WO2016110617A1 - Ballasting and/or protection devices for underwater lines - Google Patents

Abstract

The invention relates to a ballasting device (10) for an underwater line (5), wherein said device has an opening (L), said opening (L) having a cross-section substantially identical to the cross-section of the outer wall of the underwater line (5), and comprises two elements (11a, 11b) arranged to engage with one another. To facilitate the on-site assembly of the ballasting device (10), the two elements (11a, 11b) engage along a pivoting link with an axis (Ap) substantially parallel to a longitudinal axis (A1) of said opening (L). The invention also relates to an associated assembly bench for the ballasting device.

Description

 Weighting and / or protection devices for

 underwater

The invention relates to the field of weighting devices and protectors comprising such a ballasting device. These are used for all types of use and preferably but not exclusively, in application with the umbilicals associated with wells during the drilling and operating phases in the oilfields or fields, preferably but not exclusively in shallow waters (ie, about twenty to forty meters deep), in the offshore field.

Today, oil, a natural mineral oil and a mixture of hydrocarbons, is used extensively, thus being at the heart of everyone's life and therefore at the heart of the world economy. It is not for nothing that this source of fossil energy is nicknamed "black gold". Indeed, the oil:

 provides most liquid fuels, such as, by way of non-limiting examples, LPG, fuel oil, gas oil, kerosene, gasoline; is at the base of many objects of everyday life, such as by way of non-limiting examples, textiles, cosmetics, fertilizers, detergents, etc., in the form of naphtha when it is produced by refining, then transformed thanks to petrochemicals;

also included in the composition, among others, bitumens, lubricants and paraffins. On the other hand, oil has many advantages, being a source of liquid energy, it is easy to pump, store, transport and use. In addition, it offers a large amount of energy for a small volume.

 Traditionally, oil is extracted through oil wells in fields or oil fields, areas where large quantities of oil are buried since the latter is a source of natural energy. Such fields or deposits are located in oil-producing regions or oil basins, locations on or below the ground or below the sea floor in which multiple natural resources or reservoirs of oil are present. Some oil fields may extend over areas of several hundred square kilometers, requiring the presence of multiple wells to allow the operation of an entire area. The presence of oil fields and the extraction of oil through wells make it possible to build up oil reserves.

"Oil reserve" means the volume or quantity of recoverable oil present in a field or oilfield discovered taking into account current economic and technical constraints. By contrast, the term "oil resource" means the volume or quantity of oil present in said field or oil field. Current oil reserves are located throughout the world and mainly, but not exclusively, in the Middle East, North and South America and Southeast Asia. Said oil reserves may also be classified according to different criteria, such as non-limiting examples, the type of oil (conventional or unconventional) or the probability of existence in the subsoils (proved, probable and possible reserves).

The exploitation of any oilfield to obtain oil reserves is in principle composed of two main stages: first an exploration or prospecting stage, then an oil production stage.

Exploration or prospecting usually consists initially of searching for oil deposits, in particular the study of geological structures, and secondly drilling to dig a hole to check the presence of oil reserves. Once the presence of proven oil reserves, the second stage consisting in the production of oil is put in place. This production stage mainly involves the extraction of oil and can be relatively complex. In general, it breaks down into a first evaluation step followed by several recovery steps. The evaluation stage consists mainly of taking a series of samples. Said samples are to study initially the reservoir rock reservoir by coring component to evaluate various properties physico ^¬ chemical properties of the rock, such as permeability, porosity, then in a second stage the fluid located within the reservoir to measure some of its physicochemical properties, such as composition, density, viscosity, etc. This series of Samples allow to identify different existing and producing oil layers constituting the deposit. The evaluation stage ends with a production test aimed at defining the different proportions of the fluid and thus estimating the flows. The various information collected makes it possible to draw up a development plan for the deposit, said plan including in particular the number of oil wells to be drilled, the cost of elements cooperating with the wells, flow rates of fluids, etc. After estimating costs and depending on the development plan of the deposit, the operators decide on the commissioning of the operation. The development plan can subsequently be modified throughout the life of the field, depending on the actual productions.

Successively at the evaluation stage, different recovery steps can be put in place. First of all, primary recovery occurs: because of the high pressure present in the reservoir rock during the installation of the oil well, the oil reaches the surface autonomously. No other surface equipment is required during this primary recovery period, apart from a set of "Christmas Tree" valves, the main purpose of which is to close the oil well, or even a separator for extracting water from oil.

