EP4653750A1 - System for suspending at least one tubular column and method for assembling such a system - Google Patents

Abstract

System (1) for suspending at least one tubular column (12) in an underground fluid storage facility, in an oil or gas well, or in a geothermal well, said system (1) comprising:
- a recess (2) made in a plot of land (4), said recess (2) being suitable for accommodating at least one tubular column (12),
- a support structure (6) arranged in a through-way manner with respect to the recess (2),
- at least one suspension element (8) assembled to the support structure (6),
- at least one tubular column (12), and
- at least one assembly element (18),
said assembly element (18) being assembled to the tubular column (12) and to the suspension element (8) so that the tubular column (12) is suspended from the support structure (6) inside the recess (2) by means of the assembly element (18) and the suspension element (8).

Description

technical field

The invention relates to the field of systems for suspending a tubular column. In particular, the invention concerns systems for suspending at least one tubular column in an underground fluid storage facility. An underground fluid storage facility may be an underground gas storage facility, for example, for hydrogen and/or oxygen. Such a facility may be an underground high-pressure fluid storage facility. "High pressures" is understood to mean pressures greater than 100 bar, in particular pressures ranging from 100 bar to 1200 bar, and more particularly from 200 bar to 500 bar.

A system according to the invention can also be used to suspend a tubular column in an oil or gas well, or in a geothermal well.

The invention also relates to a method for assembling such a system.

Technological background

One technology for reducing the carbon footprint of industries is the use of hydrogen generated by water electrolysis. The hydrogen produced must be compressed and stored so that it can then be used on demand to power motorized vehicles, such as trucks or cars, or to supply the electrical grid, particularly during peak consumption periods. In this case, to supply the electrical grid, the hydrogen can power either a turbine or hydrogen fuel cells. As for oxygen, the second product of water electrolysis, it could be beneficial to store it for use in fields such as agriculture or for medical purposes.

Some gases, such as hydrogen, are known to be difficult to contain. Their low density necessitates high-pressure storage, and their small molecules and low viscosity make them prone to leakage. Therefore, they must be stored in a completely sealed system that meets stringent safety standards.

Such fluid storage systems are typically installed at depths of between 10 and 50 meters. These storage systems can be installed in terrains of various geological types, for example, solid rocks such as granite or basalt, or any other type of underground geological structure.

In this regard, the prior art described in the patent application WO2023209079 An underground storage system for fluid storage. The system comprises a recess in the ground, a support structure including at least one opening, a connecting element inserted into the opening of the support structure, and at least one tank. The tank is a tubular storage column having a lower end closed by a first closure means and an upper end closed by a second closure means. The upper end of the tank is assembled to the support structure via the connecting element such that the tank is suspended within the recess, and an axial clearance capable of accommodating axial thermal expansion of the tank remains between the first closure means and the bottom of the recess. The number of columns that can be suspended in such a device can be optimized. Indeed, in order to suspend more columns in such a system, it is necessary to increase the system's dimensions. This implies increasing the size of the support structure to incorporate a greater number of openings, allowing for the suspension of more storage columns. The dimensions of the recess must then be adapted accordingly. These scaling changes not only entail additional costs but also pose civil engineering challenges, particularly regarding the feasibility and safety of the installations, especially for the assembly element and the support structure. In fact, an assembly element such as the one described in the application for patent WO2023209079 is obtained by machining a solid metal bar to the desired final shape: a tubular metal part with a circular cross-section, comprising a tubular body with threaded ends and a flange. Manufacturing such a part is complex and costly because it involves using a large quantity of steel for the initial piece, followed by the removal of a significant amount of steel to obtain the final shape with the flange. The production cost of such a fastener is therefore high, primarily due to the material cost. Consequently, the weight, size, and cost of obtaining such a fastener can be optimized. Furthermore, increasing the dimensions of a support structure like the one described in the patent application can be cumbersome and expensive. WO2023209079 Therefore, such a support structure can also be optimized. In order to adapt to increasing market demand, such as the demand for hydrogen storage, it is necessary to be able to increase the number of storage columns in such a system, particularly to store much larger quantities of fluid or to store a wider variety of fluids at different pressures.

Summary

To overcome the drawbacks described above, a first idea underlying the invention is to increase the compactness of an underground fluid storage system, such as for gases. A second idea underlying the invention is to allow an underground fluid storage system to support a greater number of storage columns. More specifically, a third idea underlying the invention is to reduce the costs of obtaining such an underground fluid storage system. Finally, a fourth idea underlying the invention is to increase the safety level of such a system.

