EP2247817B1 - Underwater connection installation - Google Patents

Description

The invention relates to the field of hybrid surface tower type connection facilities ("hybrid tower" in English) for conveying fluids and in particular hydrocarbons, from a bottom installation connected to well heads, to a surface installation.

Commonly, the hybrid towers comprise at least one riser pipe, generally rigid, suspended subsurface to a float and anchored in the seabed, and at least one flexible pipe which extends in a catenary, between the riser, at the float , and a surface installation. The riser pipe and the flexible pipe are then connected by means of an underwater connection installation.

The underwater connection installation comprises a frame forming a bracket which is maintained in subsurface by the float formed of generally cylindrical air tanks. Said bracket extends along these cylindrical air tanks and has a foot at the lower end of the tanks for suspending said riser, and a portion overhanging said foot at the upper end of the tanks. It also comprises at least one gooseneck duct, called "gooseneck" in English language, which has an integral end of the foot of the stem and a curved free end outlet which extends into the upper part of the gallows and which is bent towards the lower end of the tanks. The curved free end of the gooseneck pipes engage in a first ramp and are terminated by a first connection which has a first centering lip. Furthermore, said installation comprises at least one connecting piece adapted to be mounted at one end of a flexible pipe. The connection tip comprises a second connector having a second centering lip. In addition, the connecting piece is installed on a second ramp, which may be installed on the stem by means of a plunger and then be guided in translation to the first ramp to coaxially guide said connectors. toward each other and to bring the first and second lips into contact with each other. Then, by installing locking means on the fittings, the sealing is ensured between the rising pipe and the flexible pipe. In particular, we can refer to the document FR 2,497,264 which describes a connection installation of this type.

A major disadvantage of the aforementioned connection facilities is that they require human intervention in the subsurface to establish the connection. The document US 4,102,146 discloses a subsurface installation where the waterproof connection is difficult to achieve, while the document FR 2,497,264 disclose it, a connection method for a background installation.

Also, a problem that arises and that aims to solve the present invention is to provide a connection installation that allows for a subsurface sealed connection between a riser and a flexible pipe while avoiding human intervention subsurface.

In order to solve this problem, and according to a first aspect, the invention proposes an underwater connection installation, or connector for connecting a riser and a flexible pipe intended for the transport of hydrocarbons via a set connection. The installation comprises a bracket adapted to be maintained in subsurface by a float, said bracket having a foot for suspending said riser and an upper portion overhanging said foot, said bracket comprising a gooseneck conduit having an inlet end integral with said foot and a curved free end outlet extending in said upper part of the bracket, said curved free end being terminated by a first connector having a first centering lip and forming a tubular junction. Said installation further comprising a connection piece adapted to be mounted at one end of said flexible pipe, said connection piece comprising a second coupling having a second centering lip, said connection piece and said stem comprising mechanical guiding means for coaxially guide said connectors and bring said first and second lips into contact with each other when said connecting end and said bent free end are driven towards each other. According to the invention, said mechanical guiding means comprise complementary frustoconical crowns, one of said rings being mounted on said upper part of the stem, around said curved free end, so that the axes of said one of said rings and said first connection are substantially parallel, while the other of the crowns is installed on said connecting piece coaxially with said second connector; and driving said connection piece and said curved free end causes the engagement of said frustoconical rings into one another and the coaxial alignment of said connectors, while the contact of said first and second lips causes the self-centering of the fittings.

Thus, a feature of the invention lies in the implementation of complementary frustoconical crowns, one installed around the curved free end and the other on the connection piece so that the approximation of the connection end and the free end curved towards each other causes the engagement of the frustoconical crowns one in the other and accordingly, a first guide connections relative to each other. In this way, despite the difficulties in guiding the subsurface connections, taking into account the sea currents, but also the movement of the surface installations from which the approaching operations are controlled, the connections can nevertheless be guided one towards the other. another with enough precision that their lips come into contact with each other. In addition, the lips have complementary conformations, as will be explained below, which allow precise self-centering of the fittings relative to each other and thus ensure a perfect seal.

Advantageously, the connection installation comprises first locking means, constituting a mechanical locking system, for locking said crowns when they are engaged one inside the other and kept locked and in a fixed position relative to each other. the other. In this position, the connections are held towards each other, lip against lip and they are then self-centered. Thus, preferably, the connection installation comprises second locking means, constituting a hydraulic locking system, for locking said connections when said connections are self-centering. In this way, thanks to the second locking means, the connections are locked relative to each other to ensure a perfect seal between them.

