WO2019208548A1

WO2019208548A1 - Offshore floating structure

Info

Publication number: WO2019208548A1
Application number: PCT/JP2019/017163
Authority: WO
Inventors: 俊佑岩見; 研中村
Original assignee: 三井Ｅ＆Ｓ造船株式会社
Priority date: 2018-04-24
Filing date: 2019-04-23
Publication date: 2019-10-31
Also published as: JP2019188977A

Abstract

This offshore floating structure 10 may be a floating production storage and offloading system (FPSO) in which a production facility 14 can be mounted on an upper deck 12. The offshore floating structure 10 comprises a longitudinal partition wall 18 that extends in the longitudinal direction and is connected to the lower surface of the upper deck 12. An upper surface of the upper deck 12 corresponding to the location where an upper side portion 18A of the longitudinal partition wall 18 is coupled to the upper deck 12 serves as a stool installation portion at which a stool 16 for supporting the production facility 14 can be installed. The upper side portion 18A of the longitudinal partition wall at the location where the stool installation portion is disposed is configured from a steel member having a thickness of at least 25 mm.

Description

Offshore floating structure

The present invention relates to an offshore floating structure in which production equipment is installed on an upper deck or the like.

Offshore floating structures such as floating production storage and loading equipment (FPSO) produce oil and gas from the bottom of the ocean through the riser pipe, and the crude oil produced can be stored in tanks and shipped to tankers. Unlike tankers, not only are tanks for crude oil stored, but production equipment is installed on the upper deck. This production equipment is equipped with various equipment such as gas separation equipment, dehydration equipment, metering equipment, power generation equipment, etc., and is designed according to the characteristics of the oil well and installed after the hull is manufactured. The details are often undecided. Therefore, if the design of the hull is performed after the requirements for the production equipment for each project are finalized, as a result, the manufacturing of the hull is not in time for the installation of the production equipment, and the entire construction period of the FPSO becomes longer. Occurs.

In addition, the production equipment is installed on a stool on the upper deck in a state of being fixed on the gantry, but the configuration and installation position of the stool is not only the type, arrangement, and size of the production equipment, but also the wave load. The influence of the deformation of the offshore floating structure on the gantry must be taken into consideration, and as described above, it takes time to complete the design and the construction period of the FPSO is long. Also, the load transmitted to the offshore floating structure differs depending on the type and arrangement of production equipment and the type of stool, and the upper deck may have to be reinforced. However, when it is necessary to connect with the above, there is a problem that such a girder must be considered so as not to interfere with piping on the upper deck.

For these problems, on the lower surface of the upper deck, a transverse strength member extending in the width direction of the floating body and a longitudinal strength member extending in the longitudinal direction are provided, and on the upper deck, the transverse strength member and the longitudinal direction are provided. There has been proposed an offshore floating structure provided with a stool installation part capable of installing a stool for supporting production equipment at at least a part of a plurality of points where strength members intersect (Patent Document 1).

JP 2017-65291 A

However, since the hull girder load on the hull and the load on the top side are superimposed on the longitudinal strength member directly below the stool installation position, sufficient reinforcement is provided to the longitudinal strength member when installing the stool. There is a need. Therefore, it is necessary to reinforce the strength member in the longitudinal direction after waiting for the requirements of the production equipment for each project to be established, resulting in a problem that the construction period of the FPSO becomes long.

Even after the hull construction, the present invention can freely set / change the arrangement of the top side in the direction of the captain without performing reinforcement work, etc. Even if the arrangement or weight of the top side is changed, the design of the hull itself The purpose is to provide an offshore floating structure that does not affect the construction.

The offshore floating structure of the present invention is an offshore floating structure capable of mounting production equipment on the upper deck, and has a longitudinal partition wall extending in the longitudinal direction of the offshore floating structure and connected to the lower surface of the upper deck. The upper surface of the upper deck at a position where the upper side of the vertical partition wall is connected is a stool installation section on which a stool for supporting production equipment can be installed, and the vertical passage at the position where the stool installation section is provided The upper side of the partition is made of a steel material having a thickness of 25 mm or more.

The upper side of the longitudinal partition wall is made of high tensile steel, for example. The upper side of the longitudinal partition wall is made of, for example, the same material having a uniform thickness over the entire length of the area for mounting the production equipment. The upper side part of the longitudinal partition wall at the position where the stool installation part is provided is made of, for example, a steel material having a thickness of 30 mm or more. The plate width in the depth direction of the upper side portion of the longitudinal partition wall is, for example, 1 m to 4 m.