Subsequently, over time, the oil well no longer produces enough oil spontaneously due to a decrease in pressure within the reservoir rock of the oil field. Operators of oil fields then use two recovery stages, respectively named secondary and tertiary, so-called "assisted", requiring the use of different methods or additional equipment. The secondary recovery stage advantageously comprises injections of various fluids, such as, by way of nonlimiting examples, of water, nitrogen or carbon dioxide, or the use of a pump: these techniques allow a significant increase in pressure to allow the extraction of oil. As a variant or in addition, the tertiary recovery step aims to reduce the viscosity of the oil or to improve its diffusion within the reservoir and also comprises fluid injections, such as, by way of nonlimiting examples, of the carbon, vapors, surfactants ... etc.

The extraction step requires the use of oil wells. In the case of submarine deposits, such oil wells are used in association with oil platforms, advantageously fixed or mobile. A non-limiting example of such a system is described in connection with FIG. 1. In operations on subsea oil wells, a vessel or rig 1 is generally used. Such a platform 1 is, advantageously but not limitatively, connected to a well by a large hollow tube (also known in the English terminology "Marine Riser", not shown in Figure 1), said tube of large dimension allowing in particular the descent of various equipment to the seabed, sometimes several thousand meters below the surface.

Inside said large hollow tube, are descended a hollow tube of small diameter for drilling (also known in the English terminology "Drilling Riser Pipe") and a so-called umbilical cable 5. The term "umbilical cable ", Any cable allowing the supply of consumables to a device. In the case of submarine deposits, such an umbilical cable 5, deployed closer to the seafloor SB, allows a connection between the host establishment, namely the platform 11, through which the necessary control commands, the energy, be it electrical, hydraulic or pneumatic, is transmitted or even different chemicals delivered to a subsea oil well. Such an umbilical cable 5 can also be used in connection with subsea manifolds or any underwater system requiring remote control. An umbilical cable generally consists of a long flexible assembly of tubes, cables ... contained within a protective sheath: in principle, are thus contained, within the umbilical cable, electrical cables for transmitting control commands and energy signals and low or high pressure tubes for conveying hydraulic fluids to control valves and chemicals for injection into the oil well. Such umbilical cable is referred to as "cable electro hydraulic ^¬". In addition, the umbilical cable 5 may also include other additional elements, such as by way of non-limiting examples of optical fiber cables for tracking purposes. The design of a cable Umbilical is modular, adaptable to every installation: it depends on many factors including water depth, function, environmental conditions and temperature. During drilling or maintenance operations, the underwater drilling line, comprising a column and / or drill pipe and at least one umbilical cable, must remain substantially fixed with respect to the wellhead 6 (also known as the Anglo-Saxon terminology "Wellhead").

Current oil fields are already producing many billions of barrels. Nevertheless, many operators seek to multiply these productions. Indeed, facilities advantageously comprising multiple oil wells, such as for example those described in connection with Figure 1, are implemented to ensure production for years, even decades. Nevertheless, over time, oil wells age and wear out. In addition, with the progress and development of the technology, new processes emerge making the old installations inefficient, or even obsolete, with regard to the new installations currently installed.

Today, techniques already exist to improve and promote the production of oil, especially in the submarine oil fields. Such techniques require the use of an umbilical cable as described above. Depending on the functions included within the umbilical cable, it is possible to initiate the secondary and / or tertiary recovery steps to thereby increase the pressure and / or reduce the viscosity of the fluid, in order to accelerate the flow of oil production. Other methods envisage the renovation of oil wells by carrying out the electrification of said oil wells: such methods require the installation of new valves which will subsequently cooperate with an umbilical cable.

 In principle, the installation of an umbilical cable requires the use of a first vessel. Upstream, various studies and cartographic surveys are conducted to allow a fund recognition operation and subsequently the installation of the umbilical cable. Then the umbilical cable is shipped thanks to the presence of a winding platform within said first vessel to allow its installation. Once the umbilical cable is installed, it is necessary to stabilize it and protect it so that it can perform its role correctly, namely to transmit control commands or energy to oil wells, or even to convey chemicals to these wells. . Indeed, such a cable is subject to pressure and temperature differences, while the first vessel meanwhile, advantageously control and injection vessel, is subject to meteorological conditions, such as non-standard examples. limiting, swell movements.