According to a particularly advantageous embodiment of the invention, said first connector has a first collar behind the first lip, while said second connector has a second collar also rearward of the second lip and in that said connecting tip comprises at least two ring segments with two internal shoulders to be driven radially towards each other to maintain gripping the collars to form said second locking means. Thus, before the lips of the connectors are brought into contact with each other, the two ring segments, for example semicircular, are spaced apart from each other to allow the connection of the fittings and also the collars . Then, as soon as the connections are in their position of maximum approach, the collars are also, and then the two ring segments are driven radially towards each other around the connections, so that the internal shoulders take respectively take support behind the collars. In this way, the connections are then completely prisoners of one another.

Preferably, said one of said frustoconical crowns has a base secured to said upper part of the stem and, on the opposite side, a vertex extended by a free cylindrical sleeve, said first lip extending in projection from said free cylindrical sleeve. Thus, the base of the frustoconical crown which is larger in diameter than the top, is integral with the upper part of the stem, so that the top of the frustoconical crown extends beyond the stem. In addition, the frustoconical crown, in its summit, is extended by a free cylindrical sleeve of which the first lip forming the tubular junction of the first connection, extends projecting.

Furthermore, said one of said frustoconical crowns, integral with the stem, has a groove located towards said cylindrical sleeve at the top of the frustoconical crown, while said connection piece comprises radial stop means, or mechanical locking means, adapted to be engaged in said groove, or groove, as will be explained in more detail in the following description, so as to form said first locking means.

Advantageously, said first connector is movably mounted in displacement inside said cylindrical sleeve so as to allow the connectors to be self-centering with respect to each other, when the connection piece is driven towards the upper part. of gallows and frustoconical crowns one in the other. Indeed, said other one of said frustoconical crowns being held in a fixed position with respect to the second connection, when the frustoconical crowns are engaged coaxially one inside the other, the centering of the connections relative to each other when their lips come in contact, requires to allow the lateral movement of the first connection relative to the second.

According to a particularly advantageous embodiment, said other one of said frustoconical crowns has an integral top of said connection piece and on the opposite a free base projecting from said connection piece and inside which the cylindrical sleeve of said one of said rings The frustoconical portion will engage when the connection piece is closer to said curved free end.

Moreover, and particularly advantageously, said first centering lip has a first female frustoconical bearing surface, while said second centering lip has a second male frustoconical bearing surface. In this way, when the lips come into contact, and the second male frustoconical bearing surface is engaged within the first female frustoconical bearing surface, with maximum lateral play, the self-centering of the connections is carried out as and when approaching, the bearing surfaces being driven in sliding against each other for a precise and definitive centering.

In addition, said inlet end of said gooseneck duct is advantageously secured to said foot, while said gooseneck duct extends freely in said bracket, so that said free end is elastically movable relative to said part. upper stem. Indeed, the gooseneck conduit being made of metal, and the distance between its inlet end of its free end outlet is sufficiently large, for example five meters, so that the conduit can bend substantially. This characteristic thus makes it possible to apply the second lip of the second connector against the first lip of the first connector, which is integral with the duct, and to further drive the connection piece towards the free end of the duct, allowing a slight sagging of the latter. In this way, the restoring force of the duct, allows precisely the self centering fittings, as will be explained in more detail in the following description.

According to another particularly advantageous embodiment, said connecting piece is equipped with a retractable flange forming guide means, adapted to come opposite said second connection, whereas said stem has a notch, forming a receptacle, in its part superior to the opposite of said first connection of said curved free end, and said flange being adapted to be engaged within said notch, while said connecting piece is adapted to come opposite said curved free end, said retractable flange being adapted to be retracted to drive said connection piece and said curved free end towards each other.

Thus, the connecting piece and the flexible pipe on which it is mounted, are likely to be guided vertically in the water from the surface, to a subsurface position without the intervention of divers, to come carry the flange in taken in the notch. Then, further unwinding the flexible pipe to the seabed, the connecting piece pivots around the notch through the flange that holds it and adjusts itself facing the curved free end. Then, by retracting the flange, the connection piece is driven towards said curved free end to first engage the frustoconical crowns one inside the other, and then perform self-centering of the fittings.

Preferably, said retractable flange comprises two telescopic arms having, on the one hand two first ends mounted coaxially and in a diametrically opposite position on said connecting piece and secondly, two second opposite ends joined together by a spacer. Advantageously, said retractable flange is pivotally mounted on said connection piece so as to be able to extend first substantially perpendicular to the axis of the second connection of the flexible pipe during the descent of the latter in order to engage it in the indentation. Then, the connecting piece is rotated relative to the flange so that it extends in the extension of the connecting piece opposite the flexible pipe. In this position, it can be retracted to ensure the connection. Advantageously, said connecting piece comprises pivotally locking means of said flange to be able to precisely block in the position substantially perpendicular to the axis of said second connection and in said position opposite said second connection during traction.

