OA21739A - Compression member for fluid transport pipe provided with an internal protective lining. - Google Patents

Abstract

The invention relates to a compression member for a fluid transport pipe (4) provided with an internal protective lining (6), comprising an annular ring (2) which is intended to be inserted by force inside the pipe. The thrust end (10) of the ring comprises an annular collar (14) projecting radially outwards and forming a bearing surface (14a) for a tool for pushing the ring inside the pipe, an annular cavity (16) formed upstream of the collar, and an annular cavity filling element (18) which is intended to be inserted inside the cavity of the ring, the filling element being a part independent of the ring which has a frustoconical shape so as to facilitate the passage of scrapers inside the pipe once the filling element has been inserted inside the cavity of the ring.

Description

Description

Title of the invention: Compression member for fluid transport pipe provided with an internal protective lining

Technical Domain

[0001] The present invention relates to the general field of pipes produced by assembling steel pipe elements and comprising an internal plastic lining protecting the steel walls of the pipes from corrosion.

[0002] The present invention relates more specifically to pipes carrying corrosive fluids, in particular underwater pipes carrying pressurized seawater intended to be injected into oil field wells.

Previous technique

[0003] Such submarine pipelines are generally made by butt welding the ends of steel pipeline elements. The steels constituting the pipelines and the welds between pipeline elements may be subject to corrosion when the pipeline carries a corrosive fluid, in particular water or a fluid containing water, and more particularly salt water.

[0004] A known solution to overcome this problem is to protect the internal steel surface of the pipe against corrosion by applying a liner made from a flexible coating of thermoplastic material. However, the ends of the pipe elements must not be pre-coated with this protective coating. Indeed, it does not withstand the high temperatures used during welding operations of the pipe elements together.

[0005] To ensure the continuity of the protective coating made of thermoplastic material at the ends of the two pipe elements to be welded, it is known to insert a tubular junction sleeve made of anti-corrosion material into the pipe, the sleeve overlapping in a sealed manner the ends of the two protective coatings inside the pipe and at the weld to be made. This type of solution thus makes it possible to avoid the production of a lining made of anti-corrosion alloy steel and/or a weld made of anti-corrosion alloy steel. On the other hand, these tubular junction sleeves have the disadvantage of being complex and expensive to install.

[0006] Also known from WO 2020/053511 is a solution for joining the pipe elements to be welded directly together with a peripheral weld made of anti-corrosion steel. A compression ring made of corrosion-resistant alloy steel is inserted inside the end portion of each pipe element in order to ensure the protection and insulation of the end portion from the protective coating when welding the ends of the pipe elements.

[0007]This solution thus makes it possible to ensure protection against corrosion of the internal wall of the pipe with a protective coating of thermoplastic material on the running part of the pipe elements and an anti-corrosion steel coating at the ends to be welded of the two pipe elements, and this without resorting to a tubular junction sleeve and/or without interposing a steel connection piece of smaller dimension than the pipe element to be welded between the two pipe elements on the other hand.

[0008] In this solution, the compression ring comprises a terminal portion of truncated cone shape in order to create a progressive variation in the internal diameter of the pipe at the transition between the terminal portion of the non-lined anti-corrosion alloy layer and the terminal portion of the plastic coating in excess thickness relative to the second terminal portion of the non-lined anti-corrosion alloy layer.

[0009] However, such a compression ring has the disadvantage of being difficult to insert by force inside the pipe since its truncated cone-shaped end part does not offer a sufficient bearing surface for a thrust tool (typically a hydraulic piston). A thrust tool specific to this type of compression ring must therefore be used.

Disclosure of the invention

[0010] The invention therefore aims to propose a compression member which can be easily inserted into the pipe by a conventional pushing tool while facilitating the passage of scrapers inside the pipe.

[0011]This aim is achieved by means of a compression member for a fluid transport pipe provided with an internal protective lining, comprising an annular ring which is intended to be inserted by force inside the pipe and which comprises a downstream insertion end having a frustoconical shape, an upstream thrust end opposite the insertion end, and a substantially cylindrical central part connecting the upstream and downstream ends together and intended to compress one end of the internal protective lining against an internal wall of the pipe, in which, in accordance with the invention, the thrust end comprises:

- an annular collar projecting radially outwards and forming a bearing surface for a tool for pushing the ring inside the pipe;

- an annular cavity formed upstream of the collar; and

- an annular cavity filling element which is intended to be inserted inside the cavity of the ring, the filling element being a part independent of the ring which has a truncated cone shape so as to facilitate the passage of scrapers inside the pipe once the filling element is inserted inside the cavity of the ring.

[0012] The invention is remarkable in particular in that it proposes a compression member provided both with a straight support surface to allow the pushing tool to take support to forcefully insert the ring inside the pipe, and with a truncated cone shape allowing it to facilitate the passage of scrapers inside the pipe.

[0013] Preferably, the cavity of the ring comprises at an upstream end a rim projecting inwards to ensure axial blocking of the filling element once the latter is inserted inside the cavity.