A first solution commonly used to provide the stability and protection functions of such an umbilical cable is to bury the umbilical cables used in the seabed by digging a protective underwater trench and dedicated by means of a plow. burial. Nevertheless, such a first solution has many disadvantages, since it requires special equipment and skills. Moreover, she represents a significant time, since the implementation of this solution is long tedious, resulting in significant additional costs. Faced with this plurality of disadvantages, oil plant builders and operators have sought to develop non-consumable equipment, that is to say, reusable if necessary, not requiring preparatory work. Thus, a second solution consists in the use of concrete mattresses. A nonlimiting example of such a concrete mattress is described in connection with FIG. 2. A concrete mattress 7 consists mainly of concrete modules 8, in the advantageous but nonlimiting form of cubes, said modules being connected together to form a mattress. The links between modules can be guaranteed by ropes, preferably synthetic fibers, or treated steel cables: such bonds thus provide some flexibility to the mattress for better handling. At a predetermined distance, a predetermined number, depending on the length of the umbilical cord, of concrete mattress are positioned on said umbilical cable so as to enable them not to move, but also to protect it from possible falls or interactions with other objects, such as by way of non-limiting examples of the anchors or equivalent means, and to limit the hydrodynamic effects on the umbilical cable. Nevertheless, this second solution also has several disadvantages. Indeed, after laying an umbilical cable embedded on a first vessel, a second vessel is required to route said concrete mattress, which generates significant additional costs and installation time, since the poses, stabilization and protection of an umbilical cable require the use of two vessels. In addition, the deployment of such concrete mattresses is potentially dangerous for the umbilical cable. Due to the significant weight and length of the mattress, specific devices, such as dedicated cranes, must be used to allow the mattresses to be dropped into the sea: this release is sometimes imprecise since it is due to disturbances in the seabed and visibility. at several meters depth is often reduced, despite the use of adapted robots and cameras. Incorrect calculation or improper handling to position the concrete mattresses could thus lead to damage or even rupture of the umbilical cable or other conduits that may possibly carry oil. Furthermore, said mattresses could also not be placed correctly on the umbilical cord or cables, providing neither stabilizing function nor protection function. To avoid such problems, oil field operators most of the time decide to stop the production of these oil fields while placing the concrete mattresses, resulting in extremely high production costs and downtime.

 Other devices have been developed to provide the stabilization and protection functions of an umbilical cord. By way of examples, mention may be made in particular of:

protective devices comprising mainly half-shells of a predetermined length of polyurethane interlocking one into the other; weighted systems also composed of two half-shells fitting one into the other.

 Each device provides only part of the stabilization and protection functions. In addition, such devices have other disadvantages, since they are not pre-assembled and require the expertise of operators: significant installation costs and subsequent installation times are expected for employment such devices.

The invention makes it possible to meet all or some of the disadvantages raised by the known solutions.

 Among the many advantages provided by a weighting device according to the invention, we can mention that it allows:

 to propose a reusable modular and reusable device ensuring the stability of underwater lines by the addition of mass, while minimizing the hydrodynamic profile of said device to avoid the appearance of additional drag forces;

 to provide mechanical protection of the underwater lines, for example, facing possible abrasion or falling lines;

- To reduce the number of equipment and devices used by facilitating installation by the use of pre ^¬ assembled devices;

to guarantee a saving of time of installation and important maintenance and consequently a significant reduction of the costs. To this end, it is particularly provided a ballast device for subaquatic line, having a light, said light having a substantially identical section to the section of the outer wall of the underwater line, comprising two elements arranged to cooperate with each other. 'other. To allow easy assembly and rapid installation of the ballasting device according to the invention on site by reducing the number of equipment, the two elements cooperate in a pivot connection axis substantially parallel to a longitudinal axis of said light.

 Advantageously, the pivot connection can be materialized by a hinge.

 The weighting device according to the invention may further comprise fixing means arranged to maintain the elements along a section of the underwater line and to encircle said section of the underwater line.

 Preferably, the fixing means may comprise a captive screw.

 To remain in position on a predetermined section of an underwater line, the elements may comprise means for ensuring the holding of said elements on the underwater line.

 Preferably, the means for ensuring the holding may comprise a friction pad.

 Advantageously, the two elements may have axial symmetry along a longitudinal axis of the light.

In order to adapt to the usual geometry of the underwater lines, the elements can be arranged to present a constant circular section light. Advantageously, each element may consist respectively of a cylindrical half-shell.

 To allow better penetration of the ballasting device according to the invention and have the least possible impact on the stability of the cable, the ends of each element has a tapered shape.

 As a variant or in addition, each element of the weighting device according to the invention comprises a flat respectively.

 Alternatively or additionally, to increase the life of the weighting device according to the invention, the latter may comprise means for controlling the corrosion of said ballast device.

 Preferably, the means for controlling corrosion may comprise an anode arranged to be embedded in the flat.

According to a second object, the invention relates to an assembly bench, comprising first and second portions arranged to cooperate with each other, said first portion mainly comprising an intake zone of a ballast device according to the invention. invention, substantially planar. To allow easy assembly and rapid installation of the ballasting device according to the invention on site, the second portion comprises means for guiding said ballast device to gradually and automatically fold down the two elements of said ballast device on a section of ballast. an underwater line.

