EP2171163B1 - Device for extracting a material from the bed of a body of water and associated method - Google Patents

Description

The present invention relates to a device for extracting a material situated at the bottom of a body of water according to the preamble of claim 1.

This system applies, for example, to the mining of the seabed, or the earthworks of the submarine soils for the establishment of hydrocarbon production facilities.

We know FR-A-2,467,283 a device of the aforementioned type. This device comprises a surface installation carried by a ship, and a bottom assembly. This set includes a base station and an extraction vehicle traveling on the seabed and connected to the base station by a flexible link designated by the English term "jumper".

The bottom assembly is lowered into the water using a string of rigid rods that connects the base station to the surface installation. The drill string internally delimits a circulation passage of material taken from the bottom, to convey it to the surface.

In addition, a gas injection line in the drill string and electric power transfer lines forming a link termed "umbilical", have descended into the sea to the intermediate station from the ship. An example of an umbilical is described in the application GB 2,395,539 .

To deploy the device, it is necessary to successively mount each stem of the drill string on the surface ship during the descent of the bottom assembly, then to simultaneously lower the gas injection line and the umbilical including the power lines, assembling them on each rod.

As a result, the ship must have a very large storage space for the assembly and storage of rigid tubes and the umbilical.

FR 2,313,547 and JP 49 066504 describe extraction devices. An object of the invention is to obtain a device for extracting a material located at the bottom of a body of water that is simple to implement and compact.

For this purpose, the subject of the invention is a device according to claim 1.

The device according to the invention may comprise one or more of the features of claims 2 to 14.

The invention further relates to an extraction process according to claim 15.

• la figure 1 est une vue schématique de côté et en perspective partielle d'un premier dispositif d'extraction selon l'invention, avec son conduit flexible déployé ;
• la figure 2 est une vue schématique en coupe partielle d'un détail marqué II de la figure 1 ;
• la figure 3 est une vue en perspective partiellement éclatée du conduit flexible du premier dispositif selon l'invention ;
• la figure 4 est une vue schématique partielle en perspective de trois-quarts face, du tambour d'enroulement du conduit flexible de la figure 1, le conduit flexible étant partiellement enroulé autour du tambour ;
• la figure 5 est une vue analogue à la figure 4 du tambour sans le conduit ;
• la figure 6 est une vue en bout, prise suivant la flèche VI de la figure 4 ;
• la figure 7 est une vue prise en coupe partielle suivant le plan vertical longitudinal VII de la figure 4,
• la figure 8 est une vue analogue à la figure 2 d'un deuxième dispositif selon l'invention comprenant une unité de pompage par injection d'eau ;
• la figure 9 est une vue analogue à la figure 8 d'un troisième dispositif selon l'invention ;
• la figure 10 est une vue en coupe transversale suivant le plan X-X de la figure 9 ; et
• la figure 11 est une vue analogue à la figure 1 d'un quatrième dispositif selon l'invention.

The invention will be better understood on reading the description which follows, given solely by way of example, and with reference to the appended drawings, in which:

• the figure 1 is a schematic side view and partial perspective of a first extraction device according to the invention, with its flexible conduit deployed;
• the figure 2 is a schematic view in partial section of a marked detail II of the figure 1 ;
• the figure 3 is a partially exploded perspective view of the flexible conduit of the first device according to the invention;
• the figure 4 is a partial schematic view in perspective of three-quarter faces, the winding drum of the flexible duct of the figure 1 the flexible conduit being partially wrapped around the drum;
• the figure 5 is a view similar to the figure 4 drum without the conduit;
• the figure 6 is an end view, taken along arrow VI of the figure 4 ;
• the figure 7 is a view taken in partial section along the longitudinal vertical plane VII of the figure 4 ,
• the figure 8 is a view similar to the figure 2 a second device according to the invention comprising a pumping unit by water injection;
• the figure 9 is a view similar to the figure 8 a third device according to the invention;
• the figure 10 is a cross-sectional view along plane XX of the figure 9 ; and
• the figure 11 is a view similar to the figure 1 of a fourth device according to the invention.

