KR20080102737A - Offshore structure to avoid wave frequency motion and for storing large production - Google Patents

Abstract

An offshore structure to avoid wave frequency motion and for storing large production is provided to prevent the dangers on the offshore task and store large amount of petroleum and natural gas by having single buoy shape or semi-submersible shape and using submersible storage tank. In an offshore structure, a production platform(100), having the single buoy shape or the semi-submersible shape and moving above/below the surface of the water, produces petroleum or the natural gas from the bottom of the sea through the first riser(104). A semi-submersible storage tank(112), having spherical shape and disk shape, on the bottom of the sea is connected to the production platform, producing petroleum or the natural gas, through the second riser(106).

Description

Offshore structure to avoid wave frequency motion and for storing large production}

1 is a conceptual diagram illustrating a conventional offshore structure.

FIG. 2 is a conceptual diagram illustrating a first embodiment of an offshore structure for preventing ocean wave periodic motion and mass storage according to the present invention.

3 is a conceptual diagram illustrating a second embodiment of the offshore structure for preventing ocean wave periodic motion and mass storage according to the present invention.

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

100: production platform 102: production platform mooring line

104: first riser 106: second riser

110: spherical submersible storage tank 112: submersible storage tank mooring line

120: disc shaped submersible storage tank

The present invention relates to an offshore structure for preventing ocean wave motion and storing large volumes. More specifically, the present invention relates to a single buoy shape having an inherent period much longer than a period of up and down motion of the ocean wave (about 5 to 25 sec). Simultaneously equipped with a production platform and a submersible storage tank capable of storing a large amount of crude oil and natural gas, it is possible to prevent marine wave movements and enhance the storage capacity of marine products to improve the stability of marine operations and product competitiveness in the offshore structure market. It is about a structure.

Marine oil production accounts for one-third of the total oil production and is growing faster than land oil production. According to this work trend, various offshore structures have recently appeared in the offshore market.

Offshore Structure refers to a structure that is installed on the sea or on the sea floor. The offshore structure is a facility capable of drilling, producing, and storing marine energy sources such as crude oil or natural gas. Fixed platform, complex piled tower (CPT), semi-submersible type platform (TLP), tension leg platform (SLP), spar platform (Spar platform) and marine offshore structure (FPSO) Divided by. These offshore structures are often associated with ocean wave cycles.

1 shows a conventional offshore structure. The offshore structure shown in FIG. 1 is a floating production storage offloading facility (1, FPSO), which is an offshore structure having the appearance of a ship.

This floating crude oil production storage facility (1) is a crude oil production facility and produced crude oil, including the hull, various cranes mounted on the hull deck, and various risers used to produce crude oil from subsea oil fields in the hull. The storage tank etc. which store are comprised normally.

However, this floating crude oil production storage facility (1) is equipped with a large storage tank for storing the crude oil produced, but compared to other types of offshore structures, water surface area (water-line surface), the hull cut along the waterline The cross-sectional area) is increased to have an intrinsic period (approximately 8 to 15 sec) within the range of 5 to 25 sec, which is the general ocean wave period.

The natural cycles of the floating crude oil production and storage facility 1 can be resonated with each other within a range consistent with the general ocean wave period. As a result of this phenomenon, the relative vertical motion, that is, the vertical and vertical motion Intensified, it acted as a problem that can cause various safety accidents at sea work.

On the other hand, although not shown in a separate drawing, Spar type platform (SPAR type Platform) or semi-submersible marine structure (Semi-submersible type Platform) small water surface area is not a vessel type, such as the floating crude oil production storage facility (1) ) Has inherent periods (outside 25 sec) out of the ocean wave cycle, so there is no operational risk due to the up-and-down cycle movement. However, such a sparse platform or semi-submersible offshore structure lacks a storage space for crude oil produced, and thus there is a problem in that a large amount of crude oil cannot be stored as compared to the floating crude oil production storage facility 1 described above.

Therefore, there is an urgent need to develop a new type of offshore structure with all the advantages of a floating crude oil production and storage facility 1 and a sparse platform and a semi-submersible offshore structure.

The present invention is to solve the above problems, and to provide a marine structure for preventing the ocean wave cycle movement and having a large volume storage space at the same time having a unique cycle outside the general ocean wave cycle and mass storage as a technical problem.

In order to solve the above technical problem, according to the spirit of the present invention, a single buoy shape in the vertical direction along the surface of the water so as to minimize the repair area in order to eliminate the heave and pitch motion (Heave and Pitch motion) or It has a semi-submersible shape, has a production platform for producing crude oil or natural gas from the seabed and a spherical shape or disc shape through the first riser, and can store crude oil and natural gas produced in the production platform. It provides a marine structure for preventing the ocean wave periodic movement and mass storage; and a submersible storage tank interconnected through the production platform and the second riser to be mooring on the sea floor.

