WO2016051120A2

WO2016051120A2 - Unit for connecting a structural element of an offshore platform to a reception structure and associated uses

Info

Publication number: WO2016051120A2
Application number: PCT/FR2015/053338
Authority: WO
Inventors: Mathieu GUILLOTIN; Mathieu NOIROT; Franck GAZQUEZ; Baptiste BEAUMERT
Original assignee: Techlam
Priority date: 2015-12-04
Filing date: 2015-12-04
Publication date: 2016-04-07
Also published as: WO2016051120A3; EP3384094A2

Abstract

The invention relates to a unit (200) for connecting a structural element (100) of an offshore platform to a reception structure of said unit, the latter comprising a means (201) for connecting to the reception structure, known as first connecting means, and at least one means (202) for connecting to the platform leg (100), known as second connecting means, and also a longitudinal axis (AL), characterized in that said at least one second connecting means (202) is incorporated at one end (E) of said unit (200) and is able to move with a movement comprising at least one radial component between a retracted position for positioning said unit inside the leg and a deployed position for providing the connection between the connecting unit and the leg, this radial component being defined in a plane perpendicular to said longitudinal axis.

Description

UNIT FOR CONNECTING A MARINE PLATFORM STRUCTURAL ELEMENT TO A RECEIVING STRUCTURE AND USES THEREOF

The invention relates to a unit for connecting a structural element of a marine platform to a reception structure. The invention also relates to uses of this connection unit.

The invention may in particular be applied for the connection of a marine platform leg to a reception structure for said unit, said reception structure being floating or disposed on the seabed, either by anchoring or by simply laying on the seabed.

The marine platform can then be an oil platform or a wind turbine.

The invention can also be applied for connecting an oil platform bridge to a riser.

We will more particularly describe the prior art in support of a platform leg application.

To install an offshore platform, for example an oil, wind or other platform, a method often used consists, with the help of a barge, to deposit the platform on a structure having been installed beforehand. This reception structure can be floating or arranged on the seabed. When placed on the seabed, the host structure is either anchored to the seabed or simply resting on the seabed.

This method is called "floatover" in Anglo-Saxon terminology.

For this purpose, is used for each leg of the platform, a connection unit of this leg to the host structure.

Such a connection unit is generally called "Leg Mating Unit" (LMU) in the English terminology. Sometimes, the term "Receptor Deck Mating" (DMR) is also used in the same terminology.

An LMU is integrated either inside a leg of the platform or inside its host structure.

In the case where an LMU is intended to be mounted inside a leg of the platform, it should be brought by the underside of the leg concerned during the manufacture of the platform, for example before the installation of the platform on the barge intended to take this platform to sea.

There is shown in Figure 1, a first approach currently used to mount an LMU inside a platform leg. More specifically, Figure 1 (a) shows, in a sectional view, an assembly comprising a platform leg 1 (top) and a connection unit or LMU 2 (bottom), before mounting in the leg 1 and the FIG. 1 (b) shows, again in sectional view, the LMU 2 mounted inside said leg 1.

The leg 1 is in the form of a regular hollow cylinder, whose inside diameter and thickness are given.

As for the LMU 2 unit, it comprises a base 20, a housing 21 and a pin 22 for connecting the base 20 to its housing 21. The pin 22 is in the form of a plate, intended to be fixed to the base 20 .. The base 20 comprises an axis 20A, adapted to be fixed to the pin 22. In addition, the housing 21 comprises retaining means 21 R of the pin 22. This is why the pin 22 has larger dimensions than that of an orifice OC provided in the retaining means 21 R.

In practice, the pin 22 is inserted from the top of the retaining means 21 R of the housing 21 until it comes into contact with the retaining means 21 R of the housing. Then, the base 20 is inserted through the bottom of the housing 21 and the axis 20A of the base 20 is made to cooperate with the pin 22. This cooperation is effected by screwing, the axis 20A and the pin 22 being designed for this purpose. effect. Screwing at the same time a fixing between the base 20 and the pin 22.

The LMU 2 unit is then formed.

The formation of the LMU unit is generally done in the factory, so before transport on site installation on the leg 1.

On site, the LMU 2 unit is placed inside the leg 1.

For this, the outer diameter of the housing 21 is slightly less than that of the inner diameter of the leg 1 so that the LMU unit can be mounted inside the leg 1. The attachment of the housing 21 to the leg 1 is then performed by welding. Note that the housing 21 generally comprises a widening 21 E in its lower part to come into contact with the wall of the leg 1, once the LMU unit 2 mounted inside the leg 1. This enlargement area 21 E of the housing 21 is then advantageously used to ensure the welding of the housing 21 to the leg 1 and consequently, the attachment of the LMU unit 2 to the leg 1.

It should be noted that the LMU 2 and more precisely its base 20 comprises, in its lower part, a zone 20Z (in this case of the female type, but it may be otherwise) intended to be connected with a zone complementary to the structure of the 'Home. This connection is generally limited to a corresponding engagement of male and female parts.

Thus, the LMU 2 comprises a connection means, namely the zone 20Z, with the receiving structure of the leg 1 and a connection between the housing 21 and the leg 1 (welding). During assembly, the housing or second connecting means 21 undergoes only an axial movement along the longitudinal axis AL of the LMU 2 (the axis longitudinal of the base 20, its housing 21 and the pin 22 is confused). The longitudinal axis AL merges with that of the leg 1.