To facilitate the use of a bench according to the invention and to reduce human intervention, the first portion may comprise means for automatically routing the weighting device.

 The invention also provides an underwater line cooperating with one or more weighting devices according to the invention, each device enclosing a section of said underwater line.

According to a third object, the invention relates to a parapétrolier system, comprising a parapétrolière platform, an underwater line cooperating with said platform and an oil well cooperating with said underwater line. To ensure stabilization and protection of said underwater line, the system according to the invention comprises at least one weighting device according to the invention enclosing a section of said underwater line.

Other features and advantages will emerge more clearly on reading the following description and on examining the figures that accompany it, among which:

 - Figure 1, previously described, illustrates a detailed view of a drilling rig platform system;

 - Figure 2, previously described, describes an embodiment of a weighting device according to the state of the art in the form of a concrete mattress;

FIGS. 3A and 3B show a graphic description of a first embodiment of a weighting device according to the invention; FIGS. 4A and 4B schematically describe a second embodiment of a weighting device according to the invention;

 FIGS. 5A and 5B describe assembly examples of the first and second embodiments of a weighting device according to the invention;

 FIGS. 6A and 6B illustrate an alternative embodiment of an assembly bench according to the invention;

 FIGS. 7A to 7D show different views of an alternative embodiment of an assembly bench according to the invention. FIGS. 3A and 3B schematize a first embodiment of a weighting device according to the invention, in the closed and open positions, respectively.

A weighting device 10 for underwater line 5 according to the invention advantageously has a light L. Such a weighting device 10 advantageously allows the stabilization and protection of an underwater line 5, said underwater line being integrated into a drilling system , such as by way of nonlimiting example, that described in connection with Figure 1. Preferably, such an underwater line may consist of an umbilical cable as described above, but can not be limited to this single example: it may consist of any cable or conduit cooperating advantageously with an oil platform and with an oil well. "Light" means any central orifice or cavity (e) arranged in the weighting device to allow the passage of an underwater line. Thus, said light L advantageously has a section substantially identical to the section of the outer wall of the underwater line 5: said section may advantageously be square, circular, oblong or any other section adapted to be adapted for an underwater line, or even in some cases several underwater lines. Furthermore, preferably, the device 10 comprises two elements 11a, 11b arranged to cooperate with each other: the light L is thus defined when the weighting device 10 according to the invention is in the closed position, c That is, the elements 11a and 11b cooperate with each other as they are fixed by any means with each other, as described with reference to FIG. 3A. Nevertheless, the device 10 may comprise three, four or even a plurality of elements, cooperating with each other, two by two. Each element advantageously comprises a ballast to allow the stabilization of the underwater line. The term "ballast" any heavy body ensuring the displacement of the center of gravity or the increase of the mass of the underwater line to finally guarantee said stabilization. By way of nonlimiting examples, such a ballast may consist in the use of a particular material, such as cast iron, an alloy of iron and carbon, or the integration of ballast within said elements.

Such elements 11a, 11b cooperate in a pivot connection, that is to say that they are rotatably mounted relative to each other. Such a pivot connection thus makes it possible to guide the two elements 11a, 11b in rotation around the link axis and block any other degree of freedom, including movement in translation. Advantageously, the pivot connection is made along an axis Ap substantially parallel to a longitudinal axis A1 of the light L. The term "longitudinal axis" As non-limiting examples, when the elements 11a, 11b are arranged so that the light L has a circular and constant section as described in connection with Figure 3A, the axis Ap of the pivot connection may be substantially parallel to the axis of revolution of the light L. Alternatively, when the elements 11a, 11b are arranged so that the light L has a square and constant section, the axis Ap of the pivot connection may be substantially parallel to the axis passing through the center of the square section of the light L. Advantageously but not limiting , the pivot connection can be embodied by a hinge 12. Such a hinge 12 makes it possible to quickly install the ballasting device 10 with a minimum number of different parts. For all practical purposes, it could be provided a plurality of hinges, particularly along the length of the elements lla, 11b. A hinge is a mechanical member allowing the articulation of two elements in rotation in a pivot connection. In principle, such a hinge is composed of three parts: the first immobile corresponds to the mass grave and can be fixed on the element 11a, the second intermediate corresponds to the hinge serving as an axis and finally, the third mobile corresponds to the hinge and can be attached to item 11b. Any other equivalent system enabling the implementation of such a pivot connection, such as by way of non-limiting example an axis of rotation, a connecting rod comprising a pivot connection, could also be used. The invention can not be limited to the use of a single pivot link. The cooperation of the elements 11a, 11b can be provided by means of a double pivot link or several associated pivot links if necessary.