• un évidement aménagé dans un terrain, ledit évidement étant apte à accueillir au moins une colonne tubulaire,
• une structure de support disposée de manière traversante par rapport à l'évidement,
• au moins un élément de suspension assemblé à la structure de support,
• au moins une colonne tubulaire, et
• au moins un élément d'assemblage,

ledit élément d'assemblage étant assemblé à la colonne tubulaire et à l'élément de suspension de sorte que la colonne tubulaire est suspendue à la structure de support à l'intérieur de l'évidement par l'intermédiaire de l'élément d'assemblage et de l'élément de suspension.Thus, the invention provides a system for suspending at least one tubular column in an underground fluid storage facility, in an oil or gas well, or in a geothermal well, said system comprising:

• a recess created in a plot of land, said recess being suitable for accommodating at least one tubular column,
• a support structure arranged in a through-plane manner with respect to the recess,
• at least one suspension element assembled to the support structure,
• at least one tubular column, and
• at least one assembly element,

said assembly element being assembled to the tubular column and the suspension element so that the tubular column is suspended from the support structure inside the recess via the assembly element and the suspension element.

In the context of the present invention, the expression "disposed in a through manner" means that the support structure is arranged across the recess; that is, regardless of the shape of the recess, the support structure is positioned so as to completely traverse the recess along at least one dimension of said recess, for example, across its entire width. In particular, in the case of a recess with a substantially cylindrical shape, "disposed in a through manner" means that the support structure is capable of traversing said recess along its largest diameter. In other words, the support structure is arranged so as to extend from one edge of the recess to the other, thus ensuring complete support for the tubular columns suspended inside the recess.

In a system according to the invention, the combination of the assembly element with a suspension element makes it possible to do without an assembly element comprising a collar, such as the assembly element described in the patent application. WO2023209079 This allows the use of a simple and inexpensive assembly element, obtained through an existing and well-established manufacturing process. For example, an assembly element used in the invention can follow the manufacturing process of a threaded sleeve. Such a sleeve is obtained by cutting a long tubular piece. The section of tube thus cut is then threaded and machined using well-known processes. Such an assembly element is less bulky, lighter, and less expensive to manufacture than an assembly element comprising a flange, such as the one described in the patent application. WO2023209079 Thus, a system using such an assembly element is less expensive and simpler to assemble and disassemble. Finally, using a less bulky assembly element also improves the system's compactness.

According to one embodiment, at least one suspension element is metallic.

In one embodiment, at least one suspension element is U-shaped, substantially square or rectangular. A "U-shaped, substantially square or rectangular" means that an internal surface of the suspension element has a substantially square or rectangular cross-section. Such a suspension element can be obtained by cutting a square or rectangular longitudinal piece open in a U-shape, for example, by laser cutting or any other suitable method. A suspension element in the shape of a substantially square or rectangular U prevents rotation of the assembly element and thus of the tubular column, thereby improving the integrity and safety of the system. For example, in a fluid storage application, a tubular column is connected to fluid supply and withdrawal lines. In such a system, vibrations can cause the column to rotate, for example, during an earthquake. Such rotation will result in mechanical stresses being applied to these supply and withdrawal lines, as well as to their connections to the tubular column. Such rotational movements could therefore damage the integrity of the system and cause leaks, which could in turn lead to an explosion.

In one embodiment, at least one suspension element is configured to interlock with at least one other suspension element. For example, at least one suspension element can be configured to interlock with two other suspension elements.

According to one embodiment, the suspension elements are of similar or identical shape.

Thanks to these characteristics, two successive suspension elements arranged on the same guide of the support structure can interlock, thus reducing the distance between two tubular columns compared to prior art systems. Such a suspension element therefore improves the system's compactness and allows for the suspension of more tubular columns, resulting in a more efficient and flexible system. A system according to the invention thus combines less bulky suspension elements with interlocking suspension elements. The combination of these two Combining elements within the same system further contributes to improving the system's compactness. Moreover, since the assembly element and the suspension element are simple and inexpensive to produce, their combination in a system according to the invention further contributes to reducing the costs of obtaining such a system.

According to one embodiment, at least one tubular column is suspended in a substantially vertical manner.

In one embodiment, the support structure comprises at least two metal beams arranged substantially parallel to each other, said metal beams being joined by fastening means. The fastening means may include threaded metal rods and bolts. These fastening means ensure the mechanical cohesion of the support structure in the event of strong vibrations, for example during an earthquake.

A primary advantage of metal beams is their easy integration with other equipment, allowing a system according to the invention to be readily used for other applications, such as suspending a tubular column in an oil or gas well, or in a geothermal well. A secondary advantage of metal beams is their low cost and ease of manufacture.

In one embodiment, each metal beam comprises a lower portion, an upper portion, and a metal bar fixed to said upper portion. This metal bar extends along a longitudinal axis of the beam to which it is fixed, forming a guide for the suspension element between two successive beams of the support structure. Beams with these characteristics are sometimes referred to as "I-beams" in common parlance. The suspension element can thus slide along the guide as on a rail, facilitating the joining of two suspension elements during the assembly of a system according to the invention. The movement of a suspended column in a system according to the invention is thus significantly facilitated, which is advantageous for an operator during maintenance, assembly, or disassembly of the system.

According to one embodiment, the metal bar is fixed by welding to the upper part of the metal beam.