An extraction device 10 according to the invention is represented on the Figures 1 to 10 . This device 10 is intended to collect materials located at the bottom of a body of water 12 such as a sea, an ocean or a lake.

The body of water 12 rests on a bottom 14 delimited by solid material comprising rocks and / or sediments.

The purpose of the device 10 is to carry out, for example, earthworks on the bottom 14 with a view to setting up a hydrocarbon exploitation facility, or to withdraw ores deposited on the bottom 14 with a view to making them available. subsequent exploitation at surface 16 of the body of water 12.

As illustrated by figure 1 the device 10 comprises a surface installation 18 carried by a ship 20, a bottom assembly 22 for taking the material on the bottom 14 of the water body 12, and, according to the invention, a flexible conduit 24 of the "integrated production bundle" or "Integrated Production Bundle" type for connecting the bottom assembly 22 to the surface installation 18.

The bottom assembly 22 comprises a base station 26 attached to the lower end of the conduit 24, an excavating vehicle 28, placed in contact with the bottom 14 of the water body 12, and a flexible link 30 connecting the vehicle 28 at base station 26.

The base station 26 is intended to be placed in the vicinity of the bottom 14, away from it during the exploitation of materials. The base station 26 comprises equipment (not shown) for pumping and treating the sampled material, for example pumps or filters, and control means for the excavating vehicle 28.

The excavating vehicle 28 is intended to come into contact with the bottom 14 to collect material on the bottom 14. It comprises the displacement means 32 on the bottom 14 and means 34 for taking the material, able to dig, scrape or drill the material constituting the bottom 14 and transport it to the flexible link 30.

The bottom of the base station 26 is provided with a hatch (26A ( Figure 1 ) pivoting by appropriate means, not shown. This hatch 26A allows in its open position to evacuate the materials blocked in the base station 26. In this case, the excavating vehicle 28 is placed below the base station 26 and these materials fall into the vehicle 26 where they are crushed.

An example of an excavating vehicle is described in the French application FR-A-2,467,283 .

The flexible link 30 is sometimes referred to as the "jumper". It is formed of a hollow and flexible pipe having an upper end connected to the base station 26 and a lower end connected to the vehicle 28, to take the material from the sampling means 34. The flexible pipe 36 internally delimits a light 37 of material flow opening opposite the sampling means 34 and in the base station 26.

The flexibility of the flexible link 30 is greater than that of the flexible conduit 24.

The vehicle 28 is mobile with respect to the base station 26, in particular on the bottom 14, up to a maximum distance from the base station 26 substantially equal to the length of the flexible pipe 36. This maximum distance is between 10 m and 40 m and preferably less than 50 m.

As illustrated by figures 1 and 2 the flexible conduit 24 extends between a first point 38 located at its upper end on the surface installation 18, and a second point 40 located at its lower end on the base station 26.

According to the invention, the duct 24 is flexible over its entire length, taken between the points 38, 40. Thus, as will be seen below, the duct 24 is adapted to be wound on a rotating drum between an unwrapped configuration and a helically wound configuration, in which it occupies a radius of curvature of between 12 m and 15 m and preferably less than 20 m.

As illustrated by figures 2 and 3 , the flexible duct 24 comprises a central pipe 42 for transporting the material taken from the bottom 14, from the base station 26 to the surface installation 18.

The duct 24 further comprises, around the duct 42, an outer functional sheet 43 receiving functional lines 44 able to transmit electrical or hydraulic power, information and / or fluids from the surface installation 18 to the bottom assembly 22, the lines 44 being disposed in the outer ply 43 around the transport pipe 42.

The duct 24 also comprises a line 46 for injecting gas for driving the material into the transport pipe 42, disposed in the ply 43 and a sheath 47 for external protection disposed around the ply 43.

The transport pipe 42 is generally in accordance with the API 17J standard. It is flexible throughout its length. It comprises, for example, from the inside to the outside, an internal tubular metal casing 47A for the resistance to pressure, a gas-tight plastic sheath 47B, an outer casing 47C and two layers of armor wires 47D to ensure tensile strength.

