EP2702210A1

EP2702210A1 - Device for extracting solid material on the bed of a body of water, and associated method

Info

Publication number: EP2702210A1
Application number: EP12720464.2A
Authority: EP
Inventors: Philippe Francois Espinasse; Thomas Parenteau
Original assignee: Technip France SAS
Current assignee: Technip Energies France SAS
Priority date: 2011-04-27
Filing date: 2012-04-27
Publication date: 2014-03-05
Also published as: JP2014512469A; FR2974585B1; KR20140030166A; BR112013027782B1; CA2833650C; RU2013147618A; BR112013027782B8; AU2012247461B2; FR2974585A1; NZ617710A; US9062434B2; WO2012146730A1; CA2833650A1; BR112013027782A2; US20140041262A1; AU2012247461A1

Abstract

The invention relates to a device comprising: an assembly (22) for collecting material on the bed (12) of a body of water (14), a riser (48) for lifting the solid material, and a pump (90) for lifting the solid material collected by the collection assembly (22) in the riser (48) toward the surface facility (26). The device also comprises a separator (42) for generating a stream having a high content of solid material and a stream having a low content of solid material, said separator (42) including a lower outlet (76) for discharging the stream rich in solid material. The device comprises an upstream hose (40) connecting the collection assembly (22) to the separator (42), and an intermediate pipe (44) connecting said or each discharge outlet (76) to the riser (48), the delivery outlet (100) of the pump being tapped into the intermediate pipe (44).

Description

Device for extracting solid material on the bottom of a body of water and associated method

The present invention relates to a device for extracting solid material on the bottom of a body of water, of the type comprising:

- a collection of material on the bottom of the body of water;

- a rising column of the solid material to a surface installation;

- A pump, capable of pumping a liquid for raising the material taken by the sampling assembly in the riser to the surface installation, the pump comprising an inlet inlet and a discharge outlet.

Such a device is for example for the mining of submarine bottoms, or earthworks of the seabed for the establishment of hydrocarbon production facilities.

The solid material taken from the bottom of the body of water is for example formed by rocks or / and by sediments.

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. The bottom assembly comprises a material removal assembly formed by an excavating vehicle.

In this device, the solid material taken from the bottom of the body of water is conveyed to the surface by means of a pneumatic lifting system. For this purpose, an air pipe is stitched on the riser to inject air into this column.

The pneumatic system can be substituted by a pumping system using a pump which drives up the flow of liquid loaded with solid material.

Alternatively, a discontinuous leaking system for pumping seawater is cited, but is not described in detail.

The first system requires gas injection into the middle part of the riser. Such a system is therefore not always easy to implement. In particular, it is necessary to separate the gas injected into the liquid stream containing the solid material, in order to recover the solid material.

The second solution requires pumping the sample stream containing the solid material through a pump.

Such a solution does not give complete satisfaction. Indeed, the passage of solid material through the pump causes premature wear of the pump components in contact with the solid material. It is therefore necessary to frequently replace the pump, or its components, which requires complicated interventions in depth, or even an interruption of production.

An object of the invention is to obtain a device for the removal and recovery of solid material on the bottom of a body of water that is very reliable, while allowing continuous production of material.

Another object of the invention is to provide and convey a material having an improved flow, minimizing the internal wear of the pipe carrying it.

Yet another object of the invention is to provide a pumping station of easily accessible material.

For this purpose, the subject of the invention is a device of the aforementioned type, characterized in that the device comprises:

a separator, intended to process the sampling flow received from the sampling assembly to form a stream rich in solid material and a stream that is poor in solid material, the separator comprising an injection inlet for the sampling stream, and at least one a lower discharge outlet of the flow rich in solid material;

an upstream hose connecting the sampling assembly to the separator;

- An intermediate pipe connecting the or each solid material-rich discharge outlet and a lower section of the riser, the discharge outlet of the pump being stitched on the lower section of the riser or on the intermediate pipe.

The device according to the invention may comprise one or more of the following characteristics, taken in isolation or in any technically possible combination:

- The separator comprises a support placed on the bottom of the body of water or carried by the riser.

the separator comprises an upstream tank for separating the sampling stream and at least one downstream tank for evacuating the stream rich in solid material, the separator further comprising a distributor interposed between the upstream receiving tank and the downstream evacuation tank; , the dispenser being adapted to selectively allow the passage of the flow rich in solid material from the upstream separation tank to the downstream discharge vessel.

the separator comprises at least two downstream evacuation tanks, the dispenser being controllable between a first configuration of passage of the flow rich in solid material from the upstream separation tank to a first downstream evacuation tank, and isolation of the second downstream evacuation tank, and a second configuration of passing the flow rich in solid material from the separation tank to the second downstream discharge tank, and isolating the first downstream discharge tank.

the dispenser comprises a rotary barrel

- The sampling assembly comprises an excavating vehicle intended to come into contact with the bottom of the body of water to collect solid material on the bottom of the body of water.

the collection assembly comprises a material collection support intended to be placed on the bottom of the body of water and sampling means deployable from the surface independently of the collection medium.

- It includes a floating surface installation on the body of water, the riser opening into the surface installation.

- The intake inlet of the pump is adapted to be connected to the body of water, the device comprising a filter assembly interposed between the body of water and the intake inlet.