In addition, said bracket has receiving means forming a stop between said upper portion and said foot to receive in abutment said connecting piece when the latter pivots around the notch.

The present invention also relates, in a second aspect, a method of laying a hybrid tower, which is intended for the transport of hydrocarbons. The hybrid tower comprises a riser, for example a rigid pipe, an anchoring system of the rising pipe on the seabed and a buoyancy element for suspending said riser substantially vertically to the right of said anchoring system. In addition, said hybrid tower comprises a connection assembly, and more specifically an underwater connection installation for connecting together said riser and a flexible pipe that extends over a catenary from a surface installation to the connection installation. underwater. Said installation comprises a bracket adapted to be maintained in subsurface by said buoyancy element or float. This bracket has a foot for suspending the rising pipe and an upper portion overlooking said foot. It also comprises a gooseneck conduit having an inlet end integral with said foot and a curved free end outlet which extends into said upper part of the bracket. The bent free end is terminated by a first connector having a first centering lip. Furthermore, the bracket has a notch, or receptacle of the connection assembly, in its upper part opposite to said first connection of the curved free end, and whose function will be explained below. The installation also comprises a connection piece adapted to be mounted at one end of the flexible pipe, and it itself comprises a second connection having a second centering lip. The connecting end and the stem comprise mechanical guiding means for coaxially guiding the connections and bringing the first and second lips in contact with each other when the connection piece and the stem are driven towards each other. the other ; said mechanical guiding means comprise complementary frustoconical crowns, one of said rings being mounted on said upper part of the stem, around said curved free end, so that the axes of said one of said rings and said first connection are substantially parallel, while the other said rings are installed on said connecting piece coaxially with said second fitting. The connection piece is equipped with a retractable flange, or guide means, adapted to come opposite said second connection, and also first and second locking means, or locking means. The first locking means are intended to lock said crowns when engaged in one another, while the second locking means are intended to lock together said connectors when they are self-centering. Thus, said method being of the type according to which, in an installation step, the rising rigid pipe is installed with its anchoring means and its buoyancy elements. In addition, said laying method comprises a deployment step, in which is deployed vertically the flexible pipe having its connecting end, which is equipped with its retractable flange and its first and second locking means or locking means. The method comprises an engagement step in which said flange is engaged within said notch or guide means, with the receptacle of the connection assembly. Then, according to a tilting step, one tilts according to a predetermined curve of the flexible pipe until the alignment of the fastening elements, and more precisely said connection piece comes opposite said curved free end. Then finally, according to a traction step, said retractable flange is retracted to drive said connecting piece and said free end curved towards each other. The connection end of the flexible pipe is driven until the engagement of the flexible pipe fastening means with the connection assembly. In other words, the driving of the connection piece towards the free end curved and hence of said connections towards each other causes the engagement of said frustoconical crowns one inside the other and the coaxial alignment of said connectors, while the contact of said first and second lips causes the self-centering of the connectors.

• la Figure 1 est une vue schématique d'une installation de connexion conforme à l'invention dans une situation installée;
• la Figure 2 est une vue schématique en perspective de l'installation de connexion dans la situation telle que représentée sur la figure 1;
• la Figure 3 est une vue schématique en coupe axiale de l'installation de connexion conforme à l'invention ;
• la Figure 4 est une vue schématique de détail de l'installation de connexion représentée sur la figure 3 dans une première position;
• la Figure 5 est une vue schématique de détail de l'installation de connexion représentée sur la figure 3 dans une seconde position; et,
• les Figures 6a à 6d, sont des vues schématiques illustrant les étapes principales de mise en oeuvre de l'installation de connexion conforme à l'invention.

Other features and advantages of the invention will emerge on reading the following description of a particular embodiment of the invention, given by way of indication but not limitation, with reference to the accompanying drawings in which:

• the Figure 1 is a schematic view of a connection installation according to the invention in an installed situation;
• the Figure 2 is a schematic perspective view of the connection installation in the situation as shown in FIG. figure 1 ;
• the Figure 3 is a schematic view in axial section of the connection installation according to the invention;
• the Figure 4 is a schematic detail view of the connection installation shown in FIG. figure 3 in a first position;
• the Figure 5 is a schematic detail view of the connection installation shown in FIG. figure 3 in a second position; and,
• the Figures 6a to 6d are schematic views illustrating the main steps of implementation of the connection installation according to the invention.

