KR20100008437A - Apparatus for roll damping of offshore platform - Google Patents

Abstract

PURPOSE: A damping apparatus for the rolling of an offshore platform is provided to damp the rolling of the offshore platform by installing a vortex suppressing member. CONSTITUTION: One or more columns(110) support a deck(102) of an offshore platform and an upper structure(104). A pontoon(120) connects the columns. The pontoon provides the buoyancy of the fixed level. A vortex suppressing member(130) is installed along the outer circumference of each column. The vortex suppressing member reduces vortex inducing exercise. One or more holes with different diameters are formed on the plate of the vortex suppressing member.

Description

APAPATUS FOR ROLL DAMPING OF OFFSHORE PLATFORM}

The present invention relates to an oscillation damping device of an offshore platform, and more particularly, in the case of an offshore platform having a plurality of columns of deep draft, vibration may occur due to an algae environment. Relates to a device.

Operations for offshore oil and gas drilling and production require drilling, production and storage equipment, and worker-residential facilities, which are sometimes required to have hulls or platforms called "rigs."

In general, offshore platforms use one of two types: "fixed" and "floating" platforms.

The stationary platform consists of an equipment deck supported by a support angle placed directly or indirectly on the sea floor. While they are relatively stable, a so-called compliant piled tower (CPT), also called a "baldpate" tower, can typically be installed at depths of 1648 feet (about 500 m), however. They are limitedly installed at relatively shallow depths, that is, at depths of about 500 feet (about 152 m).

Floating platforms, on the other hand, are typically used at depths of more than about 500 feet (about 152 m) and are wells by mooring lines fixed to the sea floor or by power thrusters arranged on one or both sides of the platform. The location is fixed on the site. Although floating platforms are complex to install because of their movement under wind or marine conditions, they can be installed at deeper depths than fixed platforms and are more mobile and easier to move to other wells. Has Conventional floating platforms include the so-called "drill ship", "semi-submersible" and "spar-type platforms" and "tension-leg platforms (TLP)". There are several forms, including.

1 is a perspective view of a conventional deep draft semi-submersible platform causing vortex organic movement at a deep draft.

Four columns 20 supporting the deck 10 and the superstructure 12 are installed vertically. And a pontoon (pontoon: 30) for interconnecting the four adjacent columns 20 is installed.

The pontoon 30 is for submerging the water under water to provide a buoyancy of a predetermined size.

However, in the deep-drain semi-submersible platform used for oil / gas exploration, drilling, production, storage, and gas incineration, a relatively thin and elongated column is vibrated by the algae environment, thus improving the operational efficiency of the entire offshore platform. There was a problem of deterioration.

For example, a plurality of columns may be relatively complicated to handle compared to other types of platforms in terms of their balance and stability control during offshore installation under certain conditions. In particular, because of their long and slender shape, it is easy to cause Vortex Induced Motion due to strong algae.

Vortex-induced motion is caused by the action of an external force opposite to the direction of incidence of the tidal current on the structure due to the vortices that occur at regular intervals in the rear of the column when a tidal flow of relatively constant velocity is incident on the column of the structure. Say exercise. Near the water surface where wave particle motion is relatively large, vortex-induced motion is relatively low for columns with relatively low draft because the wave particle motion is disturbed due to disturbed wave motion of tidal currents. Although it may not be a big problem, in particular, the structure having a plurality of columns with a deep draft of 40 m or more has a small size of the particle movement so that the algae incident flow is hardly disturbed, and the vibration caused by the algae is generated, thereby operating efficiency of the entire offshore platform. Will lower.

Therefore, in the present invention, by installing the vortex suppression member having a plurality of circular holes of different sizes along the vertical outer circumferential surface of each column, the normal algae movement incident at a constant speed through a plurality of holes formed in the vortex suppression member It is an object of the present invention to provide a sway damping device for a marine platform that can disturb the vortices as much as possible and thus attenuate the vortex-induced motion.

In order to achieve the above object, the present invention, in the oscillation damping device of the offshore platform, one or more columns supporting the deck and the upper structure of the offshore platform, normal algae movement is installed along the outer peripheral surface of each column incident at a constant speed To provide a disturbance damping device of the offshore platform including a vortex inhibiting member that can attenuate the vortex as much as possible to attenuate the vortex-induced movement by disturbing the regular vortex generation.

And the vortex suppression member is preferably formed with one or more holes of different diameters on a flat plate.

In addition, the vortex suppressing member is provided spirally along the axial edge of each column, characterized in that the asymmetric in the up, down, left, right direction.

In addition, the vortex suppression members of the columns facing in the diagonal direction are arranged to face in the same direction, and the vortex suppression members of the neighboring columns are arranged to face in the opposite direction to each other. That is, the vortex suppression member installation position between each column is characterized in that the asymmetric in the up, down, left, right direction.

As described above, according to the vibration damping device of the offshore platform in the present invention, the fluctuation of the overall offshore platform by providing a vortex suppressing member that can suppress the vortex induction movement on the outer peripheral surface of each vertical column corresponding to the lower structure By attenuating the effect of increasing the production efficiency.

Hereinafter, the operating principle of the present invention will be described in detail with reference to the accompanying drawings. In the following description of the present invention, when it is determined that a detailed description of a known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted. Terms to be described later are terms defined in consideration of functions in the present invention, and may be changed according to intentions or customs of users or operators. Therefore, the definition should be made based on the contents throughout the specification.