The subject of the invention is also a process for extracting solid material from the bottom of a body of water, characterized in that it comprises the following steps:

- Provision of a device as defined above;

- sampling of material on the bottom of the body of water by the collection set;

separating the sampling stream received from the sampling assembly in the separator to produce a stream rich in solid material;

- Evacuation of the flow rich in solid material through the lower discharge outlet;

- Activating the pump and injecting a liquid in a lower section of the riser or in the intermediate pipe to drive the flow rich in solid material through the riser to a surface installation.

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:

- Figure 1 is a schematic side view of the main elements constituting a first extraction device according to the invention;

FIG. 2 is a view similar to FIG. 1 of a second device according to the invention; and

- Figure 3 is a view similar to Figure 1 of a third device according to the invention. FIG. 4 is a view similar to FIG. 1 of a fourth device according to the invention;

FIG. 5 is a schematic enlarged view of the sampling assembly and the separator of the device of FIG. 4;

FIG. 6 is a view of the downstream tanks of the separator of FIG. 5;

- Figure 7 is a view similar to Figure 5 of a fifth device according to the invention.

In what follows, the terms "upstream" and "downstream" generally refer to the direction of normal flow of a fluid in a pipe.

A first device 10 for extracting solid material on the bottom 12 of a body of water 14 is illustrated in FIG.

The body of water 14 is for example an ocean, a sea, a lake or a river. The depth of the water extent 14, taken between the bottom 12 and the surface 16 facing the device 10 is for example between 50 meters and 5000 meters.

The expanse of water 14 rests on the bottom 12. The bottom 12 is thus delimited by solid material comprising rocks or / sediments.

The extraction device 10 is intended to carry out, for example, earthworks on the bottom 12, with a view to setting up an ore mining installation placed on the bottom 12, with a view to their subsequent exploitation at a later date. the surface 16 of the body of water 14. Alternatively, the device 10 is used for setting up a hydrocarbon exploitation facility.

As illustrated in FIG. 1, the device 10 comprises a surface assembly 20, a material collection assembly 22 on the bottom 12 of the water body 14 and a set 24 for conveying the material between the sampling assembly. 22 and the surface assembly 20.

In this example, the surface assembly 20 is formed by a floating installation 26 such as a ship, a barge, or a platform. The installation 26 is partially immersed in the body of water 14. Advantageously, the installation 26 floats on the body of water 14.

The installation 26 is for example equipped with means 28 for discharging the solid material recovered by the conveyor assembly 24. It may comprise a surface separator (not shown).

In this example, the sampling assembly 22 comprises an excavating vehicle 30 mounted movably on the bottom 12 of the water body 14. The excavating vehicle 30 comprises autonomous propulsion means (not shown) to enable it to move autonomously on the bottom 12 of the body of water 14. It comprises means 32 for sampling the material, which are capable of digging, scraping, or / and drilling the material constituting the bottom 12 and transporting it to the conveying assembly 24. An example of an excavating vehicle is described in FIG. French application FR-A-2 467 283.

The conveying assembly 24 comprises an upstream hose 40, connected to the sampling assembly 22, a bottom separator 42, and an intermediate bottom conduit 44.

The conveying assembly 24 further comprises a pumping assembly 46 and a riser 48 connected to the surface installation 26.

The hose 40 is sometimes referred to as "jumper". It is formed of a hose having an upstream end connected to the sampling means 32 and a downstream end connected to the separator 42.

The hose 40 has a length greater than 100 meters and in particular between 100 meters and 200 meters. It is suitable for allowing the excavating vehicle 30 to move around the separator 42 on the bottom 12 of the water body 14. This hose 40 advantageously has a minimum radius of curvature before plastic deformation ("MBR" in English) less than 1 meter.

The separator 42 is for example of the type described in the international application WO 2009/125106 of the Applicant. The separator 42 comprises a support 54, an upper upstream tank 56 for separating a sampling stream received from the sampling assembly 22 through the upstream hose 40, and downstream receiving tanks 58A, 58B. a stream rich in solid material produced in the upstream tank 56.

The separator 42 further comprises a distributor 60 interposed between the upstream vessel 56 and the downstream vessels 58A, 58B for controlling the selective distribution of fluid rich in solid material in the downstream tanks 58A, 58B.

In the assembly shown in Figures 1 and 2, the support 54 and the separator 42 are carried by the riser 48. In the variant of Figure 3, the support 54 is placed on the bottom 12.

The support 54 is held stationary relative to the sampling assembly 22. Thus, the sampling assembly 22 is able to move independently and independently from the separator 42.

During the displacement of the sampling assembly 22, the separator 42 remains substantially stationary relative to the bottom 12 of the body of water 14.

The upstream tank 56 forms a separation hopper of the sampling flow received from the sampling assembly 22. It defines an internal separation space 62. The internal space 62 opens upstream by an upper opening 64 of flow injection of sampling and advantageously, by an upper outlet 66 for discharging a liquid stream poor in solid material

The internal space 62 also opens downwards through an outlet 68 for emptying a flow rich in solid material to the distributor 60.

The upper evacuation outlet 66 of the lean stream of solid material is located above the bottom discharge outlet 68 of the flow rich in solid material. It is for example provided with a shutter valve 70. When the valve 70 is open, the outlet 66 opens into the body of water. Alternatively, the output 66 may be connected by a pipe at the inlet of the pump 100 in order to recover the fine particles on the surface to enhance them.