The Figure 1 schematically shows a hybrid tower 10 having a rigid rising pipe 12 fixed to a seabed 14 by means of an anchoring system 16. In addition, the rigid pipe 12 has an upper portion 18, or upper end, suspended from a float 20, or a buoy, in which is imprisoned a sufficient amount of air to maintain the rigid pipe in its vertical position. Furthermore, the hybrid tower 10 comprises a flexible pipe 22 which extends catenary between a surface building 24 and the upper end 18 of the rigid pipe 12. Also, an underwater connection installation 26 in accordance with the invention shown in detail on the figure 2 , and forming a connector, makes it possible to connect together the rising pipe 12 and the flexible catenary pipe 22. Reference is made to FIG. figure 2 to describe first details of the connection installation 26.

The connection installation 26 thus comprises a bracket 28, forming a connection assembly, and which is placed between the float 20 and the rising rigid pipe 12, so as to be able to connect the rising rigid pipe to the flexible pipe 22 which is extended catenary between the surface installation 24 and the bracket 28.

The flexible pipe 22 has an end 30 in which is fitted a connection piece 32. Moreover, the connection piece 32 is equipped with two telescopic arms 34, 36 having two first ends 38, 40, mounted coaxially to pivot about an axis perpendicular to the axis of the flexible pipe 22 and in a diametrically opposite position on the connection endpiece 32. The two telescopic arms 34, 36 are here extended in the extension of the connection piece 32 to the opposite of the end 30 of the flexible pipe 22, and they have two second ends 42, 44 joined by a spacer 46 which will be described in more detail in the following description and which is here masked by the bracket 28. The two telescopic arms 34, 36 connected by the spacer 46 then form a pivoting flange.

The bracket 28 has a foot 48 to which is suspended the rigid pipe 18 and an upper portion 50 overhanging the foot 48. This upper portion 50 has a notch 52 forming a hook or a receptacle, within which is precisely engaged l spacer 46 connecting the two telescopic arms 34, 36.

We will now refer to the figure 3 illustrating in more detail the underwater connection installation 26 according to the invention.

There is the upper portion 18 of the rigid pipe and the end 30 of the flexible pipe 22 provided with its connecting piece 32 and the stem 28. It also includes its foot 48 and the opposite, its upper part 50 which overhangs the foot 48 and in which is formed the notch 52.

The figure 3 further illustrates a gooseneck duct 54 which extends through the bracket 28 and which has an inlet end 56 secured to the foot 48 and opposite, a curved free end 58 which extends it, in the upper part 50. The bracket 28 consists of a metal frame with a height of between seven and twelve meters, for example eight meters. The inlet end 56 of the gooseneck conduit 54 is rigidly mounted on the leg 48 of the bracket 28, while the conduit itself extends freely through the bracket 28 through its walls by means of recesses of dimensions much greater than the diameter of the duct 54. In this way, the duct gooseneck 54 is likely to bend substantially when efforts are exerted on the curved free end 58 as will be explained below, without the walls of the gallows 28 does not prevent it. Furthermore, the gooseneck duct 54 has between the foot 48 of the bracket 28 and the upper part 50, in a part away from the bracket 28, a closable T-shaped sleeve forming a trapdoor, so as to be able to introduce the interior of the duct 54, abrasive elements, or also to be able to inject treatment liquids, for example anticorrosion, inside the riser pipe 12.

The bent free end 58 has a first connector 60, which first connector has a first centering lip 62. In addition, and this is one of the essential features of the invention, the upper part 52 of the bracket 28 is equipped with a first frustoconical crown 64 in which coaxially extends the curved free end 58 and the first connector 60 which extends. The first frustoconical crown 64 forms a conical mouth. This first frustoconical crown 64 has a base 66 secured to a wall 68 of the upper part 50, and a top 70 extended by a free cylindrical sleeve 72. In addition, the top 70 of the first frustoconical crown 64 has a groove 74 in rearward of the free cylindrical sleeve 72. Thus, the curved free end 58 extends freely inside the first frustoconical crown 64 so that the first lip 62 of the first connector 60 extends substantially protruding from the free cylindrical sleeve 72 and with play clearance in the inside of this free cylindrical sleeve 72. It will be specified hereinafter with reference to the figure 4 , the operating modalities of these elements thus adjusted.

