EP1449762A1 - Method and installation of effluent recovery at sea by using a shuttle reservoir - Google Patents

Abstract

The shuttle reservoir has a collecting (2A) and a deploying (2B) form. It is repeatedly lowered to the seabed (7) in its collecting form, where it connects to an evacuation device (6) in the hull (6) of the damaged vessel and is filled and sealed shut. Integral floatation devices lift it to a surface vessel in its deployed form, where it is emptied or stored for transportation to shore : The evacuation device (6) contains a pipe and a first valve acting with an opening in the hull and/or the vessel to recover the effluents by lifting them into the evacuation device. The shuttle reservoir has at least one main internal orifice (5) which works with the evacuation device. These steps are repeated with the same shuttle reservoir until the required amount of effluent has been recovered. The shuttle reservoir has a rigid dome with an open base, a rigid, flat, circular base and a flexible side wall which can be folded up into the filling position and unfolding as it fills to the deployed shape. The floatation elements are integral inside the dome and are preferably a syntactic mousse. The centre of buoyancy is above the apparent centre of gravity in the water. The reservoir can be moved by floating it into a submersible bridge vessel without having to lift it. The shuttle reservoir is held near the sunken vessel by an anchor cable to the seabed and a second anchor cable to the vessel. The reservoir has a second orifice and valve and contains an internal flexible fine mesh pouch to confine viscous elements.

Description

The present invention relates to a method and an installation for recovery of effluents at sea and more particularly polluting effluents contained in a sunken and damaged ship lying at the bottom of the sea.

During the sinking of tankers, the ship generally sinks after being deeply damaged and after losing part of its cargo. When the water depth is great, for example 100 or 200 meters, the recovery of the wreckage or its bailout is generally not envisaged, but the shell must be completely emptied and rinsed, so that the corrosion of the structure over time, creating localized or generalized holes, lead to the release of the contents of the ship, creating pollution which can last for years, even decades.

Many methods and devices have been studied and used in the spent trying to recover highly polluting cargoes but all are very delicate to implement and the operations take a lot of time and generally cause secondary pollution, because the rate of recovery is far from satisfactory, and all the more so since the process must be implemented at great depth.

1) on descend un réceptacle comprenant un orifice inférieur à l'aide de moyens de positionnement à proximité et à la verticale d'au moins une ouverture dans la coque et/ou la cuve du navire mettant en communication l'intérieur de la cuve du navire avec l'extérieur, de manière à récupérer lesdits effluents polluants s'écoulant de ladite ouverture par remontée de ceux-ci dans ledit orifice inférieur dudit réceptacle, et

2) lorsque ledit réceptacle est rempli d'effluents polluants, on remonte ledit réceptacle à l'aide desdits moyens de positionnement jusqu'à ce que des moyens de vidange dudit réceptacle comprenant un orifice supérieur obturable dudit réceptacle et/ou une conduite d'évacuation reliée au dit orifice supérieur à la partie supérieure dudit réceptacle soient accessibles en surface, et

3) on vide ledit réceptacle dans une installation ou navire en surface à travers lesdits moyens de vidange accessibles en surface.

4) on répète les étapes 1) à 3) jusqu'à ce que la quantité voulue d'effluents soit récupérée.

In particular, a process has been described in FR 2 804 935 in the name of the applicant for the recovery of polluting effluents, lighter than water and little or not miscible with water, contained in a tank of a sunken and / or damaged vessel resting on the seabed, which includes the following stages in which:

1) a receptacle is lowered comprising a lower orifice by means of positioning means near and vertically at least one opening in the hull and / or the vessel of the vessel communicating the interior of the vessel of the ship with the outside, so as to recover said polluting effluents flowing from said opening by raising them in said lower orifice of said receptacle, and

2) when said receptacle is filled with polluting effluents, said receptacle is raised using said positioning means until means for emptying said receptacle comprising an upper closable orifice of said receptacle and / or a discharge pipe connected to said upper orifice at the upper part of said receptacle are accessible on the surface, and

3) said receptacle is emptied into an installation or vessel on the surface through said emptying means accessible from the surface.

4) repeating steps 1) to 3) until the desired quantity of effluent is recovered.

a) ledit réceptacle consiste en une cloche en forme d'entonnoir dont la grande base ouverte constitue ledit orifice inférieur et couvre une zone de fuite desdits effluents, ladite zone comprenant une ou plusieurs dites ouvertures dans la coque et/ou la cuve dudit navire, et la petite base supérieure dudit entonnoir donne accès au dit orifice supérieur, et

b) lesdits moyens de positionnement comprennent:

• des moyens d'ancrage dudit réceptacle sur le navire comprenant des câbles reliant des points d'attache fixés sur la circonférence de ladite grande base de l'entonnoir et des points d'attache sur le navire, et
• des moyens de tensionnement comprenant :

• des flotteurs reliés à la circonférence de ladite grande base ouverte dudit réceptacle et autour de la section tubulaire en partie supérieure de la petite base dudit entonnoir, et
• des treuils correspondants aux dits points d'attache sur le navire, et

c) lesdits moyens de vidange comprennent une dite conduite d'évacuation reliée par une extrémité au dit orifice supérieur comprenant ladite section tubulaire en partie supérieure dudit entonnoir, ladite conduite étant mise en tension sensiblement verticalement à l'aide d'un flotteur relié à l'extrémité libre de ladite conduite.

In a first alternative embodiment described in FR 2 804 935:

a) said receptacle consists of a funnel-shaped bell whose large open base constitutes said lower orifice and covers an area for the leakage of said effluents, said area comprising one or more said openings in the hull and / or the tank of said ship, and the small upper base of said funnel gives access to said upper orifice, and

b) said positioning means comprise:

• means for anchoring said receptacle to the ship comprising cables connecting attachment points fixed on the circumference of said large base of the funnel and attachment points on the ship, and
• tensioning means comprising:

• floats connected to the circumference of said large open base of said receptacle and around the tubular section in the upper part of the small base of said funnel, and
• winches corresponding to the said attachment points on the ship, and

c) said draining means comprise a said discharge pipe connected by one end to said upper orifice comprising said tubular section at the top of said funnel, said pipe being tensioned substantially vertically using a float connected to the free end of said pipe.