A disadvantage of this approach lies in the use of a housing ("casing") which involves handling large masses when mounting the LMU in the leg, handling all the more delicate that the assembly must be accurate. There is shown in Figure 2, a second approach currently used to mount an LMU unit inside a platform leg.

More specifically, FIG. 2 (a) shows, in a sectional view, a platform leg V (top) and an LMU unit 2 ', before mounting in the leg and FIG. 2 (b) represents, always in a sectional view, the LMU unit 2 'mounted within said leg 1'.

In this approach, the LMU 2 'unit no longer has a dwelling.

The LMU unit 2 'thus comprises only a base 20 and a pin 22, both of which conform to the description made previously for the first approach.

Furthermore, the leg has retaining means 11 R 'in accordance with those (21 R) housing 21 of the first approach.

In practice, the entire assembly can be performed at the installation site of the LMU unit inside the leg. One can also beforehand, namely in the factory, install the pin 22 and then only the mounting operation of the base 20 on the pin 22 is performed on this site.

Thus, the pin 22 is inserted through the top of the leg 1 'until the pin 22 comes into contact with the retaining means 11 R' of the leg 1 '.

The base 20 is then inserted into the pin, by its axis 20A to the pin 22.

An attachment is then made between the base 20 and the pin, which involves the attachment of the LMU unit 2 'to the leg 1'. This fixing is generally done by screws or bolts (not shown) passing through the LMU unit 2 'along its longitudinal axis.

The LMU unit 2 'is thus formed at the same time as its mounting inside the leg.

Here again, the LMU 2 ', and more precisely its base 20, comprises, in its lower part, a zone 20Z (in this case of the female type, but it may be otherwise) intended to be connected with a corresponding zone of the reception structure.

Thus, the LMU 2 'here comprises a first connecting means, namely the zone 20Z, with the receiving structure of the leg 1' and a second connection means, namely the pin 22, with the leg 1 '. During assembly, the base 20 is translated along the longitudinal axis AL 'of the LMU 2' (the longitudinal axis of the base 20 and that of the pion 22 merge) in or as the case, around the pin 22. The longitudinal axis AL 'merges with that of the leg 1'. The fixation is then carried out.

In the second approach, the absence of housing makes the installation of the LMU 2 'inside the leg 1' a little easier, because there is less mass to handle and there is no as a result, tolerance constraints between this housing and the leg.

However, the fixing of the base 20 and the pin 22 can raise practical difficulties of accessibility, which is not the case with welding, between the housing and the leg, which is made in the first approach.

In addition, whatever the approach envisaged, it is not uncommon for the mounting of an LMU unit in a platform leg to be delayed, compared to the initial schedule planned for the installation of the platform, which generates significant additional costs.

The difficulties expressed above can also be encountered when trying to connect an oil platform bridge to a riser. This is particularly the case on oil platforms already installed at sea and for which the operator seeks to increase its production capacity.

An object of the invention is therefore to provide a connection unit which simplifies the connection operation, in particular between the connection unit and a structural element of the marine platform.

For this purpose, the invention proposes a unit for connecting a structural element of a marine platform to a structure for accommodating said unit, the latter comprising means of connection with the host structure, called the first connection means, and at least one connection means with the platform leg, called the second connection means, and a longitudinal axis characterized in that said at least one second connection means is integrated at one end of said unit and adapted to move in a movement comprising at least one radial component between a retracted position ensuring the positioning of said unit inside the leg and an extended position ensuring the connection between the connection unit and the leg, this radial component being defined in a plane perpendicular to said longitudinal axis.

The invention may also include at least one of the following features, taken alone or in combination:

said at least one second connection means comprises at least one elastic zone;

said at least one elastic zone is formed of a set of lamellae separated by openings;

said at least one second connection means is an elastic ring having at least one opening; said at least one second connection means comprises a first element, rigid, this first element being one which is able to move in a movement comprising at least one radial component between said retracted position and said deployed position and at least one second element, in contact with the first element, this second element being able to exert a force on the first element to ensure said movement of the first element;

said at least one of said at least one second element is an elastic means;

said at least one first element is rotatably mounted on an axis belonging to the plane perpendicular to said longitudinal axis;

said at least one second element, elastic, is a spring whose one end is fixed to the connection unit and whose other end is in free contact with the first element;

the axis of rotation of the first element being situated at a distance, taken radially, from said longitudinal axis which is greater than the distance, also taken radially, from the spring to this longitudinal axis, this spring being arranged to exert a force generating a torque on the axis of rotation of the first element to ensure said movement of the first element;

the first element is in the form of a hook;

the spring is arranged to exert a radial force on the first element; said at least one second element is a rigid means;

said at least one second element is rotatably mounted on an axis belonging to the plane perpendicular to said longitudinal axis, this second element having for example a curved shape;

said at least one second element, in the form of a rigid rod displaceable within the connection unit, this rod being provided with a portion whose shape is able to ensure said movement of the first element when said stem is displaced;

said connecting unit is arranged to allow either a rotation of said rod about said longitudinal axis, or a translation along said longitudinal axis so that the portion of said rod provides said movement of the first member;

said at least one second element is a counterweight to said at least one first element and wherein said at least one first element is rotatably mounted on an axis belonging to the plane perpendicular to said longitudinal axis;

said at least one second element is in the form of a chamber adapted to receive a fluid under pressure or a pyrotechnic component to ensure said movement of said at least first element.