A support structure with these characteristics is therefore made up of simple and inexpensive mechanical elements. It is thus inexpensive and easy to assemble.

According to one embodiment, at least one safety element is fixed to the support structure, said safety element covering at least partially the suspension element so that the suspension element is held between the guide and the safety element.

The presence of the safety element prevents the column from lifting. Such lifting can occur, in particular, during strong vibrations, such as during an earthquake. Without this safety element, these vibrations could cause the system to disassemble, including the column and its supporting structure, thus damaging the column and rendering the system inoperable, or even dangerous for nearby personnel and the environment.

In one embodiment, the safety element is fixed to the metal bar of all or part of the metal beams. Preferably, the safety element is fixed to the metal bar of each metal beam.

In one embodiment, the safety element is reversibly fixed. This feature allows for easy removal of the safety element, particularly for maintenance operations. This is especially advantageous when a column section needs to be replaced. Maintenance and servicing are thus facilitated, and system safety is increased.

According to one embodiment, the reversible fastening of the safety element can be any of the suitable reversible fastenings known to those skilled in the art. Preferably, the reversible fastening is a bolt.

In one embodiment, the safety element comprises at least one metal plate. Advantageously, a metal plate is attached to each metal bar of each beam.

According to one embodiment, the assembly element comprises at least two radially equidistant housings, said housings being configured to be assembled to the suspension element.

According to one embodiment, the assembly element comprises between two and six radially equidistant housings, said housings being configured to be assembled to the suspension element. Preferably, the assembly element comprises at least four radially equidistant housings, said housings being configured to be assembled to the suspension element.

The housings can be made by any suitable technique known to a person skilled in the art, for example by milling.

Such housings allow a connecting element to be assembled with at least one suspension element to transfer the weight of the tubular column to the supporting structure. "Radially equidistant" means that the housings are symmetrically arranged on either side of a longitudinal axis X of the connecting element. This housing arrangement ensures a uniform distribution of the supported load.

In one embodiment, each housing has a substantially square or rectangular cross-section. The fitting of the suspension element into housings with a substantially square or rectangular cross-section prevents rotational movement of the assembly element and thus of the tubular column. When the suspension element is U-shaped and substantially square or rectangular, this resistance to rotational movement is further enhanced. These characteristics therefore contribute to improving the system's safety.

According to one embodiment, the housings extend along an axis substantially perpendicular to the longitudinal axis X of the assembly element.

• la colonne tubulaire présente une première extrémité inférieure filetée et une première extrémité supérieure filetée,
• l'élément d'assemblage présente une deuxième extrémité inférieure filetée et une deuxième extrémité supérieure filetée, ladite deuxième extrémité inférieure filetée étant complémentaire de la première extrémité supérieure filetée de la colonne tubulaire,

la colonne tubulaire et l'élément d'assemblage étant assemblés par vissage de la première extrémité supérieure filetée avec la deuxième extrémité inférieure filetée.According to one embodiment:

• The tubular column has a first threaded lower end and a first threaded upper end.
• The assembly element has a second threaded lower end and a second threaded upper end, said second threaded lower end being complementary to the first threaded upper end of the tubular column.

the tubular column and the assembly element being assembled by screwing the first threaded upper end with the second threaded lower end.

According to one embodiment, the first threaded upper end of the tubular column includes a male thread and the second threaded lower end of the assembly element includes a female thread.

According to one embodiment, the second lower threaded end and the second upper threaded end of the assembly element each comprise a female thread.

According to one embodiment, the first threaded upper end of the tubular column includes a female thread and the second threaded lower end of the assembly element includes a male thread.

In one embodiment, at least one tubular column comprises at least one metal tube with threaded ends. For example, these could be titanium tubes or steel tubes of the type used in the oil and gas industry, particularly tubes used for drilling oil and/or gas production wells. The connection between two metal tubes can be achieved either by a full connection, i.e., by screwing a male end of one tube onto a female end of the other, or by means of a threaded connecting piece, such as a sleeve.

According to one embodiment, the assembly element has at least one unthreaded portion, the housings being provided in said at least one unthreaded portion.

According to one embodiment, at least one unthreaded portion extends between the second lower threaded end and a first distal surface of the assembly element, and/or between the second upper threaded end and a second distal surface of the assembly element.

With this housing placement, the threaded sections of the assembly element, which are already under tension from being screwed to the tubular column and any column head elements, do not experience any additional stress from the suspension element being inserted into the housings. Therefore, the sealing and mechanical properties of the assembly element are not compromised by the presence of the housings, ensuring the system's safety.

According to one embodiment, the first threaded lower end of the tubular column is closed by a first closing means, and the first The threaded upper end of the tubular column is closed by a second closing means, the tubular column thus closed being a reservoir suitable for storing a fluid.