The offshore floating structure has a transverse hull strength member extending in the width direction of the offshore floating structure on the lower surface of the upper deck, and a vertical partition wall of a reinforcing portion of the horizontal hull strength member located below the stool installation portion The area around the connection is reinforced. The stool is a plate-like longitudinal stool strength member arranged along the longitudinal direction of the offshore floating structure in an upright state, and the width direction of the offshore floating structure in an upright state intersecting with the longitudinal stool strength member And a plate-like lateral stool strength member disposed along the length of the longitudinal stool strength member. The length of the longitudinal stool strength member is longer than the length of the lateral stool strength member.

The longitudinal stool strength member and the lateral stool strength member have an isosceles trapezoidal shape. For example, a flange is formed on the side connecting the upper side and the lower side of the longitudinal stool strength member and the lateral stool strength member having an isosceles trapezoidal shape. A face material is provided. The vicinity of the lower side edge of the longitudinal stool strength member has a soft toe shape that relieves stress concentration with respect to the hull longitudinal bending moment. The lower end portion of the face member provided on the transverse stool strength member has a repellent shape spreading in the longitudinal direction, and both ends thereof have a soft toe shape that relieves stress concentration against the hull longitudinal bending moment.

The height of the stool is 45% to 55% of the production deck height, and the space from the upper deck to the stool height is the piping area for the hull. Further, the lower end portion of the face material provided on the longitudinal stool strength member may be provided with a repellent shape portion exhibiting a repellent shape extending in the width direction of the offshore floating structure, and on the lower surface of the upper deck along the longitudinal partition wall. A backing member connected to the repellent portion of the face material provided on the longitudinal stool strength member may be provided at an intermediate position between two adjacent lateral hull strength members. A bracket member connected to the front and rear edges of the longitudinal stool strength member may be provided to relieve stress concentration on the hull longitudinal bending moment.

According to the present invention, even after the hull is constructed, the top side arrangement can be freely set / changed in the direction of the ship without performing reinforcement work, and even if the top side arrangement, weight, etc. are changed, the hull itself An offshore floating structure that does not affect the design or construction can be provided.

It is a top view of the upper deck of the offshore floating body structure which is one Embodiment of this invention. It is a cross-sectional view excluding the horizontal hull strength member of the offshore floating structure showing the configuration relating to the reinforcement of the longitudinal bulkhead of the offshore floating structure. It is a cross-sectional view of an offshore floating structure showing a configuration relating to reinforcement of a transverse hull strength member of the offshore floating structure. It is a side view which shows the state which mounted and installed the production equipment in the stool installed on the upper deck. It is the (a) side view, (b) front view, (c) top view of the stool used by this embodiment. It is a perspective view of the stool of this embodiment installed on the upper deck. It is a perspective view of the stool of the 1st modification which provided the flange-shaped face material in the side which connects the upper direction and lower side of a longitudinal direction stool strength member and a horizontal direction stool strength member. It is the side view and front view of the stool of a 2nd modification. It is a side view of the stool of a 3rd modification. It is a perspective view of the stool of a 3rd modification.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
FIG. 1 is a plan view of an upper deck of an offshore floating structure according to an embodiment of the present invention.

The offshore floating structure 10 of the present embodiment is, for example, FPSO, and produces oil and gas at a production facility 14 (see FIG. 4) provided on the upper deck 12 and stores the produced crude oil in a tank. It is a facility for loading into tankers. The production facility 14 is mounted in a plant installation area P provided on the upper deck 12 between the bow portion 10S and the living section 10A. Each of the production facilities 14 is supported by a stool 16 (see FIG. 2) installed on the upper deck 12. In the present embodiment, the stool 16 is connected to the lower surface of the upper deck 12 in accordance with the design of the production facility 14, and a longitudinal partition wall 18 and a transverse hull strength member (for example, a deck cross beam or a horizontal partition wall) 20 that support the stool 16. Is installed at the position where FIG. 1 schematically shows a longitudinal bulkhead 18 and a transverse hull strength member 20 under the upper deck 12 in a plant installation area (area for mounting production equipment) P.

FIG. 2 is a cross-sectional view of the offshore floating structure 10 showing a configuration relating to reinforcement of the longitudinal partition wall 18 of the offshore floating structure 10 in the present embodiment, and is a cross-sectional view excluding the horizontal hull strength member 20. is there. In the present embodiment, of the longitudinal bulkheads 18 below the upper deck 12, the upper side 18 </ b> A in the range of about 1 m to 4 m, more preferably about 1.5 m to 2 m below the upper deck 12 is the plant installation area P. Over the entire length, it is made of a steel material having a thickness of about 25 mm or more, more preferably about 30 mm or more. As the steel material, for example, high-tensile steel is adopted.