In this first alternative embodiment, the implementation of said positioning means, during the successive descents and ascents of said receptacle, represents a very long and relatively difficult operation to perform at great depth. In addition, pumping, through a so-called pipe is not possible at such a depth, especially as soon as the effluent has a high viscosity and tends to freeze in the form of paraffin. same if a heating system is installed in the catchment area or in the upper part of the bell during the ascent, the viscous effluent tends to freeze, making pumping very difficult.

• un conteneur rigide de forme sensiblement tubulaire, qui est maintenu en position verticale à l'aide de flotteurs installés au moins à l'extrémité supérieure ou à chaque extrémité supérieure et inférieure dudit conteneur, et
• lesdits orifices supérieur et inférieur dudit conteneur étant obturables de sorte que ledit réceptacle peut être remonté en surface et installé en position horizontale flottante lorsque lesdits orifices sont obturés, ledit réceptacle pouvant alors être remorqué vers une installation ou un navire de stockage desdits effluents.

In a second alternative embodiment described in FR 2 804 935, said receptacle consists of:

• a rigid container of substantially tubular shape, which is held in vertical position by means of floats installed at least at the upper end or at each upper and lower end of said container, and
• said upper and lower orifices of said container being closable so that said receptacle can be raised to the surface and installed in a floating horizontal position when said orifices are closed, said receptacle can then be towed to an installation or a vessel for storing said effluents.

These rigid containers in the form called cigar, by their large, are difficult to descend to the bottom of the sea and, for avoid successive operations, a preferred mode has been described in which said container occupies the entire slice of water between the wreck and the surface. But he it is obvious that this second variant cannot be envisaged for depths of 1000 meters or more, as it involves a receptacle much too large, impossible to install or lower frequently.

In practice, the different embodiments described in FR 2 804 935, not suitable for procedures at depths greater than 1000 meters.

The aim of the present invention is to provide a method and an installation allowing to recover the contents of the holds of a ship, for example a tanker, resting on the seabed, in significant water depths, notably greater than 3000 meters, or even up to 4000 to 5000 meters, and which do not have the drawbacks of previous methods and devices and, in particular which are easy and simple to implement.

a) on installe un dispositif d'évacuation des effluents comprenant de préférence une canalisation et une vanne, coopérant avec une ouverture de la coque et/ou de la cuve de manière à pouvoir récupérer lesdits effluents polluants s'écoulant de ladite ouverture par remontée de ceux-ci jusqu'audit dispositif d'évacuation, et

b) on récupère lesdits effluents s'écoulant de ladite ouverture de la coque et/ou de la cuve,

To do this, the present invention provides a method for recovering pollutant effluents lighter than water, contained in a tank of a sunken and / or damaged ship resting on the bottom of the sea in which:

a) installing an effluent discharge device preferably comprising a pipe and a valve, cooperating with an opening of the shell and / or of the tank so as to be able to recover said polluting effluents flowing from said opening by rising these up to said evacuation device, and

b) recovering said effluents flowing from said opening of the hull and / or of the tank,

1- on descend ledit réservoir navette, depuis la surface jusqu'au fond de la mer, dans sa dite position ramassée et on fait coopérer ledit orifice inférieur du réservoir navette avec ledit dispositif d'évacuation, et

2- on remplit ledit réservoir navette jusqu'à ce qu'il adopte sa dite configuration déployée, puis, une fois rempli d'effluents, on ferme ladite vanne pour le rendre étanche, et

3- on laisse ledit réservoir navette remonter à la surface, une fois rempli, en configuration déployée, ledit réservoir navette, comprenant de préférence des éléments de flottabilité, remontant naturellement vers la surface, et

4- de préférence, on stocke ledit réservoir navette rempli d'effluents dans un navire en surface et on vide ledit réservoir navette dans ledit navire ou on le transporte dans un site pour y être vidé, et

5- le cas échéant, on répète les étapes 1 à 4 avec ledit réservoir navette, ou un autre réservoir navette, jusqu'à ce que la quantité voulue d'effluents soit récupérée.

According to the present invention, in step b) said effluents are recovered using a shuttle tank, which can adopt a picked up configuration and a deployed configuration, said shuttle tank comprising at least one lower orifice preferably equipped with a valve able to cooperate with said discharge device, so that the steps are carried out in which:

1- the said shuttle tank is lowered from the surface to the bottom of the sea, in its said picked-up position and said lower orifice of the shuttle tank is made to cooperate with said evacuation device, and

2- said shuttle tank is filled until it adopts its said deployed configuration, then, once filled with effluents, said valve is closed to make it watertight, and

3- the said shuttle tank is allowed to rise to the surface, once filled, in the deployed configuration, the said shuttle tank, preferably comprising buoyancy elements, naturally rising towards the surface, and

4- preferably, said shuttle tank filled with effluents is stored in a ship on the surface and said shuttle tank is emptied in said ship or it is transported to a site to be emptied there, and

5- if necessary, repeat steps 1 to 4 with said shuttle tank, or another shuttle tank, until the desired quantity of effluents is recovered.

The use of a tank shuttle that can adopt a configuration collected, that is to say compact, makes it easy to descend to the bottom from the sea, and where appropriate, joining together with the wreck, in particular by connecting said lower opening of the tank shuttle with said device evacuation, in particular using an ROV. On the other hand, this so-called shuttle tank, due to the clean buoyancy of oil and its buoyancy elements possible complementary, allows the effluent to rise without the use a bottom-surface connection pipe and / or without pumping, from the surface, effluents to be recovered.

a) un dôme rigide à base ouverte, de préférence avec un profil en forme d'obus en section verticale et une base circulaire,

b) un fond rigide, de préférence plat, dont la périphérie est de préférence circulaire, et

c) une paroi périphérique latérale souple, assurant la liaison de ladite base du dôme avec la périphérie dudit fond de sorte que :

• ladite paroi périphérique latérale peut être repliée sur elle-même, pour permettre le rapprochement dudit dôme et dudit fond, de préférence à l'aide de sangles amovibles, ledit réservoir navette étant alors en dite position ramassée et
• lesdits effluents pouvant être confinés à l'intérieur dudit réservoir navette lorsque ladite paroi latérale est dépliée, ledit réservoir navette étant alors en dite position déployée.