Moreover, the connecting end 32 carried facing the bent free end 58 has a housing 78 in the bottom 80 which opens the end 30 of the flexible pipe 22 and which on the front face 82 has a second frustoconical crown 84, forming a tapered flared end. In addition, the connecting piece 32 of the flexible pipe 22 has a metal tubular member behind said housing 78, so as to preserve it. Furthermore, the telescopic arms are installed on said tubular member, which provides a relatively rigid connection. In addition, the end 30 of the pipe has an outer protective sheath which extends behind said tubular metal member. This sheath is optionally made of relatively rigid polyurethane, both to preserve the end 30 but also to locally stiffen it so that it does not interfere with the elements of the stem 28 during installation. The end 30 of the flexible pipe 22 ends with a second connection 86 mounted coaxially with respect to the second frustoconical crown 84, and which has a second centering lip 88. It will be observed that the second frustoconical crown 84 is installed on the front face 82 of the housing 78 in contrast to the first frustoconical crown 64, the integral top of the front face 82 and the free base. In addition, the connecting piece 32 comprises first concentric locking means 90 installed inside the casing 78 and behind the second frustoconical crown 84, and also second locking means 92 located inside the casing 78 near the bottom 80, to the right of the second centering lip 88 of the second connector 86. The first concentric locking means 90 consist of two half-rings having two internal half-ribs 91, 93 and they constitute means of radial stopping intended to engage in the groove 74 as will be explained below, while the second locking means 92 comprise two ring segments, respectively having two opposite internal shoulders.

So, in the position as depicted on the figure 3 , in which the connecting piece 32, bearing on an abutment 89, is located opposite the curved free end 58 and the second frustoconical crown 84 opposite the first frustoconical crown 64, the connecting piece 32 goes to be precisely driven in translation substantially along the axis of the curved free end 58 thanks to the telescopic arms 34, 36 described with reference to the figure 2 , which are then retracted by bearing in the notch 52 via the spacer 46. In this way, despite the inherent difficulties of the mounting method and the marine environment, the outer diameter of the free cylindrical sleeve 72 is sufficiently small compared to the internal diameter of the base of the second frustoconical crown 84 so that an axial offset, precisely the second frustoconical crown 84 relative to the free cylindrical sleeve 72, nevertheless allows the engagement of the sleeve 72 inside the second frustoconical crown 84 and then guiding the connection piece 32 when it is driven even more towards the curved free end 58.

We will now explain in more detail, with reference to Figures 4 and 5 , the mode of cooperation of the frustoconical crowns in particular, when the connecting piece 32 is driven towards the curved free end 58. We find first of all on the figure 4 , the first frustoconical crown 64 integral with the wall 68, and the second frustoconical crown 84 inside which the first frustoconical crown 64 is partially engaged. Thus, the top 70 of the first frustoconical crown 64 whose external diameter de1 is equal to that of the outer diameter of the free cylindrical sleeve 72 which extends it, is engaged inside the first frustoconical crown 84 and in particular its top of which the internal diameter di1, to the functional clearance close, is equal to the outer diameter of 1 of the crown 70. In this way, when the connecting end piece 32 is driven axially in translation towards the curved free end 58 according to the arrow F, the sleeve cylindrical free 72 is by the same, guided axially in translation inside the housing 78, and therefore the second connection 86 is driven coaxially towards the first connector 60.

Furthermore, the internal diameter di2 of the free cylindrical sleeve 72 is greater than the outer diameter of 2 of the first connector 60 so as to allow a flicker play of the first connector 60 inside the free cylindrical sleeve 72 and therefore, inside. of the first frustoconical crown 64. Moreover, taking into account the mounting of the duct 54 gooseneck, the first connector 60 is also movable in axial translation relative to the first frustoconical crown 64. Of course, at equilibrium the first connector 60 extends inside the free cylindrical sleeve 72 so that their axes of symmetry are substantially parallel, and that the first centering lip 62 projects from the free cylindrical sleeve 72. On the other hand, when the first connection 60 is driven in movement relative to the free cylindrical sleeve 72, that is to say with respect to the first frustoconical crown 64 and the upper part 50 of stem 28, a restoring force is generated, since the duct 54 in gooseneck is deformed.

Furthermore, the first centering lip 62 has a first female frustoconical bearing surface 94, while on the opposite side the second centering lip 88 has a second male frustoconical bearing surface 96 adapted to fit into each other. the first female frustoconical bearing surface 94. In addition, the first coupling 50 has a first collar 98 bordering the first centering lip 62 and forming a first substantially flared outer shoulder 100, while on the opposite side, the second coupling 86 presents him, a second collar 102 having a second external and flared shoulder 104.

