BRPI0814574B1 - DEVICE AND PROCESS FOR EXTRACTION OF A MATERIAL SITUATED UNDER A WATER EXTENSION - Google Patents

Description

(54) Title: DEVICE AND PROCESS OF EXTRACTION FROM A MATERIAL LOCATED AT THE BACK OF A WATER EXTENSION (51) Int.CI .: E02F 7/00; E02F 7/10; E21B 17/20; E21B 19/22; E21C 50/00; E21C 45/00 (30) Unionist Priority: 07/18/2007 FR 07 56579, 07/24/2007 FR 07 56718 (73) Holder (s): TECHNIP FRANCE (72) Inventor (s): THOMAS PIERRE-ARMAND “ DEVICE AND PROCESS OF EXTRACTION FROM A MATERIAL LOCATED AT THE BACK OF A WATER EXTENSION ”

The present invention relates to a device for extracting a material located at the bottom of an extension of water, of the type comprising:

- a surface installation intended to extend at least partially above the surface of the water extension;

- a bottom set comprising means for removing material at the bottom of the water extension;

- a conduit for transporting the material, which connects a first point located on the surface installation to a second point located on the bottom set, the transport conduit bounded by at least one passage of material circulation;

at least one flexible functional line over substantially its entire length, which connects the bottom set to the surface installation, the functional line being able to transmit an electrical or hydraulic power, information or a fluid between the surface installation and the set of bottom, the surface installation comprising at least one winding drum of the or each functional line.

This device applies, for example, to the mining of undersea bottoms, or to earthworks for submarine soils with a view to placing hydrocarbon production facilities.

A device of the type described is known from FR-A-2 467 283. This device comprises a surface installation carried by a ship, and a bottom assembly. This set comprises a base station and an extraction vehicle that circulates on the seabed and is connected to the base station by a flexible connection designated by the English term "jumper".

The bottom set is lowered into the water with the aid of a rigid rod train that connects the base station to the surface installation. The rod train internally delimits a circulation passage for the material removed at the bottom, to transport it to the surface.

On the other hand, a gas injection line in the rod train and electric power transfer lines that form a connection designated by the term “umbilical”, are descended into the sea towards the intermediate station from the ship. An example of umbilical is described in order GB 2 395 539.

To extend the device, it is necessary to successively mount each rod of the rod train on the surface on the occasion of the descent of the bottom set, and then simultaneously descend the gas injection line and the umbilical that comprises the electric power lines, joining them on each rod.

Then, the ship must have a very large storage space for the union and storage of the rigid and umbilical tubes.

An object of the invention is to obtain a device for the extraction of a material located at the bottom of an extension of water that is simple to perform and light in volume.

For this purpose, the invention has as its object a device of the precited type, characterized by the fact that the transport conduit is flexible in substantially its entire length, the or each functional line being arranged around the transport conduit to form a flexible conduit, the transport line and the or each functional line being foldable together between a resting configuration wound on the winding drum and a configuration extended towards the bottom of the water extension.

The device according to the invention can comprise one or more of the following characteristics (s), taken alone or according to all the technically possible combination (s):

- the flexible conduit comprises an annular blanket that surrounds the transport conduit, the blanket delimiting longitudinal passages for receiving the or each functional line in which the or each functional line is inserted;

- the surface installation comprises a ship, the drum being rotary mounted on a ship's platform;

- the ship delimits a lateral edge, the flexible conduit being extended transversely towards the outside of the ship in front of the lateral edge;

- the flexible conduit comprises a plurality of segments joined end to end;

- each segment comprises a tubular part and, at each end of the tubular part, a connection flange to an adjacent segment, with a transverse dimension greater than that of the central part;

- and the drum delimits;

- a support surface for the duct, and

- at least one flute for receiving the connection flanges of at least two adjacent segments, displaceable around the support surface, said flanges being inserted into the flute when the flexible conduit occupies its coiled configuration;

- the bottom set comprises a base, and an extractor vehicle connected to the base by a flexible connection that delimits a material transport gap, the gap opening into the circulation passage and in front of the withdrawal means;

- the surface installation comprises a gas / liquid / solid separator that delimits a separation chamber connected to the circulation passage;

- the separation chamber comprises:

• an evacuation outlet of a separate solid in the separation chamber, and • an evacuation outlet shut-off valve, suitable to be controlled to maintain the separation chamber at a pressure higher than atmospheric pressure when discharging material from the circulation passage in the separation chamber;

- the flexible conduit comprises at least one gas injection line for driving the material, the gas injection line flowing into the circulation passage at a distance from the surface installation, the surface installation comprising a compressor with an inlet connected to the separator and an outlet connected to the gas injection line;

- in the extended configuration, the flexible conduit comprises at least one liquid injection unit under pressure in the circulation passage, the liquid under pressure being suitable for dragging the material towards the surface installation;

- the winding drum delimits an interior volume, the separation chamber being arranged at least partially within the interior volume;

- the bottom set comprises an extractor vehicle provided with removal means; and

- the bottom set comprises a material collection support, connected to the flexible conduit, the collection support being intended to be placed on the bottom to collect the material removed by the removal means, the removal means being extendable from the installation regardless of the collection medium.

On the other hand, the invention has as its object a process of extracting a material located at the bottom of an extension of water, with the aid of a device as defined above, the process being of the type that comprises the following steps:

- positioning of the surface installation in front of a bottom region in which the material must be extracted, the flexible conduit being wound around the winding drum in its resting configuration;

- unfolding of the flexible conduit in the direction of its configuration extended by unwinding out of the winding drum, to immerse it together with the bottom set until the withdrawal means reach said bottom region;

- extraction of the material from said bottom region by means of removal and transportation of the extracted material to the surface installation through the circulation passage of the transport conduit.

The invention will be better understood by reading the description that follows, given only as an example, and made with reference to the attached drawings, in which:

figure 1 is a schematic side and partial perspective view of a first extraction device according to the invention, with its flexible duct extended;

figure 2 is a schematic partial sectional view of a detail marked 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 view in perspective of three-quarters of the front of 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;

figure 6 is a top view, taken according to the arrow VI of figure 4;

figure 7 is a partial section view according to the longitudinal vertical plane VII of figure 4;

figure 8 is a view similar to figure 2 of a second device according to the invention comprising a water injection pumping unit;

figure 9 is a view similar to figure 8 of a third device according to the invention;

figure 10 is a cross-sectional view according to the X-X plane of figure 9; and

figure 11 is a view similar to figure 1 of a fourth device according to the invention.

An extraction device 10 according to the invention is shown in figures 1 to 10. This device 10 is designed to remove materials located at the bottom of a water extension 12 such as a sea, an ocean or a lake.

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

The device 10 aims to carry out, for example, earthworks on the bottom 14 with a view to placing a hydrocarbon exploration installation, or to remove ores placed on the bottom 14 with a view to its further exploration on the surface 16 of the water extension 12.

As illustrated in figure 1, the device 10 comprises a surface installation 18 carried by a ship 20, a bottom assembly 22 for removing material at the bottom 14 of the water extension 12, and, according to the invention, a conduit flexible “integrated production bundle” type 24, or “Integrated Production Bundle” to connect bottom assembly 22 with surface installation 18.

The bottom assembly 22 comprises a base station 26 attached to the lower end of the conduit 24, an excavator vehicle 28, placed in tact with the bottom 14 of the water extension 12, and a flexible connection 30 that connects the vehicle 28 with the base station 26.

The base station 26 is intended to be placed in the vicinity of the bottom 14, at a distance from the bottom when exploring materials. The base station 26 comprises equipment (not shown) for pumping and handling the removed material, such as pumps or filters, and excavator vehicle control means 28.

The excavator 28 is intended to come into contact with the bottom 14 to remove material on the bottom 14. It comprises means 32 for displacement on the bottom 14 and means 34 for removing the material, suitable for digging, scraping or drilling the material that constitutes the bottom 14 and to transport it to the flexible connection 30.

The bottom of the base station 26 is provided with a trap door 26A (Figure 1) pivoted by appropriate means, not shown. This hatch 26A allows in its opening position to evacuate the blocked materials at the base station 26. In that case, the excavator vehicle 28 is placed under the base station 26 and these materials fall into the vehicle 26 where they are crushed.

An example of an excavator is described in French order FR-A-2 467 283.