The invention also relates to the use of a connection unit according to the invention for connecting a marine platform leg to a reception structure for said unit, said reception structure being floating or disposed on the seabed, or by anchoring, or simply by laying on the seabed. The invention also relates to the use of a connection unit according to the invention for connecting an oil platform bridge to a riser forming a reception structure for said unit.

The invention will now be described in more detail, in support of the appended figures and for which:

Fig. 3, which comprises Figs. 3 (a) to 3 (e), shows a first embodiment of the invention;

Figure 4 shows an alternative embodiment in the first embodiment;

Fig. 5, which includes Figs. 5 (a) to 5 (d), shows another variant in the first embodiment;

FIG. 6, which comprises FIGS. 6 (a) to 6 (c), represents a second embodiment of the invention,

FIG. 7, which comprises FIGS. 7 (a) to 7 (c), shows an alternative to the second embodiment;

Figure 8 shows another variant in the second embodiment; Fig. 9, which comprises Figs. 9 (a) to 9 (b), shows a third embodiment of the invention;

FIG. 10, which comprises FIGS. 10 (a) to 10 (d), shows an alternative to the third embodiment of the invention;

Fig. 11, which includes Figs. 11 (a) and 11 (b), shows another variant in the third embodiment;

Fig. 12 shows another variant in the third embodiment; FIG. 13, which comprises FIGS. 13 (a) and 13 (b), shows a fourth embodiment of the invention;

Fig. 14, which includes Figs. 14 (a) to 14 (c), shows various possible states of a connection unit according to the invention, in use.

In the description which follows, all the embodiments described in support of FIGS. 3 to 14 are made in relation to the application of a connection unit between a marine platform leg and a reception structure for said unit.

Figure 3 shows a first embodiment of the invention. Variations of this first embodiment are described in support of FIGS. 4 and 5.

The common point of these variants with the first embodiment lies in the use of a connection means, between the connection unit and the leg, comprising at least one elastic zone.

More specifically, FIGS. 3 (a) and 3 (b) show a marine platform leg 100 and a connection unit 200 (LMU) before the latter is mounted inside the leg 100, according to a view of section and partial sectional view respectively. Figure 3 (c) shows the connection unit 200 connected to the inside of the leg 100.

The leg 100 comprises a retaining means comprising a plate P extending in the radial plane and fixed to the inner wall of the leg. The plate P also has a central orifice OC intended to receive an end of the connection unit 200. This plate P is advantageously, as shown in the accompanying figures, reinforced by a plurality of fins ALT, belonging to the retaining means, attached to both the plate P and the inner wall of the leg 100. The leg 100 is generally in the form of a hollow cylinder.

The connection unit (LMU) 200 of the marine platform leg 100 to a reception structure (not shown) comprises two connection means 201, 202.

The first connection means 201 is a connection means between the connection unit (LMU) 200 and the host structure. This first connection means 201 is generally in the form of a hole forming a female part for a complementary means provided in the host structure.

The second connection means 202 is a connection means with the platform leg. This second connection means 202 is integrated at one end (E) of said unit. This end E is the opposite end to that which comprises the first connecting means 201 intended to be connected to the receiving structure of the leg. Furthermore, this second connection means 202 is able to move in a movement comprising at least one radial component between a retracted position, ensuring the positioning of the connection unit (LMU) 200 inside the leg 100 and , an extended position, providing the connection between the connection unit (LMU) 200 and the leg 100, this radial component being defined in a plane perpendicular to the longitudinal axis AL of the connection unit (LMU) 200. longitudinal axis AL merges with that of the leg 100 (see Figure 3 (c) for example).

More specifically, in this first embodiment, the second connection means 202 is in the form of at least one elastic element.

This elastic element 202 is integrated at the end E of the connection unit (LMU) 200 by one of its ends E1. This integration secures the elastic member 202 to the connection unit. For example, and as shown in Figures 3 (d) and 3 (e) this integration can be done by housing the end E1 in a housing 203 of the end of the connection unit (LMU) 200, for example by welding. The other end E2 of the elastic element 202 is free. The desired elasticity can in particular be obtained by providing an elastic element provided with LM lamellae. Advantageously, the elastic element has a taper.

In the state of rest (no radial stresses), the elastic element 202 is in an extended position (this is what is shown in all of Figures 3 (a) to 3 (e)). The dimensions of the elastic element 202, at its end E2, are then greater than those of the orifice OC of the retaining means MR provided in the leg 100.

When it is desired to mount the connection unit (LMU) 200 inside the leg 100, the end E of the connection unit passes through the orifice OC of the retention means MR provided for in FIG. inside the leg, which deforms the elastic element, due to the stress applied by the plate P on this elastic element 202. The deformation of the elastic member 202 then allows its passage through the orifice OC. Once this orifice OC crossed, the elastic member 202 returns to its natural position (rest) and then ensures the connection between the connection unit (LMU) 200) and the leg 100.

