FR2475681A1 - DEVICE FOR STORING FLEXIBLE TUBULAR CABLES OR CONDUITS IN THE SUB-MARINE BOTTOM - Google Patents

Abstract

BURIAL DEVICE FOR FLEXIBLE CABLES OR TUBULAR PIPES IN THE SEA BOTTOM, FEATURING A MOBILE TROLLEY ON THE SEA BOTTOM, CONNECTED TO A SURFACE VESSEL FROM WHICH THE TROLLEY IS CONTROLLED AND FROM WHICH THE PIPE TO BE LAYED IS SUBMERSIBLE, A FRONT PART INCLUDING A ROTARY CUTTING DISC LIKELY TO ROTATE AROUND A HORIZONTAL AXIS BY BEING DRIVEN BY MOTOR MEANS AND EQUIPPED WITH ITS PERIPHERY WITH SHARP ATTACK ELEMENTS AND A REAR PART FOR RECEIVING START FROM THE TOP THE LINE TO BE LAYED, AND GUIDE IT TO THE BOTTOM OF THE TRENCH HOLLOWED BY THE FRONT PART WHEN THE TROLLEY MOVES FORWARD. THE ROTARY CUTTING DISC 4 AND THE RECEPTION AND GUIDING CHUTE 8 OF THE PIPE 9 TO BE FITTED ARE IN ONE OF A MOBILE CHASSIS 13 VERTICALLY RELATIVE TO THE TROLLEY 2.

Description

The present invention relates to a device for de-watering

  flexible tubular cables or pipes in the

  soil forming the bottom of a volume of water, in particular the subsoil

  marine. Although the invention can also be applied to other volumes of water such as rivers or lakes, for the

  clarity of the description reference will be made below to the merits

  submarine. Similarly, the product to be buried will be designated under the generic term of conduct without this term being in no way

limiting manner.

  Numerous devices are already known for immersing from the surface a tubular pipe, in particular a

  flexible conduct and to ensnare it in the seabed, that is

  to deposit it in a trench dug for this purpose in the background. A first category of so-called "JETTING" devices is thus known which consists in making a trench with the aid of a mobile carriage on the submarine bottom connected to a surface vessel from which the carriage is driven and from which the pipe to be laid is submerged, the carriage being equipped with arms provided with nozzles for injection of pressurized fluid, especially water, for digging the soil and evacuate the

debris on the sides of the cart.

  Such devices are not satisfactory

  especially when the underwater ground is hard, for example

staggered with rock.

  In addition, with these devices it is not possible or at least very difficult to control the depth of the trench and ensure its recovery after laying the pipe.

  A second category of arrangement is also known.

  so-called "CUTTING" devices comprising on a mobile carriage on the seabed, a front portion shaped as a mechanical cutting member and a rear portion arranged as a chute for receiving

  from the top the pipe to lay this rear part com

  also generally taking means to guide

  the pipe to be laid when it is flexible, until it is pressed against the bottom of the trench dug by the front part during the controlled advance of the truck. Devices of this type are already known in which the mechanical cutting member is constituted by the plough portion of an articulated hinged plow -2 and other devices of this type in which the mechanical cutting member is similar to a cutter, that is to say a disc, rotatable about a horizontal axis being driven by appropriate motor means, and provided at its periphery sharp cutting elements. Such devices are not always satisfactory for certain categories of submarine soils, especially hard soils and also do not allow precise control of the depth of the trench to be dug depending on the nature of the

  floor and depending on the installation requirements.

  The present invention proposes to provide a dis-

  improved positive of the type in which the cutting member

  is a rotating cutting disc allowing

  with relatively low energy costs of flexible tubular pipes and similar products, whatever the nature of the submarine soil and at significant water depths of tens or even hundreds

meters.

  The device according to the invention may also allow

  simultaneously laying and burying several pipes from a single laying vessel, these pipes being able to be deposited in the seabed at depths

  will and up to 1.5 meters.

