KR20150070513A - Anti-heave device for Semi-submersible Drilling Rig - Google Patents

Abstract

The present invention relates to a device to stabilize the pitching of a semi-submersible oil prospecting ship. The device is installed on a plurality of columns standing on an upper part of a pontoon included in a semi-submersible oil prospecting ship but the device protrudes from both sides of the columns to be placed at an operation water plane height of the semi-submersible oil prospecting ship and comprises a plurality of sub tanks to inject or discharge sea water, and therefore, more stable drilling work is enabled in an ocean environment with big waves and preparatory buoyancy is secured by adding a ballast tank function.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semi-submersible drilling rig,

The present invention relates to an up-and-down rocking stabilizing device for installing a semi-submersible drilling rig. More specifically, the sub-submersible drilling rig is provided with a plurality of sub- The present invention relates to an up-and-down rocking stabilization device for a semi-submersible drilling rig capable of securing pre-buoyancy through ballast tanks as well as reduction of heave.

In general, a drill ship is a vessel for collecting crude oil or gas from the ocean, and refers to a special ship capable of performing drilling operations in the deep sea region or in the sea where the waves are severe.

These drilling rigs are one of the advanced vessels for developing deep-sea oilfields, which are equipped with a crude drilling facility in the hull to extract and refine deep-sea crude oil.

Therefore, the drill ship is a high-tech ship, and is equipped with various advanced equipments such as Derrick (pylon) which can install a pipe for deep drilling in the deep sea.

These drill ships can be broadly classified into general drill-ship types and semi-submersible drilling rigs.

The semi-submersible drilling rig is intended to drill crude oil in deep-sea deep-sea areas. Unlike general ship structure, the submerged drill ship submerges below the water surface to minimize the effects of waves, Which has a number of column structures that can be less affected by the impact.

As shown in FIG. 1, the drill line includes a pontoon 100 that is submerged below the water surface, a plurality of columns 110 that are installed on the upper part of the Puntung 100, A deck 130, and a drilling rig 150.

Therefore, the semi-submersible drill ship is a ship that can float crude oil while minimizing the influence of waves in the state that Floun (100) keeps floating in the sea while it is locked under water.

However, this semi-submersible drilling rig is better than the ship-type drilling rig in the rough sea environment, but since there is no separate device for reducing and stabilizing the heave, the drilling operation causes deterioration of the marine environment The drilling operation has to be stopped frequently, and there has been a problem that the loss due to the incapability of operation is increased.

In addition, semi-submersible drill ships have a relatively small height of heave compared to general merchant ships. However, due to their structural characteristics, the total displacement is small and it is difficult to secure the reserve buoyancy corresponding to the variable deck load.

Conventionally, there is a method of enlarging the column or the Punchun itself in order to reduce the up-and-down shake or to increase the buoyancy. However, this method has a problem that the price increases greatly.

Korean Patent Publication No. 10-2011-0024681 (Mar. 3, 2011)

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and it is an object of the present invention to provide a plurality of columns, which are installed on both sides of a plurality of column outer circumferential surfaces of a semi-submersible drilling rig, By adding the upper and lower rocking stabilization devices made of tanks, it is possible to facilitate the reserve buoyancy by the function of the ballast tanks as well as to reduce the up-and-down movement by enlarging the outer shape of the column at the water surface (surface where the sea surface and the column meet) And an auxiliary pin is added to the lower side of the tank to increase the vertical sway reducing effect.

In order to achieve the above object, according to the present invention, an up-and-down rocking stabilization device is installed in a plurality of columns installed on the upper part of Puntung which is provided in a semi-submersible drilling rig, And a plurality of auxiliary tanks protruding from both sides of the outer circumferential surface of the column and capable of injecting or discharging seawater therein.

The auxiliary tank may be installed on both sides of the outer circumferential surface of the column so as to be symmetrical in the transverse direction.

Further, the column may further include an auxiliary pin spaced downwardly from the auxiliary tank and projecting laterally so as to be submerged below the sea surface.

As described above, according to the present invention, by using a large number of auxiliary tanks and auxiliary pins installed on both sides of the column outer peripheral surface of a semi-submersible drill rig, it is possible to easily reduce the up- There is an effect that stable drilling can be performed in a severe marine environment.