Thus, when the connecting piece 32 is driven axially more towards the curved free end 58, simultaneously the second frustoconical crown 84 will come to cap the first frustoconical crown 64 and come to rest there, while the first and second lips centering 62, 88 will come into contact with each other and more specifically, the frustoconical bearing surface female 94 will also come to cap the male frustoconical bearing surface 96. In this way, before the frustoconical crowns 64, 84 do not support one against the other, the connecting end being nevertheless guided in translation through the cylindrical sleeve 72, thanks to the frustoconical bearing surfaces, female 94 and male 96, which come in contact with each other, the two connections 60, 86 are centered relative to each other, the bearing surfaces coming into friction against one another by forming a ramp, one compared to each other, which can pro to evoke a movement in movement of the first connector 60 inside the free cylindrical sleeve 72. On the other hand, since the frustoconical crowns 64, 84 are supported one inside the other, the connection piece 32 is then locked in translation towards the curved free end 58, while the second connection 86 exerts a slight axial return force on the first connector 60, which is elastically reminded of it by the gooseneck conduit 54, which makes it possible to ensure a support of the centering lips 62, 88 against each other and thus a perfect hydraulic seal.

When this position is reached, the first operation is to actuate the first concentric locking means 90, bringing the two half-rings toward one another to engage respectively the two inner half-ribs 91, 93 in the groove 74 Thus, the two frustoconical crowns 64, 84 are completely integral with one another and they ensure a mechanical locking of the end 30 of the flexible pipe 22 and the curved free end 58 of the gooseneck pipe 54.

We find such a situation on the Figure 5 , where the frustoconical crowns 64, 84 are engaged one inside the other, while the two inner half-ribs 91, 93 are engaged in the groove 74. The centering lips 62, 88, have the first 62, a circular facial groove, while on the opposite side, the second 88 has a circular circular rib engaged in the facial circular groove. In this way, tightness and coaxiality are perfectly ensured. Furthermore, the two ring segments, constituting the second locking means 92, are respectively brought closer to one another so that their two opposite internal shoulders respectively bear against the first outer shoulder 100 of the first collar 98. and the second outer shoulder 104 of the second collar 102. These outer shoulders 100,104 being flared, the radial movement of the two ring segments causes the same, the axial approximation of the two connectors 60, 86. This allows to perfect the seal. These second locking means 92 then constitute a hydraulic locking system ensuring complete sealing of the junction of the two connectors 60, 86.

The present invention also relates to a second object, a method of installation and installation of the hybrid tower. According to the invention, the flexible pipe 22 illustrated is connected to the figure 1 , on the rigid riser 12 previously installed and fixed in its vertical position. Thus, the rigid riser 12 is conventionally fixed to the seabed 14 by means of an anchoring system 16 of the known type and is therefore maintained in its vertical position by means of the buoyancy element, or the float 20, connected at the head of the pipe, and more precisely connected via the bracket 28 illustrated on the Figure 2 , to ensure the tensioning of the riser 12.

The bracket 28 or connection assembly has been pre-installed between the float 20 and the upper part 18 of the rigid riser 12. The connection of the end 30 of the flexible pipe 22 is carried out according to the following illustrated steps on the Figures 6a to 6d .

Thus, we find on the figure 6a the float 20 to which is suspended the bracket 28 which holds the riser 12 via its upper end 18. There is also the flexible pipe 22 which has been deployed vertically away from the buoyancy element, or float 20 connected to the rising rigid pipe 12. Furthermore, the flexible pipe 22 is equipped with its connecting end 32 and the two telescopic arms 34, 36 joined by the spacer 46 are here extended substantially perpendicularly to the axis of the pipe flexible 22 and they are kept locked in this position.

Then, the flexible pipe 22 is directed from the surface building so as to allow the approach and then the engagement of the articulated arm, and more precisely of the two telescopic arms 34, 36 joined by their spacer 46, in the receptacle, or notch 52 located on the connection element, or gallows 28. There is thus on the figure 6b , the spacer 46 which joins the two telescopic arms 34, bearing pivotally in the notch 52, while the two arms, 34, 36 extend perpendicularly to the bracket 28 on either side of its upper portion 50 In this position, the flexible pipe 22 and the riser 12 extend in substantially parallel directions.

In a third step, the articulation of the guide arm, and more precisely the telescopic arms 34, 36 around their respective first two ends 38, 40, is then unlocked and the flexible pipe 22 is deployed according to a predetermined curve, or a predefined stroke, so as to impose at the end 30 of the flexible pipe 22 a rotational movement, and more specifically a reversal movement close to 180 °.

So, the Figure 6c illustrates an intermediate phase of this reversal movement. Indeed, the connecting piece 32 and the end 30 of the flexible pipe 22 are pivotally driven according to the arrow T illustrated in FIG. Figure 6c . This pivoting or rotational movement of the end 30 of the flexible pipe 22 enables it to be brought into the axis of the frustoconical mouth, and more precisely of the first frustoconical crown 64 integral with the connection element. , or stem 28. The perfect orientation of the flexible pipe 22 and more precisely of the connection piece 32, in the axis of the first frustoconical crown 64, or the mouth of the connection element, is obtained after the flexible pipe 22 has been sufficiently deployed below the level of the underwater connection installation 26 and when a point of contact is obtained between the stop 89 and the end 30 of the flexible pipe 22.