In such a system, the tank is suspended within the recess, and an axial clearance capable of absorbing axial thermal expansion of the tank remains between the first tank closure and the bottom of the recess. The integrity of the tank is not compromised by mechanical stresses related to axial thermal expansion during fluid injection and withdrawal operations. Indeed, the axial clearance prevents axial thermal expansion from compressing the tank against the bottom of the recess during such operations. Repeatedly applied stresses of this kind weaken the tank's seal, particularly at the closure.

Another advantage of such a system is that it can include multiple tanks of varying lengths. This is particularly beneficial because the length of a tank can be adjusted to facilitate the necessary pressure increases or decreases depending on the fluid's storage conditions. Therefore, different fluids can be stored within the same system.

According to one embodiment, at least one of the first closing means and the second closing means is configured to close the tubular column by screwing.

According to one embodiment, at least one of the first closing means and the second closing means is a weld.

In one embodiment, the support structure separates an upper cavity of the recess from a lower cavity of the recess. This upper cavity is open and comprises a first width L1 greater than a second width L2 of the lower cavity. Here, "open" means that the upper cavity is in direct contact with the surface; that is, there is no cavity separating it from the surface. Thus, a tank is entirely buried below ground level, including the second closure means that seals the upper end of the tank. This configuration helps to guide a deflagration occurring within the recess and thus to reduce the deflagration angle in the event of an explosion.

• (i) aménager un évidement dans un terrain, ledit évidemment étant apte à accueillir au moins une colonne tubulaire,
• (ii) disposer une structure de support de manière traversante par rapport à l'évidement,
• (iii) assembler au moins un élément de suspension avec la structure de support,
• (v) assembler un élément d'assemblage avec au moins une colonne tubulaire,
• (vii) assembler l'élément d'assemblage avec l'élément de suspension de sorte que la colonne tubulaire qui est assemblée avec ledit élément d'assemblage soit suspendue à la structure de support à l'intérieur de l'évidement par l'intermédiaire de l'élément d'assemblage et de l'élément de suspension.

Another object of the invention relates to a method for assembling a system for suspending at least one tubular column in an underground fluid storage facility, in an oil or gas well, or in a geothermal well, said method comprising the following steps:

• (i) to create a recess in a plot of land, said recess being suitable for accommodating at least one tubular column,
• (ii) arrange a support structure in a through-proportion with respect to the recess,
• (iii) assemble at least one suspension element with the support structure,
• (v) assemble a connecting element with at least one tubular column,
• (vii) assemble the assembly element with the suspension element so that the tubular column which is assembled with said assembly element is suspended from the support structure inside the recess via the assembly element and the suspension element.

• préalablement à l'étape (v), une étape (iv) au cours de laquelle :
  • ∘ l'au moins une colonne tubulaire est assemblée avec un dispositif d'arrêt destiné à faire butée avec l'élément de suspension,
  • ∘ l'au moins une colonne tubulaire qui est assemblée au dispositif d'arrêt est suspendue à la structure de support par l'intermédiaire du dispositif d'arrêt qui fait butée avec l'élément de suspension de sorte que la colonne tubulaire repose sur la structure de support par l'intermédiaire du dispositif d'arrêt lors d'uneétape (v) suivante,
• après l'étape (v) et avant l'étape (vii), une étape (vi) au cours de laquelle le dispositif d'arrêt et l'au moins une colonne tubulaire sont désassemblés.

According to one embodiment, the process further comprises the following steps:

• prior to step (v), a step (iv) during which:
  • • at least one tubular column is assembled with a stopping device designed to abut against the suspension element,
  • ∘ at least one tubular column which is assembled to the stopping device is suspended from the support structure by means of the stopping device which abuts against the suspension element so that the tubular column rests on the support structure by means of the stopping device in a subsequent step (v),
• after step (v) and before step (vii), a step (vi) in which the stop device and at least one tubular column are disassembled.

These steps allow the tubular element to be held and suspended directly from the support structure during assembly with another tubular element or with the connecting element. This eliminates the need for a drilling platform to assemble a tubular column or the entire system, as is the case with conventional tubular column assembly and suspension methods. Since renting a drilling platform is expensive, this method significantly reduces the cost of assembling and disassembling the system.

According to one embodiment, the process further includes a step (vi) of fixing a safety element to the support structure.

Brief description of the figures

• [fig. 1]La figure 1 est une vue schématique de la structure générale d'un système pour suspendre au moins une colonne tubulaire dans une installation de stockage souterrain de fluide, selon un mode de réalisation de l'invention.
• [fig. 2] La figure 2 est une vue schématique de la structure générale d'un système pour suspendre au moins une colonne tubulaire dans une installation de stockage souterrain de fluide, selon un mode de réalisation de l'invention.
• [fig. 3]La figure 3 est un schéma d'un élément de suspension et d'un élément d'assemblage tels qu'assemblés dans les systèmes illustrés aux figures 1 et 2.
• [fig. 4] La figure 4 est un schéma de l'élément de suspension illustré à la figure 3.
• [fig. 5] La figure 5 est un schéma d'une vue en coupe d'une partie des systèmes illustrés aux figures 1 et 2.
• [fig. 6] La figure 6 est un schéma d'une vue de dessus des systèmes illustrés aux figures 1 et 2, qui comprend un élément de sécurité.
• [fig. 7] La figure 7 est un schéma d'une vue en coupe d'une partie du système illustré à la figure 6.