FIG. 3 is a cross-sectional view of the offshore floating structure 10 showing a configuration relating to reinforcement of the transverse hull strength member 20 of the offshore floating structure 10 in the present embodiment. The transverse hull strength member 20 is a deck cross beam or a horizontal bulkhead, and a deck cross beam is illustrated in FIG. In FIG. 3, the reinforcing portion 20 </ b> A of the transverse hull strength member 20 is indicated by a hatched area. The reinforcing portion 20A has a width including the bottom of the stool 16 within the range of about 1 m to 4 m, more preferably about 1.5 m to 2 m below the upper deck 12 in the lateral hull strength member 20 below the upper deck 12. The reinforcing portion 20A is made of a steel material having a thickness of about 25 mm or more, more preferably about 30 mm or more over the entire length of the plant installation area P. As the steel material, for example, high-tensile steel is adopted.

FIG. 4 is a side view showing a state in which the production equipment 14 is mounted / installed on the stool 16 installed on the upper deck 12. On the stool 16, for example, a gantry 22 is installed as a top side support, and a production deck 24 on which the production equipment 14 is mounted is installed via the gantry 22. In the present embodiment, the height h from the upper deck 12 of the stool 16 is 45% to 55% with respect to the height H from the upper deck 12 of the production deck 24, and from the upper deck 12 to the height of the stool 16. This space is a piping area for the hull. Note that the space between the top surface of the stool 16 and the production deck 24 is left as a space for use on the top side (production facility) side.

FIG. 5 is a (a) side view, (b) front view, and (c) plan view of the stool 16 used in the present embodiment. FIG. 6 is a perspective view of the stool 16 of the present embodiment installed on the upper deck 12. A more detailed configuration of the stool 16 of the present embodiment will be described with reference to FIGS.

As shown in FIG. 5, the stool 16 of the present embodiment includes a longitudinal stool strength member 160 and a lateral stool strength member 162 having an isosceles trapezoidal shape using, for example, a steel plate (the shape may be rectangular). ), Both stand vertically on the upper deck 12, and cross each other at the center. Further, a top plate 164 is provided at the top of the longitudinal stool strength member 160 and the lateral stool strength member 162 so as to cover them. That is, the gantry 22 or the like shown in FIG. 4 is installed on the top plate 164 by welding or the like so as to allow sliding.

The longitudinal stool strength member 160 is attached by welding or the like along the longitudinal partition wall 18, and the lateral stool strength member 162 is attached by welding or the like along the transverse hull strength member 20. It is done. In the present embodiment, the length L1 of the bottom side of the longitudinal stool strength member 160 is, for example, about 40% longer than the length L2 of the bottom side of the lateral stool strength member 162. Further, both ends of the bottom side of the lateral stool strength member 162 coincide with one position of the longitudinal rib 19 provided under the upper deck 12, for example.

FIG. 7 shows a first example in which flange-shaped

face members

166 and 168 are provided on the sides connecting the upper side and the lower side of the longitudinal stool strength member 160 and the lateral stool strength member 162 in the stool 16 of FIGS. A modification is shown. In the stool 16 of FIG. 7, the vicinity 160A of the side edge of the longitudinal stool strength member 160 has a soft toe shape that relaxes stress concentration with respect to the hull longitudinal bending moment (in the longitudinal bulkhead L.BHD direction) The stress relaxation part. In addition, the lower end portion of the face member 168 provided on the transverse stool strength member 162 has a repellent shape spreading in the longitudinal direction of the hull, and both ends of the repellent shape portion 168A are softening materials that reduce stress concentration against the vertical hull bending moment. It is a tow shape.

FIG. 8 is an enlarged view showing the structure of the stool according to the second modified example at the installation position, FIG. 8A is a side view along the longitudinal partition wall 18, and FIG. 8B is a horizontal hull. 3 is a front view along the strength member 20. FIG.

