JPS63227489A - Method and device for mooring off-shore structure - Google Patents

Abstract

PURPOSE:To simplify a work to mount and demount a mooring stay, by a method wherein 8 mooring stay is formed with two stays with a universal joint therebetween, the upper stay is inserted into an off-shore structure introduction hole, and the lower stay is locked to a hook by means of a rope, serving as a guide and locked to the down hook with a guide of a template. CONSTITUTION:An introduction hole 6 is formed in a leg 5 of a tension leg off-shore structure 1 for oil excavation and the like, a down hook 14 having an arcuate guide member 15 is situated to a template 3 installed on a sea bottom, and a rope 17 provided at its tip with a buoy 16 is provided. A mooring stay 4 is formed with two stays with a universal joint 9 therebetween, and an upper stay 7 is inserted into the introduction hole 6. A lower stay 8 is mounted to a down hook 14 through an arcuate guide member 15 by means of the rope 17, serving as a guide, in a state to insert an annular metal 11 outwardly of the rope 17. This method and constitution enables simplification of a work to mount and demount the mooring stay.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method and apparatus for mooring offshore structures such as tension leg platforms for oil drilling installed in the ocean.

[Conventional technology]

For example, a tension leg platform for oil drilling installed in the ocean, as shown in a schematic perspective view in FIG.
A platform 1 on which various equipment and equipment such as an excavation turret and a crane are mounted is moored to a template 3 set on the seabed 2 using multiple supports 4 called Tendons. It will be done.

The depth of the sea area in which such a platform is installed is generally 100 m or more. Therefore, conventionally, the pillar 4
The column was constructed of a plurality of tubes each having a length of about 10 m, and the support column was attached by connecting the plurality of tubes to each other with threaded joints.

[Problem that the invention seeks to solve]

As mentioned above, the installation of the struts 4 for mooring the platform 1 to the template 3 on the seabed 2 has conventionally been done by connecting multiple pipes, so the work is not easy and requires a lot of effort for installation. It takes 4-5 days to
The deeper the water is, the longer it will take in stormy weather.

Therefore, installing the support pillar 4 requires a large amount of expense, and until the installation of the support support 4 is completed, the platform l will be floating in an unstable state on the sea surface, which is extremely expensive. It was dangerous. Such a problem is caused by the need to move the installed platform 1 on the seabed 2.
The same applies when removing the strut 4 moored to the template 3 above. Therefore, an object of the present invention is to easily and quickly attach and remove the strut for mooring the platform to the template on the seabed. The object of the present invention is to provide a method and apparatus for mooring marine structures that can be carried out reliably and economically.

[Means for solving problems]

The present invention provides a method for mooring a marine structure, which comprises mooring a platform to a template installed on the seabed with a support, in which a vertical guide hole is provided in a column of the platform, and the support is connected to the guide hole. an upper tube to be inserted; and a lower tube having a length from the lower end of the column to the template and having an annular connecting fitting at the other end, one end of which is connected to the upper tube through a flexible joint. and attaching a rope having a guide at the tip to a downward hook-shaped hook having an arcuate guide member and provided on the template;
The upper tube of the support is inserted into the guide hole provided in the column of the platform, the upper part thereof is locked to the upper end of the guide hole, and the other end of the lower tube of the support is connected in an annular manner. The present invention is characterized in that the metal fitting is hooked to the downward hook-shaped hook provided on the template through the rope.

Next, the present invention will be explained with reference to the drawings.

1 to 3 are explanatory diagrams showing one embodiment of the present invention, and FIG. 4 is a front view of a support column used in the present invention. As shown in the drawings, in the present invention, a column 5 of a platform 1 is provided with a vertical guide hole 6 of a predetermined height. The column 4 has an upper tube body 7 that is inserted into the guide hole 6 and has approximately the same length as the guide hole 6, and a lower end of the column 5, one end of which is connected to the upper tube body 7 via a flexible joint 9. A lower tube body 8 having a length extending from to the template 3
It consists of A screw lO is carved into one end of the upper tubular body 7, and an annular connecting fitting 11 is attached to the other end of the lower tubular body 8. The other end of the lower tubular body 8, which becomes the lower part and which is hooked on the template 3, is thicker and heavier than the one end which becomes the upper part. A rope 13 having a buoy 12 at its tip is attached to the annular connecting fitting 11 of the lower tube body 8.

The pillar 4 having such a structure is manufactured in a factory, a floating body is attached to it, and then towed over the sea to the site. At this time, the rope 13 attached to the annular connection fitting 11 is also used as a tow rope.

A downward hook-shaped hook 14 is provided at the location where the template 3 installed on the seabed 2 is attached to the support. An arc-shaped guide member 15 centered on the upper end of the lower tube body 8 is attached to the tip of the downward hook-shaped hook 14 .