The conveying line 42 delimits internally a passage 48 for circulation of sampled material which opens on the one hand, at the first point 38, and on the other hand, at the second point 40. The transport pipe 42 is connected in series with the tube flexible 36, so that the inner lumen 37 opens into the passage 48.

The sheet 43 is of generally annular shape. It is arranged externally around the transport pipe 42 and internally delimits longitudinal passages 48A for receiving lines 44, 46 in which lines 44, 46 are inserted.

The functional lines 44 comprise, for example, an electric power transfer line electrically connecting the surface installation 18 to the bottom assembly 22 to electrically power the base station 26 and the vehicle 28. The lines 44 further comprise a line transporting information connecting the surface installation 18 to the control means on the base station 26 for controlling the vehicle 28.

The length of the flexible duct 24, taken between the first point 38 and the second point 40, is variable depending on the depth at which the seabed is located and preferably greater than 1000 m.

In the example shown in the figure 1 , the flexible duct 24 is formed by the end-to-end assembly of a plurality of flexible unitary sections 50 of length preferably between 300 m and 400 m.

Each section 50 thus comprises a tubular central portion 52 and at each end a fastening flange 54 to an adjacent section 50.

As illustrated by figure 2 , the flanges 54A, 54B of two adjacent sections 50 are fixed against each other for example by screwing.

The flanges 54A, 54B protrude radially outwardly relative to the central portion 52. They have an outside diameter greater than the average outside diameter of the central portion 52.

Each unit section 50 delimits a portion of the inner passage 48 and carries a unitary section of the lines 44 and 46 which are interconnected through the attachment flanges 54A, 54B.

The vessel 20 defines a platform 60 supporting the surface installation 18 extending between two side edges 62 of the ship.

The ship 20 further comprises a work station 63 provided with a clamp 64 for selectively retaining the conduit 24 which protrudes from a lateral edge 62. The conduit 24 is engaged vertically through the clamp 64 above and below. view of a side edge 62.

As illustrated by Figures 1 to 7 , the surface installation 18 comprises a winding drum 68 of the flexible duct 24, means 70 for rotating the drum 68, a separator 72 for the treatment of the sampled material, placed in the drum 68, and a compressor 74 for injecting gas into the inner passage 48 through the gas injection line 46.

Depending on the flow or flow of the flexible conduit 24 on the drum 68, the work station 63 moves on a rail 64A disposed on a side of the ship 20.

As shown on the figure 2 the surface installation 18 further comprises control means 76 and electrical supply means 78.

As illustrated by figures 4 and 5 , the winding drum 68 extends along a substantially horizontal longitudinal axis XX 'of the vessel 20.

The drum 68 comprises a hollow cylinder 80, which has at its left and right ends transverse locking flanges 82 of the flexible duct 24.

The cylinder 80 delimits an outer cylindrical surface 84 intended to support the wound conduit 24, and a cylindrical internal volume 86 into which the separator 72 is inserted.

As illustrated by figure 5 , the drum 68 further has, on at least one circumference taken along the outer surface 84, two support wedges 88 of two adjacent sections 50 of the conduit.

The shims 88 protrude from the outer surface 84 and delimit between them a longitudinal groove 90 for receiving the flanges 54 for fixing two adjacent sections 50.

Thus, when the flanges 54 are introduced into the groove 90, the central portions 52 of the two adjacent sections respectively rest on one of the wedges 88, which limits their radius of curvature in the vicinity of the flange 54. The risk of damage of the conduit 24 by torsion are thus limited.

The shims 88 are movable jointly about the X-X 'axis on at least one periphery of the surface 84.

More generally, the drum 68 could be used to wind any flexible conduit.

In the example shown on the Figures 1 to 7 , the diameter of the drum 68 is between 12 m and 15 m and in any case less than 20 m.

The drum 68 is further provided, in the inner volume 86, rollers 92 which are located in the vicinity of the end flanges 82 and which are distributed around the axis X-X '. The rollers 92 are placed in abutment on an outer surface of the separator, to allow, as will be seen below, the rotation of the drum 68 about the axis X-X 'by rolling on the separator 72.

