RU2502630C1 - Sea gravity platform - Google Patents

Abstract

FIELD: transport.

SUBSTANCE: invention relates to sea gravity platforms for exploration of oil and gas deposits at continental shelf. Proposed platform comprises submersible offshore platform composed by bottom and top bearing plates, sidewalls and internal bulkheads. Bell consisting of separate sections is hinged to submersible platform bottom part. Every said section comprises vertical wall, stiffness ribs and guide pipes. Stiffness ribs have support elements at the points of abutting on bottom plate. Submersible platform sidewalls includes element for attachment of said bell in transport position and recesses to accommodate retainer pints.

EFFECT: higher stability, low draft, fast assembly and disassembly.

5 dwg

Description

The invention relates to hydraulic engineering, in particular to marine gravity platforms for the development of oil and gas deposits on the continental shelf.

Known marine ice-resistant stationary platform described in patent RU 2151842 C1, class. E02B 17/00, E02B 15/02, publ. 06/27/2000, containing a caisson and a steel skirt at the bottom.

The disadvantage of this platform is the rigid fastening of the skirt to the bottom base plate, which leads to an increase in the draft of the platform afloat and an increase in towing resistance during sea haul. The stationary skirt also limits the use of the platform in shallow water areas and requires a deeper ship course when posting to the installation point.

The gravitational platform according to A.S. 1492793 A1, cl. E02B 17/00, publ. 06.22.87, including a housing with a support block equipped with a skirt in the lower part in the form of ribs with a shoe and a clip.

The disadvantage of this platform is the need to completely or partially replace the skirt when moving the platform to another operating point, as well as an increase in draft, afloat, which limits the use of the platform in shallow water and requires a deeper ship course when posting to the installation point.

Known marine gravity platform by A.S. 1515801 A1, cl. E02B 17/00, publ. 12/01/86. The platform contains a submersible base, around the perimeter of which a removable skirt is made of separate sections, each of which contains a vertical wall, a horizontal shelf with a counterweight and stiffeners.

The disadvantage of this platform is the need for complex and time-consuming operations to establish the skirt under the support base (in marine conditions), the difficulty of keeping the skirt in a vertical working position when it is pressed into the ground; as well as the need for additional costs for removing the skirt from the bottom soil or the manufacture of a new skirt in case of relocation of the platform.

Marine gravitational platform described in A.S. 1515801, is the closest analogue of the claimed platform.

The present invention is the creation of a marine gravity platform having high stability on the ground, a small draft afloat, as well as a short installation time on site.

The specified technical problem is solved by the fact that the marine gravity platform contains a submersible base formed by the bottom and top support plates, side walls and internal bulkheads. On the submersible base, in its lower part, there is a skirt reclining on swivel loops from individual sections. Each section of the skirt contains a vertical wall, stiffeners and guide tubes located in the plane of the stiffeners for installing the finger-retainers. Stiffeners in the area adjacent to the bottom plate are made with support elements. The side walls of the submersible base contain niches in which the locking fingers are located, as well as the fastening elements of the skirt in the transport position of the platform.

The technical result from the use of the present invention is to improve the stability of the platform on the ground, maintaining a small draft afloat, reducing towing resistance when driving by sea, as well as reducing the time to install the platform at the point of operation and dismantling in case of relocation.

Figure 1 shows the platform with the skirt installed in the working position, cross section, figure 2 - section of the skirt in the transport position, cross section, figure 3 - the same front view, figure 4 - node A (section of the skirt in working position, cross section), figure 5 is the same, front view.

The marine gravity platform contains a submersible base 1, formed by bottom 2 and upper 3 supporting plates, side walls 4 with vertical sections in the lower part, and internal bulkheads 5. A skirt 6 is located around the perimeter of the lower part of the submersible base 1, connected to it via pivoting loops 7 consisting of individual sections 8 (see figure 1). Each section of the skirt 8 contains a vertical wall 9, stiffeners 10 and guide tubes 11. The stiffeners 10 in the area adjacent to the bottom plate 2 of the immersion base 1 are equipped with support elements 12. Niches 13 are located on the vertical sections of the side walls 4 of the immersion base 1. In the niches 13 posted on the slings 14, the locking pins 15 for fixing the sections of the skirt 8 in the working position. On the side walls 4 of the submersible base 1 are fasteners 16 sections of the skirt 8 in the transport position.

The device operates as follows.

The fabricated platform containing the submersible base 1, formed by the bottom 2 and upper 3 supporting plates, side walls 4 and inner bulkheads 5 with a skirt 6 around the perimeter of the base, is towed to the installation site. When towing the skirt 6, consisting of sections 8, is fixed by fastening elements 16 of the side walls 4 of the submersible base 1 in the transport position. The locking pins 15 are located in the niches 13 of the side walls 4 in suspension using the slings 14 (see figure 2, 3).

Upon arrival at the platform installation site, the fastening elements 16 are disconnected and the sections of the skirt 8 on the pivoting hinges 7 are folded back to their working position under their own weight, turning 180 degrees. After this, the slings 14 are pitted and the locking pins 15 from the niches 13 are lowered into the guide tubes 11 of the sections of the skirt 8. Thus, the skirt 6 is fixed in the working position (see Figs. 4, 5). Then the platform receives the ballast and sinks to the bottom, pushing the skirt 6 into the ground with its mass. To increase the overall rigidity and stability of the skirt 6 in the working position on the vertical walls 9 of the sections of the skirt 8, stiffeners 10 are provided. For supporting the concentrated load arising from the contact of the stiffeners 10 of the skirt 6 with the bottom plate 2, support elements 12 are provided on the stiffeners 10.

If it is necessary to relocate the platform to a new place of operation, it is de-ballasted and it pops up. When surfacing, the skirt 6 is removed from the soil of the seabed, after which the retaining fingers 15 are pulled out by slings 14 from the guide pipes 11 of the skirt sections 8. Then, by lifting means of the platform, the skirt sections 8 on the hinges 7 are rotated 180 degrees and fixed with fastening elements 16 on the side walls 4 submersible bases 1 in transport position. The grab of the sections of the skirt 8 for the implementation of the rotation is carried out for the free edge of the vertical wall 9. The platform is towed to a new location.

The proposed design of the marine gravity platform allows you to:

- reduce the draft platform afloat and reduce the towing resistance due to the reclining (folding) design of the skirt;

- apply a skirt with a greater height, which helps to increase the stability of the platform on the ground;

- Install and dismantle the platform as soon as possible.

Claims (1)

A marine gravity platform containing a submersible base formed by a bottom and top bearing plates, side walls and internal bulkheads, along the perimeter of the lower part of which there is a skirt consisting of separate sections made in the form of vertical walls with stiffeners, characterized in that the skirt is connected to immersion base by means of swivel hinges with the possibility of folding, on the vertical walls in the plane of the stiffeners are provided guide pipes, stiffeners in the vicinity of the prima the kicking to the bottom plate of the submersible base is provided with supporting elements, and niches with fixing fingers and fastening elements of the skirt in the transport position of the platform are made on the side walls of the submersible base.

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