The injection inlet 64 receives the downstream end 52 of the hose 40.

The discharge outlet 68 is located below the injection inlet 64. It opens vertically into the bottom of the tank 56.

Thus, the sample stream containing liquid and a solid material in divided form is able to separate in the inner space 62 to form a flow rich in solid material, to be discharged through the lower discharge outlet 68 and a poor flux of solid material to be discharged through the upper discharge outlet 66.

The downstream tanks 58A, 58B each delimit a reception space 72 of the flow rich in solid material. For each of the downstream tanks 58A and 58B, the distributor comprises two isolation valves 73A, 77A; 73B, 77B positioned one upstream and the other downstream of the tank. The space 72 is connected upstream to the distributor 60 by an upstream inlet 74 and is connected downstream to the intermediate pipe 44 via a discharge outlet 76.

The upstream inlet 74 opens up into the distributor 60. As will be seen below, it is adapted to be selectively connected to the internal space 62 through the distributor 60.

Each downstream outlet 76 opens downwards at the bottom of the downstream vessel 58A, 58B. It is connected to the intermediate pipe 44 via downstream valves 77A, 77B.

The distributor 60 is capable of controlling the selective evacuation of the flow rich in solid material to one of the tanks 58A, 58B by preventing the solid material from being conveyed to the other of the tanks 58B, 58A. The upstream valves 73A, 73B and downstream 77A, 77B downstream tanks 58A and 58B can isolate the downstream tanks 58A and 58B selectively.

Thus, the distributor 60 is operable between a first dispensing configuration and a second dispensing configuration. In the first configuration, the internal space 62 of the upstream vessel 56 is hydraulically connected to the internal space 72 of a first tank 58A. The internal space 62 of the upstream tank 56 and the internal space 72 of a second tank 58B are isolated from each other by at least one wall preventing the passage of the flow rich in solid material.

In the second configuration, the internal space 62 of the upstream vessel 56 is hydraulically connected to the internal space 72 of the second vessel 58B and the internal space 62 of the upstream vessel 56 is isolated from the internal space 72 of the first downstream vessel 58A by a wall preventing the passage of the flow rich in solid material.

The distributor 60 is for example formed by a barrel assembly as described in the application WO 2009/125106 of the Applicant, and which will not be described in more detail here.

The bottom intermediate conduit 44 connects each discharge outlet 76 of the separator 42 to the riser 48. It is for example formed by a rigid tube 80.

Preferably, the bottom intermediate pipe 44 connects the outlet outlets of the downstream tanks 58A and 58B to a point of the riser 48 situated substantially at the bottom of the riser 48.

The downstream tanks 58A and 58B are thus at a substantially lower water depth than the point of tapping of the pipe 44 on the riser 48. Thus, the stream rich in solid material flows by gravity into the intermediate pipe. bottom 44 until it enters the riser.

According to the invention, the pumping assembly 46 comprises a water pump 90 and an upstream connection 92 to the intermediate pipe 44. It also advantageously comprises a connecting pipe 94 and a filter 96.

The pump 90 is for example of the diaphragm pump type.

The injection rate of the pump 90 is for example greater than 5000 liters per minute and is in particular between 5000 liters per minute and 20000 liters per minute.

The pump 90 is able to draw water present in the body of water 14 to convey it from an intake inlet to a discharge outlet 100 for the purpose of injecting it under pressure into the intermediate pipe 44. fluid pumped by the pump 90 is substantially free of solid material. For this purpose, it contains only solid materials having particle sizes of less than 5 mm.

The upstream stitching 92 connects the discharge outlet 100 of the pump 90 to a lower section 109 of the riser 48. It opens for example transversely in the section 109 upstream of the stitching point of the pipe 44, away from the outlets. evacuation 76 and the downstream end 82. Advantageously, the tapping 92 opens transversely with respect to a local longitudinal axis of the riser 48.

The upstream tapping 92 is for example formed of a rigid pipe section, of diameter less than or equal to the diameter of the riser 1 12.

The riser 48 comprises in addition to the lower section 109, a base station 1 10 and a riser 1 12 connecting the base station 1 10 to the surface installation 26.

The intermediate pipe 44 and the pumping assembly 46 open transversely into the lower section 109, upstream of the base station 1 10, under the station 1 10.

The base station 1 10 comprises a connector connecting the downstream end 82 of the lower section 109 to the riser 1 12. More generally, the base station 1 10 can carry various equipment, such as control means or power supply electrical sampling assembly 22, or temporary storage means of solid material and the assembly 42.

The base station 1 10 is disposed above the bottom 12 of the body of water 14, for example a few meters above the bottom 12 of the body of water. The base station 1 10 is advantageously anchored in the bottom of the body of water. It is lowered facing the bottom 12 of the body of water 14 and serves as anchoring to the riser 1 12.

Once connected to the intermediate pipe 44, the base station 1 10 is advantageously carried by the riser 1 12.

The riser 1 12 extends vertically in the body of water 14 between a lower end 1 16 and an upper end 1 18.

The lower end 1 16 supports the base station 1 10. It is hydraulically connected to the intermediate pipe 44. The upper end 1 18 is located on the surface installation 26. It is hydraulically connected to the discharge means 28 on surface installation 26.