FIG. 4 represents, in a truncated perspective view, another possible form for the elastic element 202 shown in FIG.

In this variant embodiment, the elastic element is in the form of a ring having an opening O. Here again, an elastic element 202 having a taper is advantageous.

When the elastic element 202 comes into contact with the plate P from below, the latter forces the elastic element 203 to contract, radially. The opening O decreases or even closes completely (retracted position). The elastic element 203 then enters more deeply into a housing 203 provided in the end E of the base 20 to receive the elastic element 203. This then allows the elastic element to pass through the opening OC provided in the plate P and he is helped in this, if necessary by its taper. Once the elastic member 202 has passed the plate, it resumes its natural shape and expands radially to an extended position. The deployed position of the elastic element 202 is that shown in Figure 4, after passage of the orifice OC of the plate. In this deployed position, the connection between the LMU 2 'and the leg is ensured.

Figure 5 shows another variant of the second embodiment.

The first connection means is a connection means between the connection unit (LMU) 200 and the host structure, in accordance with that of the first embodiment, and is therefore not shown and described again.

The second connection means 202 is a connection means with the platform leg. This second connection means 202 is integrated at an end E of said unit. This end E is the opposite end to that which comprises the first connecting means 201 intended to be connected to the receiving structure of the leg. Furthermore, this second connection means 202 is able to move in a movement comprising at least one radial component between a retracted position, ensuring the positioning of the connection unit (LMU) 200 inside the leg 100 and , an extended position, providing the connection between the connection unit (LMU) 200 and the leg 100, this radial component being defined in a plane perpendicular to the longitudinal axis AL of the connection unit (LMU) 200. This longitudinal axis AL merges with that of the leg 100.

In this case, the second connection means 202 comprises an end E11 integrated in a housing 203 provided in the connection unit. This integration is performed so that the end E11 can translate along the housing 203 of the connection unit, in the direction given by the longitudinal axis AL of the connection unit. The housing 203 thus also extends along this longitudinal axis AL. The other end E12 of the first element 202 _! is in the form of a tab extending radially outwards, ie away from the longitudinal axis AL of the connection unit. In this way this tab E12 is able to come into contact with the plate P (from below) belonging to the retaining means of the leg 100.

Between the two ends E11 and E12, the first element 202τ comprises at least one elastic zone LM. This elastic zone is for example in the form of a plurality of elastic lamellae LM separated from one another in pairs by an opening O. A common opening is then provided between each elastic lamella LM and the tab E12. embodiment, the connection unit advantageously has a portion 210 of indented shape, for example conical or pyramidal, to interact with the elastic lamellae LM.

Thus, in FIG. 5 (a), the elastic zone ZE of the connection means 202 is constrained by the presence of the wall P in the retracted position and no relative movement between the end E11 of the first element 202i and the connection unit 200 does not happen. When the leg E12 bears against the wall P, as shown in FIG. 5 (b), any subsequent movement of the connection unit 200 relative to the leg 100 involves the application of an elastic force which tends to deploy, by a movement comprising a radial component, the connecting means 202. This movement is advantageously aided by the notched portion 210 of the connection unit. The connection between the connection unit (LMU) 200 and its leg is thus performed.

Figure 6 shows a second embodiment. Figures 7 and 8 show variants in this second embodiment.

The common point to these variants with the second embodiment lies in the fact that the connecting means between the connection unit and the leg comprises two elements, one of which is rigid and the other elastic.

More specifically, FIGS. 6 (a) and 6 (b) represent the assembly formed by the leg 100, and more particularly its plate P provided with an orifice, and by the connection unit (LMU) 200 with two steps different from the connection between this leg 100 and the connection unit. Figure 6 (c) is a view from above. As for the first embodiment, the connection unit (LMU) 200 of the marine platform leg 100 to a reception structure (not shown) comprises two connection means.

The second connection means 202 is a connection means with the platform leg. This second connection means 202 is integrated at one end (E) of said unit. This end E is the opposite end to that which comprises the first connecting means 201 intended to be connected to the receiving structure of the leg. Furthermore, this second connection means 202 is able to move in a movement comprising at least one radial component between a retracted position, ensuring the positioning of the connection unit (LMU) 200 inside the leg 100 and , an extended position, providing the connection between the connection unit (LMU) 200 and the leg 100, this radial component being defined in a plane perpendicular to the longitudinal axis AL of the connection unit (LMU) 200. longitudinal axis AL merges with that of the leg 100.

The second connection means 202 here comprises a first rigid element 202, mounted on an axis AX belonging to the radial plane, therefore perpendicular to the longitudinal axis AL of the connection unit (LMU) 200. present in the form of a shaft fixed in the connection unit. This assembly allows a pivoting of the first element 2Q2-I around said axis AX. This axis AX is located in the upper part of the end E of the connection unit (LMU) 200.