The means 70 for rotating the drum comprise, at each end of the rotary cylinder 80, a toothed outer ring 94 and two motorized drive wheels 96 meshing with the ring gear 94.

Each ring 94 extends from the outer surface 84 on a periphery about the X-X 'axis. It is integral with the cylinder 80.

The wheels 96 are rotatably mounted on the platform 60 on either side of a vertical plane passing through the axis X-X 'of rotation of the cylinder. The drive wheels are able to rotate the drum 68 about the axis X-X 'in two different directions of rotation to wind or unwind the flexible conduit 24.

As illustrated by figures 6 and 7 , the separator 72 comprises a cylindrical tank 100 disposed in the interior volume 86, a tank 102 for retaining the separated material in the cylindrical tank 100, means 104 for discharging the separated material into the tank towards the holding tank 102, and means 106 for pressurizing the tank 100.

More generally, the tank 100 of the separator 72 can be placed in the interior volume delimited by any winding drum present on the vessel 20.

The tank 100 is generally cylindrical in shape and slightly smaller in diameter than the cylinder 80 in which it is placed. It has a cylindrical peripheral wall 108 closed transversely with respect to the axis X-X 'by first and second end walls 110, 112.

The walls 108, 110, 112 internally delimit a cavity 114 for separating the material brought to the surface by the flexible duct 24.

The tank 100 is fixedly mounted on the platform 60 by means of fixing arms 116. Each arm 116 is attached to an end wall 110, 112 and on the platform 60.

The peripheral wall 108 is cylindrical in shape of axis X-X '. The rollers 92 of the drum 68 roll on an outer surface of this wall 108 during the rotation of the drum 68 about its axis X-X '.

As illustrated by figure 6 , the left end wall 110 has three nozzles 118 for connection to the flexible conduit 24 distributed around the axis X-X '. Each nozzle 118 comprises a head 120 for connection to a flange 54 of an end section of the flexible conduit 24.

Each nozzle 118 further comprises an injection member 122 of the material from the conduit 24 inside the separation chamber 114. The injection member 122 is curved in the form of a helix toward the wall 108 so as to tangentially direct the flow of material coming from the nozzle 118 onto the peripheral wall 108 of the tank 100. This avoids the deterioration of the equipment present in the separation chamber 114.

In the example shown on the figure 6 , the left wall 110 comprises three connection nozzles 118, which makes it possible to adapt to different positions of the end section 50 of the duct 24, when the latter is wound on the drum 68.

The left wall 110 further comprises an upper outlet 123 of gas discharge connected to the compressor 74. The compressor 74 is thus connected at the inlet, at the gas evacuation outlet 123 and at the outlet, to the injection line. gas in the inner passage 48, as shown in FIG. Figure 2 .

The right end wall 112 comprises, in its upper part, a pressurized fluid injection inlet 124, and in its lower part, an outlet 126 for discharging a separated material into the separator, connected to the retention tank 102 via an intermediate conduit 128.

The retention tank 102 is disposed on the platform 60. It is intended to be maintained at atmospheric pressure, for the recovery of solid materials from the separator 72.

The evacuation means 104 comprise a worm 130 disposed in the separation chamber 114, and a controllable pressurization valve 132 disposed on the intermediate duct 128, between the chamber 114 and the retention tank 102.

The worm 130 is placed in a lower part of the chamber 114 near its bottom. It extends parallel to the axis X-X 'and has an end facing the discharge outlet 126.

The worm 130 is motorized to allow the conveying of a solid material and / or liquid to the intermediate conduit 128 when the valve 132 is open.

A guide plate 130A is placed over the auger 130 to channel the sediments to the intermediate conduit 128.

The valve 132 is controllable to be opened during the evacuation of materials from the chamber 114 and to be closed to maintain the chamber 114 under pressure during the separation of the material from the pipe 42, as will be seen below.

The pressurizing means 106 comprise a compressed water source 134 connected to the inlet 124.