At this time, the spherical shape is preferably the eccentricity (e) is in the range 0≤e≤1. If the eccentricity (e) is 0, it becomes a perfect sphere, and if the eccentricity (e) is within the range of 0 <e <1, it may be a slightly distorted ellipsoid shape. Such a shape is easy to withstand high pressure and its material and thickness. In addition, various modifications are possible depending on the respective application requirements.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

In the drawings, FIG. 2 is a conceptual diagram illustrating a first embodiment of an offshore structure for preventing ocean wave motion and mass storage according to the present invention, and FIG. 3 is for preventing ocean wave motion and mass storage according to the present invention. A conceptual diagram illustrating a second embodiment of an offshore structure.

With reference to the respective drawings will be described a preferred first embodiment and a second embodiment according to the spirit of the present invention.

First Example

Referring to the first embodiment of the marine structure for preventing ocean wave cycle motion and mass storage according to the spirit of the present invention with reference to Figure 2, the production platform 100 with a minimum water surface area centered on the sea surface (100) And, it includes a spherical submerged storage tank 110 moored on the seabed to store the crude oil and natural gas produced in the production platform.

The production platform 100 has a single buoy shape or a semi-submersible shape in the vertical direction in order to minimize the repair area around the sea surface. In this embodiment, a plurality of connections are used. In addition to minimizing the repair area, structural stresses are also used.

On the outer peripheral surface of the lower end of the production platform 100, a plurality of production platform mooring lines 102 having one end fixed to the sea bottom is fixedly connected, and thus the production platform 100 is not separated from the working position.

In addition, a plurality of risers (104, 106) is mounted on the lower surface of the production platform 100, for convenience of description, divided into functional side and divided into the first riser 104 and the second riser (106). .

The first riser 104 is a rising pipe that is used to drill crude oil and natural gas from a deep seabed below seabed or undersea gas fields, and the second riser 106 is directed to the first riser 104. Drilled and produced crude oil is sent from the production platform 100 to the spherical submerged storage tank 110 or the crude oil stored in the spherical submerged storage tank 110 is withdrawn to the production platform 100 again. Rising pipe to use.

Since the spherical submersible storage tank 110 is subjected to a large hydraulic pressure, for this purpose it has a good spherical shape with good pressure resistance, it is good to be made of a separate pressure-resistant material and multiple layers of multilayer structure, for such materials and structures See the pressure vessel geometry. The spherical submersible storage tank 110 preferably has a complete spherical shape in which the eccentricity e is e = 0. It may have an ellipsoidal shape that is crushed up and down.

Such a spherical submersible storage tank 110 is mooring to the sea bottom that the operation is in progress, one end is fixedly connected to the plurality of submersible storage tank mooring lines 112 fixed to the sea bottom. Because of this, the spherical submerged storage tank 110 is not separated from the working position.

2nd Example

With reference to Figure 3 looks at a second embodiment of the marine structure for preventing ocean wave cycle motion and mass storage according to the spirit of the present invention.

This embodiment is an embodiment in which the spherical submersible storage tank 110 used in the above-described first embodiment is replaced with the disc-shaped submersible storage tank 120, except for the detailed description and technical configuration. Since the same, redundant description will be omitted.

Disc-shaped submersible storage tank 120 is a form that is strong to relatively large hydraulic pressure and easy to manufacture, a multi-layered multi-layer structure inside the material and resistant to internal pressure can be adopted. In this way, safety can be secured in case of emergency.

It has been described above the marine structure for preventing ocean wave cycle motion and mass storage according to the present invention.

It will be appreciated that the technical construction of the present invention may be implemented in various embodiments without departing from the technical spirit or essential features of the present invention.

Therefore, the above-described embodiments are to be understood in all respects as illustrative and not restrictive, and the scope of the present invention is indicated by the claims to be described below rather than the detailed description above, and the meaning and scope of the claims. And all changes or modifications derived from the equivalent concept should be interpreted as being included in the scope of the present invention.

As described above, according to the present invention, the marine structure for preventing ocean wave cycle movement and mass storage, and produced with a production platform having a single buoy shape or semi-submersible shape to minimize the repair area Simultaneous use of spherical or disc shaped submersible storage tanks capable of storing a large amount of crude oil or natural gas on the seabed prevents various risks of offshore operations due to sea wave and pitch motion. Of course, it is possible to store a large amount of crude oil or natural gas as compared to the conventional, there is a technical effect that can improve the work stability and product competitiveness.

Claims (2)

The first riser has a single buoy or semi-submersible shape in the vertical direction along the surface of the water so that the water line area is minimized to eliminate the heave and pitch motion. Production platform for producing crude oil or natural gas from the seabed; And It has a spherical shape or disk shape, and the submersible storage tank interconnected through the production platform and the second riser to store the crude oil and natural gas produced by the production platform, and mooring on the seabed; Made, Offshore structure for prevention of ocean wave cycle movement and mass storage The method of claim 1, The spherical shape is, Characterized in that the eccentricity (e) is in the range 0≤e≤1, Offshore structure for prevention of ocean wave cycle movement and mass storage.

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