In a particular embodiment, said shuttle tank comprises:

a) a rigid dome with an open base, preferably with a shell-shaped profile in vertical section and a circular base,

b) a rigid bottom, preferably flat, the periphery of which is preferably circular, and

c) a flexible lateral peripheral wall, ensuring the connection of said base of the dome with the periphery of said bottom so that:

• said lateral peripheral wall can be folded back on itself, to allow said dome and said bottom to be brought together, preferably by means of removable straps, said shuttle tank then being in said picked up position and
• said effluents being able to be confined inside said shuttle tank when said side wall is unfolded, said shuttle tank then being in said deployed position.

Said dome, with its profile in particular in the form of a shell in section vertical, associated with said buoyancy elements facilitates the ascent to the shuttle tank surface when full, using only clean buoyancy petroleum and, if necessary, additional buoyancy elements.

Here, by shell profile, we mean an ellipsoid or paraboloid well known to those skilled in the art.

Advantageously, said buoyancy elements of said shuttle tank are integrated inside said dome, said buoyancy elements consisting of preferably in syntactic foam.

Even more advantageously, said buoyancy elements are integrated inside said dome in its upper part, so that the center of buoyancy of said effluent shuttle tank is shifted upwards by relative to its apparent center of gravity in water.

We install enough buoyancy and in a sufficiently high position so that the center of buoyancy, thus shifted upwards, associated with the shape dome profile, allows the shuttle tank to keep, throughout its natural ascent, a substantially rectilinear and vertical trajectory, then, arrived on the surface, to be easily maintained in a horizontal position to be taken trailer and then directed to a storage vessel, preferably a deck vessel submersible, allowing the introduction of said shuttle tank of said vessel without having removing said shuttle tank from the water.

In a particular embodiment, said shuttle tank is kept close to said effluent discharge device using means anchor, comprising cables connecting the first attachment points fixed on the circumference of said bottom of the shuttle tank and of the second attachment points on the ship, or on the seabed, preferably, winches corresponding to said second attachment points, for anchoring said shuttle tank on said ship or on the bottom of the sea.

Said buoyancy elements associated with said shuttle tank ensure the tensioning said cables, thereby maintaining said tank shuttle suspended near and vertically to said hull opening and / or tank and, where appropriate, in cooperation with said discharge device. These anchoring means can be easily implemented using an ROV.

In a preferred embodiment, said shuttle tank comprises, preferably at the bottom, at least a second orifice equipped with a second valve.

This complementary orifice makes it possible to fill said reservoir with sea water. shuttle, once it is stowed so as to cooperate with said device evacuation and thus allowing said shuttle tank to pass from said configuration picked up in its so-called deployed configuration and allowing subsequently the evacuation of sea water when filling said tank shuttle with said effluents flowing from said discharge device.

More preferably, said shuttle tank includes an internal pocket flexible, preferably made of a fine mesh net, capable of confining said viscous effluents, said pocket comprising an opening capable of cooperating, by reversible connection, with said main hole at the bottom allowing the filling of the shuttle tank.

This embodiment, comprising an internal pocket, facilitates emptying of the shuttle tank when it has reached its destination at the emptying site. It will be explained later.

According to a first alternative embodiment, said device for evacuating effluent is installed through an opening in the hull and / or the tank.

In this preferred embodiment, the shuttle tank is manipulated by ROV and is installed directly on the wreckage by making cooperate the lower orifice of said shuttle tank and the opening created in the hull, in a sealed manner, the various elements, as well as the means for locking said elements being able to support the forces created by the overall buoyancy of the tank shuttle full of oil, as well as all the efforts due to sea currents.

According to a second alternative embodiment, said evacuation device, cooperates with an upper orifice of a receptacle, said receptacle comprising a lower orifice positioned near and vertically at least one opening in the shell and / or tank so as to be able to recover said effluents pollutants flowing from said opening by rising thereof in said orifice lower of said receptacle.

This second alternative embodiment makes it possible to recover effluents flowing, in particular from several openings in said shell.

In this second alternative embodiment, a receptacle can be used as described in FR 2 804 935.

• des seconds moyens d'ancrage dudit réceptacle sur ledit navire ou ladite cuve ou ledit fond de la mer comprenant des seconds câbles reliant des points d'attaches fixés sur la circonférence de ladite grande base de l'entonnoir et des points d'attaches sur le navire ou dite cuve ou dit fond de la mer, et
• des moyens de tensionnement comprenant :
  • des flotteurs (reliés à la circonférence de ladite grande base ouverte dudit réceptacle et autour de la section tubulaire en partie supérieure de ladite petite base dudit entonnoir, et
  • de préférence, des treuils correspondant aux dits points d'attaches sur ledit navire ou dite cuve ou dit fond de la mer.

More particularly, said receptacle has a funnel shape, the large open base of which constitutes said lower orifice and covers an area for the leakage of said effluents, said area comprising one or more said openings in the hull and / or the vessel of the ship, and the small upper base of said funnel giving access to said upper orifice of said receptacle and said receptacle cooperating with positioning means comprising:

• second means for anchoring said receptacle on said vessel or said tank or said sea floor comprising second cables connecting attachment points fixed on the circumference of said large base of the funnel and attachment points on the vessel or said tank or said bottom of the sea, and
• tensioning means comprising:
  • floats (connected to the circumference of said large open base of said receptacle and around the tubular section in the upper part of said small base of said funnel, and
  • preferably winches corresponding to the said attachment points on the said vessel or said tank or said bottom of the sea.

The evacuation device can be installed on an existing opening or a pre-drilled opening specially to introduce the evacuation device.