Then, the end 30 of the flexible pipe 22 and more precisely the connecting piece 32 which extends it, extends in the axis of the frustoconical mouth of the connection assembly, comprising the first frustoconical crown 64, and the free cylindrical sleeve 72 which extends as well as the connector 60 projecting from the sleeve. The figure 6d indeed shows such an adequate positioning at rest.

In this position, in which the end 30 of the flexible pipe and the connecting piece 32 extend substantially in the axis of the first frustoconical crown 64, and where the telescopic arms 34, 36 extend parallel to this axis, the telescopic arms 34, 36 are then locked in rotation relative to the connection piece 32 at the first end 38, 40. Then, the end 30 of the flexible pipe and more precisely the connection end 32 is then engaged and connected to the frustoconical mouth of the connection assembly, the first frustoconical crown 64, the free cylindrical sleeve 72 which extends and the connector 60, by a traction movement. This movement of traction is ensured by the telescopic articulated arms 34, 36 of the guide element, or flange, which retract to drive the connection piece 32 towards the upper portion 50 of the stem 28 to ensure the embedding of the end 30 of the flexible pipe with the connection assembly. The embedding is then greatly facilitated by the complementary shapes of the mouth and the end of the flexible pipe, or more precisely, by the complementary shapes, on the one hand the two frustoconical crowns 64, 84 which engage one in the other and provide a first guide, and secondly, the lips 62, 88 of the connectors 60, 86 which also engage one into the other, as has been already described with reference to Figures 4 and 5 . Then, the first locking means 90, and the second locking means 92 are then activated sequentially, first the locking mechanical two frustoconical crowns 64, 84 together, then the hydraulic lock, two connections 60, 86.

This double locking system is highly reliable. The weight of the flexible pipe 22 and the environment induce significant forces at the connections of the flexible pipe, and more precisely the second connection 86, with the second connector 60, or tubular junction. The mechanical forces are then taken up by the mechanical locking system and the frustoconical piece, more precisely the first frustoconical crown 64, and are transmitted to the metal structure of the bracket 28, or connection assembly, because of the difference in stiffness between the gooseneck conduit 54 and the metal part.

According to another object, the invention also relates to the housing 78. The latter has the bottom 80 and opposite the front face 82. The front face 82 has the second frustoconical crown 84. The housing 78 includes the first means of concentric locking 90 consisting of two half-rings having two internal half-ribs 91, 93. These concentric locking means 90 are installed inside the housing 78 and behind the second frustoconical crown 84. The housing 78 also includes the second locking means 92 installed close to the fund 80 opposite the first locking means 90. These second locking means 92 comprise two ring segments respectively having two identical internal shoulders.

Claims (17)