The invention will be better understood, and other objects, details, features and advantages thereof will become more apparent from the following description of several particular embodiments of the invention, given solely by way of illustration and not limitation, with reference to the accompanying drawings.

• [ Fig. 1 ]There figure 1 is a schematic view of the general structure of a system for suspending at least one tubular column in an underground fluid storage facility, according to an embodiment of the invention.
• [ Fig. 2 ] There figure 2 is a schematic view of the general structure of a system for suspending at least one tubular column in an underground fluid storage facility, according to an embodiment of the invention.
• [ Fig. 3 ]There figure 3 is a diagram of a suspension element and an assembly element as assembled in the systems illustrated in Figures 1 And 2 .
• [ Fig. 4 ] There figure 4 is a diagram of the suspension element illustrated in the figure 3 .
• [ Fig. 5 ] There figure 5 is a diagram of a cross-sectional view of part of the systems illustrated in Figures 1 And 2 .
• [ Fig. 6 ] There figure 6 is a diagram of a top view of the systems illustrated in Figures 1 And 2 , which includes a security element.
• [ Fig. 7 ] There figure 7 is a diagram of a cross-sectional view of part of the system illustrated in the figure 6 .

Description of the implementation methods

In the figures and description of this patent application, the symbol " " used in references 14" and 16" forms an integral part of said references 14" and 16" and is not to be confused with the unit of measurement "inch". Therefore, 14" and 16" are simply references and not measurements of 14 inches and 16 inches.

In the embodiments illustrated below, the tubular columns 12 are reservoirs of an underground fluid storage facility.

There figure 1 is a three-dimensional diagram of a system 1 for suspending at least one tubular column 12 according to an embodiment of the invention. Such As illustrated, system 1 is placed in a coordinate system (x; y) in which the x-axis of the coordinate system (x; y) is a horizontal axis, and the y-axis of the coordinate system (x; y) is a vertical axis.

System 1 comprises a recess 2 made in a terrain 4, a support structure 6 placed on a first surface of a first soil S1 of terrain 4, and twenty-one tubular columns 12 suspended from the support structure 6 in the recess 2. Each of the twenty-one tubular columns 12 is assembled to an assembly element 18. Each assembly element 18 of each tubular column 12 is assembled to a suspension element 8. Each suspension element 8 is assembled to the support structure 6.

The recess 2 has a background 3 (not shown on the figure 1 The recess 2 can be obtained by drilling or excavation. The recess 2 is substantially cylindrical in shape and has an average diameter of 4 meters. Advantageously, the recess includes a lining (not shown) that extends vertically from the first surface of the first soil S1 to the bottom 3 of the recess 2. The lining can be made of concrete, cement, or steel.

The support structure 6 comprises six metal beams 20 (only five metal beams are visible on the Figures 1 And 2 ) arranged across the opening 2. The beams 20 are arranged in a substantially parallel and equidistant manner with respect to each other. As illustrated in Figures 5 And 7 , the 20 metal beams used in the systems illustrated in Figures 1 And 2 These are so-called "I-beams". Thus, each metal beam 20 extends along a longitudinal axis and comprises a lower part 21 and an upper part 23. A metal bar 26 is welded to the upper part 23 of each metal beam 20; however, other types of fasteners can be used to attach the metal bars 26 to the metal beams 20. Each metal bar 26 extends along the longitudinal axis of the beam 20 to which it is attached so as to form, between two successive beams 20 of the support structure 6, a guide 28 for the suspension element 8. In the embodiment illustrated in the figure 1 The metal bars 26 and the metal beams 20 are of the same length. The metal bars 26 have a square cross-section. One width of the square cross-section of the metal bars 26 is less than one width of the upper part 23 of the metal beams 20, so that a portion of the upper part 23 of the beams 20 remains available to form the guide 28 and accommodate the suspension element 8. The guide 28 is therefore delimited by the upper parts 23 and the metal bars 26 of two successive metal beams 20 of the support structure 6. Thus, the suspension elements 8 can slide in translation on the upper parts 23 of the metal beams 20 along a longitudinal axis of the guide 28, said longitudinal axis of the guide 28 being parallel to the longitudinal axis of the metal beams 20 and the metal bars 26 that define it. Such an arrangement of the support structure 6 and the suspension elements 8 facilitates the movement by an operator of the tubular columns 12, in particular for maintenance, assembly, and disassembly operations of the system 1 or the tubular columns 12. The metal beams 20 are assembled by fastening means 22, 24 as illustrated in more detail in the figure 7 Each metal beam 20 has a first end 20a and a second end 20b. A threaded metal rod 24 with a circular cross-section joins the six metal beams 20 at their first ends 20a, and another threaded metal rod 24 with a circular cross-section joins the six metal beams 20 at their second ends 20b. The threaded metal rods 24 are fixed to the beams by bolts 22. The support structure 6 thus assembled exhibits improved stability. Such fastening means 22, 24 ensure the mechanical cohesion of the support structure 6, particularly in the event of strong vibrations, for example, during an earthquake. Although not shown in the figures, it is also possible to fix several threaded metal rods 24, for example, two, to each end 20a, 20b of the metal beams 20 in order to further reinforce the support structure 6.