The flexible connection 30 is sometimes referred to by the English term “jumper”. It is formed by a hollow and flexible tube that has an upper end connected to the base station 26 and a lower end connected to the vehicle 28, to remove the material from the removal means 34. The flexible tube 36 delimits a gap 37 inside circulation of the material that flows in front of the withdrawal means 34 and at the base station 26.

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

The vehicle 28 is movable in relation to the base station 26, notably on the bottom 14, up to a maximum distance from the base station 26 substantially equal to the length of the flexible tube 36. This maximum distance is between 10 m and 40 m and is 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 in the surface installation 18, and a second point 40 located at its lower end at the base station 26.

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

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

The conduit 24 also comprises, around the conduit

42, an outer functional mat 43 that receives functional lines 44 for transmitting electrical or hydraulic power, information and / or fluids from the surface installation 18 to the bottom assembly 22, lines 44 being arranged on the outer mat 43 around of the transport conduit 42.

The conduit 24 also comprises a gas injection line 46 for driving the material into the transport conduit 42, arranged on the blanket 43 and an outer protection sheath 47 arranged around the blanket

43.

Transport conduit 42 is generally in accordance with API 17J. It is flexible throughout its length. It comprises, for example, from the inside to the outside, an internal 47A tubular metal housing for pressure resistance, an elastic gas-tight 47B sheath, an external 47C housing and 47D reinforced wire layers to ensure tensile strength .

The transport conduit 42 inwardly delimits a circulation passage 48 of withdrawn material that flows on the one hand, at the first point 38, and on the other hand, at the second point 40. The transport conduit 42 is mounted in series with the flexible tube 36 , so that the inner gap 37 ends at the passage 48.

The blanket 43 has a general annular shape. It is disposed externally around the transport conduit 42 and internally delimits longitudinal passages 48A for receiving lines 44, 46 in which lines 44, 46 are inserted.

Functional lines 44 comprise, for example, an electric power transfer line that electrically connects surface installation 18 to bottom assembly 22 to electrically supply base station 26 and vehicle 28. Lines 44 further comprise a line of information transport that connects the surface installation 18 to the control means at the base station 26 for the control of 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 in which the seabed is located and preferably greater than 1000 m.

In the example shown in Figure 1, the flexible conduit 24 is formed by the end-to-end connection of a plurality of flexible unit segments 50 of length preferably between 300 m and 400 m.

Each segment 50 thus comprises a central tubular part 52 and at each end a fixing flange 54 to an adjacent segment 50.

As shown in figure 2, flanges 54A, 54B of two adjacent segments 50 are secured against each other for example by screwing.

The flanges 54A, 54B project radially outwardly in relation to the central part 52. They have an outer diameter greater than the average outer diameter of the central part 52.

Each unit segment 50 delimits a part of the inner passage 48 and carries a unitary section of lines 44 and 46 that are connected to each other through the fixing flanges 54A, 54B.

The vessel 20 delimits a platform 60 to support the surface installation 18 which extends between two lateral edges 62 of the vessel.

On the other hand, the ship 20 comprises a work station 63 provided with a clamp 64 for selective retention of the conduit 24, which protrudes from a lateral edge 62. The conduit 24 is introduced vertically through the clamp 64 above and in front of a side edge 62.

As illustrated by figures 1 to 7, the surface installation 18 comprises a winding drum 68 of flexible conduit 24, rotating drive means 70 of the drum 68, a separator 72 for treating the removed material, arranged on the drum 68, and a compressor 74 for the injection of gas in the inner passage 48 through the gas injection line 46.

Depending on the winding or unwinding of the flexible conduit 24 on the drum 68, the work station 63 moves on a track 64 arranged on the side of the ship 20.

As shown in figure 2, the surface installation 18 further comprises control means 76 and power supply means 78.

As illustrated by figures 4 and 5, the winding drum 68 extends along the substantially horizontal longitudinal axis X-X 'of the ship 20.

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

The cylinder 80 delimits an outer cylindrical surface 84 designed to support the rolled conduit 24, and an inner cylindrical volume 86 into which the separator 72 is inserted.

As illustrated in Figure 5, the drum 68, on the other hand, has at least one circumference taken along the outer surface 84, two shims 88 supporting two adjacent segments 50 of the conduit.

The shims 88 protrude from the outer surface 84 and delimit a longitudinal flute 90 designed to receive the flanges 54 for fixing two adjacent segments 50.

