FR2919015A1 - DEVICE FOR EXTRACTING A MATERIAL LOCATED AT THE BOTTOM OF A WATER EXTEND AND ASSOCIATED METHOD - Google Patents

Abstract

The device (10) includes a surface facility (18), a bottom assembly (22) including an extractor vehicle (28), and a material transport line (42) connecting the surface facility (18) to the bottom assembly (22). The device (10) comprises at least one flexible functional line (44) over substantially its entire length. The surface installation (18) comprises at least one winding drum (68) of the functional line (44). The conveying conduit (42) is flexible over substantially its entire length, where the or each functional line (44) is disposed around the conveying conduit (42) to form a flexible conduit (24). The transport pipe (42) and the or each functional line (44) are jointly deployable between a rest configuration wound on the drum (68) and a deployed configuration toward the bottom (14) of the water body (12). ). Application to earthworks or mining of the seabed.

Description

Device for extracting a material located at the bottom of a body of water and

  associated process. The present invention relates to a device for extracting a material situated at the bottom of a body of water, of the type comprising: a surface installation intended to extend at least partially above the surface of the body of water ; - A bottom assembly comprising an extractor vehicle provided with means for sampling the material on the bottom of the body of water; a material transport pipe, connecting a first point located on the surface installation to a second point located on the bottom assembly, the transport pipe delimiting at least one circulation passage of the material; at least one flexible functional line over substantially its entire length, connecting the bottom assembly to the surface installation, the functional line being capable of transmitting electrical or hydraulic power, information or a fluid between the installation surface and the bottom assembly, the surface installation comprising at least one winding drum of the or each functional line. 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. FR-A-2 467 283 discloses a device of the aforementioned type. This device comprises a surface installation carried by a ship, and a bottom assembly. This assembly comprises a base station and a mining 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 de-limits internally a passage of circulation of the material taken from the bottom, to convey it to the surface.

  In addition, a line of gas injection into the drill string and electric power transfer lines forming a link referred to as the umbilical term, have descended into the sea to the intermediate station from the ship. An example of an umbilical is described in 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. An object of the invention is to obtain a device for extracting a material si-killed at the bottom of a body of water that is simple to implement and little incombant. To this end, the invention relates to a device of the aforementioned type, characterized in that the transport pipe is flexible over substantially its entire length, the or each functional line being arranged around the transport pipe to form a flexible conduit , the transport pipe and the or each functional line being deployable jointly between a rest configuration wound on the winding drum and a deployed configuration towards the bottom of the body of water. The device according to the invention may comprise one or more of the following characteristic (s) taken in isolation or according to any combination (s) technically possible (s): - the flexible conduit comprises an annular-shaped sheet surrounding the transport pipe, the sheet delimiting longitudinal passages for receiving the or each functional line into which the or each functional line is inserted; The surface installation comprises a ship, the drum being rotatably mounted on a platform of the ship; the vessel delimits a lateral edge, the flexible duct being deployed transversely towards the outside of the ship facing the lateral edge; the flexible conduit comprises a plurality of end-to-end assembled sections; each section comprises a tubular part and, at each end of the tubular part, a connection flange to an adjacent section, of transverse dimension greater than that of the central part, and the drum defines: a support surface of the duct and at least one groove for receiving the connecting flanges of at least two adjacent sections, movable around the bearing surface, said flanges being inserted into the groove when the flexible duct occupies its wound configuration; - The bottom assembly comprises a base, the vehicle being connected to the base by a flexible link delimiting a material transport light, the light opening into the circulation passage and facing the sampling means; the surface installation comprises a gas / liquid / solid separator delimiting a separation chamber connected to the circulation passage; the separating chamber comprises: an outlet for discharging a separated solid into the separation chamber; and a shut-off valve for the discharge outlet, which can be controlled to maintain the separation chamber. at a pressure above atmospheric pressure when unloading material from the circulation passage (48) into the separation chamber; the flexible duct comprises at least one gas injection line of the material, the gas injection line opening into the circulation passageway away from the surface installation, the installation of surface comprising a compressor having an input connected to the separator and an output connected to the gas injection line; in the deployed configuration, the flexible duct comprises at least one unit for injecting liquid under pressure into the circulation passage, the pressurized liquid being able to drive the material towards the surface installation; and - the winding drum defines an interior volume, the separation chamber being disposed at least partially in the interior volume.