The riser 1 12 delimits between the lower end 1 16 and the upper end 1 18, an inner passage 120 flow flow rich in solid material. The length of the riser 1 12 is substantially greater than the depth of the water extent 14 in order to allow the relative movements between the surface installation 20 and the station 1 10.

In the embodiment shown in Figures 1 and 2, the separator 42 is carried by the base station 1 10 with the pump 90 without ground connection in the case where the riser 48 is supported by the surface installation 20 . In a variant, shown in FIG. 3, the separator 42 is carried by a support 54 placed in abutment on the bottom 12.

In one embodiment, the riser 1 12 is made based on a rigid pipe. In this case, the rigid pipe is formed of an assembly of rigid tubular sections welded or fixed to each other.

Alternatively, the riser 1 12 is formed by a flexible pipe over its entire length. The flexible pipe is then adapted to be wound and unrolled from a drum or basket present on a laying ship.

When the device 10 is put in place, a continuous fluid path runs between the sampling assembly 22, through the conveying assembly 24 to the surface installation 26.

In particular, the continuous fluidic path extends from the sampling means 32 through the upstream hose 40, the separator 42, the intermediate pipe 44, the lower section 109, the base station 1 10 and the riser 1 12.

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

Initially, the extraction device 10 is put in place. The sampling assembly 22 is lowered to the bottom 12 of the body of water 14, as well as the separator 42. The separator 42 is placed at the bottom 12 of the body of water 14 by the base 54 and is connected to the sampling assembly 22 by the hose 40.

The intermediate pipe 44 is mounted under the separator 42.

In a variant, the separator 42 is lowered by the column 48 during its assembly.

The riser 1 12 is deployed in the body of water carrying the lower section 109 and the base station 1 10 at its lower end 1 16. The riser 1 12 is then deployed vertically in the body of water 14 until the base station 1 10 is located near the bottom 12 of the body of water 14.

The pump assembly 46 is then connected to the lower section 109.

The intermediate pipe 44 is also mounted on the lower section 109, below the pump assembly 46.

When solid material is to be taken from the bottom 12 of the body of water 14, the sampling assembly 22 is activated. The sampling means 32 are then started to collect rocks and / or sediments on the bottom 12 of the body of water 14. This makes it possible to carry out an earthwork, or to recover solid materials on the bottom 12. The sampled material is then conveyed to the separator 42 through the upstream hose 40. For this purpose, a sampling flow containing liquid and solid material in dispersed form travels through the upstream hose 40. This material enters the internal space 62 delimited by the upstream vessel 56 through the injection inlet 64.

In the internal space 62, the sample flow separates by sedimentation, between a lower flow relatively rich in solid material, collected in the bottom of the tank 56 and a relatively poor upper flow of solid material, formed in the upper part of the tank 56.

Advantageously, the stream of poor solid material contains particles smaller than 5 mm The distributor 60 occupies its first configuration. The solid material present in the stream rich in solid material passes into the first tank 58A. The passage of the solid material in the second tank 58B is prevented by the distributor 60.

The downstream valve 77A present at the discharge outlet 76 of the first tank 58A is then closed while the upstream valve 73A is open. The solid material accumulates in the interior space 72 of the first tank 58A.

In this first configuration, the internal space 62, the inside of the pipe 40, and the internal space 72 of the first tank 58A are equipressure. This pressure is equal to the surrounding hydrostatic pressure (for example 200 bar). When the inner space 72 of the first tank 58A is substantially filled with solid material, the upstream valve 73A of the first tank 58A is closed, the upstream valve 73B of the second tank 58B is open and the distributor 60 is tilted in its second configuration.

In this configuration, the flow of solid material continuously collected in the upstream tank 56 is evacuated in the second evacuation tank 58B. The passage of the solid material in the first tank 58A is prevented by the upstream valve 73A of the first downstream tank 58A.

Simultaneously, the valve 77A located at the downstream discharge outlet 76 of the first tank 58A is opened. The pressure in the interior space 72 of the first tank 58A is then brought to the pressure in the lines 44 and 92 (for example 250 bars). The solid material present in the interior space 72 of the first tank 58A is then free to flow by gravity through the intermediate pipe 44.

The previous steps of switching the distributor 60 are then repeated throughout the extraction of the solid material.

At the same time, the pump 90 is activated continuously. As a result, a flow of water taken from the body of water 14 is pumped, the connecting pipe 94, the intake inlet 98 and the discharge outlet 100 to the downstream tap 92. Pressurized water is thus injected transversely into the lower section 109 to go up to the riser 48.

This injection of pressurized water causes the continuous entrainment of the flow rich in solid material from the tank 58A, 58B through the intermediate pipe 44, the lower section 109 to the base station 1 10, then through the internal passage 120 of the riser 1 12.

The fluid rich in solid material then rises to the surface installation 26 to be collected in the loading means 28.

The energy required to drive the solid material from the bottom to the surface is provided mainly between the separator outlet 42 and the recovery means 28 at the surface by the injection of pressurized water into the intermediate pipe 44, upstream riser 48.

This injection is therefore effective, since it is carried out in a concentrated flow of solid material from the separator 42, and in a lower section of the riser 48.