The second connection means 202 also comprises a second element 202 ₂ , elastic, for example a spring, one end of which is fixed to the connection unit and whose other end cooperates with the first element 202 ^. The attachment between the second element 202 ₂ and the connection unit (LMU) 200 is provided in the lower part of the end E of the connection unit, so that the force exerted by the elasticity of this second element 202 ₂ on the first element 202 ^ maximizes the rotational torque of the first element 202 _! around its AX axis. More generally, an axial offset DA is therefore used between the end of the second element 202 ₂ which is fixed to the connection unit and the axis of rotation AX of the first element 202i to maximize this torque. The existence of this torque is also possible because the second element 202 ₂ is oriented to exert an axial force, a radial offset DR must exist between the position of the axis AX and the fixing position of the second element 202 ₂ on the connection unit (LMU) 200 (the axis AX is radially further from the longitudinal axis AL than is the position of attachment of the second element 202 ₂ to the connection unit). Without this radial offset, the second element 202 ₂ could not print a movement, comprising a radial component, to the first element 202 ^ to move it from its retracted position to its deployed position, in the absence of stress exerted by the plate P . Of course, the spring could be oriented otherwise, that is to say in a radial direction and this question of radial shift DR would no longer be of interest.

It is therefore understood that it is the first element 202 which is caused to undergo a movement comprising at least one radial component. The second element 202 ₂ , in particular when it is a spring, is caused to have an axial movement, along the longitudinal axis AL of the connection unit (LMU) 200.

The connection means 202 may be, at least in part, housed in a housing 203 of the connection unit (LMU) 200, provided for this purpose.

In FIG. 6 (a), the first element 202 _! is constrained by the plate P of the leg retaining means in a retracted position, against the force exerted by the second element 202 ₂ , elastic (spring, for example) on the first element 202T. When a housing 203 is provided, the first element 202 ^ is then held by the wall P in its housing 203. This also implies that the second elastic element 202 ₂ is forced into a retracted position by the first element 202 _! . Once the orifice provided in the plate P has passed, as shown in FIG. 6 (b), the plate P no longer constrains the first element 202-, which, pushed by the force exerted by the second element 202 ₂ , elastic, rotates around its AX axis. The release of the second element 202 ₂ , which for example takes its natural position (case of a spring for example) then allows to maintain the first element 202 · in an extended position. The connection between the connection unit (LMU) 200 and the leg is then ensured.

In FIG. 6 (c), one can observe, by way of nonlimiting example, the presence of several first elements 202. Each of them is associated with a second element 202 ₂ , such as a spring. For example, these first elements may be distributed at regular angular intervals around the longitudinal axis AL of the connection unit (LMU) 200. Thus, if three first elements are provided, an angle α of 120 ° may be provided between However, it should be noted that these angular intervals may be irregular, depending on the dimensional constraints likely to be encountered.

Figure 7 provides an alternative to the second embodiment.

Here, the first element 202i has a hook shape C. Furthermore, the axis AX around which the hook C (202 ^ can pivot is located in the lower part of the end E of the connection unit (LMU) 200 And the fixing of the second element 202 ₂ , elastic (spring, for example) on the connection unit is provided in the upper part of the end E of the connection unit.

When the lower part of the hook C comes into contact with the plate (Figure 7 (a)), this causes the rotation (anti-clockwise, here) of the hook C around its axis AX. This then releases the second element 202 ₂ , which comes to help the rotation of the hook C around its axis AX, always in the same direction of rotation and also prevent any counter-rotation (clockwise, here). Fig. 7 (a) shows the initial step of engaging hook C with plate P and Fig. 7 (b) an intermediate step. After the step shown in Fig. 7 (b), the hook continues its rotational movement to ensure that the bottom portion of the hook C is not or no longer in contact with the plate. Once the second element resumes its natural position, the hook C can no longer disengage from the plate P. The connection unit (LMU) 200 is then connected to the leg and the lower part of the hook does not prevent the normal operation of the connection unit (LMU), operation which will be explained later with the support of figure 14.

The other characteristics of this variant are common with the description carried out in support of FIG. 6. This is particularly the case for the comments of FIG. 7 (c), which are similar to those provided for FIG. vs). In particular also, the second element 202 ₂ , elastic and for example formed of a spring could be oriented radially.

Figure 8 shows another variant of the second embodiment.

In this variant, the first element 202i of the second connection means does not rotate about an axis.

The second element 202 ₂ , elastic is for example in the form of a spring whose one end is fixed to the connection unit and the other end is in contact with the first element 202 ^ so as to exert a force radial on this first element 202 _! .

This radial force is translated by a radial movement of the first element 202

Fig. 9 shows a third embodiment. Alternative embodiments are described in support of Figures 10 to 12.

The common point to these different variants with the third embodiment lies in the fact that the connecting means between the connection unit and the leg comprises two elements, both rigid.

FIG. 9 (a) is a sectional view of an assembly comprising the leg, and more specifically the plate P, and a connection unit 200 before connection and FIG. 9 (b) represents the same thing, but after the connection between the connection unit and the leg.

The second connection means 202 is a connection means with the platform leg. This second connection means 202 is integrated at an end E of said unit. This end E is the opposite end to that which comprises the first connecting means 201 intended to be connected to the structure home leg. Furthermore, this second connection means 202 is able to move in a movement comprising at least one radial component between a retracted position, ensuring the positioning of the connection unit (LMU) 200 inside the leg 100 and , an extended position, providing the connection between the connection unit (LMU) 200 and the leg 100, this radial component being defined in a plane perpendicular to the longitudinal axis AL of the connection unit (LMU) 200. longitudinal axis AL merges with that of the leg 100 (see Figure 3 (c) for example).