  The invention further relates to a method of extracting a material located at the bottom of a body of water, using a device as defined above, the method being of the type comprising the following steps: -positioning the surface installation facing a bottom region in which the material is to be extracted, the flexible conduit being wound around the winding drum in its rest configuration; -deploying the flexible conduit to its deployed configuration by routing out of the winding drum, to immerse it together with the bottom assembly until the extractor vehicle reaches said bottom region; extraction of the material from said bottom region by means of sampling and conveying of the extracted material to the surface installation through the circulation passage of the transport pipe. The invention will be better understood on reading the following description, given solely by way of example, and with reference to the appended drawings, in which: FIG. 1 is a schematic side view and in partial perspective of FIG. a first extraction device according to the invention, with its flexible duct unfolded; - Figure 2 is a schematic partial sectional view of a marked detail II of Figure 1; - Figure 3 is a partially exploded perspective view of the flexible conduit of the first device according to the invention; - Figure 4 is a partial schematic perspective view of three-quarter face, the winding drum of the flexible conduit of Figure 1, the flexible conduit being partially wound around the drum; - Figure 5 is a view similar to Figure 4 of the drum without the conduit; FIG 6 is an end view, taken along the arrow VI of Figure 4; FIG. 7 is a view taken in partial section along the longitudinal vertical plane VII of FIG. 4; FIG. 8 is a view similar to FIG. 2 of a second device according to the invention comprising a pumping unit; by water injection; FIG. 9 is a view similar to FIG. 8 of a third device according to the invention; and - Figure 10 is a cross-sectional view along the X-X plane of Figure 9.

  An extraction device 10 according to the invention is shown in 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 in FIG. 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 body of water 12, and, according to the invention, a flexible conduit 24 of integrated production bundle type, or Integrated Production Bundle 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 the 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 includes equipment (not shown) for pumping and treating the sampled material, such as 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 means 32 of displacement-ment on the bottom 14 and 34 means for sampling the material, able to dig, scrape or drill the material constituting the bottom 14 and to the bottom of the base station 26 is provided with a trapdoor (26A (Figure 1) pi-voting by appropriate means, not shown.This 26A door allows in its open position In this case, the excavating vehicle 28 is placed beneath the base station 26 and these materials fall into the vehicle 26 where they are ground.

  An example of an excavating vehicle is described in French Application FR-A-2 467 283. The flexible link 30 is sometimes referred to as the English 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 delimits internally 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 relative 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 in FIGS. 1 and 2, the flexible duct 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 FIGS. 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 external functional layer 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 pressure resistance, a gas-tight plastic sheath 47B, an outer casing 47C and two layers of wires. 47D armor to provide 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 ply 43 is of generally annular shape. It is arranged externally around the transport pipe 42 and internally defines longitudinal passages 48A for receiving lines 44, 46 in which lines 44, 46 are inserted. The functional lines 44 comprise, for example, a power transfer line. electrical connector 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 an information transport line connecting the surface installation 18 to the control means on the base station 26 for driving the vehicle 28. The length of the flexible conduit 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 FIG. 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 in 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 5 a unitary section of the lines 44 and 46 which are interconnected through the fixing flanges 54A, 54B. The vessel 20 defines a platform 60 for supporting the surface installation 18 extending between two lateral edges 62 of the ship. The vessel 20 further comprises a work station 63 provided with a selective clamp 64 for retaining the conduit 24 which protrudes from a lateral edge 62. The conduit 24 is engaged vertically through the clamp 64 above and facing a lateral edge 62. As illustrated by FIGS. 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, disposed in the drum 68, and a compressor 74 for the injection of gas into the inner passage 48 through the gas injection line 46. Depending on the flow or flow 24 of the flexible duct 24 on the drum 68, the work station 63 moves on a rail 64A disposed on a side of the ship 20. As shown in FIG. 2, the surface installation 18 further comprises control means 76 and electric feeding means 78. As illustrated by FIGS. 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 The cylinder 80 delimits an outer cylindrical surface 84 intended to reinforce the wound conduit 24, and a cylindrical internal volume 86 into which the separator 72 is inserted.

  As illustrated in FIG. 5, the drum 68 also has, on at least one circumference taken along the outer surface 84, two support wedges 88 for supporting two adjacent sections 50 of the duct. 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 risks of Damage to the conduit 24 by twisting is thus limited. The wedges 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 in 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 arranged resting on an outer surface of the separator, to allow, as will be seen below, the rotation of the drum 68 about the axis XX 'by rolling on the separator 72. The drive means 70 rotation of the drum comprises, at each end of the rotary cylinder 80, a toothed outer ring 94 and two drive wheels 96 motorized geared on the ring gear 94.