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

The shims 88 are movable together about the XX 'axis on at least one periphery of the surface 84.

More generally, drum 68 could be used to wrap any flexible duct.

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

The drum 68 is furthermore provided, in the inner volume 86, with rolling wheels 92 which are located in the vicinity of the end rings 82 and which are distributed around the X-X 'axis. The casters 92 are arranged in support on an outer surface of the separator, to allow, as will be seen below, the rotation of the drum 68 around the X-X 'axis by bearing on the separator 72.

The rotating means 70 of the drum comprise, at each end of the rotating cylinder 80, an outer toothed crown 94 and two motorized driving wheels 96 engaged in the toothed crown 94.

Each toothed crown 94 extends from the outer surface 84 at a periphery around the X-X 'axis. It is supportive of cylinder 80.

The wheels 96 are mounted movable in rotation on the platform 60 on one side and on the other from a vertical plane that passes through the axis X-X 'of rotation of the cylinder. The drive wheels are designed to rotate the drum 68 around the X-X 'axis in two different directions of rotation to roll or unroll the flexible duct 24.

As illustrated by figures 6 and 7, the separator 72 comprises a cylindrical vat 100 arranged in the inner volume 86, a material retention tank 102 in the cylindrical vat 100, means 104 for evacuating the separated material in the vat towards the holding tank 102, and vessel 106 pressurizing means 106.

More generally, the bowl 100 of the separator 72 can be placed in the inner volume bounded by any winding drum present in the vessel 20.

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

The walls 108, 110, 112 inwardly delimit a cavity 114 for separating the material which rises to the surface by the flexible conduit 24.

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

The peripheral wall 108 has a cylindrical shape of axis XX '. The casters 92 of the drum 68 rotate on an outer surface of that wall 108 when the drum 68 rotates around its X-X 'axis.

As shown in Figure 6, the left end wall 110 has three conduits 118 for connection with flexible conduit 24 distributed around the X-X 'axis. Each conduit 18 comprises a head 120 connecting to a flange 54 of an end segment of the flexible conduit 24.

Each pipeline 118 further comprises an injection device 122 of the material coming from the conduit 24 inside the separation chamber 114. The injection member 122 is curved like a helix towards the wall 108 to tangentially direct the flow of matter from the conduit 118 to the peripheral wall 108 of the bowl 100. This prevents the deterioration of the equipment present inside the separation chamber 114.

In the example shown in Figure 6, the left wall 110 comprises three connecting channels 118, which allows it to adapt to different positions of the end segment 50 of the conduit 24, when the latter is wound on the drum 68.

The left wall 110 on the other hand comprises an upper gas evacuation outlet 123 connected with compressor 74. Compressor 74 is thus connected at the inlet, with the gas evacuation outlet 123 and at the outlet, with the gas injection line 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 the evacuation of a separate material in the separator, connected to the holding tank 102 by means of a intermediate conduit 128.

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

The evacuation means 104 comprise an endless screw 130 disposed in the separation chamber 114, and a controllable pressurizing valve 132 disposed in the intermediate conduit 128, between the chamber 114 and the holding tank 102.

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

The worm 130 is motorized to allow the transport of a solid and / or liquid material to the intermediate duct 128 when the valve 132 is opened.

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

The valve 132 is controllable to be opened when evacuating materials out of chamber 114 and to be closed to keep chamber 114 under pressure when separating material coming from conduit 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 conduit 24 is assembled by end-to-end union of the different unit segments 50 through its fixing flanges 54.

This connection can be made on land, or directly on the ship 20. During this connection, lines 44, 46 are joined by end-to-end connection of the line sections present in a unitary segment 50. Likewise, the inner passage 48 is continuous between the first point 38 and the second point 40.

Once the conduit 24 is joined, or at the time of their joining, it is rolled over the drum 68. For this purpose, the motorized wheels 96 are activated to wind the conduit 24 helically around the outer surface 84, in substantially its entire length.

When placing 68 of each pair of fastening flanges 54 joined together, a pair of facing pads 88 is moved around a periphery of the cylinder 80 to make the flanges 54 penetrate a groove 90 and make both segments 50 adjacent to the fixing flanges 54 rest on the shims 88.