1. An underwater connection installation (26) for connecting a riser (12) and a flexible pipe (22) intended for carrying fluids, said installation comprising a post (28) suitable for being held below the surface by a float (20), said post having a base (48) for suspending said riser (12) and a top portion (50) overhanging said base, said post (28) comprising a gooseneck pipe (54) having an inlet end (56) secured to said base and a curved free outlet end (58) which extends into said top post portion, said curved free end being terminated by a first coupling (60) having a first centering lip (62), said installation also comprising a coupling endpiece (32) suitable for being mounted at one end of said flexible pipe (22), said coupling endpiece comprising a second coupling (86) having a second centering lip (88), said coupling endpiece (32) and said post (28) comprising mechanical guidance means (64, 84) for coaxially guiding said couplings and supporting said first and second lips (62, 88) in contact with one another when said coupling endpiece and said curved free end are driven toward one another;
   characterized in that said mechanical guidance means comprise matching frustoconical rings (64, 84), one of said rings (64) being mounted on said top post portion (50), around said curved free end (58), so that the axes of said one of said rings (64) and of said first coupling (60) are substantially parallel, while the other of said rings (84) is installed on said coupling endpiece (32) coaxially with said second coupling (88);
   and in that the driving of said coupling end piece (32) and of said curved free end (58) causes the engagement of said frustoconical rings (64, 84) in one another and the coaxial alignment of said couplings (60, 86), while the contact of said first and second lips (62, 88) causes the self-centering of the couplings.
2. The connection installation as claimed in claim 1, characterized in that it comprises first locking means (90) for locking said rings (64, 84) when they are engaged in one another.
3. The connection installation as claimed in claim 1 or 2, characterized in that it comprises second locking means (92) for locking said couplings (60, 86) when said couplings are self-centered.
4. The connection installation as claimed in claims 2 and 3, characterized in that said coupling endpiece (32) also comprises a casing (78) and in that said first locking means (90) and said second locking means (92) are installed inside said casing (78).
5. The connection installation as claimed in claim 3 or 4, characterized in that said first coupling (60) has a first collar (100) while said second coupling (86) has a second collar (102) and in that said coupling endpiece (32) comprises at least two hoop segments with two inner shoulders designed to be driven radially toward one another in order to keep the collars (100, 102) engaged so as to form said second locking means (92).
6. The connection installation as claimed in any one of claims 1 to 5, characterized in that said one of said frustoconical rings (64) has a base (66) secured to said top post portion (50) and at the other end a top (70) extended by a free cylindrical sleeve (72), said first lip (62) protruding from said free cylindrical sleeve.
7. The connection installation as claimed in claim 2 and 6, characterized in that said one of said frustoconical rings (64) has a groove (74) situated toward said cylindrical sleeve (72), while said coupling endpiece (32) comprises radial stopping means (91, 93) suitable for being engaged in said groove so as to form said first locking means (90).
8. The connection installation as claimed in any one of claims 1 to 7, characterized in that said first coupling (60) is mounted so as to have a range of movement inside said cylindrical sleeve (72).
9. The connection installation as claimed in any one of claims 1 to 8, characterized in that said other of said frustoconical rings (84) has a top secured to said coupling endpiece (32) and at the other end a free base protruding from said coupling endpiece.
10. The connection installation as claimed in any one of claims 1 to 9, characterized in that said first centering lip (62) has a first female frustoconical bearing surface (94), while said second centering lip has a second male frustoconical bearing surface (96).
11. The connection installation as claimed in any one of claims 1 to 10, characterized in that said inlet end (56) of said gooseneck pipe (54) is secured to said base (48), while said gooseneck pipe extends freely in said post (28), so that said free end (58) is able to move elastically relative to said top post portion (50).
12. The connection installation as claimed in any one of claims 1 to 11, characterized in that said coupling endpiece (42) is fitted with a retractable flange (34, 36, 46) suitable for coming to face said second coupling (86), while said post (28) has a recess (52) in its top portion opposite to said first coupling (60) of said curved free end (58), and in that said retractable flange (34, 36, 46) is suitable for being brought into engagement inside said recess (52), while said coupling endpiece (32) is capable of coming to face said curved free end (58), said retractable flange being suitable for being retracted in order to drive said coupling endpiece (32) and said curved free end toward one another.
13. The connection installation as claimed in claim 12, characterized in that said retractable flange comprises two telescopic arms (34, 36) having, on the one hand, two first ends (38, 40) mounted coaxially and in a diametrically opposed position on said coupling endpiece (32) and, on the other hand, two second opposite ends (42, 44) joined together by a crosspiece (46).
14. The connection installation as claimed in claim 12 or 13, characterized in that said retractable flange (34, 36, 46) is mounted pivotingly on said coupling endpiece (32).
15. The connection installation as claimed in claim 14, characterized in that said coupling endpiece (32) comprises means for stopping the pivoting of said retractable flange (34, 36, 46) in a position that is substantially perpendicular to the axis of said second coupling (86) and in said position facing said second coupling.
16. The connection installation as claimed in any one of claims 12 to 15, characterized in that said post (28) has receiving means (89) forming an abutment between said top portion (50) and said base (48) in order to receive as a support said coupling endpiece (32).
17. A method of laying a connection installation as claimed in any one of claims 12 to 16, characterized in that it comprises the following steps:

    - a flexible pipe (22) is supplied fitted with a coupling endpiece (32) at one of its ends, said coupling endpiece having a retractable flange (34, 36, 46) ;

    - a post (28) is supplied having a base (48) and a top portion (50) overhanging said base, said post comprising a gooseneck pipe (54) having an inlet end (56) secured to said base (48) and a curved free outlet end (58) which extends into said top post portion (50), said top portion having a recess (52) forming a hook;

    - a float (20) is provided in order to suspend said post (28) below the surface, between a sea surface and a seabed;

    - a riser (12) is suspended from said base (48) of said post and said riser is anchored in the seabed;

    - said flexible pipe (22) is paid out from said surface by engaging said retractable flange (34, 36, 46) in said recess (52), so that said coupling endpiece (32) swivels around said top post portion (50) in order to extend facing said curved free end (58); and

    - said retractable flange (34, 36, 46) is retracted in order to link together said curved free end (58) and said coupling endpiece (32).

Images