The operation of the extraction device 10 according to the invention will now be described.

Initially, the flexible duct 24 is assembled by end-to-end assembly of the different unit sections 50 by means of their fixing flanges 54.

This assembly can be performed on the ground, or directly on the ship 20. During this assembly, the lines 44, 46 are assembled by end-to-end connection of the line sections present on a unit section 50. Similarly, the interior passage 48 is continuous between the first point 38 and the second point 40.

Once the duct 24 assembled, or during its assembly, it is wound on the drum 68. For this purpose, the motorized wheels 96 are activated to wind the duct 24 helically around the outer surface 84 over substantially its entire length.

When positioning on the drum 68 of each pair of fastening flanges 54 assembled, a pair of shims 88 opposite is moved around a periphery of the cylinder 80 to penetrate the flanges 54 in a groove 90 and to rest the two sections 50 adjacent the fastening flanges 54 on the shims 88.

The conduit 24 is thus stored in a simple and space-saving manner on the ship 20. It is furthermore ready to be deployed rapidly and at a lower cost when a material exploitation operation is to be carried out.

To do this, the surface installation 18 on the vessel 20 is placed opposite the bottom region on which material is to be taken. The bottom assembly 22 is extracted from the holds of the vessel 20 and the lower end of the flexible conduit 24 is connected to the base station 26.

The conduit 24 is engaged through the selective clamp 64 on the edge 62 of the vessel.

Then, the bottom assembly 22 is immersed under water by being retained at the lower end 40 of the conduit 24 and by an auxiliary winch 140 mounted on the platform 60. The assembly 22 is lowered to the bottom 14 by release of the clamp 64 and progressive unwinding of the conduit 24 out of the drum 68, and the winch 140. If necessary, the course of the conduit 24 is stopped and the conduit 24 is held in position by clamping the retaining clip 64.

When the excavating vehicle 28 touches the bottom 14, the base station 26 is kept away from the bottom 14. The flexible pipe 24 is then stretched substantially linearly between the retaining clip 64 and the base station 26.

In this expanded configuration of the duct 24, the upper end of the duct 24 is fixed on a connection nozzle 118. The lumen 37 inside the flexible pipe is connected to the internal passage 48, which opens into the separation chamber 114 of the separator 72.

The duct 24 is deployed above the lateral edge 62 of the ship 20 outwardly overlapping this edge 62. It is therefore not necessary to have a vessel 20 comprising a central well for deploying the extraction device. 10.

Similarly, the functional lines 44 are connected to the control means 76 and the power supply means 78 on the surface installation 18 and to the base station 26 and the vehicle 28.

Thus, the vehicle 28 and the base station 26 are electrically powered from the surface installation 18 through the lines 44 to propel the vehicle 28 and activate the sampling means 34. Similarly, the movement of the vehicle 28 and the setting on the way sampling means 34 by the control means 76 are controlled from the surface installation 18 through the lines 44.

In addition, the inlet of the compressor 74 is connected to the gas discharge outlet of the tank 100 and the outlet of the compressor 74 is connected to the gas injection line 46.

To start the exploitation of the material located on the bottom 14, the control means 76 send an activation signal to the base station 26 and the vehicle 28 to electrically power the sampling means 34 and control the movement of the vehicle 28 on the bottom 14.

The sampling means 34 take the material located on the bottom and bring it to the entrance of the light 37.

The pumping means present on the base station 26 initiate the ascent of the material to the installation 18 consisting of a liquid / solid mixture.

To facilitate the return of the material to the surface installation 18, the compressor 74 is started. The compressor 74 then injects gas into the passage 48, for example compressed air at about 100 bar, into an injection point 142 situated between the first point 38 and the second point 40.

This injection point 142 is for example located at a depth of about 1000 m to allow to lighten the column of material flowing in the passage 48 above the injection point 142 and thus cause the material to the installation surface 18.

A continuous flow of material taken is then established between the sampling means 34 and the separation chamber 114 through successively the light 37, the passage 48 and the connection nozzle 118. The mixture collected at the nozzle 118 is constituted liquid, solid and gas flowing at a suitable speed preferably between 15 and 20 m per second.

