MXPA99004564A - Anchor - Google Patents

Abstract

An anchor for anchoring floating structures at sea, in particular floating platforms for the production of oil and/or gas, comprising a hollow body (2) which is designed to be submerged in the sea bed by means of suction or by some other means. The solution is characterised in that the body is a polygon with concave side surfaces.

Description

ANCHOR FIELD OF THE INVENTION The present invention relates to an anchor or fastener for anchoring or securing underwater structures, such as pipes, and floating structures in the sea, in particular, floating platforms for the production of oil and / or gas, comprising a hollow body which It is designed to be submerged at the bottom of the sea by means of suction or by some other means.

BACKGROUND OF THE INVENTION Previously known are circular suction anchors or anchors, so-called anchors or hub clips, of the above type. Such anchors or bucket fasteners have a large volume and long terminal surfaces which suggest that the anchor or fastener has a large dynamic weight during the installation phase.

REF .: 30346 During the suction phase, the hull or frame of the anchor or cube holder is subjected to instability. This applies in particular to installations where there are large anchoring or clamping forces and where the soil is deficient. Anchors or bucket fasteners with a very large diameter are required here, which suggest that the hull or frame can be immovable with a very thick plate. This results in the weight of the steel itself being very large. Together with the enormous additional dynamic force, which originates in the count of the resonance, confined water and amount of resonance of the water to the ends, this results in that the requirements made of the installation vessels are very strict when referring to the size, stability, winch power and other conditions.

The known type of solution of anchors or bucket fasteners, is thus costly for its construction and for its installation.

DF.S RTPCTON OF, t.A TNVF.NCTQN The present invention represents a solution for anchors or fasteners which are lighter, have a lower additional dynamic force when the anchor or fastener is installed and thus greatly reduce construction and installation costs, but which still have an anchoring capacity or fastening (anchoring or clamping force) which is at least as large as that of the anchor or bucket fastener.

The present invention is characterized in that the body of the anchor or fastener consists of a polygon with concave side surfaces.

The dependent claims 2-6 indicate the advantageous features of the present invention.

The present invention will be described in further detail in the following by means of examples and with reference to the following drawings: Figure 1 shows a perspective diagram of a platform which is anchored or fastened with anchors or fasteners in accordance with the present invention.

Figure 2 shows one of the anchors or fasteners shown in Figure 1 in perspective and on a large scale.

Figure 3 shows a horizontal section of the anchor or fastener shown in Figure 2, with a force arrow "F" which indicates the tension force and its direction for the anchoring or clamping line.

Figure 4 is a schematic diagram which shows how the anchor or fastener in accordance with the present invention is subjected to a load in the operative state.

Figure 5 shows an alternate design of an anchor or fastener in accordance with the present invention.

Figure 1 shows, as established, a perspective diagram of a platform 1 which is anchored or clamped, via anchoring or securing lines 3, to the anchors or fasteners 2 in accordance with the present invention.

As shown in Figure 2, the anchor or fastener 2 is, in the example shown here, is triangular (star-shaped) with concave (curved) side surfaces 4, but with straight generants and corners 5, 6 and 7 which are aligned in the vertical direction to the anchor or fastener. An anchor or fastener which is designed for suction, is fixed with an upper plate 12, while an anchor or fastener which is down (expelled) on the ground in another form is properly open at both ends.

Figure 3 shows a horizontal section of the anchor or fastener shown in Figure 2, with a force arrow "F" which indicates the tension force and its direction for the anchoring or clamping line.

The side surfaces 4 suggest the corners 5, 6 and 7, which are preferably without eccentricity (see, in particular, Figure 4) so that there are no back and forth moments around the corners. The corners 5, 6 and 7 can be more easily formed by the welds of the side surfaces 4 directly to each other but should preferably, as shown in the figure, be formed by welding the side surfaces 4 to a hollow section in the form of a square section, tubular section or possibly a flat bar.

The corner 7, which also forms the fixing point for the anchoring line 3, should be provided with a reinforced part (not shown in detail), preferably a thick plate, in the area of the fixing eye 9 (see Figure 2) for line 3.