The conduit 24 is thus stored in a simple and non-bulky manner on vessel 20. It is, on the other hand, ready to be extended quickly and at a lower cost when a material exploration operation must be carried out.

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

The conduit 24 is introduced through the selective retention clamp 64 at the edge 62 of the vessel.

Then, the bottom assembly 22 is immersed under water and for this purpose is 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 releasing the clamp 64 and progressive unwinding of the conduit 24 out of the drum 68, and the winch 140. If necessary, the unwinding of the conduit 24 is interrupted and the conduit 24 is held in position by tightening the retaining clip 64.

When the excavator 28 touches the bottom 14, the base station 26 is kept at a distance from the bottom 14. The flexible conduit 24 is then extended substantially linearly between the retaining clip 64 and the base station 26.

In this extended configuration of conduit 24, the upper end of conduit 24 is attached to a connection pipe 118. The gap 37 inside the flexible tube is connected to the inner passage 48, which leads to the separation chamber 114 of the separator 72.

The conduit 24 is extended above the side edge 62 of the ship in the outward direction, overlapping it to that edge 62. It is therefore not necessary to have a ship 20 comprising a central well to extend the extraction device 10.

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

Thus, vehicle 28 and base station 26 are electrically powered from surface installation 18 via lines 44 to propel vehicle 28 and activate withdrawal means 34. Likewise, vehicle 28 displacement and placement in operation of the withdrawal means 34 by the control means 76 are controlled from the surface installation 18 via lines 44.

On the other hand, the compressor inlet 74 is connected to the gas evacuation outlet of bowl 100 and the compressor outlet 74 is connected to the gas injection line 46.

To initiate the exploration of the material located at the bottom 14, the control means 76 send an activation signal to the base station 26 and to the vehicle 28 to electrically feed the removal means 34 and command the movement of the vehicle 28 over the bottom 14.

The withdrawal means 34 removes the material located at the bottom and takes it to the entrance of the gap 37.

The pumping means present in the base station 26 begin to raise the material to the installation 18 composed of a liquid / solid mixture.

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

This injection point 142 is located, for example, at a depth of about 1000 m to make the column of material circulating in the passage 48 above the injection point 142 lighter and thus drag the material to the surface installation 18.

A continuous flow of withdrawn material is then established between the withdrawal means 34 and the separation chamber 114 through successively the gap 37, the passage 48 and the connection pipe 118. The mixture collected at the level of the pipe 118 consists of liquid, per solid and gas circulating at an appropriate 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 inside the separation chamber 114 is higher than the atmospheric pressure. This pressure is, for example, between 15 and 30 bars.

The liquid / solid / gas mixture then penetrates into chamber 114 where it is subjected to gravity separation.

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

Solid material accumulates at the bottom of chamber 114 around worm 130. When chamber 114 is to be emptied, valve 132 is opened and worm 130 is activated to evacuate solid material dust and a part of the liquid, through the intermediate duct 128 to a holding tank 102. To maintain a pressure between 15 and 30 bars inside the chamber 114, pressurized water is injected through the inlet 124.

When the extraction operation is completed, the bottom assembly 22 is brought back to the surface by winding the conduit 24 around drum 689 as described above.

In a variant, the flexible conduit 24 has no electrical power transfer line. An umbilical comprising electric power lines is lowered simultaneously when the flexible conduit 24 descends to ensure the power supply to the excavator 28.

In a variant not shown, the separation chamber is not kept under pressure when the material is discharged into the latter. In that case, the size of the compressor 74 is larger and the injection point is located lower than in the first device 10 according to the invention.

In another variant, the bottom assembly is devoid of base station 26. The flexible connection 30 is connected directly to the flexible conduit 24 by means of an adaptation tip.

A second device 210 according to the invention is partially shown in figure 8. Unlike the first device 10, the second device 210 comprises, in the extended configuration of the flexible conduit 24, a plurality of units 212 for injection of a liquid under pressure in the passage circulation 48 to transport the material to the surface installation 18.

Each injection unit 212 is for example mounted between two adjacent flanges 54A, 54B of two adjacent segments 50 when extending flexible conduit 24 out of drum 68. Units 212 are, for example, assembled by operators positioned at the assembly station 63 and these units 212 are held on flanges 54A, 54B by respective fixing collars 213.