In addition, the pump 90 does not pump solid material. Its wear decreases considerably, which makes reliable the extraction of solid material and avoids frequent interventions.

The reliability of the pump 90 can be further increased when a filter 96 is mounted upstream of the pump 90.

The separator 42 disposed at the bottom 12 of the body of water 14 has the advantage of isolating the chambers 58A and 58B which are alternately placed in communication with the outside (filling), then with the riser 48.

A second device 130 according to the invention is illustrated in FIG. 2. Unlike the first device 10, the sampling assembly 22 comprises a sampling tool 132 operable from the surface 16 of the body of water 14 and receiving means 134 placed on the bottom 12 of the body of water 14 to collect the material taken by the sampling tool 132.

The sampling tool 132 is connected to the surface by means of an actuating cable 136 controlled by a crane 138 carried by a surface vessel 140.

The sampling tool 132 is for example a sampling clamp and / or a jack hammer secured to the clamp, or a jack hammer deployed from the ship 140 by an additional cable deployment and displacement. The receiving means 134 comprise an adjustable support support 142 advantageously provided with a crusher / crusher and a funnel for receiving the sampled material.

The sampling tool 132 is movable relative to the support 142 between a material withdrawal position, in contact with the bottom 12 of the body of water 14, and a position of discharge of the material into the support 142.

The hose 40 is connected to the support 142 to collect the material deposited in the support 142.

The operation of the second device 130 according to the invention differs from the operation of the first device 10 according to the invention in that the sampling tool 132 is maneuvered from the surface by means of the cable 136 between its sampling position and its position. spill. The material taken by the tool 132 is then poured into the support 142 before being conveyed to the separator 42 through the upstream hose 40.

The operation of the second device 130 is moreover analogous to that of the first device 10.

Although the invention has been described for the extraction of ore, it could be applied to land applications for the extraction of sludge where the same problems of wear of the pumps are posed.

In a variant (not shown) of the device 130 of FIG. 2, the sampling assembly 22 comprises both an excavating vehicle 30 movably mounted on the bottom 12 of the body of water 14, an actuatable sampling tool 132 from the surface 16 of the body of water 14 and the receiving means 134 placed on the bottom of the body of water to collect the material taken by the sampling tool 132.

For this purpose, each excavating vehicle 30 is connected to the receiving means

134 via a hose similar to the hose 40 of Figure 1.

In a variant, the device comprises a plurality of vehicles 30, each connected to the separator 42 or to the receiving means 134 via a hose similar to the hose 40 of FIG.

A fourth device 230 according to the invention is illustrated in FIGS. 4 to 6.

The fourth device 230 differs from the first device 10 and the second device 130 in that the pump 90 is carried by the surface installation 26. The pump 90 is connected downstream to the lower end of the riser 48 by the intermediate of a branch pipe 92 extending through the body of water 14.

This piping pipe is then a water injection pipe under pressure. Advantageously, the intake inlet of the pump 90 is connected to the unloading means 28 of the solid material on the surface installation 26, formed for example by a surface separator, in order to use the water from the means of unloading 28.

In this example, the sampling assembly 22 comprises both at least one excavating vehicle 30 mounted to move on the bottom 12 of the water body 14 and a sampling tool 132 that can be actuated from the surface 16 of the extension. 14. The sampling assembly 22 further comprises receiving means 134 for collecting the material taken by the excavating vehicle 30 and by the sampling tool 132.

As described above, the excavating vehicle 30 comprises autonomous propulsion means (not shown) to allow it to move autonomously on the bottom 12 of the body of water 14. It comprises means 32 for sampling the material, which are capable of digging, scraping, and / or drilling the material constituting the bottom 12 of the body of water and transporting it to the conveying assembly 24. An example of an excavating vehicle is described in FIG. French application FR-A-2 467 283.

Each excavating vehicle 30 is connected to the receiving means 134 via a hose 232.

As described in FIGS. 4 and 5, the receiving means 134 comprise a support, a crusher / crusher 135, a funnel (not shown) for receiving the material taken by the tool 132 and a flange 235 for connecting the hose 232.

The hose 232 is similar to the hose 40 described for the device 10 of FIG. It has a downstream end 52 connected to the receiving means 134. It is connected either upstream of the mill / crusher 135 so that the solid material from the hose 232 passes through the crusher / crusher 135, or downstream of the mill / crusher, for example on the separator to open directly into the upstream tank 56.

The sampling tool 132 is operable from the surface 16 of the body of water 14. It is connected to the surface by means of an actuating cable 136 controlled by a crane 138 carried by the installation of surface 22.

The sampling tool 132 is for example a sampling clamp and / or a jack hammer integral with the clamp, or a jack hammer deployed from the surface installation 22 by an additional cable deployment and displacement.

According to one embodiment of the invention, the conveying assembly 24 comprises a separator 42 provided with an upstream tank 56 for separating a sampling flow received from the crusher / crusher 135 and provided with downstream tanks 58A, 58B and 58C for discharging a stream rich in solid material produced in the separation tank 56. The separator 42 comprises a valve distributor 60 interposed between the upstream vessel 56 and the downstream tanks 58A, 58B, 58C.