  Each ring 94 extends from the outer surface 84 on a periphery about the X-X 'axis. It is secured to 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 adapted to rotate the drum 68 about the axis XX 'in two distinct directions of rotation to wind or unroll the flexible conduit 24. As shown in Figures 6 and 7, the separator 72 comprises a tank cylindrical 100 disposed in the inner volume 86, a tray 102 for retaining the separated material in the cylindrical vessel 100, means 104 for discharging the separated material in the tank to the holding tank 102, and means 106 for pressurizing the 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 in diameter less than that of the cylinder 80 in which it is placed. It has a cylindrical peripheral wall 108 closed transversely with respect to the axis XX 'by first and second end walls 110, 112. The walls 108, 110, 112 internally delimit a cavity 114 for separating the material reassembled at the end. The vessel 100 is fixedly mounted on the platform 60 via attachment arms 116. Each arm 116 is attached to an end wall 110, 112 and to the platform 60. The wall Device 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 in FIG. 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 coming from the conduit 24 inside the chamber 114 of separation. The injection member 122 is curved in the form of a helix towards the wall 108 so as to direct tangentially the flow of material coming from the nozzle 118 on 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 in FIG. 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 this it 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 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 through 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 means discharge 104 comprise a worm 130 disposed in the separation chamber 114, and a controllable pressurization valve 132 disposed on the intermediate conduit 128, between the chamber 114 and the reten-tion tray 102. The worm 130 is placed in a lower part of the chamber 114 near its bottom. It extends parallel to the axis XX 'and has an end facing the discharge outlet 126. The worm 130 is motorized to allow the conveying of a solid material material and / or liquid to the intermediate duct 128 when the valve 132 is open. A guide plate 130A is placed above the worm 130 for channeling 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 comprises 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 carried out 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. Likewise, the internal passageway 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 pipe 24 is thus stored in a simple and space-saving manner on the ship 20. It is also ready to be deployed rapidly and at a lower cost when Material mining operation must be performed.

  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 removed 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 ship. 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 duct 24 out of the drum 68, and the winch 140. If necessary, the unwinding of the duct 24 is stopped and the duct 24 is held in position by clamping the retaining clip 64. 13 When the excavating vehicle 28 touches the bottom 14, the base station 26 is kept away from the bottom 14. The flexible conduit 24 is then stretched substantially linearly between the retaining clip 64 and the base station 26. In this deployed 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 conduit 24 is deployed above the side edge 62 of the vessel 20 outwardly overlapping this edge 62. It is therefore not necessary to have a vessel 20 comprising a central well for deploying the device. In the same way, 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 in the course of the 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 output 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 for electrically powering 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. era 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 surface installation 18. A continuous flow of sampled material is then established between the sampling means 34 and the separation chamber 114 through successively the lumen 37, the passage 48 and the connecting nozzle 118. The mixture collected at the nozzle 118 consists of 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 held 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 green and the worm 130 is activated to discharge the solid material and a portion of the liquid, through the intermediate pipe 128 to to the retention tank 102. To maintain a pressure of 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 comprising electric power lines is lowered 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 shown in FIG. 8. Unlike the first device 10, the second device 210 comprises, in the deployed configuration of the flexible conduit 24, a plurality of injection units 212. a pressurized liquid in the circulation passage 48, for conveying 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 during the deployment of the flexible duct 24 out of the drum 68. The units 212 are for example mounted by operators placed on the mounting station 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 circulation passage 48, a nozzle 216 for taking water from the body of water 12, and distribution in the passage 48, and a turbine hydraulic 218 for pumping and pressurizing the injected water. The nozzle 216 delimits a generally transverse lumen 230 which de-mouths outwardly in the expanse 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. 8, the turbine 218 is fed hydraulically through a tapping 224 on a functional line 44A coming from the installation 18. The tapping 224 opens into the 12 of the water expanse 226 after passing through the turbine 218, without being connected to a lower portion of the line 44A located in the section 50 under the sleeve 214. The sleeve 214 further delimits at least one section 228 another functional line 44B for supplying another pumping unit located below 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, then the pressurization of 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 duct 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 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 in Figures 9 and 10 differs from the second device 210 in that the injection units 212 are devoid of 15 hydraulic turbines. The pressurized liquid to be injected into the circulation passage 48 is stored in a pressurized reservoir disposed on the vessel 20 in the surface installation 18. Each unit 212 comprises an annular distributor 252 of pressurized liquid around the sleeve 214. The annular distributor 252 defines a peripheral cavity 254, of toric shape around the axis of the conduit 24. The cavity 254 is connected to the reservoir of liquid under pressure on the surface via the line functional 44A. It is connected to the pas-sage 48 by four radial injection ports 256 angularly distributed about the axis of the conduit 24, as shown in Figure 10.

Each injection port 256 opens axially upwardly into the passage 48. In operation, the pressurized water is supplied into the cavity 254 of the distributor 252 from the reservoir of the surface installation 18, through the functional line. 44A. It is evenly distributed in the cavity 254 to be injected by each orifice 256. More generally, such pumping units could be used on a flexible conduit of any installation.