Each pumping unit 212 thus comprises a sleeve 214 that internally delimits part of the circulation passage 487, a water withdrawal channel 216 in the water extension 12, and distribution in the passage 48, and a hydraulic turbine 218 for pumping and putting the injected water under pressure.

The conduit 216 delimits a generally transverse crevice 230 that flows outwardly into the water extension 12 through a drain 222, and inclines axially upwards in the passage 48.

Hydraulic turbine 218 is attached to sleeve 214. In the example shown in figure 8, turbine 218 is powered hydraulically through a perforation 224 in a functional line 44A that comes from installation 18. Perforation 224 flows into the water extension 12 through a evacuation 226 after passing through turbine 218, without being connected to a lower part of line 44A located in segment 50 under sleeve 214.

Sleeve 214 further delimits at least a section 228 of another functional line 44B intended to supply another pumping unit located under unit 212.

In operation, turbine 218 is fed with hydraulic fluid from surface installation 18 via line 44 a and drilling 224. Feeding turbine 118 causes water to be sucked into the gap 230 through the drain 222, and then pressurized the water aspirated in the gap 230. The pressurized water thus obtained is injected in the passage 48 to drag the material that circulates within that passage 48 to the surface installation 18.

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

In a variant, the 218 turbines are electrically powered by a functional line positioned in the flexible conduit or by an external 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 hydraulic turbines. The liquid under pressure to be injected in the circulation passage 48 is stored in a pressurized reservoir arranged on the ship 20 in the surface installation 18.

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

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

Each injection port 256 flows axially upward in passage 48.

In operation, the water under pressure is taken to 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 cavity 254 to be injected through each hole 256.

More generally, such pumping units could be used in a flexible conduit in any facility.

A fourth device 310 according to the invention is shown in Figure 11. Unlike the first device 10, the withdrawal means 34 comprise an excavating crane 312, extendable and operable from the surface installation 18 regardless 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 water extension 16 and for this being connected to the flexible conduit 24.

The crane 312 comprises a gripper 316 for removing material at the bottom 14, and a gripper extension cord 318 for lowering the gripper 316 from the vessel 20 towards the bottom 14.

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

The support 320 delimits a funnel 324 for receiving the material removed by the gripper 316 opened upwards and which flows in front of the crusher / crusher 322. The support 320 can be extended from the surface installation 18 towards the bottom 14, by means (not shown) independent of the 312 crane.

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

The holder 320 and the crusher / crusher 322 are connected at a free end of the flexible connection 30, to connect the flexible tube 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 being immobilized on the bottom 14.

The crane 312 is then maneuvered to bring the removal clamp 316 into contact with the bottom 14. The clamp 316 is then activated to remove material on the bottom 14, and then is moved in front of the funnel 324 to place the material removed by the clamp 316 inside the crusher / crusher 322.

The material treated in the crusher / crusher 322 is then carried to the surface installation 18 through flexible tube 36 and flexible conduit 24, as described above.

Claims (2)