In addition, the ballasting device 10 according to the invention may comprise fixing means arranged to maintain the relative position of the elements 11a, 11b along a section of the underwater line 5 and to encircle said section of the underwater line. Such fastening means guarantee the cohesion of the weighting device 10 around the underwater line, in the closed position, a situation described in connection with FIG. 3A. Such fastening means may advantageously comprise any bolt, fastening screw or equivalent means for clamping or locking the two elements 11a, 11b and their fasteners. Alternatively or additionally, the fastening means may comprise one or more captive screws 13. Such captive screws have many advantages since they allow to obtain a captive screwing function. Indeed, during assembly operations, a screw can easily escape the hands of an operator, which can lead to serious consequences, particularly involving the safety of said operator and / or braking the assembly process of said weighting device. According to FIGS. 3A and 3B, such captive screws can advantageously be integrated within one of the elements 11a or 11b. In a complementary manner, one or more orifices or recesses 13o, depending on the number of captive screws included in the weighting device, are arranged in the other of the elements 11a or 11b, in order to accommodate said screws. captives 13. Preferably, but not limited to, the fixing means consist of two locking screws to ensure the fixing of the ballasting device 10 in case of failure of one or the other of said screws.

When laying said device on the underwater line, the attachment of the latter may be more or less effective: if the locking of said device is not appropriate because it is too loose, the weighting device may be slide along the underwater line, which may also cause loss of system stability. Conversely, when the elements of the ballasting device are fixed by excessively compressing the underwater line, they can damage the integrity of the latter. To remedy this drawback, the elements 11a, 11b of a weighting device according to the invention may comprise means for ensuring the holding of said elements on the underwater line. In a preferred but nonlimiting manner, the means for ensuring the holding may comprise a friction pad 17. Such a friction pad 17, also known under the terminology "anti-slip pad", may advantageously be made of a material adapted to reduce, brake , or completely stop, the relative movements between the elements 11a, 11b of the weighting device and the underwater line, more particularly the outer wall of the latter. Said friction pad can also reduce the compression applied to the underwater line to tighten said line without damaging it. According to FIG. 3B, one or more friction pads 17 may advantageously be positioned on the inner wall of one or both elements 11a, 11b, so as to cooperate in a recess connection. Said friction pads 17 may be permanent or removable.

As previously stated, the two elements 11a, 11b comprise or consist of a ballast to allow the stabilization of the underwater line. To allow a permanent stabilization of the underwater line, the two elements 11a, 11b may have an axial symmetry along a longitudinal axis A1 of the light L: such a configuration allows a better weight distribution. In addition, said elements 11a, 11b may advantageously be identical. By way of nonlimiting example, in connection with FIGS. 3A, the section of the light L being circular and constant, the elements 11a, 11b have an axial symmetry along the axis of revolution of the light L. Preferably, each element 11a, 11b may consist respectively of a cylindrical half shell, as described in connection with Figures 3A and 3B. Such a particular shape advantageously allows to marry the usual outer walls of the underwater lines. In addition, such elements 11a, 11b have conventional shapes commonly manufactured and used in the field of offshore. Such half-shells are considered particularly suitable for improving the stability of the underwater line.

In addition, each element 11a, 11b may have a particular hydrodynamic profile, having the least possible impact on the stability of the underwater line 5 and the associated ballasting device. Among a non-exhaustive set of modifications of the hydrodynamic profile of each element 11a, 11b, the invention provides that:

 - The outer ends 16 of each element 11a, 11b may have a tapered shape and that consequently, the ends of the ballasting device 10 according to the invention can have a conical shape: the end sections are smaller. Such a profile facilitates the passage in equipment for launching said ballast device and the underwater line;

 the inner ends of each element 11a, 11b may have a slightly flared shape to guarantee, if necessary, flexural movements of the underwater line without hindrance;

 one or more elements 11a, 11b may have a bevel or chamfer, that is to say a small surface formed by a cut edge or obliquely cut edge, in order to increase the stability of the weighting device according to the invention before and after installation on the underwater line;

 each element 11a, 11b may comprise respectively a flat part 15.