In this configuration, the outlet valve 132 of the separator 72 is kept closed, so that the pressure in the separation chamber 114 is greater than the atmospheric pressure. This pressure is for example between 15 and 30 bar.

The liquid / solid / gas mixture then enters the chamber 114 where it undergoes separation by gravity.

The gas collected in the upper part of the chamber 114 is reinjected into the compressor 74 through the outlet 123, which limits the pressure drop and the size of the compressor 74.

The solid material accumulates in the bottom of the chamber 114 around the worm 130. When the chamber 114 is to be drained, the valve 132 is opened and the worm 130 is activated to evacuate the solid material and a part liquid, through the intermediate pipe 128 to the retention tank 102. To maintain a pressure between 15 and 30 bar in the chamber 114, pressurized water is injected through the inlet 124.

When the extraction operation is complete, the bottom assembly 22 is raised to the surface by winding the conduit 24 around the drum 68 as previously described.

In a variant, the flexible conduit 24 does not have an electric power transfer line. An umbilical with power lines has descended simultaneously during the descent of the flexible conduit 24 to provide power to the excavating vehicle 28.

In a variant not shown, the separation chamber is not maintained under pressure when unloading the material therein. In this case, the size of the compressor 74 is greater and the injection point is lower than in the first device 10 according to the invention.

In another variant, the bottom assembly does not have a base station 26. The flexible link 30 is connected directly to the flexible conduit 24 via an adapter nozzle.

A second device 210 according to the invention is partially represented on the figure 8 . Unlike the first device 10, the second device 210 comprises, in the deployed configuration of the flexible conduit 24, a plurality of units 212 for injecting a liquid under pressure into the circulation passage 48, to convey the material to the surface installation 18.

Each injection unit 212 is for example mounted between two fixing flanges 54A, 54B of two adjacent sections 50 when the flexible duct 24 is deployed out of the drum 68. The units 212 are for example mounted by operators placed on the station. mounting 63 and these units 212 are held on the flanges 54A, 54B by respective fixing clamps 213.

Each pumping unit 212 thus comprises a sleeve 214 internally defining a portion of the flow passage 48, a nozzle 216 for taking water from the body of water 12, and a distribution in the passage 48, and a hydraulic turbine 218 for pumping and pressurizing the injected water.

The nozzle 216 defines a generally transverse lumen 230 which opens outwardly into the body of water 12 through a strainer 222, and inclined axially upwards in the passage 48.

The hydraulic turbine 218 is fixed on the sleeve 214. In the example shown in FIG. figure 8 , the turbine 218 is fed hydraulically through a tapping 224 on a functional line 44A from the installation 18. The tapping 224 opens into the body of water 12 by a discharge 226 after passing through the turbine 218, without being connected to a lower part of the line 44A located in the section 50 under the sleeve 214.

The sleeve 214 further delimits at least one section 228 of another functional line 44B intended to feed another pumping unit located under the unit 212.

In operation, the turbine 218 is supplied with hydraulic fluid from the surface installation 18 via the line 44A and the tapping 224. The feed of the turbine 118 causes the water to be drawn into the lumen 230 through the strainer 222 and pressurizing the water sucked into the lumen 230. The pressurized water thus obtained is injected into the passage 48 to entrain the material flowing in this passage 48 to the surface installation 18.

The presence of injection units 212 distributed along the flexible conduit 24 makes it possible to eliminate the pump on the base station 26 and the injection of transport gas into the passage 48. This simplifies, in particular, the surface installation 18 which is devoid of compressor.

Alternatively, the turbines 218 are powered electrically by a functional line placed in the flexible conduit or by an outer umbilical.

The third device 250 shown on the Figures 9 and 10 differs from the second device 210 in that the injection units 212 are devoid of hydraulic turbines. The pressurized liquid to be injected into the flow passage 48 is stored in a pressurized reservoir disposed on the vessel 20 in the surface facility 18.