  The device according to the invention is essentially characterized in that the rotary cutting disc and the guide receiving chute and the pipe to be installed, are integral with a frame movable vertically relative to the carriage. It is thus understood that by simply adjusting the vertical position of the mobile frame comprising the rotary cutting disc and the receiving and guiding chute, the depth of the trench dug by the rotation of the trench can be adjusted.

disc when advancing the carriage.

  In a preferred embodiment, the mobile frame is connected to the carriage by arms forming an articulated parallelogram structure, the operation of the movable frame being ensured by jacks, in particular jacks substantially

vertical, integral with the carriage.

  According to an advantageous characteristic of the invention, the receiving and guiding chute can be relieved by

  movable frame by pivoting about a horizontal axis

  zontal including the mounting axis of the chute on the mobile frame in particular under the action of a cylinder mounted obliquely between the movable frame and the chute. After raising the mobile chassis to completely clear the trench, especially for the crossing of an obstacle, the pivoting of the bucket facilitates the introduction of a pipe to pose in said

  receiving and guiding chute.

  According to another advantageous characteristic of the in-

  vention, it is provided on the chute ensuring the introduction, guiding and the establishment of the conduit an access door, preferably hydraulically controlled, articulated on said chute, on top of it, this door allowing access to driving when the need arises, this operation

  access after the pivoting movement

  the chute mentioned above.

  The rotary cutting disk can be rotated by any suitable motor means, in particular by one or preferably several hydraulic or variable speed electric motors. This disc carries on its periphery removable segments on which are fixed cutting tools. These tools make it possible, during the rotation of the disk, to disaggregate

  hard rocks, the excavated material being evacuated preferably

  compared to the truck with side mounted ducts.

  typically on each side of the carriage at the cutting disc and in which fluid circulation is effected, in particular

of water, under pressure.

  The device according to the invention naturally further comprises means, in the form of sensors and indicators, for controlling the direction of the carriage, its advance and the cutting depth. This information is transmitted to the surface vessel by a connecting umbilical line which also supplies from the surface to the carriage the fluids necessary for driving the carriage, the cutting disk and the actuating cylinders. The surface vessel advantageously has at this

  effect a hydraulic and / or electric power plant.

  The device according to the invention has been revealed

  suitably adapted for laying cables or flexible tubular conduits such as, for example, flexible hydrocarbon transport pipes, in particular those marketed

-4- 2475681

  in large length by the applicant company, control lines ("CONTROL LINES"), power transmission cables and

  telecommunication cables.

  Other advantages and characteristics of the invention

  will appear on reading the following description given in

  as an example in no way limiting a way of realizing

  1 is a longitudinal elevation of the device according to the invention, the guide chute and the rotary cutting member being shown schematically in several operating positions.

  FIG. 2 is an end elevational view of the arrangement

according to the invention.

  Figure 3 is a view from above.

  The device according to the invention essentially comprises

  a carriage designated generally by 1 and formed of a rigid support frame 2 supporting two tracks 3, preferably a hydraulic or electric motor with variable speed, these

  caterpillars being of all-terrain type.

  The carriage 1 is connected to a surface vessel (not shown) by at least one umbilical line, such as for example of the electrohydraulic type manufactured in great length.

  by the applicant company, allowing the

  surface all hydraulic and / or electrical control fluids

  necessary for the implementation of the device and also making it possible to route from the device to the surface the

  information concerning the function check.

  Instead of being of a motorized crawler type, the carriage 1 can also be of a towed type, from the surface vessel, for example consisting of a metal frame supported on two profiled hollow lateral pads, in particular circular section, can be filled completely

  or partially prior to ballast water.

  The device according to the invention comprises a rotary cutting disk 4 which is best seen in FIG. 1, this rotary disk being mounted on a reduction plate and driven in rotation by motors, preferably hydraulic or electric motors. the example shown the engines are at

  number of two, without this number being restrictive, corresponding to

  with an installed power of approximately 400 hp, the rotating disk having an outside diameter of 3400 mm, a width of 600 mm for a speed of rotation of the disc between

  about 10 and about 30 rpm.