Advantageously, the evacuation device is placed in the upper part of the tank to facilitate installation of the receptacle above the end of the pipe. However, the use of a pipeline allows when necessary install the drainage device on the side walls of the tank in the extent that said pipe can be cleared from the side wall as a function the shape that we make him adopt. The peripheral skirt around the lower opening allows styling, that is to say completely covering said end of the pipe from above and from the sides, so that the effluents go up well in the direction of the open interior orifice and cannot escape.

Said receptacle is kept in suspension close to the vertical of the opening through which the effluents flow so as to overcome the geometry of the ship and not to be dependent on possible instability of the ship.

All the devices described in the present invention allow the recovery of fluids immiscible or not very miscible with sea water and whose density is less than 1 compared to said seawater.

The technology is particularly applicable to hydrocarbons whose density varies from 0.75 for the lightest, up to values close to 1 for the heaviest.

The present invention also relates to the installation useful in a process for recovering polluting effluents contained in the tanks of a ship sunk and / or damaged lying on the seabed according to the invention, characterized in that it includes a said shuttle tank as defined above and, if applicable where appropriate, a said receptacle and, where appropriate, said anchoring means, said positioning means and said tensioning means as defined above.

la figure 1 est une coupe en vue de côté de la cuve ou d'une épave 6 sur laquelle est installé un réservoir navette selon l'invention, en cours de remplissage,

la figure 2 est une coupe en vue de côté d'un réservoir navette 2 en position déployée (2B),

la figure 3 est une coupe en vue de côté d'un réservoir navette 2 en position complètement ramassée (2A),

la figure 4 est une coupe en vue de côté d'un réservoir navette 2 en position intermédiaire (2C) entre les positions déployée (2B) et ramassée (2A),

la figure 5 est une vue de côté d'un réservoir navette 2 en cours de remontée vers la surface, à proximité d'un navire de transport à pont submersible 10,

la figure 6 est une vue en plan d'un navire submersible 10 et de son chargement inachevé de 10 réservoirs navettes,

la figure 7 est une coupe en vue de côté d'une épave ou cuve 6 sur laquelle a été installé un réceptacle 20 de captage de fuites, prêt à recevoir un réservoir navette 2,

les figures 8 et 9 représentent des coupes en vue de côté d'un réservoir navette comportant une poche interne 2₁.

Other characteristics and advantages of the present invention will emerge more clearly on reading the description which follows, given in an illustrative and nonlimiting manner, with reference to the appended drawings in which:

FIG. 1 is a sectional side view of the tank or of a wreck 6 on which a shuttle tank according to the invention is installed, during filling,

FIG. 2 is a sectional side view of a shuttle tank 2 in the deployed position (2B),

FIG. 3 is a sectional side view of a shuttle tank 2 in the fully picked up position (2A),

FIG. 4 is a sectional side view of a shuttle tank 2 in the intermediate position (2C) between the deployed (2B) and picked up (2A) positions,

FIG. 5 is a side view of a shuttle tank 2 being raised to the surface, near a transport ship with a submersible bridge 10,

FIG. 6 is a plan view of a submersible ship 10 and of its unfinished load of 10 shuttle tanks,

FIG. 7 is a sectional side view of a wreck or tank 6 on which a receptacle 20 for capturing leaks has been installed, ready to receive a shuttle tank 2,

Figures 8 and 9 show sections in side view of a shuttle tank having an internal pocket 2 ₁ .

In FIG. 1, the hull of a wreck or a wall of tank 6 resting on the bottom of the sea 7 filled with hydrocarbon 1 whose density is lower than sea water. Said hydrocarbon is confined in the part upper part of the tank or wreck 6, the lower part being filled with water sea. The ship generally having multiple closed openings tightly at the deck, leaks may occur as soon as this seal would be degraded by deformation or rupture of the hull during the sinking.

Is installed, through the shell and / or the wall of the tank 6, an evacuation device 6 ₁ -6 ₃ of the effluents comprising a valve 6 ₁ and a pipe 6 ₂ equipped at its end with a connection flange 6 ₃ to which is connected a corresponding flange 5 ₃ secured to a shuttle tank 2, at its lower part.

The installation of an evacuation device 6 ₁ , 6 ₂ of the effluents is done for example according to the so-called "hot tap" technique, that is to say hot or charged tapping. This technique consists in fixing directly on the outside of the tank, for example by welding, a short length of pipe 6 ₂ equipped with a full-flow valve 6 ₁ . A special machine, not shown, is then installed in the axis of said pipe is y and connected in a sealed manner. The machine is equipped with a drilling machine which, using a tool, will reach the wall of the tank and drill a hole in it, generally with a diameter corresponding to that of the pipe. At the end of the drilling operation, the drill bit is released, the valve closed and the machine can then be dismantled to be replaced by a pipe 6 ₂ , rigid or flexible which will allow the product to be evacuated, without any leakage. has been generated.

Advantageously, the evacuation device described above can be lowered onto the wreck and temporarily stabilized by a dead body, a suction bell device, or a magnetic device, then when the hole has been drilled, said evacuation device. 6 ₁ -6 ₃ is locked permanently by fingers actuated by the ROV, in particular by resting, from the interior of the duct, on the internal face of the hole in the shell and pressing it firmly and tightly, said device on the wall of the wreck.

We will greatly simplify the piercing task by using, within said device, in place of the drill, a high explosive configured in a circle and whose the firing line is directed towards the wall of the wreck, the firing plane being in direct contact with said wall. The explosive fired by the ROV creates in the hull a substantially circular hole of precise size, allowing the transfer of oil gross to the shuttle tank.

Said shuttle tank 2 is shown in FIGS. 1 to 4 and is made up of a flexible and watertight side wall 4, for example made of high strength reinforced plasticized fabric, secured in the upper part of a dome 3 with circular horizontal section and with profile in vertical section in the form of a shell made of a resistant and rigid material, preferably of composite material, and secured in the lower part of a resistant and rigid planar bottom, preferably circular, also preferably of material composite, so as to represent a minimum apparent weight in water, while guaranteeing extreme rigidity and resistance. Said bottom 5 is pierced in its center with a main orifice 5 ₁ and is equipped with a valve 5 ₂ , preferably with full passage, for example of the ball valve type, the latter being equipped with a flange 5 ₃ . A complementary lateral orifice of smaller diameter is provided with a valve 5 ₄ , thus allowing the exchange of sea water between the interior of the shuttle tank and the marine environment, and in particular when filling the tank with oil, to the sea water to escape.