Each unit 212 comprises an annular distributor 252 of liquid under pressure disposed around the sleeve 214. The annular distributor 252 delimits a peripheral cavity 254, of toric shape around the axis of the duct 24.

The cavity 254 is connected to the surface pressure liquid reservoir via the functional line 44A. It is connected to the passage 48 by four radial injection orifices 256 distributed angularly around the axis of the duct 24, as illustrated by FIG. figure 10 .

Each injection orifice 256 opens axially upwards into the passage 48.

In operation, the pressurized water is fed into the cavity 254 of the distributor 252 from the reservoir of the surface installation 18, through the functional line 44A. It is distributed uniformly in the cavity 254 to be injected through each orifice 256.

More generally, such pumping units could be used on a flexible conduit of any installation.

A fourth device 310 according to the invention is represented on the Figure 11 . Unlike the first device 10, the sampling means 34 comprise an excavation crane 312, deployable and operable from the surface installation 18 independently of the flexible conduit 24.

The bottom assembly 22 further comprises means 314 for receiving and treating the material, placed on the bottom 14 of the body of water 16 while being connected to the flexible conduit 24.

The crane 312 comprises a gripper 316 for picking up the material on the bottom 14, and a cable 318 for deploying the gripper 316, in order to lower the gripper 316 from the vessel 20 to the bottom 14.

The receiving means 314 comprise an adjustable support support 320 placed on the bottom 14 and a crusher / crusher 322 mounted in the support 320.

The support 320 delimits a funnel 324 for receiving the material taken by the clamp 316 open upwards and opening opposite the mill / crusher 322. The support 320 is deployable from the surface installation 18 to the bottom 14 by means Deployment (not shown) independent of the crane 312.

The support 320 has adjustable feet to maintain it substantially horizontally and fixed on the bottom 14.

The support 320 and the crusher / crusher 322 are connected to a free end of the flexible link 30, to connect the hose 36 to the crusher / crusher 322.

To carry out a material removal operation, the receiving means 314 and the flexible conduit 24 are lowered towards the bottom 14, until the support 320 is placed on the bottom 14 while being immobilized on the bottom 14.

The crane 312 is then operated to bring the gripper 316 into contact with the bottom 14. The gripper 316 is then activated to take material on the bottom 14, then is moved opposite the funnel 324 to deposit the material removed by the clamp 316 in the mill / crusher 322.

The material processed in the crusher / crusher 322 is then reassembled at the surface installation 18 through the hose 36 and the flexible conduit 24, as previously described.

Claims (15)

1. Device (10; 210; 250; 310) for extraction of a material from the bed (14) of a body of water (12), of the type comprising:

   - a surface apparatus (18) which is to extend at least partially above the surface (16) of the body of water (12);

   - a bed unit (22) comprising means (34) for removing material from the bed (14) of the body of water (12);

   - a material transport pipe (42) which connects a first point (38) situated on the surface apparatus (18) to a second point (40) situated on the bed unit (22), the transport pipe (42) delimiting at least one passage (48) for circulation of material;

   - at least one functional line (44) which is flexible over substantially its entire length and which connects the bed unit (22) to the surface apparatus (18), the functional line (44) being capable of transmitting electric or hydraulic power, information or a fluid between the surface apparatus (18) and the bed unit (22), the surface apparatus (18) comprising at least one drum (68) around which the or each functional line (44) is wound;