The tubular columns 12 are suspended substantially vertically along the y-axis. Each tubular column 12 consists of at least one metal tube with threaded ends, the threads of which may be male or female. For example, these may be titanium metal tubes, or steel tubes of the type used in the oil and gas industry, particularly tubes used for drilling oil and/or gas production wells. These tubes may also be used to form reservoirs in underground fluid storage facilities. The connection between two metal tubes may be made either by a full connection, i.e., by screwing a male end of one tube to a female end of another tube, or by means of a threaded connecting piece, such as than a sleeve. As illustrated in figures 2 And 5 Each tubular column 12 comprises a first threaded lower end 14 and a first threaded upper end 16. Each first threaded lower end 14 is closed by screwing on a first closing means 34, and each first threaded upper end 16 is closed by screwing on a second closing means 36. The first closing means 34 therefore have a thread (not shown) complementary to the thread of the first threaded lower ends 14, and the second closing means 36 have a thread complementary to the thread of the first threaded upper ends 16. The thread of a first closing means 34 may be male or female. The thread of a second closing means 36 may be male or female. The tubular columns 12 thus closed form reservoirs suitable for storing a fluid.

As illustrated in figures 3 And 5 The assembly element 18 is a cylindrical metal part extending along a longitudinal axis X between a first distal surface 19a and a second distal surface 19b. As illustrated in more detail in the cross-sectional view of the figure 5 The assembly element 18 has a second threaded lower end 14" and a second threaded upper end 16". The thread of the second threaded lower end 14" is female, and the thread of the second threaded upper end 16" is also female. The second closing means 36 has a male thread complementary to the female thread of the second threaded upper end 16". Thus, the second closing means 36 closes the second threaded upper end 16" by screwing. The female thread of the second lower threaded end 14" of the assembly member 18 is complementary to a male thread of the first upper threaded end 16 of the tubular column 12. Thus, each assembly member 18 is assembled to a tubular column 12 by screwing its second lower threaded end 14" to the first upper threaded end 16 of the tubular column 12. In addition, the assembly member 18 has an unthreaded portion 17 that is adjacent to the second lower threaded end 14". The unthreaded portion 17 extends between the second lower threaded end 14" and the first distal surface 19a. The unthreaded portion 17 comprises four radially equidistant recesses 30 (only two recesses being visible on the figures 3 And 5 ). The four 30 apartments are arranged within a thickness of said unthreaded portion 17. The housings 30 can completely pass through the thickness of the unthreaded portion 17. In the illustrations of Figures 1 , 2 , 3 And 5 The recesses 30 are not through-holes. The recesses 30 are formed perpendicular to the longitudinal axis X of the assembly element 18. The recesses 30 can be formed by milling. An assembly element 18 having the characteristics described above can be easily obtained by any known method of manufacturing metal sleeves that are commonly used to assemble threaded tubes, for example, when assembling oil or gas well columns. One difference is that the length of an assembly element 18 according to the invention incorporates a section dedicated to an unthreaded portion at at least one of its ends, such as the unthreaded portion 17 of the figure 5 . Consequently, such an assembly element 18 can be obtained by an already existing and well-controlled manufacturing chain, with very few modifications, making its production simple and inexpensive.

There figure 4 is a diagram of a top view of a suspension element 8 that can be used in the systems 1 shown in Figures 1 And 2 The suspension element 8 is a metal part with a general U-shape and substantially uniform thickness. The suspension element 8 comprises a first lateral edge 80, a second lateral edge 82, and a central edge 81. The first lateral edge 80 has a third width L3, and the second lateral edge 82 has a fourth width L4. The third width L3 and the fourth width L4 are equal. The first lateral edge 80 comprises a first internal face 87a, the second lateral edge 82 comprises a second internal face 87b, and the central edge 81 comprises a third internal face 87c. The central edge 81 connects the two lateral edges 80 and 82 to form an opening 86 delimited by the first, second, and third internal faces 87a, 87b, and 87c. The opening 86 is configured to accommodate an assembly element 18 and a tubular column 12. The central edge 81 has a protrusion 83 on a face opposite the inner face 87c of the central edge 81. The protrusion 83 has a rectangular cross-section. Depending on the dimensions of the suspension element 8, the protrusion 83 may also have a square cross-section. The protrusion 83 forms a first shoulder 84 with the first lateral edge 80, and a second shoulder 85 with the second lateral edge 82. The protrusion 83 is dimensioned so that a protrusion 83 of a first suspension element 8 can fit into an opening 86 of a second suspension element 8. Thus, two successive suspension elements 8 arranged on the same guide 28 of the support structure 6 can fit together, which makes it possible to improve the compactness of the system 1 and to suspend more tubular columns 12.