The dome 3 and the bottom 5 can have a diameter of 5 to 10 m, the dome 3 a height of 2 to 5 m and the side wall 4, once unfolded, a height from 10 to 50 m.

Depending on the viscosity of the oil to be recovered, it may be necessary to envisage large diameters for the main orifice 5 ₁ and its associated valve 5 ₂ , for example 10 to 24 ", or even more, and one or more complementary orifices of 1 to 4 "fitted with 5 ₄ valves of corresponding diameter.

The shuttle tank 2 is shown in the deployed position (2B) in Figure 2, the main valve 5 ₂ with full passage being in the open position.

In Figure 3, there is shown in sectional side view the shuttle tank 2 in the final phase of preparation before use, that is to say before it is put in the water and its descent to the wreck or tank 6. In due to the flexibility of the side wall 4, a multiplicity of folds 4 _{1 is created} distributed over the periphery, which makes it possible to reduce the length of the shuttle tank by bringing the bottom 5 closer to the dome 3. Once the folds 4 _{1 have been} initiated, as detailed in FIG. 4, the bottom 5 and the dome 3 are brought as close as possible to obtain a shuttle tank 2 in the picked up position (2A), therefore occupying a minimum of volume, which presents a considerable advantage for its handling, for its Descent to the wreck or tank 6 and for its installation on the evacuation devices 6 ₁ -6 ₃ which have been prepared on the hull of the said wreck or wall of the said tank 6. In the picked up position (2A) such that detailed in FIG. 3, the shuttle tank 2 is firmly held by straps 7 connecting the bottom 5 and the dome 3 each equipped with hooks 7 ₁ at their periphery.

The apparent weight in the water of the shuttle tank 2 is advantageously adjusted by incorporating buoyancy, for example syntactic foam 3 ₁ , made up of glass microspheres coated in epoxy resins, into the highest part of the dome 3, polyurethane or others.

Thus, the shuttle tank 2 is lowered towards the wreck or tank 6 in the picked up position (2A), and has a very low apparent weight in the water and which can be adjusted in positive as in negative, which facilitates its installation directly. by a ROV 30 (automatic submarine piloted from the surface and equipped with manipulator arms). Thus, the ROV manipulates the shuttle tank so as to make the flange 5 ₃ integral with the lower orifice 5 ₁ of the bottom 5 of said shuttle tank 2 coincide, and the corresponding flange 6 _{3 of} said evacuation device installed on the hull of the 'wreck or tank wall 6, then the two flanges 5 ₃ and 6 ₃ are locked together to seal the connection.

In a first embodiment of the method of the invention, the shuttle tank 2 is positioned by the ROV near the wreck and above the evacuation device 6 ₁ -6 ₃ using cables 12 ₁ coming from winches 14 ₁ installed on the shell or wall of the tank 6 or close to it, and connected to attachment ears 13 ₁ secured to the bottom 5 of said shuttle tank 2. By acting on the winches 14 ₁ , the shuttle tank 2 of its connection point constituted by the fixed flange 6 ₃ installed on the hull of the wreck or tank wall 6, then the two flanges 5 ₃ , 6 _{3 are} locked using the ROV.

When the connection is complete, the ROV releases the straps 7 which hold the shuttle tank 2 in the picked up position (2A), then the additional lateral orifice provided with a valve 5 ₄ is open, thus allowing the water to enter, this which leads to the deployed position (2B) described in Figures 1 and 2.

The main valve 5 ₁ with integral passage integral with the bottom 5 of the shuttle tank 2 is then open, likewise the valve 6 ₁ of the evacuation device located on the hull of the wreck or tank wall 6, which, by simple density difference effect between petroleum 1 and sea water, transfers said petroleum 1 upwards, that is to say completes the filling of said shuttle tank. During filling, the corresponding volume of seawater escapes through the additional lateral opening 5 ₄ .

At the end of filling, the two valves 5 ₂ and 5 ₄ of the bottom 5 are closed, the two flanges 5 ₃ and 6 ₃ are released and the shuttle tank 2 full then has positive buoyancy, which allows its transfer to the surface. Advantageously, the shuttle tank 2 is allowed to rise naturally towards the surface because, the shell shape of the dome 3, associated with the buoyancy created by the syntactic foam 3 ₁ integrated into the dome 3 and the weight of the bottom 5, including in particular the flange 5 ₃ connection and the main valve 5 ₂ with ball valve, shifts up the center of buoyancy and downwards the apparent center of gravity in the water, which allows the shuttle tank 2 to keep during all the ascent substantially straight and vertical trajectory, as shown in FIG. 5. The shuttle tank 2 arriving at the surface 11 then floats naturally and can be taken in tow, then directed towards a storage ship 10, preferably a ship with a submersible bridge. Such a ship with a submersible bridge, allows ballasting to maintain the main deck under several meters of water, thus allowing the packages to be transported by flotation, then by deballasting remove the bridge from the water and carry out the transport. "dry" packages. Such vessels are available from many owners, for example Mamoeth (Holland).

Because the shuttle tank 2 is completely free and uncontrollable, it can surface anywhere in the area of operations, and, to avoid any incident, the dome of the shuttle tank is advantageously fitted with a acoustic transponder, so as to be able to locate, during the entire phase of lift, said shuttle tank and thus avoid any collision, by moving the if necessary, the various vessels operating on the surface.

By loading the vessels, as detailed on the Figures 5 and 6, you never have to directly lift the load that represents the filled shuttle tank 2, a load which can be considerable and can reach 200 to 300 tonnes for a shuttle 2 tank of 5 m diameter and 15 m in length.

As detailed in FIG. 6, the shuttle tanks 2 are advantageously stored side by side on simple supports and thus secured with the deck of the carrier ship 10. Ship 10, once loaded, is deballasted, then directed to a port where it is reballasted to effect the transfer shuttle tanks to recovery units. Once released, the ship returns to site for a new load.