   the transport pipe (42) being flexible over substantially its entire length, characterized in that the or each functional line (44) is arranged around the transport pipe (42) to form a flexible pipe (24), the transport pipe (42) and the or each functional line (44) being deployable conjointly between a rest configuration, in which they are wound on the winding drum (68), and a configuration in which they are deployed towards the bed (14) of the body of water (12).
2. Device (10; 210; 250; 310) according to claim 1, characterized in that the flexible pipe (24) comprises an annular layer (43) surrounding the transport pipe (42), the layer (43) delimiting longitudinal passages (48A) for receiving the or each functional line (44), into which passages the or each functional line (44) is inserted.
3. Device (10; 210; 250; 310) according to either claim 1 or claim 2, characterized in that the surface apparatus (18) comprises a ship (20), the drum (68) being mounted for rotation on a platform (60) of the ship (20).
4. Device (10; 210; 250; 310) according to claim 3, characterized in that the ship (20) delimits a lateral edge (62), the flexible pipe (24) being deployed transversely towards the outside of the ship (20) opposite the lateral edge (62).
5. Device (10; 210; 250; 310) according to any one of the preceding claims, characterized in that the flexible pipe (24) comprises a plurality of sections (50) assembled end to end.
6. Device (10; 210; 250; 310) according to claim 5, characterized in that each section (50) comprises a tubular portion (52) and, at each end of the tubular portion (52), a flange (54) for connection to an adjacent section, the transverse dimension of the flange (54) being greater than that of the central portion (52),
   and in that the drum (68) delimits:

   - a support surface (84) for the pipe (24), and

   - at least one groove (90) for receiving the connection flanges (54) of at least two adjacent sections (50), displaceable around the support surface (84), said flanges (54) being inserted into the groove (90) when the flexible pipe (24) is in its wound configuration.
7. Device (10; 210; 250; 310) according to any one of the preceding claims, characterized in that the bed unit (22) comprises a base (26) and an extractor vehicle (28) which is connected to the base (26) by a flexible link (30) delimiting a material transport port (37), the port (37) opening into the circulation passage (48) and opposite the removal means (34).
8. Device (10; 210; 250; 310) according to any one of the preceding claims, characterized in that the surface apparatus (18) comprises a gas/liquid/solid separator (72) which delimits a separation chamber (114) connected to the circulation passage (48).
9. Device (10; 210; 250; 310) according to claim 8, characterized in that the separation chamber (114) comprises:

   - an outlet (126) for evacuation of a solid separated in the separation chamber (114), and

   - a valve (132) for closing off the evacuation outlet (126), which valve is capable of being controlled in order to maintain the separation chamber (114) at a pressure greater than atmospheric pressure during the discharge of material issuing from the circulation passage (48) into the separation chamber (114).
10. Device (10; 310) according to claim 8 or 9, characterized in that the flexible pipe (24) comprises at least one line (46) for the injection of gas for carrying the material, the gas injection line (46) opening into the circulation passage (48) away from the surface apparatus (18), the surface apparatus (18) comprising a compressor (74) which has an inlet connected to the separator (72) and an outlet connected to the gas injection line (46).
11. Device (210; 250) according to any one of the preceding claims, characterized in that, in the deployed configuration, the flexible pipe (24) comprises at least one unit (212) for injecting liquid under pressure into the circulation passage (48), the liquid under pressure being capable of carrying the material towards the surface apparatus (18).
12. Device (10; 210; 250; 310) according to any one of claims 8 to 10, characterized in that the winding drum (68) delimits an interior space (86), the separation chamber (114) being arranged at least partially in the interior space (86).
13. Device (10; 210; 250) according to any one of the preceding claims, characterized in that the bed unit (22) comprises an extractor vehicle (28) equipped with removal means (34).
14. Device (310) according to any one of the preceding claims, characterized in that the bed unit (22) comprises a material collection support (320), connected to the flexible pipe (24), the collection support (320) being intended to be placed on the bed (14) in order to collect the material removed by the removal means (34), the removal means (34) being deployable from the surface apparatus (18) independently of the collection support (320).
15. Method of extracting a material from the bed (14) of a body of water (12) with the aid of a device (10; 210; 250; 310) according to any one of the preceding claims, the method being of the type comprising the following steps:

    - positioning the surface apparatus (18) opposite a region of the bed (14) from which material is to be extracted, the flexible pipe (24) being wound around the winding drum (68) in its rest configuration;

    - deploying the flexible pipe (24) into its deployed configuration by unwinding it from the winding drum (68) in order to immerse it conjointly with the bed unit (22) until the removal means (34) reach said region of the bed (14);

    - extracting the material from said region of the bed (14) by the removal means (34), and conveying the extracted material towards the surface apparatus (18) through the circulation passage (48) of the transport pipe (42).

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