  As best seen in FIG. 1, the rotary disc 4 carries on its periphery removable segments 6 on

  which are attached cutting tools 7.

  The rear part 1 of the device is constituted by a mechanically welded chute 8 which receives from the top the product to be laid 9, unwound from the surface vessel, and the

  guide to the bottom of the trench 10 dug by the device.

  The arrangement of the product, in particular the flexible tubular pipe to be buried 9 inside the trough 8, is

schematically in Figure 1.

  The chute 8 has at its rear part a door 11 hinged laterally and above the chute, to allow access to the pipe 9 in the chute. The door 11 is operated using hydraulic control means,

in particular cylinders 12.

  In the device according to the invention the roLa-if cutting tool 4 and the receiving and guiding chute 8 of the product

  to be installed are mounted integral on a mobile vertical frame 13

  calemernt relative to the frame 2 of the carriage.

  The mobile frame 13 is connected to the frame 2 of the carriage by arms 14 forming an articulated parallelogram structure, the maneuver for the vertical displacement of the movable frame 13 relative to the carriage being provided by jacks 15 hinged on the one hand to their part lower at 16 to frame 2 of the carriage and

  on the other hand at their upper part at 17 to the mobile chassis 13.

  FIG. 1 shows diagrammatically the position of the rotary cutting disk 4 and the guide chute 8 after vertical displacement to obtain a larger

trench depth.

  In one embodiment of the invention, with the disk dimensions indicated above, it is possible to adjust the trench depth at values up to 1500 mm. FIG. 1 also shows a position

  of the rotating cutting disc and the guide chute.

  dage. This position is obtained after vertical lifting of the mobile frame 13 by tilting the guide chute -6- around its horizontal mounting axis on the mobile frame, to

  using a hydraulic cylinder 18 connected at 19 to said chute.

  This high position makes it possible to completely clear the trench for the crossing of obstacles or for the installation of a pipe to be laid, in which case it is carried out beforehand

  at the opening of the side door 11.

  The cuttings produced during the advance of the device by the rotation of the cutting disc 4 are advantageously discharged by lateral ducts 20. These ducts are fed by pumps (not shown) for performing an upward movement of pressurized fluid including water resulting in excavated products that are laterally evacuated from the

trench dug.

  The device according to the invention further comprises control and control means, in the form of sensors, N indicators and / or a television circuit for controlling the direction, the advance of the carriage and the depth of chopped off. Although the invention has been described in connection with a particular embodiment, it is obvious that it is in no way limited and that it can be made many changes without departing neither from its frame nor of his mind.

Claims (5)

CLAIMS I   1. Device for burying cables or flexible tubular conduits in the sea floor, comprising on a mobile carriage on the seabed, connected to a surface ship from which the truck is driven and from   of which the pipe to be laid is immersed, a front part   taking a rotary cutting disk rotatable about a horizontal axis driven by motor means and provided at its periphery with cutting drivers and a rear portion arranged in a chute for receiving from above the driving line. lay, and guide it to the bottom of the trench dug by the front part during the controlled advance of the carriage, characterized in that the rotating cutting disc and the receiving and guiding chute of the pipe to be laid are attached to a mobile frame vertically by report to the cart.   2. Device according to claim 1, characterized in that the movable frame is connected to the carriage by arms forming an articulated parallelogram structure, the operation of the movable frame relative to the carriage being provided by   jacks mounted between the carriage and the movable frame.   3. Device according to any one of the claims   1 and 2, characterized in that the discharge trough   ception and guide is pivotally mounted relative to the mobile frame about a horizontal axis under the action of a jack mounted   between the mobile frame and said chute.   4. Device according to any one of the claims   1 to 3, characterized in that the chute comprises an access door, in particular with hydraulic control, hinged on   said chute on top of it.   5. Device according to any one of the claims   precedents, characterized by the fact that it includes, for the purpose   cuation of the cuttings, lateral ducts in which is   performed a flow of fluid, especially water, under pressure.