Figure 4 shows, in principle, how the anchor or fastener is subjected to a load in the operating state. The tension on the front side surfaces 4, represented by "S" in Figure 4, balances the compressive forces on the lateral surfaces while the pressure represented by "C" supports the compressive forces which act along the surface Posterior 4. By giving the lateral surfaces and the posterior surfaces a curvature relative to the loads along the sides, a balance between these two forces is achieved in the corners without the corners being subjected to a greater cut. The plates are preferably so soft that, if the tension is any other than that assumed, the corners will assume a different position until a new equilibrium is achieved.

The pressure on the lateral surfaces is also in equilibrium, with tension the tension membrane in the plates does not perform great flexion due to tension. The principle of membrane tension occurs without tension bending due to the curved shape of the side surfaces and contributes to allow the thickness of the material to be made to be very thin compared to a similar anchor or fastener with straight sides so that the weight of the anchor or fastener is consequently reduced.

The design of the present invention with curved lateral surfaces also contributes to improving the transmission force from the line of the anchor or fastener, since the forces are absorbed mainly as tension and compression forces on the lateral surfaces (tension membranes). ). With a cube anchor or clamp, the transmission force from the anchor or clamping line will result in great stress bending.

The size of an anchor or suction clamp, designed for a floating platform in the North Sea, with curved faces in accordance with the present invention may be from 10-15 meters in height (depth) and 8-10 meters for the width of the lateral surfaces. For an anchor pile or fastener, the height should be 15-20 meters, while the width of the lateral surfaces should be 4-6 meters.

Figure 5 shows an alternate design of an anchor or fastener in accordance with the present invention which is provided with four side surfaces. However, it should be noted that the present invention as described above and shown in the figures is not restricted to anchors or fasteners with three or four side surfaces, if it can not in fact, also be used for anchors or fasteners with any number of sides. .

An anchor or fastener in accordance with the present invention with three side surfaces as shown in Figure 3, will be in an operational situation, that is, when it has been sufficiently submerged in the bottom, it will be "self-supported" in the sense that it does not it is necessary to have some transverse support or additional reinforcement to that which was mentioned above concerning the fixing eye by the line of the anchor or fastener. When used as an anchor or suction clamp and that depends on the quality of the soil (depth), however, it may be necessary to have a central retaining wall or support 11, for example at the end of the lower insert of the anchor or fastener to dramatically prevent contraction or changing shape. Under normal operating conditions, after the anchor or fastener has been submerged in the bottom, the support will not perform any function, however.

So that an anchor or fastener with four side surfaces, as shown in Figure 5, is supported by connecting to the corners 13, 14, and 15, 16 respectively, it will be necessary to connect with the suction of the anchor or fastener, while during the operation, the anchor or fastener will currently only require support in which the contact refers to 15 and 16 to maintain a balance force for the corners.

The advantage of the shapes of an anchor or fastener with four or more corners is that it is allowed for the lateral surfaces with large curvatures, which increase the firmness of the anchor or fastener in cases in which the anchor or fastener has been tightened again ( suction of anchor or fastener), for example due to incorrect positioning.

It is noted that, in relation to this date, the best method known by the applicant to carry out the aforementioned invention is that which is clear from the present description of the invention.

Having described the invention as above, the content of the following is claimed as property.

Claims (6)

1. An anchor or fastener for anchoring or securing floating structures in the sea, in particular floating platforms for the production of oil and / or gas, comprising a hollow body which is designed to be submerged at the bottom of the sea by means of suction or by other means, characterized in that the body is a polygon with concave side surfaces.

2. An anchor or fastener according to claim 1, characterized in that the faces or sides of the anchor or fastener are connected to each other directly to each of the corners by means of welds.

3. An anchor or fastener according to claim 1, characterized in that the faces are connected to each other at each of the corners by means of welds via a flat bar or section.

4. An anchor or fastener according to claim 3, characterized in that the section is a square section or a tubular section.

5. An anchor or fastener according to claims 1-4, characterized in that an anchor or fastener is an anchor or suction fastener and the upper end of the anchor or fastener is closed.

6. An anchor or fastener according to claims 1-5, characterized in that the body is provided with supports which extend from each of the corners and are connected to the others up to the central axes.