Once installed on the underwater line, the ballasting device is planned to remain several years, or even decades in the seabed. The materials used to make said device are not always suitable for this kind Job. In fact, in addition, the weighting device 10 according to the invention may comprise means for controlling the corrosion of said ballast device. In a preferred but nonlimiting manner, the means for controlling the corrosion may comprise an anode 14 arranged to be "embedded", that is to say inserted, within the flattened portion 15. Such anode may be of sacrificial type, such as that is to say it will be composed of a metal more reducing than the metal to be protected constituting the elements 11a, 11b to ensure the dissolution and / or oxidation of said anode before that (s) of said elements. By way of nonlimiting example, such anode may advantageously be composed of an aluminum alloy.

Figures 4a and 4b schematically a second embodiment of a ballasting device according to one invention.

As in FIGS. 3a and 3b, such a subaqueous line weighting device 5 advantageously has a light L. Such a weighting device 10 advantageously allows the stabilization and protection of an underwater line 5, said underwater line being integrated in a drilling system, such as by way of non-limiting example, that described in connection with Figure 1. Preferably, such an underwater line may consist of an umbilical cable as described above, but can not be limited this example alone: it may consist of any cable or duct cooperating advantageously with an oil platform and with an oil well. Thus, said light L advantageously has a section substantially identical to the section of the outer wall of the underwater line 5: said section may advantageously be square, circular, oblong or any other section adapted to be adapted for an underwater line. Furthermore, preferably, the device 10 comprises two elements 11a, 11b arranged to cooperate with each other: the light L is thus defined when the weighting device 10 according to the invention is in the closed position, c that is, the elements cooperate with each other, as they are fixed by any means with each other, as described with reference to FIG. 3A. Nevertheless, the device 10 may comprise three, four or even a plurality of elements, cooperating with each other, two by two. Each element advantageously comprises a ballast to allow the stabilization of the underwater line. By way of non-limiting examples and according to FIG. 4A, the ballast 18 may be "flooded", that is to say covered with a suitable material, to prevent any corrosion phenomenon and consequently a loss of mass and stability, instead of the anode used in the first embodiment of the device according to the invention: said ballast device and have a limited life. As a preferred but nonlimiting example, the polyurethane may be used to cover said ballast: the ballast 18 is advantageously in the form of an insert.

Such elements 11a, 11b cooperate in a pivot connection, that is to say that they are rotatably mounted relative to each other. Such a pivot connection thus makes it possible to guide the two elements 11a, 11b in rotation about the connection axis and to block any other degree of freedom, especially the movements in translation. Advantageously, the pivot connection is made along an axis Ap substantially parallel to a longitudinal axis A1 of the light L. The term "longitudinal axis" As non-limiting examples, when the elements 11a, 11b are arranged so that the light L has a circular and constant section as described in connection with Figure 4B, the axis Ap of the pivot connection may be substantially parallel to the axis of revolution of the light L. Alternatively, when the elements 11a, 11b are arranged so that the light L has a square and constant section, the axis Ap of the pivot connection may be substantially parallel to the axis passing through the center of the square section of the light L. Advantageously but not limiting , the pivot connection can be embodied by a hinge 12. Such a hinge 12 makes it possible to quickly install the ballasting device 10 with a minimum number of different parts. For all practical purposes, it could be provided a plurality of hinges, particularly along the length of the elements lla, 11b. As a preferred but non-limiting example, the use of an elastic hinge is preferred instead of the use of a hinge screw. Any other equivalent system allowing the implementation of such a pivot connection, such as by way of non-limiting example an axis of rotation, a rod having a pivot connection, could also be used. The systems used to materialize said pivot link may be identical or similar to those employed in the ballasting devices according to the first embodiment. In addition, the ballasting device 10 according to the invention may comprise fixing means arranged to maintain the relative position of the elements 11a, 11b along a section of the underwater line 5 and to encircle said section of the underwater line. Such fastening means guarantee the cohesion of the weighting device 10 around the underwater line, in the closed position, a situation described in connection with FIG. 3A. Such fastening means may advantageously comprise any bolt, fixing screw or equivalent means for clamping or locking the two elements 11a, 11b and their fasteners. Alternatively or additionally, the fastening means may comprise one or more strips, metal strips used to keep said elements 11a, 11b locked together. Said strips may advantageously be made of stainless steel or a suitable alloy to prevent possible corrosion phenomena. As stated previously, the two elements binds,

11b comprise or consist of a ballast to allow the stabilization of the underwater line. To allow a permanent stabilization of the underwater line, the two elements 11a, 11b may have an axial symmetry along a longitudinal axis A1 of the light L: such a configuration allows a better weight distribution. In addition, said elements 11a, 11b may advantageously be identical. By way of non-limiting example, in connection with FIGS. 4A and 4B, the section of the light L being circular and constant, the elements 11a, 11b have an axial symmetry along the axis of revolution of the light L. Preferably, each element 11a, 11b may consist respectively of a cylindrical half-shell, as described in connection with FIGS. 4A and 4B. Such a particular shape advantageously allows to marry the usual outer walls of the underwater lines. In addition, such elements 11a, 11b have conventional shapes commonly manufactured and used in the field of offshore. Such half-shells are considered particularly suitable for improving the stability of the underwater line. In addition the ballast 18 may advantageously have a double curvature profile so as not to hinder the possible bending movements of the underwater line.