The upstream tank 56 forms a separation hopper of the sampling flow received from the crusher / crusher 135. It defines an internal separation space 62. The internal space 62 opens upstream by an upper opening 64 for injection of sampling flow, and advantageously by an upper outlet 66 for discharging a liquid flow for a solid material.

The internal space 62 also opens downwards through an outlet 68 for emptying a flow rich in solid material to the distributor 60. The upper outlet 66 for evacuating the lean flow of solid material is located above the lower outlet 68 for emptying the flow rich in solid material.

In a variant shown in FIG. 5, the upper outlet 66 for evacuating the lean solid liquid stream is connected to a pump 234 provided at the outlet of a filter 236 intended to remove the solid particles present in the liquefied liquid stream. solid material. The presence of the filter 236 allows to reject in the body of water 14 a liquid substantially free of solid.

The injection inlet 64 is connected to the outlet of the crusher / crusher 135. The emptying outlet 68 is located below the injection inlet 64. It advantageously opens vertically into the bottom of the tank 56. the sample stream containing liquid and a solid material in divided form is able to separate in the inner space 62 to form a stream rich in solid material, to be discharged through the bottom discharge outlet 68, and a poor flux of solid material to be discharged through the upper discharge outlet 66.

The downstream tanks 58A, 58B, 58C each delimit a reception space 72 of the flow rich in solid material. The space 72 is connected upstream to the distributor 60 by an upstream inlet 74 and is connected downstream to a respective upstream section 44A, 44B, 44C of the intermediate pipe 44 via a discharge outlet 76.

The respective upstream sections 44A, 44B, 44C are advantageously inclined relative to the vertical to favor gravity flow of the solid material.

In this example, the distributor 60 may comprise a rotary barrel. In a variant, it is devoid of a rotary barrel.

The distributor comprises, for each downstream tank 58A, 58B, 58C an upstream isolation valve 73A, 73B, 73C disposed between the upper tank 56 and the downstream vessel 58A, 58B, 58C, and a downstream isolating valve 77A, 77B , 77C interposed between the receiving space 72 and each upstream section 44A, 44B, 44C of the line 44. The distributor 60 is capable of controlling the selective evacuation of the flow rich in solid material to one of the tanks 58A, 58B, 58C by preventing the solid material from being conveyed to the other tanks 58A, 58B, 58C.

The upstream isolation valves 73A, 73B, 73C and the downstream isolation valves 77A, 77B, 77C, downstream tanks 58A, 58B, 58C are used to selectively isolate the downstream tanks 58A, 58B, 58C.

Thus, the distributor 60 is controllable between a first distribution configuration and at least a second distribution configuration.

In the first dispensing configuration, the internal space 62 of the upstream vessel 56 is hydraulically connected to the internal space 72 of a first tank 58A. The internal space 62 of the upstream tank 56 and the internal space 72 of each other tank 58B, 58C are separated by a valve 73B, 73C preventing the flow of the flow rich in solid material.

In each second configuration, the internal space 62 of the upstream vessel 56 is hydraulically connected to the internal space 72 of a second vessel 58B, and the internal space 62 of the upstream vessel 56 is isolated from the internal space 72 of the first downstream vessel 58A through the valve 73A.

In an exemplary embodiment, the downstream tanks 58A, 58B, 58C consist of rigid tube sections of sufficient length to regulate the gravity drop of the material and prevent the accumulation of too much material.

Each downstream vessel 58A, 58B, 58C advantageously extends along an axis inclined with respect to a vertical axis.

In a particular embodiment, represented in FIG. 6, upstream protection valves 80A, 80B and 80C are respectively arranged upstream of the isolation valves 73A, 73B and 73C to prevent the agglomeration of material on the valves 73A, 73B, 73C during the distribution phases.

Similarly, downstream protection valves 82A, 82B, 82C are respectively disposed upstream of the downstream isolation valves 77A, 77B, 77C to prevent any agglomeration of material on these valves during the filling phases of the downstream tanks 58A, 58B, 58C.

Each valve 80A at 80C; 82A to 82C is thus controllable between a transverse closure configuration of the passage of solid material and a longitudinal passage configuration of the solid material.

In the shutter configuration of the valve 80A at 80C; 82A to 82C, the valve 73A at 73C; 77A to 77C, located respectively downstream of the valve 80A can be operated in view of its opening, before the opening of the valve 80A at 80C; 82A to 82C, without being blocked by solid material.

The operation of the second device 230 according to the invention will now be described.

Initially, the extraction device 230 is put in place as previously described. The establishment of the extraction device 230 will not be described in more detail below.

Unlike the device 10, the pump 90 is maintained on the surface installation 26. The discharge outlet 100 is connected to the lower end of the riser 48 via the piping line 92 immersed in the water. water body 14.

When solid material is to be taken from the bottom 12 of the body of water 14, the sampling assembly 22 is activated. The sampling means 32, 132 are then started to collect rocks and / or sediments on the bottom 12 of the body of water 14. This makes it possible to carry out an excavation, or to recover solid materials on the bottom 12.

The solid material collected by the sampling tool 132 is then introduced into the crusher / crusher 135 to reduce its particle size.

Then, the solid material is conveyed to the separator 42 and enters the internal space 62 defined by the upstream vessel 56 through the injection inlet 64.