The second connection means 202 comprises a first element 202 ^ rigid, able to translate in a radial direction, therefore perpendicular to the longitudinal axis AL of the connection unit (LMU) 200.

The second connection means 202 also comprises a second element 202 ₂ , also rigid, which is mounted on an axis AX of pivoting. This axis AX may be in the form of a shaft attached to the connection unit (LMU) 200. This second element 202 ₂ has a non-linear shape from one end to the other, for example curved (cf. figures). This second member 202 ₂ is disposed below the first member 202 ^ The end of this second member 202 ₂ which is furthest radially from the longitudinal axis AL of the connection unit is dimensioned to cooperate with the plate P of the leg, without being able to pass through the orifice OC of this plate P. Its other end, namely the radially closest end of the longitudinal axis AL of the connection unit is as for it in contact with the first element 202i.

The first 202 and second 202 ^ ₂ elements of the connection means 202 are preferably at least partly accommodated in a housing 203 of the connection unit (LMU) 200 in which they can move.

When one seeks to connect the connection unit (LMU) 200 inside the leg 100, the second element 202 ₂ of the connection means 202 comes into contact with the plate P. The plate P then prints throughout the subsequent raising of said unit 200 inside the leg 100, a rotation of the second element 202 ₂ about its axis AX (anti-clockwise here). The end of the second element 202 which is in contact with the first element 202i then prints a translation movement, in the radial direction, of the first element 202T. The first element then comes into contact with the wall P, from above (FIG. 9 (b)). As for the end of the second element 202 ₂ which is furthest from the longitudinal axis AL of the connection unit, it deviates sufficiently from the wall P so as not to interfere, in use, with the movement of the LMU . The connection between the connection unit (LMU) 200 and the leg 100 is established (not shown).

This solution has similarities to that of Figure 7, in that the two elements 202 ^ 202 ₂ finally act in this third embodiment as a hook. Although this is not shown in the accompanying figures, it is of course conceivable to provide several elements 202 ^ 202 ₂ around the periphery of the connection unit, as has been shown for example in FIGS. 6 (c) or 7 (c) for other achievements.

Figure 10 shows a variant of the third embodiment.

FIG. 10 (a) shows in sectional view an assembly formed by the leg 100, and more precisely the wall P of the retaining means of this leg, and a connection unit (LMU) 200, in which the second connection means is in the retracted position and Figure 10 (b), the same set but when the second connecting means is in the deployed position. Figure 10 (c) is a top view of Figure 10 (a) and Figure 10 (d) is a top view of Figure 10 (b).

The second connection means 202 is a connection means with the platform leg. This second connection means 202 is integrated at an end E of said unit. This end E is the opposite end to that which comprises the first connecting means 201 intended to be connected to the receiving structure of the leg. Furthermore, this second connection means 202 is able to move in a movement comprising at least one radial component between a retracted position, ensuring the positioning of the connection unit (LMU) 200 inside the leg 100 and , an extended position, providing the connection between the connection unit (LMU) 200 and the leg 100, this radial component being defined in a plane perpendicular to the longitudinal axis AL of the connection unit (LMU) 200. longitudinal axis AL merges with that of the leg 100.

In this embodiment, the second connection means 202 comprises at least a first element 202 ^ rigid, able to translate in a radial direction, therefore perpendicular to the longitudinal axis AL of the connection unit (LMU) 200.

The second connection means 202 also comprises at least a second element 202 ₂ , also rigid, intended to cooperate with the first element 202 This second element 2022 is in the form of a rod housed in the connection unit (LMU) 200 pivotable about the longitudinal axis AL of this unit and a portion PT has a suitable shape, during a rotational movement of the rod 202 ₂ about said axis AL to control the deployment of the first element 202 _! .

A housing 203 is advantageously provided in the connection unit for housing the two elements 202 ^ 202 ₂ of the second connection means 202.

The PT portion of the second element 202 ₂ is in this case in the form of a solid whose section is rectangle. In the position shown in Figs. 10 (a) and 10 (c), the first element 202 _! is in its retracted position, and is in this case in the housing 203 of the connection unit (LMU) 200. In this position, the connection unit can pass through the orifice OC of the plate P belonging to to the leg 100. Once the OC orifice exceeded, it actuates the rod 202 ₂ , that is to rotate the rod about its longitudinal axis corresponding to that AL of the connection unit. The portion PT of this rod 202 ₂ , rectangular, also rotates and causes the output of the first element 202i out of its housing 203 to its deployed position. In this deployed position, shown in Figures 10 (b) and 10 (d), the connection unit (LMU) 200 is then connected to the inside of the leg 100. No disconnection is then possible as long as a subsequent rotational movement is not printed on the second member rod 202 ₂ of the second connection means 202.

As can be understood, by rotating the rod 202 ₂ about its axis, the distance (taken radially) between the axis of rotation AL of this rod and the point of contact between the part PT of this rod and the first one is changed. element 202 ^ Indeed, the distance d ₂ (Figure 10 (d) is larger than the distance di (Figure 10 (c)).

The rectangular section for the part PT of the second element 202 ₂ is not the only one that can be envisaged and any solid that makes it possible to obtain a distance d ₂ , taken radially between the longitudinal axis AL of the connection unit and the point of contact. between the second element 202i and the second element 202 ₂ greater than the distance di taken radially between the longitudinal axis AL of the connection unit and the point of contact between the second element 202i and the second element 202 ₂ , when the first element is retracted, may be suitable.