In some cases, the sections of underwater line to protect and stabilize may be of different lengths, depending on the depths in which said sections are positioned. As a non-limiting example, when the underwater line is positioned on the seabed, the sections of line to be protected are much larger. Thus, in accordance with FIGS. 4A and 4B, the weighting device 10 according to the invention may comprise hooking means 19 for interconnecting the different successive weighting devices and for ensuring continuity of protection and stabilization of the ballast. underwater line. Advantageously but not limiting, such hooking means may comprise corresponding male-female devices. FIGS. 5A and 5B illustrate assembly examples of the first and second embodiments of a weighting device according to the invention. Such a weighting device 10 according to the invention is advantageously mounted crimped on an underwater line 5 so that said weighting device 10 encloses said underwater line 5. The underwater line 5 occupies the empty space defined by the light L of each The invention provides that a plurality of weighting devices 10 is used in series on the underwater line 5 to stabilize and protect the various sections of the underwater line 5, said sections being able to be of different lengths. . Such weighting devices 10 can thus guarantee the implementation of modular systems, adaptable to the needs and types of underwater lines. According to said requirements, the weighting devices may be assembled on successive subaqueous line sections, a situation described in connection with FIG. 5B, or on dissociated subaquatic line sections, a situation described with reference to FIG. 5A.

FIGS. 6A and 6B illustrate an alternative embodiment of an assembly bench according to the invention. Such a bench allows to assemble a weighting device according to the invention and an underwater line in a minimum of time on site. It is advantageously positioned on the platform or the vessel allowing the installation of an underwater line.

Said bench 30 advantageously comprises first and second portions respectively 31 and 32 arranged to cooperate with each other. According to Figure 6A, said portions advantageously cooperate in a recess connection, allowing permanent or removable attachment of the first and second portions. Alternatively, the first and second portions may constitute one and the same entity. The first and second portions 31 and 32 may advantageously have an inverted "L" shape, allowing space saving within the vessel and easier assembly.

Said first portion mainly comprises an intake zone of a ballasting device according to the invention which is substantially flat, allowing said device to be transported to the underwater line for assembly, said underwater line being in movement along the second portion. During its passage within the first portion, the weighting device according to the invention is advantageously in its initial position, as described in connection with FIGS. 6A and 6B. The "initial position" is defined as the position in which the elements 11a, 11b, constituting the weighting device, are substantially included in the same plane. In addition, the first portion 31 may advantageously comprise guiding means to prevent the weighting device, when it is conveyed along this portion, from coming out of its path. Such guiding means may advantageously comprise two bars positioned along the transverse walls of the first portion at a height sufficient to contain said device. Any equivalent system may also be used. Moreover, the first portion 31 may also include "automatic" routing means allowing the arrival of the device to the within the second portion 32 without human intervention. Such conveying means 31c may advantageously comprise a roller conveyor, conveyor belt or any other equivalent means without limiting the scope of the present invention.

The second portion 32 allows the "automatic" assembly of the ballasting device according to the invention around the underwater line. As specified above, the weighting device 10 according to the invention is advantageously mounted crimped on an underwater line 5 so that said weighting device 10 encloses a section of said underwater line 5. It is thus necessary to facilitate said assembly, since the installation and installation of underwater lines and their equipment take place online. The assembly bench is designed to facilitate installation by the use of pre-assembled devices. According to Figure 6A, an underwater line 5 is advantageously unwound along the second portion 32, to allow the assembly of the weighting devices around said line. Said underwater line 5 follows a continuous longitudinal movement to allow its installation on the seabed in particular. Such a movement can be initiated using a suitable winch or any equivalent system, advantageously positioned within the vessel. The continuous movement of the underwater line 5 drives the ballasting device 10 according to the invention, when one or more of the elements 11a, 11b of the device comes into contact with said line. Such a drive is particularly in connection with FIGS. 7A to 7D, said figures presenting different views of a variant of realization of an assembly bench according to the invention at different positions within the second portion 32. In addition, like the first portion 31, said second portion may include "automatic" routing means for facilitate the driving of the weighting device along the second portion 32. Such routing means 32c may advantageously comprise a roller conveyor, conveyor belt or any other equivalent means without limiting the scope of the present invention.