In the internal space 62, the sample flow separates by sedimentation between a lower flow relatively rich in solid material, collected in the bottom of the tank 56, and a relatively poor upper flow of solid material, formed in the upper part of the the tank 56.

The low flux of solid material advantageously contains particles smaller than 1 mm in size. In this configuration, it is discharged through the opening 66, then passed into the pump 234, and into the filter 236 to form a liquid discharged into the water body substantially free of particles.

The distributor 60 is then passed into its first filling configuration of the first tank 58A.

For this purpose, in the variant of Figure 6, the valve 80A is first kept closed. The valve 73A is then maneuvered to release the passage to the internal space 72.

The valve 80A is then placed in its passage configuration allowing the passage of solid material, through the valve 80A and the valve 73A. In this configuration, the downstream valve 82A is kept closed. The downstream valve 77A present at the evacuation outlet 76 of the first tank 58A is also closed. The solid material accumulates in the interior space 72 of the first tank 58A.

In this first configuration, the internal space 62 of the upstream tank and the inner space 72 of the first downstream tank 58A are equipressure. This pressure is for example equal to the surrounding hydrostatic pressure (for example 170 bars).

Then, when the inner space 72 of the first downstream vessel 58A is substantially filled with solid material, the upstream valve 80A is first closed. Then the upstream valve 73A is closed.

The upstream valve 80B of the second downstream tank 58B is first kept closed, and the upstream valve 73B of the second tank 58B is open to switch the distributor 60 in its second configuration.

The upstream valve 80B is then open and the flow of solid material continuously collected in the upstream tank 56 is evacuated in the second downstream vessel 58B.

The passage of the solid material in the first tank 58A is prevented by the upstream valve 80A and by the upstream valve 73A of the first downstream tank 58A.

Simultaneously, the downstream valve 82A is closed. The downstream isolating valve 77A located at the downstream discharge outlet 76 of the first downstream tank 58A is then opened.

The downstream valve 82A is then opened.

The pressure in the interior space 72 of the first downstream vessel 58A is then brought to a value substantially equal to the pressure in the pipe 44, for example

150 bars. The solid material present in the interior space 72 of the first tank 58A is free to flow by gravity through the upstream section 44A of the intermediate pipe 44.

In the case where the distributor 60 is barrel-free, the tanks 58A, 58B and

58C can be filled simultaneously or one after the other to always obtain a continuous flow in the pipe 44.

Beforehand, the pump 90 is activated continuously. The pressurized water advantageously taken from the means 28 for discharging the solid material is pumped through the pump 90, the discharge outlet 100 and the tapping duct 92.

This pressurized water is then injected into the lower section 109 of the riser 48 to ascend through the riser 48. The injection of pressurized water causes the continuous entrainment of the flow rich in solid material from each tank 58A , 58B, 58C, through the intermediate pipe 44, the lower section 109 of the riser 1 12, then through the internal passage 120 of the riser 1 12. The flow rich in solid material then back to the surface installation 26 to be collected in the unloading means 28.

The water injection pressure in the riser 48 depends in particular on the internal diameter of the riser 48, the size of the particles, the density of the material, the water depth, the flow velocity of the Thus, the injected pressure is calculated by those skilled in the art according to these parameters. It is generally at least 50 bar higher than the measurable hydrostatic pressure on the bottom. By way of example, when the depth is 1700 m, the hydrostatic pressure at the bottom is about 170 bars, and the injected pressure is greater than 220 bars.

In a variant, the riser 48 has a configuration similar to that described in the French application FR 2 929 638 of the Applicant. It then has an intermediate portion stretched vertically between an anchor point in the bottom 12 of the body of water 14 and a submerged intermediate buoy (not shown). It also has a U-shaped, J or S-shaped upper section for its connection to the surface installation 26. The upper section allows rapid disconnection of the surface installation 26, where necessary and absorption. effective movements caused by waves and / or swell.

In an advantageous variant, the pipe 92 also has a configuration similar to that described in FR 2 929 638, with a vertical intermediate section stretched between an anchoring point on the bottom 12 of the body of water 14 and a submerged buoy. . The pipe 92 has a U-shaped, J, or S-shaped upper section.

In a variant, the anchoring point of the riser 48 is formed directly by the receiving means 134. In this case, the solid material receiving funnel is offset relative to the axis of the column 48 to allow depositing solid material in the receiving means 134 without damaging the riser 48.

FIG. 7 illustrates a variant of the device 230 of FIG. 5. This device comprises a system 250 for diverting pressurized water connected to the downstream tanks 58A, 58B, 58C.

The water diversion system 250 comprises a bypass pipe 252, stitched on the tapping pipe 92, upstream of each upstream section 44A, 44B, 44C of the pipe 44, an isolation valve 254 and, for each tank downstream 58A, 58B, 58C, a branch 256A, 256B, 256C which connects the line 252 to the intermediate space 72 each downstream vessel 58A, 58B, 58C, upstream of the downstream valve 82A, 82B, 82C and the downstream valve 77A, 77B, 77C.

Thus, pressurized water from the pump 90 through the tapping line 92 can be introduced into each downstream vessel 58A, 58B, 58C to cause cleaning, or unclogging of the vessel 58A, 58B, 58C and of the valve 77A, 77B, 77C.

For this purpose, the isolation valve 254 is opened to supply water under pressure of the pipe 92 and pumped into each of the tanks 58A, 58B, 58C.