Thus, a solid having a polygonal section, for example square, or rhombus or an elliptical section of this portion PT may be suitable.

Figure 1 1 proposes another variant to the third embodiment.

FIG. 11 (a) shows in sectional view an assembly formed by the leg 100, and more specifically the wall P of the retaining means of this leg, and a connection unit (LMU) 200, in which the second means of connection is in the retracted position and Figure 1 1 (b), the same set but when the second connection means is in the deployed position.

In this variant, the rod forming the second element 202 ₂ of the second connection means 202 does not rotate about its longitudinal axis, which merges with that of the connection unit, but can translate along this axis.

The portion PT of the rod 202 ₂ has an indented shape, for example a pyramidal or conical shape which makes it possible, during the axial displacement of the rod 202 ₂ , to modify the distance between the longitudinal axis AL of the connection unit ( LMU) 200 and the point of contact with the first element 202 _! .

Thus, in FIG. 11 (a), the rod 202 ₂ is held at the bottom of the housing 203 provided in the connection unit and said at least one first element 202i is located in 203. In FIG. 11 (b), the rod 202 ₂ has been moved downwards until the portion PT of this rod is seated against the walls of the housing 203. During the descent of the 202 ₂ rod, causes the radial displacement of the first element 202- _! , which comes to ensure the connection between the connection unit 200 and the leg 100.

Fig. 12 shows another variant in the third embodiment.

In this variant, the first element 202 _! has an axis of rotation AX which extends in a plane perpendicular to the longitudinal axis of the connection unit 200 (LMU). The second element 202 ₂ is a counterweight, of mass M.

When the first element 202i comes into contact, from below, the plate P of the leg, it rotates about its axis AX (anti-clockwise here) and is placed in a retracted position. The force exerted by the plate on the first element 202i then involves the raising of the counterweight 202 ₂ (see Figure 12).

Once the orifice OC of the plate P exceeded, the counterweight 202 ₂ descends by gravity (only force then applied) and causes the rotation (clockwise here) of the first element 202 _! towards his deployed position.

The operation of this variant embodiment thus has similarities with that of the third embodiment (FIG. 9).

Figure 3 proposes a fourth embodiment.

FIG. 13 (a) shows in sectional view an assembly formed by the leg 100, and more specifically the wall P of the retaining means of this leg, and a connection unit (LMU) 200, in which the second connection means is in the retracted position and Figure 13 (b), the same set but when the second connecting means is in the deployed position.

In this other variant, there is no rod to form the second element 202 ₂ of the second connection means 202.

This rod is replaced by a chamber 202 ₂ which can be fed with a fluid under pressure, from a reservoir (not shown).

The remainder is identical to the third embodiment, in its variants using an actuating rod.

In FIG. 13 (a), the chamber is at a pressure that does not involve a pressure differential between this chamber 202 ₂ and the outside of the connection unit (LMU) 200. In practice, the connection unit 200 being intended to be mounted inside the leg 100 out of the water, the pressure in the chamber 202 ₂ is then the atmospheric pressure.

In this case, the first element 202 _! is in its retracted position and is therefore in the housing 203. When a pressurized fluid is injected into the chamber 202 ₂ , this causes the first element 202-1 to move out of the chamber 202 ₂ , thus its deployment in its connection position.

The connection position between the connection unit (LMU) 200 and the leg 100 is shown in Fig. 13 (b). This position does not evolve until the fluid under pressure is removed from the chamber 202 ₂ .

According to one variant, the chamber 202 ₂ is not filled with a fluid under pressure, but with a pyrotechnic component.

When this pyrotechnic component is fired, it generates a force that forces the movement of the at least one first element 202τ in the radial direction.

The various embodiments of the invention described above, or their variants, are particularly advantageous for the intended application.

Indeed, they do not include a housing for the connection unit (LMU) intended to fit into the platform leg, unlike the embodiment of the prior art illustrated in Figure 1. The masses to be handled are therefore lower. The connection proposed in these embodiments is also much easier and poses less practical difficulties than inserting a housing in the leg.

In addition, and with respect to the embodiment of the prior art illustrated in FIG. 2, no non-screw fastening is envisaged. There are therefore few or no accessibility issues. In addition, it is a guarantee of safety because there is no need for an operator performed a screwing operation below the LMU.

In addition, the connection proposed in the context of the invention is fast.

This contributes to meeting the deadlines set in the project.

Finally, it should be noted that once the connection established between the connection unit and the leg, this connection makes reliable the transport of all on the barge to the installation site of the offshore platform.

FIG. 14 generically shows different possible positions of the connection unit 200 (LMU), with respect to the leg 100, in use, namely at rest (FIG. 14 (a)), partially compressed. by the receiving structure 300 (Fig. 14 (b)) and completely compressed by the receiving structure 300 (Fig. 14 (c)).

An LMU indeed comprises, in a conventional manner, an elastomer / metal laminate which thus comprises elastomer layers CELA separated by CME metal layers.