To allow easy assembly and rapid installation of the ballast device on site, while minimizing human interventions as far as possible, the second portion 32 comprises guide means 33 of said weighting device for progressively and automatically folding the elements over a section of the ballast. 'an underwater line. Such guiding means 33 are advantageously positioned along the transverse walls of the second portion at a height sufficient to contain said device. The distance between the guide means 33 decreases along the second portion 32, as described in connection with Figures 6A, 7A and 7B, to ensure the assembly of the device around the underwater line 5. As examples non-limiting, said guide means 33 may advantageously comprise two bars or any other equivalent system. The guiding means 33 could also be constituted by a gutter, advantageously arranged within the second portion 32. In addition, the second portion may also comprise means 34 to allow the locking of any fastening means present on the weighting device 10, as described in connection with Figures 7C and 7D, said means 34 being arranged successively to the guide means 33. As previously stated, the fixing means may be present, said fixing means being arranged to maintain the position relative elements 11a, 11b along a section of the underwater line 5 and encircle said section of the underwater line and thus ensure the cohesion of the ballasting device 10 around the underwater line 5, in the closed position.

The invention also provides a parapétrolier system, comprising a parapétrolière platform, an underwater line cooperating with said platform and an oil well cooperating with said underwater line. To reduce the costs and installation time of said system, said system comprises at least one weighting device according to the invention enclosing a section of said underwater line. Said oil platform can advantageously be fixed or mobile, or even be a floating unit. The invention can not be limited to the type of platform comprised by said system. The invention has been described when used in connection with the laying of umbilical cables associated with wells in oilfields or fields. It can also be implemented for all types of underwater lines that require stabilization and protection functions. Other modifications may be envisaged without departing from the scope of the present invention defined by the appended claims.

Claims

1. Weighting device (10) for an underwater line (5), having a light (L), said light (L) having a section substantially identical to the section of the outer wall of the underwater line (5), comprising two elements (IIa, 11b) arranged to cooperate with each other, said device (10) being characterized in that the two elements (11a, 11b) cooperate in a pivot connection axis (Ap) substantially parallel to a longitudinal axis (Al ) of said light (L). Weighting device (10) according to the preceding claim, wherein the pivot connection is embodied by a hinge (12). Weighting device (10) according to any one of the preceding claims, further comprising fastening means arranged to maintain the relative position of the elements (11a, 11b) along a section of the underwater line (5) and to encase said section of the underwater line. . Weighting device (10) according to the preceding claim, wherein the fastening means comprise a captive screw (13). The weighting device (10) according to any one of the preceding claims, wherein the elements (11a, 11b) comprise means for ensuring the holding of said elements on the underwater line. . Weighting device (10) according to the preceding claim, for the means for ensuring the holding comprise a friction pad (17). Weighting device (10) according to any one of the preceding claims, wherein the two elements (11a, 11b) have an axial symmetry along a longitudinal axis (Al) of the light (L). 8. Weighting device according to any one of the preceding claims, wherein the elements (11a, 11b) are arranged to present a light (L) of constant section and circular. . Weighting device according to the preceding claim, wherein each element (11a, 11b) consists respectively of a cylindrical half-shell. 10. Weighting device according to the preceding claim, wherein the ends (16) of each element (11a, 11b) has a tapered shape. 11. Weighting device (10) according to any one of claims 8 to 10, wherein each element (11a, 11b) respectively comprises a flat (15). 12. Weighting device (10) according to any one of the preceding claims, comprising means for controlling the corrosion of said ballast device. 13. Weighting device (10) according to claims 11 and 12, wherein the means for controlling corrosion comprises an anode (14) arranged to be embedded within the flat (15). 14. Bench assembly, comprising first and second portions arranged to cooperate with each other, said first portion mainly comprising an intake zone of a weighting device according to any one of claims 1 to 13. substantially flat, said bench being characterized in that the second portion comprises means for guiding said weighting device to gradually and automatically fold down the two elements (11a, 11b) of said weighting device (10) on a section of an underwater line (5). Assembly bench (30) according to the preceding claim, for which the first portion (31) includes means (31c) for automatically routing the weighting device (10). 16. Underwater line (5), cooperating with one or more weighting devices (10) according to any one of claims 1 to 13, each device (10) enclosing a section of said underwater line (5). 17. A petroleum system, comprising an oil platform (1), an underwater line (5) cooperating with said platform (1) and an oil well (6) cooperating with said underwater line (5), said system being characterized in that it comprises at least one weighting device (10) according to any one of claims 1 to 13 enclosing a section of said underwater line (5).