As shown in FIG. 8, in the second modification, a repellent repellent shape portion 166 </ b> A is also provided at the lower end portion of the face material 166 of the longitudinal stool strength member 160 in order to withstand a greater weight. That is, the repellent shape portion 166A is arranged along the hull width direction. In addition, a backing member 170 is provided on the lower surface of the upper deck 12 along the repellent shape portion 166A. That is, the repellent shape portion 166 </ b> A is connected to the backing member 170 through the upper deck 12. Here, in order to allow the stool 16 to be retrofitted to any stool installation part in the plant installation area P, two backing members are provided on the lower surface of the upper deck 12 in advance for each lateral hull strength member 20. 170 needs to be installed. However, in this modification, the length in the ship length direction of the stool 16 is made to coincide with the interval (transspace) T between the transverse hull strength members 20, and one backing member 170 is shared by the adjacent horizontal hull strength members 20. By doing so, the number is halved.

Next, an enlarged side view and a perspective view showing a structure of the third modified example at the installation position of the stool are shown in FIGS. 9 and 10, respectively.

In the second modification, the stool can withstand a greater weight by providing a repellent shape portion 166A also at the lower end portion of the face material 166 provided on the longitudinal stool strength member 160 along the longitudinal partition wall 18. However, in such a structure, stress concentration occurs with respect to the longitudinal bending moment of the hull in the vicinity of the repellent shape portion 166A, and the strength of the stool 16 itself may not satisfy the requirement. Therefore, in the third modified example, in addition to the configuration of the second modified example, the lower front edge (front side) and the lower rear edge (rear side) of the longitudinal stool strength member 160 are Then, a bracket member 172 having a soft toe shape that relieves stress concentration is connected to form a stress relieving portion.

As described above, according to the present embodiment, the longitudinal partition wall on which the stool can be installed is reinforced in advance, so that the top side can be arranged in the ship's direction without performing reinforcement work after the hull construction. It can be freely set / changed, and even if the top side arrangement, weight, etc. are changed, there is no impact on the design and construction of the hull itself. Therefore, it is possible to prevent the hull construction period from being delayed due to the design change on the top side.

In this embodiment, the degree of freedom of stool installation is also increased by reinforcing the periphery of the connecting portion of the transverse hull strength member that intersects the longitudinal bulkhead in the plant installation area.

Further, in the present embodiment, the hull is divided between the upper deck and the production deck with the lower side as a space for hull piping and electric wire laying and the upper side as a space used for the top side with the top surface of the stool as a boundary. Piping and wire laying design and construction are not affected by changes in the top side, and delays in the hull construction period can be prevented more reliably.

In addition, in the stool placed on the upper deck, the hull longitudinal bending moment greatly affects the strength of the stool, but in this embodiment, the longitudinal stool strength member has a soft toe shape to alleviate stress concentration, and the hull. The influence of the longitudinal bending moment can be reduced.

In this embodiment, the upper side of the longitudinal bulkhead is configured to be uniformly reinforced over the entire length of the plant installation area, but the longitudinal bulkhead reinforcement is similar to the reinforcing portion of the transverse hull strength member. It is also possible to adopt a configuration that is performed only in the vicinity of the connecting portion of the intersection. In addition, the relationship of the length between the longitudinal direction stool strength member and the horizontal direction stool strength member applied to the stool of FIGS. 5 and 6 can be applied to each modification. Moreover, the soft tow shape demonstrated in the modification can also be applied to the end of the longitudinal stool strength member of the stool shown in FIGS.

From the viewpoint of giving sufficient strength to the vertical bending moment of the offshore floating structure to the stool that supports the production equipment installed on the upper deck of the offshore floating structure, a stool having the following configuration is used. It is considered as an invention.

A stool according to the first invention is a stool for mounting production equipment on an upper deck on an offshore floating structure, and is a plate-like shape installed along the longitudinal direction of the offshore floating structure in an upright state. A longitudinal stool strength member, and a plate-like lateral stool strength member installed along the width direction of the offshore floating structure in an upright state intersecting with the longitudinal stool strength member. And the length of the upper side and the lower side of the horizontal stool strength member is the same, or the upper side is shorter than the lower side, and a face material is provided in a flange shape on the side connecting the upper side and the lower side, and the surface provided on the horizontal stool strength member The lower end of the material has a repellent shape that exhibits a repellent shape spreading in the longitudinal direction, and both ends of the repellent shape have a soft tow shape that relieves stress concentration against the hull longitudinal bending moment It is.

The stool related to the second invention is the stool according to the first invention, wherein the stool has a soft tow shape in the vicinity of the lower side edge of the longitudinal stool strength member to reduce stress concentration against the hull longitudinal bending moment. Is provided.

A stool according to a third invention is the stool according to the second invention, wherein the stress relaxation portion includes a bracket member connected to a front edge and a rear edge of the longitudinal stool strength member.

