SU1668553A1 - Sea rig - Google Patents

Abstract

FIELD OF THE INVENTION The invention relates to hydraulic engineering. The purpose of the invention is to increase the stability of the platform and simplify installation and disassembly when working in ice conditions. The offshore platform includes a superstructure and a support structure 2 of the graphitic type, made in the form of a cone and directed downwards with a large base. Along the perimeter of the lower part of the supporting structure 2, the adjustable buoyancy pontoons 3 are uniformly mounted with a hinged joint with the supporting structure. The pontoons 3 are provided with a flexible supporting wall 5, which is located along the periphery of the pontoons and connect adjacent pontoons to form a closed loop. The space between the pontoons is filled with a stone bed 7, which is held by a flexible wall 5. 3 Il.

Description

The invention relates to the construction of hydraulic structures and can be used in the construction of offshore platforms intended for arctic conditions.

The purpose of the invention is to increase the stability of the platform and simplify installation when working in ice conditions.

FIG. 1 depicts a marine platform, general view; in fig. 2 is a section A-A in FIG. 1 (placement of pontoons around the perimeter of the supporting structure); FIG. 3 is a section BB in FIG. 2 (lower part of the supporting structure with stone filling).

The offshore platform contains the upper structure 1, the supporting structure 2 of the gravitational type, made in the form of a cone and directed downwards with a large base. Along the perimeter of the lower part of the supporting structure 2, the adjustable buoyancy pontoons 3 are uniformly mounted so that they can rotate around the horizontal axis of the attachment unit 4 to the supporting structure 2 in the radial direction and fix the rotation angle relative to the platform. The pontoons 3 are equipped with a flexible supporting wall 5, which is placed along their periphery and the adjacent pontoons, forming a closed loop. With the horizontal placement of penetrations 3 on the seabed 6, the space between them is filled with a stone bed 7, which is held by a flexible wall 5.

The invention is as follows.

The marine platform in the assembled video is transported afloat to the base with the help of floating volumes of the supporting structure 2 (not shown) and the pontoons 3, which are fixed in a horizontal position. At the same time, the stability of the GlSG form afloat is provided thanks to

YaKa &

ABOUT

about with

Ca

square and shape of the waterline. At the installation site of the platform, the floating volumes of the support structure 2 are ballastised. As the pontoons are immersed, they are transferred to a vertical position and fixed, thus ensuring sufficient moment of inertia of the waterline of the structure: so, under the influence of horizontal loads, tilting of the platform leads to an increase in the moment of inertia of the waterline and returning the platform to a vertical position.

On the seabed 6, the pontoons 3 are ballast and again shifted to a horizontal position. The fastening of the pontoons 3 in the nodes 4 provides a sufficiently large shoulder of the restoring force of the own weight of the structure and thereby reliably protects it from overturning. A flexible supporting wall 5, made, for example, of cables and not permeable to the backfill material, occupies a vertical position, forming an opening of the cavity in the platform volume, bounded on the other sides by pontoons 3 and the supporting structure 2, and This cavity is filled with backfill material 7. Wall 5, having a cellular structure, does not create conditions favorable for erosion of the bottom 6. Backfill material 7, limited by the size of the cavities formed, is rigidly tied to the bottom in the horizontal direction. of the porous structure 2 and at the same time repeats the surface of the bottom 6, thereby increasing the dimensions of the lower part of the supporting structure 2 in the platform volume, and copies the relief, i.e., a sufficiently high resistance of the structure to sliding along the bottom when exposed to an external horizontal force is created, except In addition, the presence of backfill prevents soil from flowing out of the platform,

If platform reshuffle is necessary, the pontoons 3 are deballised and simultaneously shifted to a vertical position. The floating volumes of the support structure 2 are then deallured, and the platform floats. As the pontoons 3 emerge, they are transferred from a vertical position to a horizontal position, providing at this time sufficient moment of inertia of the waterline to maintain stability. The ascent from the position on the bottom proceeds unhindered, since the backfill material, although it exerts pressure on the walls of the cavities and the underlying soil, is not associated with them (except for friction forces).

Thus, the use of an offshore platform in arctic conditions allows to achieve stability of its position during transportation, installation and dismantling, and secure attachment at the base.

Claims (1)

Claims of the invention The marine platform includes an upper structure placed on a supporting structure, in the lower part of which pontoons are installed with the possibility of turning around a horizontal axis and fixing the angle of rotation, which is designed to increase the stability of the platform and simplify installation and dismantling ice conditions, it is provided with a flexible wall, while the supporting structure is made conical and directed with a large base downwards, the pontoons are installed evenly around the perimeter of the lower part of the supporting structure, and the flexible wall is installed on the periphery of the pontoons with the formation of a closed contour, the free space of which is filled with stone backfill. IG6 I / // /// W /% g 7 7 / V / Z Editor E. Horin Fig.Z Compiled by R. Beschastnova Tehred M. Morgentalkorrektor M. Kucher va