System for protecting the mouth of a pipe and method for implementing such a system

Description

TECHNICAL FIELD

[0001] The present invention relates to a system for protecting the mouth of a pipeline, particularly of the "I-Tube" type, for oil production. The invention also relates to a method for implementing such a system. PREVIOUS ART

[0002] Various systems are known to protect pipelines against solid objects or fluids during transport or storage.

[0003] US2977993A describes an example of a protective system consisting of a cover made of plastic material, particularly elastomer, intended to be fitted to the end of a pipe to protect its interior. The cover includes a closed, dome-shaped central portion to prevent the ingress of dust, water, or other foreign matter into the pipe.

[0004] US5004016 describes another example of a protective system consisting of an elastomeric component designed to be fitted to the end of a tube to protect its threads. The component includes a skirt for covering the external threaded surface of the tube. The component is equipped with a hook for removal from the outside. The hook is located in a central opening that allows fluid to pass through the component.

[0005] Also known is document US4777985 which describes the preamble of claim 1. STATEMENT OF THE INVENTION

[0006] The aim of the present invention is to provide a protection system for pipelines intended to be submerged, in particular for oil exploitation by a floating production, storage and offloading unit (FPSO: “Floating Production Storage and Offloading” in English), a tension-leg platform (TLP: “Tension-leg platform”), or a floating liquefied natural gas (FLNG: “Floating Liquefied Natural Gas”) complex.

[0007] For this purpose, the invention relates to a system for protecting the mouth of a pipeline, in accordance with the object of claim 1.

[0008] Thus, the invention makes it possible to protect the mouth of the pipe against fluid and foreign bodies (seawater and marine organisms such as algae, shells, etc.), while offering the possibility of selectively removing the protective piece from the inside or outside of the pipe.

[0009] The protective part is designed to withstand the transport of the pipeline, for example connected to an FPSO unit, which may be towed at sea between two continents.

[0010] At the same time, the protective piece is designed to allow non-manual removal, i.e. by mechanized means.

[0011] This removal can be carried out externally using a remotely operated underwater vehicle (ROV) several meters underwater, which has a low traction force. However, such an operation is costly and complex. External removal by a diver is strictly prohibited due to the risk of death.

[0012] A particularly advantageous method is removal from inside the pipeline, from a floating unit, platform, or vessel, using a winch that pulls on a rope or strap attached to the protective piece. This causes the piece to deform and fold back on itself, allowing it to be lifted up the pipeline. This removal method is much simpler and less expensive than using an underwater robot.

[0013] According to other advantageous features of the invention, taken individually or in combination: The protective piece has tapered areas to facilitate deformation and removal. These tapered areas are formed on the peripheral portion. They include lines distributed in axial planes on the peripheral portion. They also include at least some of the junction angles between the skirts of the peripheral portion. The tapered areas are formed on the central portion. They include tapered sections formed on the radii of the central portion. The radii have a cylindrical cross-section. The radii are inclined relative to a radial plane of the protective piece. The peripheral portion has at least three skirts designed to protect, respectively, an inner surface, a frontal surface, and an outer surface of the pipe inlet.The peripheral section is equipped with four skirts designed to protect, respectively, an inner surface, a front surface, an outer surface, and a rear surface of the pipe inlet. The system includes attachment means designed to hook traction means to the protective section for removal. The attachment means are designed to hook traction means to the protective section from above and below, for selective removal from either inside or outside the pipeline. The attachment means include an anchoring element fixed to the hub of the central section. The anchoring element is made of a harder material than the protective section. The attachment means include an anchoring member integral with the hub of the central section. The attachment means include the hub of the central section, which directly receives the traction means.The attachment means comprise elements arranged on the peripheral part of the protective piece and designed to receive the traction means. The protective piece is made of polyurethane material, preferably Courbhane (registered trademark). The anchoring piece is made of polyurethane material, preferably Courbhane (registered trademark), which is harder than the material of the protective piece.

[0014] The invention also relates to a method of implementing a protection system as mentioned above, the method comprising a step of mounting the protective part on the mouth of the pipe, and a step of removing the protective part, selectively from the inside or from the outside of the pipe.

[0015] During the assembly stage, the protective piece is pressed onto the pipe inlet. This operation does not require any tools to come into contact with the inlet being protected.