In the port area equipped for final recovery, the shuttle tanks 2 are maintained in buoyancy and preferably led into an isolated retention basin, with a view to being emptied of their contents, to avoid any pollution of the environment. The emptying is advantageously carried out horizontally, the shuttle tank 2 still being in flotation, by connecting, on the flange 5 ₃ secured to the bottom 5 of the shuttle tank 2, a pipe, preferably flexible, connected to the pumping system. Since the recovered oil is generally extremely viscous, emptying is facilitated by creating a heating of the area close to the outlet orifice 5 ₁ of the shuttle tank 2, for example by injecting a hot fluid through the complementary lateral orifice 5 ₄ , said hot fluid preferably being crude oil brought to high temperature, that is to say 80 to 100 ° C., which makes it possible to fluidize the viscous oil located near the outlet orifice. When the shuttle tank 2 has been almost emptied, it can then be placed in a vertical position, still within the retention basin, to complete its emptying and rinsing with heated crude oil. Once the emptying is completely finished, the shuttle tank 2 is in the intermediate position (2C) as shown in Figure 3, then it is picked up (2A) as shown in Figure 4 and the assembly is firmly held by straps 7 connecting the bottom 5 and the dome 3. The shuttle tank 2 is again ready to be sent back to the site for a new filling cycle.

a) un réceptacle 20 consistant en une cloche en forme d'entonnoir dont la grande base ouverte constitue un orifice inférieur 19 et couvre une zone de fuite desdits effluents, ladite zone comprenant une ou plusieurs ouvertures 6₄ dans la coque et/ou la cuve 6 dudit navire, et la petite base supérieure dudit entonnoir donne accès à un orifice supérieur 18, équipé d'un dispositif d'évacuation 6₁-6₃, et

b) desdits moyens de positionnement comprenant :

• des moyens d'ancrage dudit réceptacle 20 sur le navire comprenant des câbles 12₂ reliant des points d'attache 13₂ fixés sur la circonférence de ladite grande base de l'entonnoir et des points d'attache 14₂ ou des corps morts existants ou installés sur le navire, ou à proximité dudit navire sur le fond de la mer et
• des moyens de tensionnement comprenant :
  • des flotteurs 15, 16 reliés à la circonférence de ladite grande base ouverte dudit réceptacle et autour de la section tubulaire 17 en partie supérieure de la petite base dudit entonnoir, et
  • des treuils 14₂ correspondants aux dits points d'attache sur le navire,
  de manière à maintenir ledit réceptacle 20 en tension et en suspension à proximité et à la verticale desdites ouvertures 6₄.de la coque ou cuve 6.

FIG. 7 shows an alternative embodiment of an installation according to the present invention in which the shuttle tank 2 cooperates with a drainage device installed at the top of a receptacle 20 as described in FR 2 804 935. More specifically, the installation includes:

a) a receptacle 20 consisting of a funnel-shaped bell whose large open base constitutes a lower orifice 19 and covers an area for the leakage of said effluents, said area comprising one or more openings 6 ₄ in the hull and / or the tank 6 of said vessel, and the small upper base of said funnel gives access to an upper orifice 18, equipped with an evacuation device 6 ₁ -6 ₃ , and

b) said positioning means comprising:

• means for anchoring said receptacle 20 on the ship comprising cables 12 ₂ connecting attachment points 13 ₂ fixed on the circumference of said large base of the funnel and attachment points 14 ₂ or existing dead bodies or installed on or near the ship on the seabed and
• tensioning means comprising:
  • floats 15, 16 connected to the circumference of said large open base of said receptacle and around the tubular section 17 in the upper part of the small base of said funnel, and
  • winches 14 ₂ corresponding to the said attachment points on the ship,
  so as to keep said receptacle 20 in tension and in suspension near and vertically to said openings 6 _{4. of} the shell or tank 6.

Said receptacle 20 is in the form of an inverted umbrella or a funnel of circular or trapezoidal section which covers an entire area comprising several openings emitting polluting effluents.

The size of the funnel of the receptacle 20 can correspond to a diameter of about 25 to 50 m, or even more, and a height of about 25 to 50 m also. It consists of a rigid frame associated with a flexible membrane or a rigid funnel-shaped structure, the upper part 17 of which is equipped with an evacuation device 6 ₁ -6 ₃ comprising a valve 6 ₁ with a pipe 6 ₂ fitted at its upper part with a flange 6 ₃ cooperating with a corresponding flange 5 ₃ at the bottom 5 of the shuttle tank 2.

The bell 20 is held in position by a set of cables 12 ₂ connected, on the one hand, to a fastener 13 ₂ secured to the bell and, on the other hand, to a winch 14 ₂ on the tank or the wreck 6 These cables, preferably 3 cables, are installed to form a pyramid, preferably with an equilateral triangular base. Thus, the position of said bell can be adjusted and kept as close as possible to the wreck, for example at 50 cm or 1 m, so that the lower end of the large open base of the funnel which constitutes the peripheral skirt defining the lower opening 19 of said receptacle 20 can cover the evacuation device 6 ₁ -6 ₃ possibly equipped with a valve pipe 6 ₅ from the wall of the tank or wreck 6 as shown in FIG. 7 , and so as to avoid pollution being carried away by the current and then escaping from the collector that constitutes the bell. In the event that the wreck rests horizontally on the bottom, the entire system of ship's pipes will interfere with the bell which cannot be installed as close as possible, but by adjusting, by means of the winches 14 ₂ , the lengths of the cables 12 ₂ . Said bell 20 will be held in a position allowing the recovery effect to be optimized. The winches 14 ₂ can be installed either on the wreck or on the bell or on moorings placed on said wreck or located in the immediate vicinity of the wreck.

Said receptacle 20 is made floating by means such as buoys 15, 16 in syntactic material resistant to bottom pressure or by buoys hollow in various materials, such as plastics, steel or materials composites.

The receptacle is held in position using a peripheral float 16 surrounding the tubular upper part of the funnel and a series of floats 15 connected to the circumference of the large base of the funnel in its part lower.