The stool according to the fourth invention is characterized in that in the stools of the first to third inventions, the length of the longitudinal stool strength member is longer than the length of the lateral stool strength member.

A stool according to a fifth invention is the stool according to the first invention, wherein the lower end portion of the face material provided on the longitudinal stool strength member has a repellent shape portion exhibiting a repellent shape extending in the width direction of the offshore floating structure. A backing member connected to a repellent shape portion of a face material provided on a longitudinal stool strength member at a middle position between two adjacent lateral hull strength members on the lower surface of the upper deck along the longitudinal bulkhead Is provided.

DESCRIPTION OF SYMBOLS 10 Offshore structure

10A Residential division

10S Bow part 12 Upper deck 14 Production equipment 16 Stool 18 Longitudinal bulkhead 18A Upper side part 19 Longitudinal rib 20 Lateral hull strength member 20A Reinforcement part 22 Base 24 Production deck 160 Longitudinal stool strength member 162 Horizontal stool strength member 164

Top plate

166, 168 Face material 170 Backing member 172 Bracket member

Claims

An offshore floating structure that can be equipped with production equipment on the upper deck,
A longitudinal partition wall extending in the longitudinal direction of the offshore floating structure and connected to the lower surface of the upper deck;
The upper surface of the upper deck at a position where the upper side portion of the longitudinal bulkhead is connected is a stool installation portion capable of installing a stool for supporting the production facility,
An offshore floating structure characterized in that the upper side portion of the longitudinal partition wall at the position where the stool installation portion is provided is made of a steel material having a thickness of 25 mm or more.
The offshore floating structure according to claim 1, wherein an upper side portion of the longitudinal partition wall is made of high-tensile steel.
The upper side portion of the longitudinal partition wall is made of the same material having a uniform thickness over the entire length of the area for mounting the production facility. The offshore floating structure described.
The offshore floating structure according to any one of claims 1 to 3, wherein an upper side portion of the longitudinal partition wall at a position where the stool installation portion is provided is made of a steel material having a thickness of 30 mm or more. object.
The offshore floating structure according to any one of claims 1 to 4, wherein a plate width in a depth direction of an upper side portion of the longitudinal partition wall is 1 m to 4 m.
A transverse hull strength member extending in the width direction of the offshore floating structure on the lower surface of the upper deck; and the longitudinal bulkhead of the reinforcing portion of the horizontal hull strength member positioned below the stool installation portion; The offshore floating structure according to any one of claims 1 to 5, wherein the periphery of the connecting portion is reinforced.
A plate-like longitudinal stool strength member disposed along the longitudinal direction of the offshore floating structure in an upright state, and the offshore floating structure in an upright state intersecting the longitudinal stool strength member And a plate-like lateral stool strength member arranged along the width direction of the object, wherein the length of the longitudinal stool strength member is longer than the length of the lateral stool strength member. Item 7. The offshore floating structure according to any one of Items 1 to 6.
The longitudinal stool strength member and the lateral stool strength member have an isosceles trapezoid shape, and a flange shape is formed on a side connecting the upper side and the lower side of the longitudinal stool strength member and the lateral stool strength member exhibiting an isosceles trapezoid shape. The offshore floating structure according to claim 7, wherein a face material is provided on the surface.
The offshore portion according to any one of claims 7 to 8, wherein the vicinity of the lower side edge of the longitudinal stool strength member has a soft tow shape that relieves stress concentration against a hull longitudinal bending moment. Floating structure.
The lower end portion of the face material provided on the transverse stool strength member has a repellent shape that spreads in the longitudinal direction, and both ends thereof have a soft toe shape that relieves stress concentration against a hull longitudinal bending moment. The offshore floating structure according to any one of claims 8 to 9, wherein
2. The height of the stool is 45% to 55% with respect to the height of the production deck, and a space from the upper deck to the stool height is a piping area for a hull. The offshore floating structure according to any one of 1 to 10.
The lower end portion of the face material provided on the longitudinal stool strength member includes a repellent shape portion exhibiting a repellent shape extending in the width direction of the offshore floating structure, and is provided on a lower surface of the upper deck along the longitudinal partition wall. A backing member connected to the repellent shape portion of the face material provided on the longitudinal stool strength member is provided at an intermediate position between two adjacent lateral hull strength members. Item 9. A floating structure on the ocean according to Item 8.
The offshore floating structure according to claim 12, further comprising a bracket member connected to a front edge and a rear edge of the longitudinal stool strength member to relieve stress concentration with respect to a hull longitudinal bending moment.