1 is a schematic structural view of a general semi-
FIG. 2 is a schematic structural view of a semi-submersible drilling rig equipped with a vertical rocking stabilizer of the present invention;
3 is a top view of a column provided in the semi-
FIG. 4 is a schematic structural view of a semi-submersible drill rig equipped with another embodiment of the up-and-down rocking stabilizer according to the present invention,
5 is a perspective view of the auxiliary tank and the auxiliary pin shown in FIG.

Hereinafter, the present invention will be described in detail with reference to the drawings.

First, the structure of a semi-submersible drilling rig will be briefly described with reference to FIG.

1 is a schematic structural view of a general semi-submersible drilling rig.

1, the semi-submersible drilling rig comprises a pontoon 100, a column 110, an upper hull 130, and a drilling rig 150. As shown in FIG.

The Punctun 100 is used to create buoyancy so that the drilling line can float on the sea. The two are installed parallel to each other in parallel, and when drilling, they are completely submerged under the water to minimize the resistance by waves Section.

Therefore, the interior of the Punctun 100 is made up of a number of tanks that can be filled with seawater. Most of these tanks consist of ballast tanks that can be used to control buoyancy and balance the drilling lines. have.

Though not shown, a plurality of thrusters are installed as a propulsion unit below the Pultun 100.

Meanwhile, the column 110 serves to support the upper deck 130, and is divided into a plurality of sections in order to minimize the influence of waves. The inside of the column 110 is made of a ballast tank, a storage tank, or the like.

Herein, the column 110 is typically installed on each of the Puntun's 100 at two to four.

On the other hand, the upper deck 130 is equipped with various facilities required for drilling such as Moonpool, derrick, etc., a work space, a residence for crew members, and the like.

Thus, semi-submersible drilling rigs are able to drill crude oil while the influence of waves is minimized in the deep-sea region where the Punchun (100) and the column (110) are partially submerged in seawater.

However, semi-submersible drilling rigs are required to perform the oil drilling work while receiving the influence of the waves continuously. Therefore, continuous waves are generated by the rough waves, and it is not easy to secure sufficient reserve buoyancy due to the structural characteristics.

Therefore, in the present invention, the up-and-down rocking stabilizer 50 is attached to the plurality of columns 110 to ensure sufficient reserve buoyancy and to reduce the up-and-down rocking.

Hereinafter, the up-and-down rocking stabilizer of the present invention will be described in detail with reference to FIGS. 2 and 3. FIG.

FIG. 2 is a schematic structural view of a semi-submersible drill rig equipped with the up-and-down rocking apparatus of the present invention, and FIG. 3 is a plan view of a column provided in the semi-submersible drill rig of FIG.

The semi-submersible drill rig shown in FIG. 2 is schematically shown for convenience of explanation.

As shown in the figure, the up-and-down rocking stabilizer 50 of the present invention is installed on the outer circumferential surface of the column 110 provided on the top of Puntunt 100 of semi-submersible drilling rig.

The upper and lower stabilization device 50 includes a plurality of auxiliary tanks 10, 20, and 30 installed on the outer circumferential surface of each column 110, respectively.

The auxiliary tanks 10, 20 and 30 are connected to the respective columns 110 (see FIG. 2) so as to be located at the operating water surface (the surface where the sea surface and the column meet) during the drilling operation of the semi-submersible drilling rig ) On both sides of the outer circumferential surface.

At this time, the auxiliary tanks 10, 20 and 30 are provided at the same height so as to be positioned on the operating water surface S1 of each column 110, so that the auxiliary tanks 10, 20 and 30 are symmetrically disposed in the respective columns 110, Is installed.

Here, the operation water surface S1 represents the position of the sea surface during the drilling operation of the drill ship.

Meanwhile, the auxiliary tanks 10, 20, and 30 may be formed of a closed tubular body having a rectangular cross-sectional shape with a predetermined length.

Here, the auxiliary tanks 10, 20, and 30 may be welded to the column 110, and the auxiliary buoyant force may be appropriately adjusted so as to effectively reduce the vertical buoyancy, You will have to choose the size.