Said receptacle 20 comprises heating means 21 of said polluting effluents 1 to make them less viscous and means of insulation thermal of its outer wall 22.

Indeed, in the case of light products, therefore with low viscosity, the difference in density of the product with respect to seawater is sufficient for the product to be transferred upwards naturally. On the other hand, as soon as the product has a density close to 1 as well as a high viscosity, or tends to freeze in the form of paraffin, an additional heating system 6 ₆ is advantageously installed in the collection zone 6 ₄ , thus than in the upper part of the bell 20, the outside of said bell preferably being protected by thermal insulation 22.

An assistance vessel 31 supplies the power necessary for reheating and the operation of ROV 30 via an umbilical 32, as explained in Figure 7.

Preferably, as shown in patent application FR 2 804 935, the attachment points on the wreck or tank 6 and in particular the winches 14 ₁ and 14 ₂ are advantageously fixed to the wreck using a suction box comprising an open face at the interface with the wreck and which cooperates therewith by a peripheral seal and a suction pipe making it possible to create a vacuum in the interior of the box. Indeed, if out of water, such a device allows with a high vacuum, or about -1 bar, to obtain a holding force of 10 t / m ² of surface at the joint plane, by depths of 100 m, the pressure difference between vacuum and ambient pressure will be 11 bars and the same surface will then allow a holding force of 110 tonnes for the surface of 1 m ² .

The pipe can either be in communication with a pump installed on ROV, either replaced by a pump secured to the suction box and supplied by said ROV or directly from the service vessel installed on the surface.

In a preferred version shown in Figures 8 and 9, the shuttle tank 2 has a removable bottom 5 connected, for example by means of bolts not shown, to a peripheral flange 5 ₅ secured to the lower end of the flexible side wall 4 Inside the shuttle tank 2, an internal pocket 2 ₁ is advantageously installed constituting, by itself, a second flexible envelope, of dimensions similar or even slightly smaller than those of the external envelope constituted by the whole of the dome 3 of the flexible side wall 4 and of the bottom 5 of the shuttle tank 2. Said pocket 2 ₁ consists of a fine mesh net, having a single opening downwards, the latter coming to cooperate with a portion of pipe 5 ₆ in continuity from the main port 5 ₁ from the bottom 5 of the shuttle tank 2 inwards. Said second inner envelope or pocket 2 ₁ is made integral with said pipe portion 5 ₆ by a strap 5 ₇ . Thus, during the filling of the shuttle tank 2 with crude oil 1 with very high viscosity, the entire product is stored inside the pocket 2 ₁ and remains confined therein because of the small size of the meshes and the viscosity considerable intrinsic to crude oil. When the shuttle tanks 2 have been unloaded in the recovery port site, each of the shuttle tanks is towed horizontally into the retention basin, then, still in a horizontal position, a ring 3 ₂ secured to the dome 3 is connected to a mooring point 9 secured to the edge of the basin; the fixing bolts, or the latches of the flange 5 ₅ , connecting the flexible side wall 4 and the bottom 5 of the shuttle tank 2, are then released, then the whole of the bottom 5, secured to the internal pocket 2 ₁ , and the dome 3, integral with the side wall 4, constituting an external envelope, are separated over a few meters.

A link made with a simple cord is tightened around the lower orifice of the pocket 2 ₁ at the level of the plane AA, passing through eyelets 5 ₈ , then tightened firmly so as to close, tightly, the pocket. The pocket 2 ₁ is then separated from the bottom 5 of the shuttle tank 2 by loosening the strap 5 ₇ , and said bottom 5 is removed. The pocket 2 ₁ is then completely removed from the shuttle tank 2.

The shuttle tank is then released and, after reinstallation of a new internal pocket 2 ₁ , strapped 5 ₇ on the bottom 5 of said shuttle tank 2, the latter is re-assembled using bolts on an external envelope, consisting in the dome 3 secured to the flexible side wall 4, and the assembly is then ready to be placed in the picked up position (2A) as explained in FIGS. 3 and 4.

The pocket 2 ₁ once extracted, floats within the retention basin. It is then directed, still in flotation, towards a cradle, which will then be extracted from the basin using a high capacity crane, to be transferred, after draining the residual water, to a second retention basin where the bag will be unloaded in order to be prepared, either to be eliminated, or to be treated for the reuse of some of its constituents.

Depending on the type of oil that we want to recover, we are led to favor certain characteristics of the various devices according to the invention. Thus, in the case of very high viscosity oils, for example from 500,000 to 1 million centistokes, the diameter of the main orifice 5 ₁ , of the pipes 6 ₂ and of the valves 5 ₂ -6 _{1 will be increased} as much as possible. transfer and we will try to minimize the length of said evacuation device 6 ₁ -6 ₃ between the shuttle tank and the wall of the wreck. Likewise, the full-flow valves may, due to the very high viscosity of the product, only exhibit poor sealing, therefore being of very simplified technology, for example of the iris type, that is to say of the "diaphragm type. photographic "with full closure.

In the case of fluid oils, the diameter of the main orifice may be reduced to 10-12 "or less and the valves replaced by simple portions of rubber tubing which can be closed off by simply pinching between two rules, type of seal being commonly used in peristaltic pumps, will not be developed in these details and constitutes within the framework of the invention a type of full-flow shut-off valve.

We remain in the spirit of the invention when we partially replace or totally the rigid dome 3 previously described by an inflatable structure, dome-shaped, said structure being of the type used by small craft Zodiac type, the inflation to obtain the shape being carried out with sea water by the ROV, after lowering the shuttle tank and placing it on the wreck.