A rope 1 having a buoy 16 is attached to the tip of the guide member 15.
7 is installed.

[Effect]

The support column 4 is towed to the mooring position of the platform and the floating body is removed. Next, a rope 18 is attached to one end of the upper tube body 7 where the screw 10 is cut, and as shown in FIG. 1, the rope 18 is passed through the guide hole 6 provided in the column 5 of the platform 1. Its upper end is attached to a winch 19 provided at the top of the column 5.

By winding the rope 18 onto the winch 19, the upper tube 7 of the strut 4 is inserted into the guide hole 6 of the column 5. Next, as shown in FIG.
Screw the inverted U-shaped locking fitting 20 onto the
Attach to the upper end of the

Then, the annular connecting fitting 11 attached to the other end of the lower tubular body 8 is inserted through the rope 17 attached to the guide member 15 of the hook-shaped hook 14 of the template 3. As a result, the annular connecting fitting 11 at the other end of the lower tube body 8 is connected to the rope 1
7 and is inserted into the hook-shaped hook 14 of the template 3 while being guided by its guide member 15. In addition, at the time of the above-mentioned operation, the platform 1 is preliminarily settled to some extent by introducing glast water into a palast tank (not shown) provided in the column 5.

In this way, the upper tube 7 of the support column 4 is locked to the upper end of the guide hole 6 provided in the column 5, and the annular connecting fitting 11 of the lower tube 8 is inserted into the hook-shaped hook 14 of the template 3. After that, the pantyhose water in the noglast tank provided in the column 5 is discharged.

As a result, the platform 1 rises and tension is applied to the column 4, so that the annular connecting fitting 11 of the lower tube body 8 is connected to the hook-shaped hook 14 of the template 3, as shown in FIG.
It is hung on. Note that the tension of the support column 4 can be adjusted by a locking fitting 20 screwed onto the upper tube body 7. Low! The upper end of 13° 17 is attached to platform 1.

The platform 1 is thus moored to the template 3 on the seabed 2 by the struts 4.

Although only one pillar 4 is shown in the drawing, typically 12 to 24 pillars 4 are provided on one platform.

When the support column 4 is removed in order to move the platform 1, water is poured into the parast tank of the platform 1 to settle the platform 1 to some extent, and the upper end of the rope 13.17 is connected to the platform 1.
Remove from.

Next, the locking fitting 20 is removed to separate the upper tubular body 7 from the guide hole 6 of the column 5, and the rope 13 attached to the annular connecting fitting 11 of the lower tubular body 8 is operated to remove the annular connecting fitting 11. , pass the rope 17 through the hook-like hook 14 of the template 3 and remove it.

Thus, the strut 4 connects the platform l and the seabed 2
can be easily removed from template 3.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to easily, reliably, and economically perform the installation and removal of struts for mooring a platform to a template on the seabed in a short period of about one day. Excellent effects are brought about.

[Brief explanation of drawings]

1 to 3 are explanatory diagrams showing one embodiment of the present invention, FIG. 4 is a front view of a support column used in this invention, and FIG.
The figure is a schematic perspective view of the tensioning platform. In the drawings: 1... Platform, 2... Seabed, 3
... Template, 4... Support, 5... Column, 6... Guide hole, 7... Upper pipe body,
8... Lower pipe body, 9... Flexible joint, IO... Screw s 11... Annular connection fitting, 12.16... Gui, 13.17.1
8... Rope, 14... Hook-shaped hook, 15... Guide member, 19... Winch, 20... Locking metal fitting.

Claims (2)

[Claims] (1) A method for mooring a marine structure, which comprises mooring a platform to a template installed on the seabed with a support, in which a vertical guide hole is provided in the column of the platform, and the support is connected to the guide hole. an upper tube body inserted into the upper tube body; and a lower tube having a length from the lower end of the column to the template and having an annular connecting fitting at the other end, one end of which is connected to the upper tube body via a flexible joint. A rope having a buoy at the tip is attached to a downward hook-shaped hook having an arcuate guide member provided on the template, and the upper tube body of the support is provided on the column of the platform. The rope is inserted into the guide hole, and its upper part is locked to the upper end of the guide hole. A method for mooring a marine structure, characterized by latching it to a hook-shaped hook. (2) A guide hole provided vertically in the column of the platform, a downward hook-shaped hook with an arcuate guide member provided in the template on the seabed, and a flexible joint at the lower end of the upper tube and the upper tube. a lower tube body connected by a column, and an upper tube body of the column is inserted into a guide hole of the column, and its upper part is locked to the upper end of the slot; The mooring device for a marine structure is characterized in that the platform is moored to the template by hooking a lower end of the lower tube of the support to a hook-like hook of the template.