[0016] During the removal stage, the protective piece is pulled and deformed to dislodge it from the pipe opening. To remove it from the inside, the piece is folded back on itself so that its outer diameter (or largest outer dimension) becomes smaller than the inner diameter of the pipe. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The invention will be better understood upon reading the following description, given solely by way of non-limiting example and made with reference to the accompanying drawings in which: [ Fig 1 ] is an exploded perspective view of a pipe inlet protection system, showing said pipe inlet, and the system consisting of two parts, namely a protective part and a mounting part. Fig 2 [ ] is an axial view of the system without the piping. Fig 3 ] is a cross-section of the system and the pipeline, along line III-III to the figure 2 . [ Fig 4 ] is a larger-scale view of detail IV at the figure 3 showing one side of the protective piece. Fig 5 ] is a larger-scale view of detail V at the figure 3 showing a second side of the protective piece. Fig 6 ] is a perspective view of the hanging piece. Fig 7 ] is a larger-scale view of detail VII at the figure 2 showing the mounting piece. Fig 8 ] is a larger-scale view of detail VIII to the figure 3 showing the mounting piece. Fig 9 ] is a perspective and cross-sectional view of a protection system according to a second embodiment of the invention. Fig 10 ] is a perspective view of a protection system conforming to a third embodiment of the invention. DETAILED DESCRIPTION OF THE INVENTION

[0018] On the figures 1 à 8 is represented a system (1) for protecting the mouth (4) of a pipeline (2).

[0019] In the example shown in the figures, the pipeline (2) is of the "I-Tube" type, designed to equip a floating FPSO unit, a TLP platform, or an FLNG complex. The pipeline (2) comprises a tubular body (3) and an outlet (4) with a truncated conical section (5) and an annular flange (6). As an example, an FPSO unit may have twenty-four pipelines (2) of this type requiring protection.

[0020] The collar (6) forms a flange to fix the pipe (2) to another pipe, for example a bend stiffener of flexible or umbilical conduit.

[0021] The collar (6) comprises four surfaces (61, 62, 63, 64) which are to be protected by the system (1), namely an inner cylindrical surface (61), a front annular surface (62), an outer cylindrical surface (63), and a rear annular surface (64). The collar (6) comprises a plurality of through bores (65) formed between the front surface (62) and the rear surface (64).

[0022] A fluid (F) flowing in the pipe (2) is represented by a double arrow on the figure 3 . The fluid (F) is for example seawater, flowing freely in one direction or the other while the mouth (4) of the pipeline (2) is immersed, during its transport or on the operating site.

[0023] The system (1) comprises a protective part (10) and an anchoring part (40). The protective part (10) comprises a central part (20) and a peripheral part (30).

[0024] The central part (20) is wheel-shaped. The central part (20) comprises a set of spokes (21), openings (22) formed between the spokes (21), and a central hub (23). The openings (22) allow the fluid (F) to pass through the system (1).

[0025] It is evident that, in order not to impede the passage of the fluid (F) through the system (1), the central part (20) does not include any additional element such as a membrane to close the openings (22). The openings (22) of the central part (20) represent a total surface area corresponding to at least 30% of the cross-section of the pipe (2), and preferably more than 50%.

[0026] The spokes (21) extend between the hub (23) and the peripheral part (30). The spokes (21) have a cylindrical cross-section, minimizing hydrodynamic resistance to the fluid (F), compared to a flat cross-section. The spokes (21) are inclined with respect to a radial plane (P10) of the part (10), minimizing hydrodynamic resistance to the fluid (F), compared to spokes (21) that would all be arranged in the same radial plane (P10).

[0027] The central portion (20) includes a collar of stiffening ribs (24) arranged between the spokes (21), all around the hub (23). The central portion (20) also includes a series of stiffening elements (25) arranged on either side of the spokes (21) and against the peripheral portion (30). These stiffening means (24, 25) ensure that the protective piece (10) does not break during its removal.

[0028] The peripheral portion (30) comprises four skirts (31, 32, 33, 34) designed to protect four surfaces (61, 62, 63, 64) of the inlet (4) from the fluid (F) and foreign matter. More specifically, the peripheral portion (30) comprises an inner cylindrical skirt (31), a front annular skirt (32), an outer cylindrical skirt (33), and a rear annular skirt (34), protecting respectively the inner cylindrical surface (61), the front annular surface (62), the outer cylindrical surface (63), and the rear annular surface (64) of the inlet (4) of the pipe (2). In practice, the geometry of the peripheral portion (30) is adapted to the geometry of the flange (6). The skirts (31-34) cover the surfaces (61-64), preferably by being pressed against these surfaces (61-64).

[0029] The protective piece (10) is made of a deformable material so that it is designed to be removed from inside the pipe (2). The folded piece (10) has an outer diameter that is smaller than the inner diameter of the pipe (2). The piece (10) exhibits elastomeric behavior, with the ability to deform upon retraction and return to its initial shape and dimensions after removal.

[0030] Preferably, the protective piece (10) is made of Courbhane polyurethane material (registered trademark).

[0031] Advantageously, the protective piece (10) may have tapered areas to facilitate its deformation, folding, and removal. The tapered areas may be formed on the peripheral portion (30) and / or on the central portion (20). In the example shown in the figures, the tapered areas include lines (35) distributed in axial planes (P30) on the peripheral portion (30), as well as the junction angles (36) between the skirts (32, 33) and the function angles (37) between the skirts (33, 34). In an alternative not shown, the tapered areas may include tapered sections formed on the radii (21) of the central portion (20).