As illustrated in the figure 3 The housings 30 are configured to be assembled to the suspension element 8. The housings 30 therefore have a shape and dimensions complementary to the shape and dimensions of the suspension element 8, in particular complementary to the thickness of the suspension element 8. Thus, through the housings 30, the assembly elements 18 can interlock with the lateral edges 80 and 82, the central edge 81, and the protrusion 83 of the suspension elements 8 so as to suspend the tubular columns 12 in the recess 2. Thus, within a system 1 comprising several tubular columns 12 suspended on the same guide 28 of the support structure 6, as illustrated in Figures 1 And 2 The assembly of a suspension element 8 is achieved, on the one hand, by fitting the lateral edges 80 and 82, and the central edge 81 into three recesses 30 of a first assembly element 18, and on the other hand, by fitting the protrusion 83 into a recess 30 of a second assembly element 18. The cross-sectional view of the figure 5 allows us to observe that only a portion of the third width L3 of the first lateral edge 80, and only a portion of the fourth width L4 of the second lateral edge 82 is fitted into the housings 30 of the assembly element 18, which allows each lateral edge to retain part of its width available to rest on the upper parts 23 of the metal beams 20, in other words on the guide 28, in order to ensure the suspension of a tubular column 12 to the support structure 6.

Thanks to the elements described above, in a system 1 according to the invention, the tubular columns 12 are suspended in the recess 2. Thus, for each tank of the underground fluid storage installation, an axial clearance G remains between the first closure means 34 and the bottom 3 of the recess 2. This axial clearance G serves to absorb an axial thermal expansion of the reservoir, which occurs particularly during filling and emptying operations.

System 1 may also include a security element 40. figures 6 And 7 Figures 1 illustrate a system according to the invention, equipped with such a safety element 40. The safety element 40 comprises a set of identical metal plates. The metal plates are reversibly attached to the metal bars 26 of the metal beams 20 of the support element 6. For example, the metal plates of the safety element 40 can be attached to the metal bars 26 by bolting (not shown). It is therefore possible and easy to remove the safety element 40, particularly for maintenance. Each metal plate of the safety element 40 is rectangular and extends along the entire length of the metal bar 26 to which it is attached. Each metal plate of the safety element 40 has a width such that it covers only a portion of the width of the lateral edges 80 and 82 of the suspension elements 8 located on either side of the metal bar 26 to which said metal plate is attached. Thus, the suspension elements 8 are housed and held between the guides 28 and the metal plates of the safety element 40, which prevents the tubular columns 12 from lifting in the event of strong vibrations, for example during an earthquake.

Boards 42 can be added to a system 1 according to the invention. These boards 42 are preferably metallic. The boards 42 have a general shape similar to that of the suspension elements 8 so that they can be fitted together and with the suspension elements 8 in the same way that the suspension elements 8 fit together. Thus, the boards 42 have the same protrusion as the protrusion 83 of the suspension elements 8. However, the lateral edges of the boards 42 are shorter than those of the suspension elements 8, so they form a smaller opening than the opening 26 of the suspension elements 8. This is because the boards 42 are not designed to receive an assembly element 18 for suspending a tubular column 12. The function of these boards 42 is to further secure the assembly of tubular columns 12 to the support structure 6 and to form a platform on which an operator can move, particularly to more easily access the tubular columns 12. Thus, the opening of the boards 42 is configured to be fitted with a protrusion 83 of a suspension element 8 or a protrusion of another board 42.

There figure 2 is a three-dimensional diagram of a system 1 for suspending at least one tubular column 12 according to an embodiment of the invention. As in the figure 1 , in the figure 2 System 1 is placed in a coordinate system (x; y) in which the x-axis of the coordinate system (x; y) is a horizontal axis, and the y-axis of the coordinate system (x; y) is a vertical axis.

All the elements of system 1 illustrated in the figure 2 are identical to the elements of the system illustrated in the figure 1 , with the obvious exception of 2, whose structure is different in the embodiment illustrated in the figure 2 .

In the embodiment illustrated in the figure 2 , the recess 2 comprises an upper cavity C1 and a lower cavity C2.

The upper cavity C1 has a rectangular cross-section and a first width L1 of 10 meters. The upper cavity C1 also includes a second surface of a second floor S2 of terrain 4, said second surface of the second floor S2 extending over said first length L1 of 10 meters.

The lower cavity C2 is identical to the recess 2 illustrated in the figure 1 Thus, the lower cavity C2 is of roughly circular cylindrical shape and has an average diameter of 4 meters and a bottom 3.

