure characterized by exhibiting a streamlined shape in which a lower part of the waterline at the time of movement is narrowed toward the rear.   The outer surface of the rear portion has an upper region connected to a side wall extending vertically downward from an edge of the upper deck, a lower region connected to the bottom, and an intermediate region formed between the upper region and the lower region. The offshore floating structure according to claim 1, wherein an inclination angle of the intermediate region is smaller than that of the upper region and the lower region.   The offshore floating structure according to claim 2, wherein the intermediate region is constituted by a ruled surface.   The offshore structure according to claim 3, wherein the intermediate region is configured by a developable surface at a portion close to a rear end portion and a twisted surface at a portion close to the center portion.   The offshore floating structure according to claim 2, further comprising an inclined surface having an inclination angle that decreases as the upper region approaches the rear end.   The offshore floating structure according to claim 5, wherein the upper region is constituted by a ruled surface.   The offshore floating structure according to claim 2, wherein the lower region is composed of a ruled surface except for a bilge portion.   2. The offshore floating structure according to claim 1, wherein a length of the central portion is 50 to 70% of a total length of the offshore floating structure.   The outer surface of the front portion provided continuously in the central portion is connected to the edge of the upper deck, and an upper region that inclines so as to form an acute angle with respect to the upper deck, and vertically downward from the upper region. 2. The offshore floating structure according to claim 1, further comprising a lower area extending, and the lower area is formed by a developable surface except for a bilge portion.   The central portion, the front portion provided continuously to the central portion, and the width of the rear portion are in a range of 49 to 63 m, the length of the front portion is 90 to 110% of the width, and the rear portion The length of a part shall be 120 to 140% of the width, The offshore floating structure according to any one of claims 1 to 9.

Images