[0032] The anchoring piece (40) provides attachment means for attaching traction means to the part (10) for its removal. The anchoring piece (40) is secured to the hub (23), for example by overmolding. In the example shown in the figures, the anchoring piece (40) has an upper portion (41) with an upper attachment hole, a lower portion (42) with a lower attachment hole, and a middle portion (43) that is thinner than portions (41, 42) and has several holes (44) for receiving material from the hub (23).

[0033] The pulling means may include a metal hook (50) attached to the upper portion (41) of the anchor piece (40), and a rope or strap attached to the hook (50) and extending up through the inside of the pipe (2), to remove the protective piece (10) from the inside. If necessary, a hook (50) and a rope may be attached to the lower portion (42) of the anchor piece (40), to remove the protective piece (10) from the outside.

[0034] The anchoring piece (40) can be made of a harder material than the protective piece (10) to better withstand tensile forces. Preferably, the anchoring piece (40) is made of polyurethane, a harder material than the protective piece (10). Even more preferably, the anchoring piece (40) can be made of Courbhane polyurethane (registered trademark).

[0035] Other embodiments of a protection system (1) according to the invention are shown in the figures 9 And 10 . Some constituent elements are comparable to those of the first embodiment described above and, for the sake of simplification, bear the same numerical references.

[0036] There figure 9 This shows a protection system (1) consisting of a single protective piece (10). The center of the hub (23) has an anchoring element (26) attached to the central part (20). Two ropes (51, 52) or straps can be attached to the element (26), one above and one below. A first rope (51) runs up through the channel (2) to allow the protective piece (10) to be retrieved from the inside. A second rope (52) can be attached below the protective piece (10) to remove it from the outside, if necessary.

[0037] There figure 10 This shows a protection system (1) consisting of a single protective piece, the central part (20) of which is completely hollow. The peripheral part (30) has four attachment points (38) for securing ropes or straps. These ropes are raised through the conduit (2) to allow the piece (10) to be retrieved from the inside. Alternatively, the ropes can remain below the piece (10) for retrieval by a submersible vehicle.

[0038] The part (10) is generally one piece, so the system (1) is mainly made from a single material.

[0039] Furthermore, the protection system (1) and the pipeline (2) can be shaped differently from figures 1 à 10without departing from the scope of the invention, which is defined by the claims. Furthermore, the technical features of the various embodiments and variants mentioned above may be combined, in whole or in part. Thus, the system (1) can be adapted in terms of cost, functionality, and performance.

Claims

1. A system (1) for protecting the mouth (4) of a pipe (2), the system (1) comprising a protective part (10) that has a central portion (20) provided with at least one opening (22) for the passage of a fluid (F) circulating in the pipe (2), and a peripheral portion (30) provided with skirts (31, 32, 33, 34) provided to protect surfaces (61, 62, 63, 64) of the mouth (4) from the fluid (F), the protective part (10) being made of a deformable material, so as to be able to be removed from the interior of the pipe (2), characterised in that the central portion (20) is wheel-shaped, with at least two radii (21) that are connected to the peripheral portion (30) and separated by openings (22) for the passage of fluid (F), and the central portion comprises also a central hub (23) and the radii (21) extend between the central hub (23) and the peripheral portion (30).

2. The system (1) according to any one of the preceding claims, characterised in that the piece (10) has thinned areas (35, 36, 37) in order to facilitate deformation and removal.

3. The system (1) according to claim 1, characterised in that the radii (21) have a cylindrical cross-section.

4. The system (1) according to claim 1 or 3, characterised in that the radii (21) are inclined relative to a radial plane (P10) of the protective part (10).

5. The system (1) according to any one of the preceding claims, characterised in that the peripheral portion (30) is provided with at least three skirts (31, 32, 33) in order to protect, respectively, an internal surface (61), a front surface (62) and an external surface (63) of the mouth (4) of the pipe (2).

6. The system (1) as claimed in any one of the preceding claims, characterised in that the system (1) comprises attaching means (26; 38; 40) designed to attach tensile means to the protective part (10), so that it may be removed.

7. The system (1) according to claim 7, characterised in that the attaching means (26; 38; 40) are designed to attach tensile means to the protective part (10) from above and below, so that it may be removed selectively from the interior or exterior of the pipe (2).

8. The system (1) according to any one of the preceding claims, characterised in that the protective part (10) is made of a polyurethane material.

9. The system of implementing a protection system (1) according to any one of claims 1 to 8, characterised in that the method comprises a step for assembling the protective part (10) onto the mouth (4) of the pipe (2), and a step for removing the protective part (10) selectively from the interior or exterior of the pipe (2).