At this time, the auxiliary tanks (10, 20, 30) serve as a ballast tank by injecting or discharging seawater to the inside by using a pump (not shown) separately installed in the column 110.

Therefore, the auxiliary tanks 10, 20, and 30 are positioned on the operation water surface S1 so that the water surface where the sea surface and the column 100 meet increases by enlarging the outer shape of the column 110, And the seawater is selectively injected or discharged to secure reserve buoyancy.

In general, the state of a drill ship at sea is classified into an operating draft when a conventional drilling operation is performed and a survival condition when an offshore deterioration occurs.

In this case, the drill ship will be in a survival condition that floats above the sea level in case of worsening of the sea due to deterioration of the sea.

Therefore, the drilling line is located at a relatively higher level than the survival waterline S2 corresponding to the survival condition, which corresponds to the operating draft at the drilling operation.

In this case, as the water surface at which the sea surface and the column 110 meet at the drilling operation is larger, the effect of reducing the vertical vibration is increased. In addition, when the sea surface is deteriorated due to aggravation, The smaller the surface, the lower the vertical and horizontal yoga.

Therefore, the auxiliary tanks 10, 20 and 30 of the present invention are located on the operation water surface S1 during the drilling operation and are located above the survival water surface S2 in the survival condition.

That is, according to the present invention, when drilling the drill ship, the drill is located on the operation water surface S1 to reduce the vertical sway by increasing the water surface, and when the water is heavy, So that there is no increase in water surface area.

Hereinafter, another embodiment of the present invention will be described with reference to FIGS. 4 and 5. FIG.

FIG. 4 is a structural view of a semi-submersible drilling rig equipped with another embodiment of the up-and-down rocking apparatus of the present invention, and FIG. 5 is a perspective view of the sub-tank and the auxiliary pin shown in FIG.

As shown in the figure, the upper and lower shake stabilizer 50 is provided with auxiliary pins 10 ', 20' and 30 'on the lower side of the auxiliary tanks 10, 20 and 30 provided on the outer peripheral surface of the column 110, respectively.

The auxiliary fins 10 ', 20', and 30 'are installed on both sides of the outer circumferential surface of the column so as to be spaced apart from the lower portions of the plurality of auxiliary tanks 10, 20, Likewise, they are horizontally projected in the lateral direction.

At this time, the auxiliary pins 10 ', 20', and 30 'are installed at a height that can be kept locked under the sea surface at all times.

The auxiliary fins 10 ', 20', and 30 'may be welded to the outer peripheral surfaces of the respective columns 110 like the auxiliary tanks 10, 20,

Therefore, the auxiliary fins 10 ', 20', and 30 'in the embodiment of FIG. 4 increase the resistance to the up-and-down motion of the drill ship in a state of being always locked below the sea surface and serve as a damper, It will reduce the fluctuation.

Therefore, according to the present invention, it is possible to enlarge the water surface by enlarging the outer shape of the column 110 due to the auxiliary tanks 10, 20, 30 installed in the column 110 of semi-submersible drill ships, The ballast tank can be used to reduce the up-and-down movement of the drill ship, and to secure the buoyant buoyancy. Further, by installing a plurality of auxiliary pins 10 ', 20', and 30 ' And the drilling operation can be performed more stably due to the addition of the damping function.

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and similarities.

Description of the Related Art [0002]
10, 20, 30: auxiliary tank 10 ', 20', 30 ': auxiliary pin
50: Up and down shake stabilizer
100: Punctun 110: Column
130: upper deck
150: Drilling rig
S1: Working water surface S2: Survival water surface

Claims (3)

The up and down rocking stabilizers are installed on a number of columns which are installed on the upper part of Puntung which is equipped with semi -
The up-and-down rocking-
And a plurality of auxiliary tanks installed on both sides of the outer circumferential surface of the column so as to be positioned at an operational water surface height of the semi-submersible drilling rig and capable of injecting or discharging seawater therein. Stabilizer. The method according to claim 1,
Wherein the auxiliary tank is installed to be symmetrically transversely on both sides of the outer circumferential surface of the column. 3. The method of claim 2,
Wherein the column further comprises an auxiliary pin spaced downwardly from the auxiliary tank and projecting laterally so as to be submerged below the surface of the sea.

Images