Figure 2 is a front view of the shaking damping device of the offshore platform according to an embodiment of the present invention, Figure 3 is a perspective view of the offshore platform according to an embodiment of the present invention, Figure 4 is a marine according to an embodiment of the present invention This is a cross-sectional view showing the flow of vortices according to the platform damping device.

The marine platform 100 shown in FIGS. 2-3 is vertically provided with a deck 102 and an upper structure 104, commonly called decks, and a column 110 corresponding to the lower structure supporting them. . Column 110 is preferably three to four in the cylindrical or polygonal installation, a pontoon (pontoon: 120) for interconnecting these columns (110) is installed.

The pontoon 120 is to submerge in the water under water to provide a buoyancy of a predetermined size.

A vortex suppressing member 130 is provided which can attenuate the vortex induced motion by disturbing the regular vortex generation by disturbing the normal algal motion that is incident at a constant speed to the column 110 of the platform 100.

The eddy current suppression member 130 may be formed of a material that can withstand water pressure or a strong current, and is made of a flat square plate shape, and one or more holes 132 having different diameters are formed on the plate shape.

Vortex suppression member 130 is installed so that a large area along the axial outer circumferential surface of each column 110 to strike the algae, preferably along the corner portion in the clockwise or counterclockwise direction from the upper side of the column 110 It is installed spirally so as to be asymmetric in the up, down, left and right directions. And the vortex suppression members 130 of the column 110 facing in the diagonal direction as shown in each of the cross-sectional view in FIG. 4 are arranged to face the same direction, the vortex suppression members 130 of the neighboring column 110 is It is arranged to face in opposite directions to each other. Therefore, the installation position of the vortex suppression member 130 between the respective columns 110 is preferably asymmetric in the up, down, left and right directions.

The function of the attenuation damper of the offshore platform having such a structure is as follows.

Floating offshore platforms 100, such as "deep draft semi-submersible" and "tension-leg platform (TLP)" and "spar platform" Vortex-induced movement (VIM) is generated during towing or strong algae with a plurality of column 110 structures having drafts.

Therefore, in the present invention, the vortex-induced movement is suppressed to the maximum through the vortex suppressing members 130 installed in each column 110, thereby attenuating the fluctuation of the entire offshore platform 100.

That is, as shown in FIG. 4, the vortex suppressing members 130 of the columns 110 are formed to be asymmetric in the up, down, left, and right directions along the edges of each column 110, and face each other in a diagonal direction. ) Are disposed to face in the same direction, and the vortex suppression members 130 of the neighboring columns 110 are arranged to face in opposite directions, so that vortices occur even in which direction the algae are incident in each column 110. This can be suppressed. In particular, in the vortex suppressing member 130, the normal tidal current incident at a constant speed is disturbed to the maximum while passing through the plurality of holes 132, so that the normal vortex that can generate vibration can be broken to reduce the vortex inducing motion.

Here, the plurality of holes 132 are formed to have different diameters, which is advantageous to disintegrate normal algae rather than holes of a predetermined diameter. Furthermore, the vortex suppression member 130 is spirally installed to form asymmetry in each column 110. It is advantageous to disturb.

Therefore, when the offshore platform 100 having the lower structure of the deep draft multiple column 110 is towed at a constant speed or a tidal current of a constant speed is continuously incident, regular left due to the vortices occurring behind the column 110 is caused. In addition, the wobbling motion can be substantially attenuated or removed through the vortex suppression member 130.

What has been described above is just one preferred embodiment of the oscillation damping device of the offshore platform according to the present invention, the present invention is not limited to the above embodiment, as claimed in the following claims of the present invention Without departing from the gist of the present invention, one of ordinary skill in the art will have the technical spirit of the present invention to the extent that various modifications can be made.

1 is a perspective view of a conventional semi-submersible platform,

Figure 2 is a front view of the shaking damping device of the offshore platform according to an embodiment of the present invention,

3 is a perspective view of an offshore platform according to one embodiment of the invention,

Figure 4 is a plan sectional view showing the flow state of the vortex according to the shaking damping device of the offshore platform according to an embodiment of the present invention.

<Description of the symbols for the main parts of the drawings>

100: offshore platform 102: deck

104: upper structure 110: column

120: pontoon 130: vortex control member

132: hall

Claims (5)

In the fluctuation damping device of offshore platform, At least one column supporting the deck and superstructure of the offshore platform; Vortex suppression member installed along the outer circumferential surface of each column to disturb the normal algal motion incident at a constant speed as much as possible so as to attenuate the vortex induced motion by interrupting regular vortex generation Shaking damping device of the offshore platform comprising a. The method of claim 1, The vortex suppressing member is a vibration damping device of the offshore platform is formed with one or more holes of different diameters on a flat plate. The method of claim 1, The eddy current suppressing member, Spiral damping device of the offshore platform characterized in that the spirally installed along the axial edge of each column, asymmetric in the up, down, left, right direction. The method of claim 1, The vortex suppression members of the column facing in a diagonal direction are disposed to face in the same direction with each other, and the vortex suppression members of the neighboring columns face in opposite directions to each other. The method of claim 1, Wherein the vortex suppression member installation position between the columns are asymmetric in the up, down, left, right direction each other, characterized in that the shaking platform of the offshore platform.

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