Claims (12)

Method for recovering pollutant effluents (1) lighter than water, contained in a tank (6) of a sunken and / or damaged ship lying on the sea bottom (7) in which: a) installing an evacuation device (6 ₁ -6 ₃ ) of the effluents preferably comprising a pipe (6 ₂ ) and a valve (6 ₁ ), cooperating with an opening (6 ₄ ) of the hull and / or the tank (6) so as to be able to recover said polluting effluents (1) flowing from said opening (6 ₄ ) by raising them up to said discharge device (6 ₁ ), and b) recovering said effluents (1) flowing from said opening (6 ₄ ) of the shell and / or of the tank (6), characterized in that in step b) said effluents are recovered using a shuttle tank (2), which can adopt a picked up configuration (2A) and a deployed configuration (2B), said shuttle tank ( 2) comprising at least one lower orifice (5 ₁ ) preferably equipped with a valve (5 ₂ ) capable of cooperating with said discharge device (6 ₁ -6 ₃ ), so that the steps are carried out in which: 1- the said shuttle tank (2) is lowered from the surface (11) to the bottom of the sea (7), in its said picked up position (2A) and the said lower orifice (5 ₁ ) of the shuttle tank is made to cooperate (2) with said evacuation device (6 ₁ -6 ₃ ), and 2- said shuttle tank (2) is filled until it adopts its said deployed configuration (2B) then, once filled with effluents (1), said valve is closed to make it watertight, and 3- the said shuttle tank (2) is allowed to rise to the surface, once filled, in the deployed configuration (2B), the said shuttle tank (2) preferably comprising buoyancy elements (3 ₁ ), rising naturally towards the surface, and 4- preferably, store said tank filled with effluents (1) in a ship (10) on the surface and empty said shuttle tank (2) in said ship (10) or transport it to a site to be emptied there , and 5- if necessary, repeat steps 1 to 4 with a shuttle tank (2), or another shuttle tank (2), until the desired quantity of effluent (1) is recovered. Method according to claim 1, characterized in that said shuttle tank (2) comprises: a) a rigid dome (3) with an open base, preferably with a shell-shaped profile in vertical section and a circular base, b) a rigid bottom (5) preferably flat, and the periphery of which is preferably circular, and c) a flexible lateral peripheral wall (4) ensuring the connection of said base of the dome (3) with the circumference of said bottom (5) so that: said lateral peripheral wall (4) can be folded back on itself, to allow bringing together said dome (3) and said bottom (5), preferably using removable straps (7), said shuttle tank (2) then being in said picked up position (2A) and said effluents (1) being able to be confined inside said shuttle tank (2) when said side wall (4) is unfolded, said shuttle tank (2) then being in said deployed position (2B). Method according to claim 1 or 2, characterized in that said buoyancy elements (3 ₁ ) of said shuttle tank (2) are integrated inside said dome (3), said buoyancy elements (3 ₁ ) preferably consisting , into syntactic foam. Method according to claim 3, characterized in that said buoyancy elements (3 ₁ ) are integrated inside said dome (3) in its upper part, so that the center of buoyancy of said shuttle tank (2) filled with effluent (1) is offset upwards from its apparent center of gravity in water. Method according to one of claims 1 to 4, characterized in that said shuttle tank (2) filled with effluents (1), once raised to the surface, is transferred by flotation in a ship with submersible bridge (10) without having to raise. Method according to one of claims 1 to 5, characterized in that said shuttle tank (2) is kept close to said effluent discharge device (6 ₁ -6 ₃ ) by means of anchoring means (12 ₁ -13 ₁ -14 ₁ ), comprising cables (12 ₁ ) connecting first attachment points (13 ₁ ) fixed on the circumference of said bottom (5) of the shuttle tank and second attachment points (14 ₁ ) on the ship, or the sea floor (7), preferably, winches (14 ₂ ) corresponding to said second attachment points, making it possible to anchor said shuttle tank on said ship (6) or on the bottom of the sea (7). Method according to one of claims 1 to 6, characterized in that said shuttle tank (2) comprises, preferably at its said bottom (5), a second orifice equipped with a second valve (5 ₄ ). Method according to one of claims 1 to 6, characterized in that said shuttle tank (2) comprises a flexible internal pocket (2 ₁ ), preferably consisting of a fine mesh net, capable of confining said viscous effluents, said pocket comprising an opening capable of cooperating, by reversible connection, with said main orifice (5 ₁ ) at the bottom (5) allowing the filling of the shuttle tank (2). Method according to one of claims 1 to 8, characterized in that said effluent discharge device (6 ₁ -6 ₃ ) (1) is installed through an opening (6 ₄ ) in the hull and / or the tank (6). Method according to one of claims 1 to 8, characterized in that said discharge device (6 ₁ -6 ₃ ) cooperates with an upper orifice (18) of a receptacle (20), said receptacle (20) comprising a lower orifice (19) positioned near and vertically at least one opening (6 ₄ ) in the shell and / or tank (6) so as to be able to recover said polluting effluents (1) flowing from said opening (6 ₄ ) by raising them in said lower orifice (19) of said receptacle (20). Method according to claim 10, characterized in that : a) said receptacle (20) has a funnel shape, the large open base of which constitutes said lower orifice (19) and covers an area for the leakage of said effluents, said area comprising one or more said openings (6 ₄ ) in the hull and / or the vessel (6) of the ship, and the small upper base of said funnel giving access to said upper orifice (18) of said receptacle (20) and said receptacle (20) cooperating with positioning means comprising: second means for anchoring said receptacle (20) on said vessel or said tank (6) or said seabed (7) comprising second cables (12 ₂ ) connecting attachment points (13 ₂ ) fixed on the circumference of said large base of the funnel and of the attachment points (14 ₂ ) on the ship or said tank (6) or said sea bottom (7), and tensioning means (15-16-14 ₂ ) comprising: floats (15-16) connected to the circumference of said large open base of said receptacle (20) and around the tubular section (17) in the upper part of said small base of said funnel, and preferably winches (14 ₂ ) corresponding to said points of attachment to said vessel or said tank (6) or said bottom of the sea (7). Useful installation in a process for recovering polluting effluents contained in the tanks of a sunken and / or damaged ship lying on the seabed according to one of claims 1 to 11, characterized in that it comprises a said tank shuttle (2) as defined in one of claims 1 to 9 and, where appropriate, a said receptacle (20) and, where appropriate, said anchoring means (12 ₁ -13 ₁ -14 ₁ ) and said positioning means (12 ₂ -13 ₂ -14 ₂ ) and said tensioning means (14 ₂ -15-16) as defined in one of claims 6, 10 or 11.

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