Claims

1 .- Device (10; 130; 230) for extracting solid material on the bottom (12) of a body of water (14), of the type comprising:

- a set (22) of material removal on the bottom (12) of the body of water (14);

- a riser (48) for raising the solid material to a surface installation (26);

a pump (90) capable of pumping a liquid intended to raise the material taken by the sampling assembly (22) in the riser (48) towards the surface installation (26), the pump (90) comprising an inlet inlet (98) and a discharge outlet (100);

characterized in that the device (10; 130; 230) comprises:

a separator (42) for processing the sample flow received from the sample assembly (22) to form a stream rich in solid material and a stream that is poor in solid material, the separator (42) comprising an inlet (64); ) injecting the sampling flow, and at least one lower discharge outlet (76) for evacuating the flow rich in solid material;

an upstream hose (40) connecting the sampling assembly (22) to the separator (42).

an intermediate pipe (44) connecting the or each discharge outlet (76) with a flow rich in solid material and a lower section (109) of the riser (48), the discharge outlet (100) of the pump ( 90) being stitched on the lower section (109) of the riser (48) or on the intermediate pipe (44).

2.- Device (10; 130; 230) according to claim 1, characterized in that the separator (42) comprises a support (54) placed on the bottom (12) of the body of water (14) or worn by the riser (48).

3.- Device (10; 130; 230) according to any one of the preceding claims, characterized in that the separator (42) comprises an upstream tank (56) for separating the sampling flow and at least one downstream vessel (58A 58B) for discharging the flow rich in solid material, the separator (42) further comprising a distributor (60) interposed between the upstream receiving vessel (56) and the downstream discharge vessel (58A, 58B), the dispenser (60) being adapted to selectively allow the passage of solid material-rich stream from the upstream separation tank (56) to the downstream discharge vessel (58A, 58B).

4. - Device (230) according to claim 3, characterized in that the distributor (60) comprises, for each downstream vessel (58A, 58B), an upstream valve (73A, 73B) insulation and a downstream valve (77A , The distributor further comprising a controllable valve (80A, 80B, 82A, 82B) disposed upstream of each isolation valve (73A, 73B, 77A, 77B) to prevent the flow of the solid material to the isolation valve (73A, 73B, 77A, 77B) prior to opening the isolation valve (73A, 73B, 77A, 77B).

5. - Device (230) according to claim 3 or 4, characterized in that it comprises a system (250) for diverting water under pressure connected to each downstream vessel (58A, 58B, 58C) and isolated by a valve (254).

6. - Device (10; 130; 230) according to any one of claims 3 or 4, characterized in that the separator (42) comprises at least two downstream discharge tanks (58A, 58B), the distributor (60 ) being controllable between a first passage configuration of the flow rich in solid material from the upstream separation tank (56) to a first downstream evacuation tank (58A), and to the isolation of the second downstream evacuation tank (58B ), and a second configuration of passage of the flow rich in solid material from the separation tank (56) to the second downstream evacuation tank (58B), and of the isolation of the first downstream evacuation tank (58A, 58B ).

7 - Device (10; 130) according to one of claims 3 to 5, characterized in that the distributor (60) comprises a rotary barrel.

8.- Device (10; 230) according to any one of the preceding claims, characterized in that the sampling assembly (22) comprises at least one excavating vehicle (30) intended to come into contact with the bottom (12) the body of water (14) for taking solid material from the bottom (12) of the body of water (14).

9.- Device (130; 230) according to any one of the preceding claims, characterized in that the sampling assembly (22) comprises a support (142) for collecting material intended to be placed on the bottom (12). the expanse of water (14) and the sampling means (132) deployable from the surface independently of the collection medium (142).

10.- Device (10; 130; 230) according to any one of the preceding claims, characterized in that the sampling assembly (22) comprises a crusher / crusher (135) intended to reduce the particle size of the flow of sampling received from the sampling assembly, the crusher / crusher (135) being mounted upstream of the separator (42).

1 1 .- Device (10; 130; 230) according to any one of the preceding claims, characterized in that it comprises a surface installation (26), advantageously floating on the body of water (14), the riser (48) opening into the surface installation (26).

12. - Device (230) according to claim 1 1, characterized in that the pump (90) is carried by the surface installation (26), the discharge outlet (100) of the pump (90) being stitched on the riser (48) or the intermediate pipe (44) via a tapping pipe (92) extending through the body of water (14).

13. - Device (10; 130) according to any one of the preceding claims, characterized in that the intake inlet (98) of the pump (90) is adapted to be connected to the body of water ( 14), the device (10; 130) having a filter assembly (96) interposed between the body of water (14) and the inlet (98).

14. - Method of extracting solid material on the bottom (12) of a body of water (14), characterized in that it comprises the following steps:

- Providing a device (10; 130; 230) according to any one of the preceding claims;

- removal of material on the bottom (12) of the body of water (14) by the sampling assembly (22);

separating the sampling stream received from the sampling assembly (22) in the separator (42) to produce a stream rich in solid material;

draining the flow rich in solid material through the lower discharge outlet (76);

- activating the pump (90) and injecting a liquid in a lower section of the riser (48) or in the intermediate line (44) to drive the solid material-rich stream through the riser (48) to a surface installation (26).