The upper cavity C1 and the lower cavity C2 are separated from each other by the support structure 6, which is placed on the second surface of the second floor S2 of terrain 4. As in the embodiment illustrated in the figure 1 , the metal beams 20 are arranged across the recess 2 and in a substantially parallel and equidistant manner with respect to each other.

The tubular columns 12 are suspended in the lower cavity C2. Thus, for each tank of the underground fluid storage installation, an axial clearance G remains between the first closing means 34 and the bottom 3 of the recess 2. This axial clearance G has the function of absorbing an axial thermal expansion of the tank, which occurs in particular during filling and emptying operations.

Claims (15)

System (1) for suspending at least one tubular column (12) in an underground fluid storage facility, in an oil or gas well, or in a geothermal well, said system (1) comprising: - a recess (2) made in a plot of land (4), said recess (2) being suitable for accommodating at least one tubular column (12), - a support structure (6) arranged in a through-way manner with respect to the recess (2), - at least one suspension element (8) assembled to the support structure (6), - at least one tubular column (12), and - at least one assembly element (18), said assembly element (18) being assembled to the tubular column (12) and to the suspension element (8) so that the tubular column (12) is suspended from the support structure (6) inside the recess (2) by means of the assembly element (18) and the suspension element (8). System (1) according to claim 1, wherein the support structure (6) comprises at least two metal beams (20) arranged substantially parallel to each other, said metal beams (20) being assembled by fastening means (22, 24). System (1) according to claim 2, wherein each metal beam (20) comprises a lower part (21), an upper part (23), and a metal bar (26) fixed to said upper part (23), said metal bar (26) extending along a longitudinal axis of the beam (20) to which it is fixed so as to form between two successive beams (20) of the support structure (6) a guide (28) for the suspension element (8). System (1) according to claim 3, wherein at least one safety element (40) is fixed to the support structure (6), said safety element (40) covering at least partially the suspension element (8) so that the suspension element (8) is held between the guide (28) and the safety element (40). System (1) according to claim 4, wherein the safety element (40) is fixed to the metal bar (26) of all or part of the metal beams (20). System (1) according to any one of claims 4 or 5, wherein the safety element (40) is fixed reversibly. System (1) according to any one of the preceding claims, wherein at least one suspension element (8) is in the shape of a substantially square or rectangular U. System (1) according to any one of the preceding claims, wherein the assembly element (18) comprises at least two radially equidistant housings (30), said housings being configured to be assembled to the suspension element (8). System (1) according to any one of the preceding claims, wherein the assembly element (18) comprises at least four radially equidistant housings (30), said housings being configured to be assembled to the suspension element (8). System (1) according to any one of the preceding claims, wherein: - the tubular column (12) has a first threaded lower end (14) and a first threaded upper end (16), - the assembly element (18) has a second threaded lower end (14") and a second threaded upper end (16"), said second threaded lower end (14") being complementary to the first threaded upper end (16) of the tubular column (12), the tubular column (12) and the assembly element (18) being assembled by screwing the first threaded upper end (16) with the second threaded lower end (14"). System (1) according to any one of claims 8 to 10, wherein the assembly element (18) has at least one unthreaded portion (17), the housings (30) being provided in said at least one unthreaded portion (17). System (1) according to claim 11, wherein at least one unthreaded portion (17) extends between the second lower threaded end (14") and a first distal surface (19a) of the assembly element (18), and/or between the second upper threaded end (16") and a second distal surface (19b) of the assembly element (18). System (1) according to any one of claims 10 to 12, wherein the first threaded lower end (14) of the tubular column (12) is closed by a first closing means (34), and the first threaded upper end (16) of the tubular column (12) is closed by a second closing means (36), the tubular column (12) thus closed being a reservoir suitable for storing a fluid. Method of assembling a system (1) for suspending at least one tubular column (12) in an underground fluid storage facility, in an oil or gas well, or in a geothermal well, said method comprising the following steps: - (i) construct a recess (2) in a plot of land (4), said recess (2) being suitable for accommodating at least one tubular column (12), - (ii) arrange a support structure (6) in a through-proportion with respect to the recess (2), - (iii) assemble at least one suspension element (8) with the support structure (6), - (v) assemble an assembly element (18) with at least one tubular column (12), - (vii) assemble the assembly element (18) with the suspension element (8) so that the tubular column (12) which is assembled with said assembly element (18) is suspended from the support structure (6) inside the recess (2) by means of the assembly element (18) and the suspension element (8). The method according to claim 14, said method further comprising the following steps: - prior to step (v), a step (iv) during which: • at least one tubular column (12) is assembled with a stop device intended to abut against the suspension element (8), ∘ at least one tubular column (12) which is assembled to the stopping device is suspended from the support structure (6) by means of the stopping device which abuts against the suspension element (8) so that the tubular column (12) rests on the support structure (6) by means of the stopping device during a subsequent step (v), - after step (v) and before step (vii), a step (vi) in which the stop device and at least one tubular column (12) are disassembled.