This aspect is not modified within the scope of the invention and therefore applies to all of the embodiments described in support of Figures 1 to 13. This also explains the importance that the second connection means 202, whatever its shape, is designed not to hinder, in use, the movements of the LMU, in particular for Figures 7 or 9.

The invention therefore also relates to the use of an LMU connection unit, 200 according to one invention for connecting a leg of marine platform 100 to a reception structure for said unit, said host structure being floating or arranged on the seabed, either by anchoring or simply by laying on the seabed.

Another use of the connection unit may be envisaged, in which the connection unit will not comprise any laminate as shown in FIG. 1 and a first connection means with a different reception structure from that which is shown on FIG. Figures 1 to 14.

Indeed, the connection unit can be used to connect an oil platform bridge to a riser, riser forming a host structure for said unit.

In this case, the oil or gas extracted by the riser must be able to pass to the oil platform, hence the absence of laminate and a connection (first connection means) different between the connection unit and the riser.

The connection (second connection means) between the connection unit and the bridge of the platform remains however identical to what has been described.

This other use may especially be of interest when it is desired, on an existing platform, to increase the production capacity of the platform. This approach is known by the acronym EOR for "Enhanced Oil Recovery" according to the English terminology.

Claims

1. Connection unit (200) of a structural element (100) of marine platform to a host structure of said unit, the latter comprising a connection means (201) with the host structure, called first means of connection, and at least one connection means (202) with the platform leg (100), called second connecting means, and a longitudinal axis (AL) characterized in that said at least one second connection means (202) ) is integrated at one end (E) of said unit (200) and able to move in a movement comprising at least one radial component between a retracted position ensuring the positioning of said unit inside the leg and an extended position providing the connection between the connection unit and the leg, this radial component being defined in a plane perpendicular to said longitudinal axis.

A connection unit (200) according to claim 1, wherein said at least one second connection means (202) comprises at least one elastic zone (LM).

Connection unit (200) according to the preceding claim, wherein said at least one elastic zone is formed of a set of lamellae (LM) separated by openings.

A connection unit (200) according to claim 1, wherein said at least one second connection means (202) is an elastic ring having at least one opening.

Connection unit (200) according to claim 1, wherein said at least one second connecting means (202) comprises a rigid first element (202-), this first element being one that is able to move according to a movement having at least one radial component between said retracted position and said deployed position and at least one second element (202 ₂ ), in contact with the first element (202 ^, this second element (202 ₂ ) being able to exert a force on the first element (202i) for providing said movement of the first element (202 ^.

6. Connection unit (200) according to the preceding claim, wherein said at least said at least one second element (202 ₂ ) is an elastic means.

7. Connection unit (200) according to the preceding claim, wherein said at least one first element (202 ^ is rotatably mounted on an axis (AX) belonging to the plane perpendicular to said longitudinal axis (AL).

Connection unit (200) according to the preceding claim, wherein said at least one second element (202 ₂ ), elastic, is a spring whose one end is fixed to the connection unit and whose other end is in free contact with the first element (202.

Connection unit (200) according to the preceding claim, wherein the axis (AX) of rotation of the first element (202 ^ being situated at a distance, taken radially, from said longitudinal axis (AL) which is larger than the distance, also taken radially, from the spring to this longitudinal axis (AL), this spring being arranged to exert a force generating a torque on the axis of rotation of the first element (202 ·,) to ensure said movement of the first element (202 ^.

10. Connection unit (200) according to one of claims 7 to 9, wherein the first element (202-i) has the shape of a hook.

11. Connection unit (200) according to claim 6, wherein the spring (202 ₂ ) is arranged to exert a radial force on the first element (2020.

The connecting unit (200) of claim 5, wherein said at least one second member (202 ₂ ) is a rigid means.

13. Connection unit (200) according to the preceding claim, wherein said at least one second element (202 ₂ ) is rotatably mounted on an axis (AX) belonging to the plane perpendicular to said longitudinal axis (AL), this second element having for example a curved shape.

14. Connection unit (200) according to claim 12, wherein said at least one second element (202 ₂ ), being in the form of a rigid rod movable within the connection unit, this rod being provided with a portion (PT) whose shape is adapted to ensure said movement of the first element (202 ^ when said rod is moved.

15. Connection unit (200) according to the preceding claim, wherein said connecting unit is arranged to allow either a rotation of said rod (202 ₂ ) around said longitudinal axis (AL), or a translation along said longitudinal axis ( AL) so that the portion (PT) of this rod ensures said movement of the first element (202 ^.

The connection unit (200) according to claim 12, wherein said at least one second element (202 ₂ ) is a counterweight to said at least one first element (202) and wherein said at least one first element is rotatably mounted on an axis (AX) belonging to the plane perpendicular to said longitudinal axis.

17. Connection unit (200) according to claim 5, wherein said at least one second element (202 ₂ ) is in the form of a chamber (202 ₂ ) adapted to receive a fluid under pressure or a pyrotechnic component for providing said movement of said at least first element (202 ^.

18. Use of a connection unit (LMU, 200) according to one of the preceding claims for connecting a leg (100) of marine platform to a host structure for said unit, said host structure being floating or arranged on the seabed, either by anchoring or simply laying on the seabed.

19. Use of a connection unit (200) according to one of claims 1 to 17 for connecting a bridge (100) of oil platform to a riser forming a host structure for said unit.