Claims (6)

  , 1.- Apparatus (10; 210; 250) for extracting material located at the bottom (14) of a body of water (12), of the type comprising: - a surface installation (18) for extending at least partially above the surface (16) of the body of water (12); - a bottom assembly (22) comprising an extractor vehicle (28) provided with means (34) for taking the material on the bottom (14) of the body of water (12); a material transport pipe (42) connecting a first point (38) on the surface installation (18) to a second point (40) on the bottom assembly (22); transport (42) defining at least one passage (48) for circulation of the material; - at least one flexible functional line (44) over substantially its entire length, connecting the bottom assembly (22) to the surface installation (18), the functional line (44) being able to transmit an electrical power or hy - 15 hydraulic, information or fluid between the surface installation (18) and the bottom assembly (22), the surface installation (18) comprising at least one winding drum (68) of the each functional line (44); characterized in that the conveying conduit (42) is flexible over substantially its entire length, the or each functional line (44) being disposed around the conveying conduit (42) to form a flexible conduit (24), the conduit (42) and the or each functional line (44) being jointly deployable between a rest configuration wound on the winding drum (68) and a deployed configuration toward the bottom (14) of the water body ( 12). 25   2.- Device (10; 210; 250) according to claim 1, characterized in that the flexible duct (24) comprises a ply (43) of annular shape surrounding the transport pipe (42), the ply (43) defining longitudinal passages (48A) for receiving the or each functional line (44) into which the or each functional line (44) is inserted. 30   3.- Device (10; 210; 250) according to any one of claims 1 or 2, characterized in that the surface installation (18) comprises a vessel (20), the drum (68) being rotatably mounted on a platform (60) of the ship (18).   4.- Device (10; 210; 250) according to claim 3, characterized in that the vessel (20) delimits a lateral edge (62), the flexible duct (24) being deployed transversely towards the outside of the vessel (20). ) facing the side edge (62).   5.- Device (10; 210; 250) according to any one of the preceding claims, characterized in that the flexible conduit (24) comprises a plurality of sections (50) assembled end to end.   6.- Device (10; 210; 250) 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) connecting to an adjacent section, of transverse dimension greater than that of the central part (52), and in that the drum (68) delimits: a bearing surface (84) of the duct (24), and - at at least one groove (90) for receiving the connecting flanges (54) of at least two adjacent sections (50) movable around the bearing surface (84), said flanges (54) being inserted into the groove (90); ) when the flexible duct (24) occupies its wound configuration. Device (10; 210; 250) according to one of the preceding claims, characterized in that the bottom assembly (22) comprises a base (26), the vehicle being connected to the base (26) by a flexible link (30) delimiting a light (37) for transporting material, the light (37) opening into the circulation passage (48) and facing the sampling means (34). 10.-Device (10; 210; 250) according to any one of the preceding claims, characterized in that the surface installation (18) comprises a separator (72) gas / liquid / solid delimiting a separation chamber (114). ) connected to the circulation passage (48). 11.- Device (10; 210; 250) according to claim 8, characterized in that the separation chamber (114) comprises: - an outlet (126) for discharging a separated solid into the separation chamber (114). ), and - a valve (132) for closing the evacuation outlet (126), operable to be controlled to maintain the separation chamber (114) at a pressure greater than the atmospheric pressure during unloading of material from the circulation passage (48) in the separation chamber (114) .10.- Device (10) according to claim 8 or 9, characterized in that the flexible conduit (24) comprises at least one injection line (46). of material entrainment gas, the gas injection line (46) opening into the circulation passage (48) away from the surface installation (18), the surface installation (18) comprising a compressor (74) having an input connected to the separator (72) and an output connected to the injection line d e gas (46). 11.- Device (210; 250) according to any one of the preceding claims, characterized in that, in the deployed configuration, the flexible conduit (24) comprises at least one unit (212) for injecting liquid under pressure into the the circulation passage (48), the pressurized liquid being capable of driving the material towards the surface installation (18). 12.- Device (10; 210; 250) according to any one of claims 8 to 10, characterized in that the winding drum (68) defines an interior volume (86), the separation chamber (114) being disposed at least partially in the interior volume (86). 13. A method of extracting a material located at the bottom (14) of a body of water (12), using a device (10; 210; 250) according to any one of the claims preceding, the method being of the type comprising the following steps: - positioning of the surface installation (18) facing a bottom region (14) in which the material is to be extracted, the flexible conduit (24) being wound around the winding drum (68) in its rest configuration; - Deploying the flexible conduit (24) to its unfolded configuration unwinding out of the winding drum (68), to immerse it together with the bottom assembly (22) until the extractor vehicle (28) reaches said bottom region (14); extraction of the material from said bottom region (14) by the sampling means (34) and conveying the extracted material to the surface installation (18) through the circulation passage (48) of the transport pipe (42); ).30