1/10 ο 1. Device (10; 210; 250; 310) for extracting a material located at the bottom (14) of a water extension (12), of the type comprising: - a surface installation (18) designed to extend at least partially above the surface (16) of the water extension (12); - a bottom assembly (22) comprising means (34) for removing material on the bottom (14) of the water extension (12); - a material conduit (42), which connects a first point (38) located on the surface installation (18) to a second point (40) located on the bottom assembly (22), the transport conduit (42) delimited at least one passage (48) for circulation of the material; - at least one functional line (44) flexible over substantially its entire length, which connects the bottom assembly (22) to the surface installation (18), the functional line (44) being suitable for transmitting electrical or hydraulic power, a information or a fluid between the surface installation (18) and the bottom assembly (22), the surface installation (18) comprising at least one drum (68) for winding the or each functional line (44); characterized by the fact that the transport conduit (42) is flexible in substantially its entire length, the or each functional line (44) being arranged around the transport conduit (42) to form a flexible conduit (24), the conduit (42) and the or each functional line (44) being foldable together between a resting configuration wound on the winding drum (68) and a configuration extended towards the bottom (14) of the water extension (12). 2. Device (10; 210; 250; 310) according to claim 1, characterized by the fact that the flexible conduit (24) comprises an annular blanket (43) that surrounds the transport conduit (42), the blanket (43) delimiting longitudinal passages (48A) for receiving the or each functional line (44) in which the or each functional line (44) is inserted. Device (10; 210; 250; 310) according to either claim 1 or claim 2, characterized in that the surface installation (18) comprises a vessel (20), the drum (68) being rotatable on a platform (60) of the ship (18). 4. Device (10; 210; 250; 310) according to claim 3, characterized by the fact that the ship (20) delimits a lateral edge (62), the flexible conduit (24) being extended transversely towards the outside of the ship (20) in front of the side edge (62). Device (10; 210; 250; 310) according to any one of the preceding claims, characterized in that the flexible conduit (24) comprises a plurality of segments (50) joined end to end. Device (10; 210; 250; 310) according to claim 5, characterized in that each segment (50) comprises a tubular part (52) and, at each end of the tubular part (52), a flange (54) connecting to an adjacent segment, with a transverse dimension greater than that of the central part (52), and due to the fact that the drum delimits; - a support surface (84) for the duct (24), and - at least one flute (90) for receiving the connection flanges (54) of at least two adjacent segments (50), movable around the support surface (84), said flanges (54) being inserted into the flute (90 ) when the flexible conduit (24) occupies its coiled configuration. Device (10; 210; 250; 310) according to any one of the preceding claims, characterized in that the bottom assembly (22) comprises a base (26), and an extractor vehicle (28) connected to the base (26) by a flexible connection (30) that delimits a gap (37) for transporting material, the gap (37) ending at the circulation passage (48) and in front of the withdrawal means (34). Device (10; 210; 250; 310) according to any one of the preceding claims, characterized in that the surface installation (18) comprises a gas / liquid / solid separator (72) that delimits a separation (114) connected to the circulation passage (48). Device (10; 210; 250; 310) according to claim 8, characterized in that the separation chamber (114) comprises: - an outlet (126) for the evacuation of a separated solid in the separation chamber (114), and - a valve (132) for filling the evacuation outlet (126), 15 to be controlled to maintain the separation chamber (114) at a pressure higher than atmospheric pressure when discharging material from the circulation passage (48) ) in the separation chamber (Π4). A device (10; 310) according to claim 8 or 20 9, characterized by the fact that the flexible conduit (24) comprises at least one line (46) of gas for driving the material, the gas injection line (46) ending at the circulation passage (48) at a distance of the surface installation (18), the surface installation (18) comprising a compressor (74) which has an input connected to the 25 separator (72) and an outlet connected to the gas injection line (46). Device (210; 250) according to any one of the preceding claims, characterized in that in the extended configuration, the flexible conduit (24) comprises at least one unit (212) for injection of liquid under pressure in the circulation passage (48), the liquid under pressure being able to drag the material towards the surface installation (18). Device (10; 210; 250; 310) according to any one of claims 8 to 10, characterized in that the drum of 5 winding (68) delimits an interior volume (86), the separation chamber (114) being arranged at least partially within the interior volume (86). 13. Device (10; 210; 250) according to any one of the preceding claims, characterized in that the bottom assembly (22) comprises an extractor vehicle (28) provided with removal means 10 (34). 14. Device (310) according to any one of the preceding claims, characterized in that the bottom assembly (22) comprises a material collection support (320), connected to the flexible conduit (24), the collection support (320) being intended to be 15 placed on the bottom (14) to collect the material removed by the removal means (34), the removal means (34) being extendable from the surface installation (18) independently of the collection support (320). 15. Extraction process of a material located at the bottom (14) of an extension of water (12), with the aid of a device (10; 210; 250; 20 310) according to any one of the preceding claims, the process being characterized by the fact that it comprises the following steps: - positioning of the surface installation (18) in front of a region of the bottom (14) in which the material must be extracted, the flexible conduit (24) being wound around the winding drum (68) in 25 your resting configuration; - unfolding of the flexible conduit (24) in the direction of its extended configuration by unwinding out of the winding drum (68), to immerse it together with the bottom set (22) until the withdrawal means (34) reach the said bottom region (14); - extraction of material from said bottom region (14) by means of removal (34) and transportation of the extracted material to the surface installation (18) through the circulation passage (48) of the 5 transport (42). 2/10