[0014] According to a first embodiment, the filling element is a truncated cone-shaped crown made of polymer material which is capable of deforming to be forcefully inserted into the cavity of the ring.

[0015] According to a second embodiment, the filling element is composed of a material injected into a truncated cone-shaped mold previously positioned around the cavity.

[0016] According to a third embodiment, the filling element is a truncated cone-shaped ring which is made of polymer material and which is split so as to allow a reduction in its diameter when it is forcefully inserted into the cavity of the ring.

[0017] In this embodiment, the ring may further comprise a retaining ring housed in an annular groove so as to ensure retention of the ring in the cavity of the ring.

[0018]Whatever the embodiment, the upstream end of the ring is advantageously welded to the internal wall of the pipe.

[0019] Furthermore, the truncated cone shape of the insertion end of the ring is advantageously flared downstream and the truncated cone shape of the filling element is flared upstream.

[0020] The invention also relates to a method for mounting the compression member as defined above inside a fluid transport pipe provided with an internal protective lining, comprising the forceful insertion of the ring inside the pipe using a pushing tool bearing against the collar of the pushing end, the welding of an upstream end of the ring to an internal wall of the pipe, and the insertion of the filling element inside the cavity of the ring.

[0021] In the case of an application to a compression member according to the first embodiment, the crown forming the filling element is advantageously deformed by heating prior to its insertion inside the cavity of the ring.

[0022] In the case of an application to a compression member according to the second embodiment, the step of inserting the filling element advantageously comprises the positioning of the frustoconical-shaped mold around the cavity of the ring, the injection of a material into the mold to fill it, the cooling of the injected material, and the removal of the mold.

[0023] In this case, the material injected into the mold can be an epoxy resin, a polyurethane foam or a polyethylene foam.

[0024] In the case of an application to a compression member according to the third embodiment, the ring forming the filling element is advantageously deformed by reducing its diameter prior to its insertion inside the cavity of the ring.

Brief description of the drawings

[0025] [Fig. 1] Figure 1 is a perspective and partial view of a compression member according to a first embodiment of the invention.

[0026][Fig. 2A]; [Fig. 2B]; [Fig. 2C] Figures 2A to and 2C are schematic views of different stages of assembly of the compression member of Figure 1.

[0027] [Fig. 3A]; [Fig. 3B]; [Fig. 3C] Figures 3A to 3C show steps in the assembly of a compression member according to a second embodiment of the invention.

[0028][Fig. 4] Figure 4 is a schematic and perspective view of a compression member according to a third embodiment of the invention.

Description of the embodiments

[0029] The invention relates to a compression member intended to be inserted inside a corrosive fluid transport pipe which is provided with an internal protective lining.

[0030] The compression member according to the invention consists of an annular ring as shown in FIG. 1, and a filling element which is housed in a cavity of the ring.

[0031] Figure 1 schematically represents in perspective an annular ring 2 of a compression member according to a first embodiment of the invention.

[0032]As shown in FIGS. 2A to 2C, this ring 2 is intended to be inserted by force inside a pipe 4 for transporting corrosive fluids provided with an internal protective lining 6, made for example from a thermoplastic material.

[0033] The ring 2 has an axis of revolution X-X which is centered on the axis of the pipe 4 when it is inserted inside the latter.

[0034] The ring 2 comprises a downstream insertion end 8 having a truncated cone shape, an upstream thrust end 10 opposite the insertion end, and a substantially cylindrical central portion 12 connecting the downstream 8 and upstream 10 ends together.

[0035] The central part 12 of the ring is intended to compress the end of the internal protective liner 6 against the internal wall of the pipe 4.

[0036] According to the invention, the thrust end 10 of the ring 2 comprises in particular an annular collar 14 which projects radially outwards. This collar 14 has a rear flat face 14a which extends in a radial direction (relative to the axis of revolution X-X of the ring) and which thus forms a bearing surface for a tool for pushing the ring inside the pipe.

[0037] The thrust end 10 of the ring 2 also comprises an annular cavity 16 which is formed upstream of the collar 14. As shown in FIG. 2A, this cavity 16 projects radially relative to the central part 12 of the ring and comes to bear directly against the internal wall of the pipe.

[0038] The thrust end 10 of the ring further comprises an annular filling element 18 which is intended to be inserted inside the cavity 16.

[0039]This filling element 18 is a part independent of the ring 2 (it is notably inserted into the pipe after the ring has been inserted). It has a part 18a having a truncated shape so as to facilitate the passage of scrapers inside the pipe once it has been inserted inside the cavity of the ring.

[0040] Furthermore, in order to ensure axial blocking of the filling element 18 once it has been inserted inside the cavity 16 of the ring, the latter comprises at an upstream end a rim 20 projecting inwards.

[0041] Several embodiments of the filling element are possible.

[0042] Figures 2A to 2C show a first of these embodiments. In this first embodiment, the filling element is a crown 18 of truncated cone shape which is made of polymer material and which is capable of deforming to be inserted by force into the cavity 16 of the ring.

[0043] As shown in FIG. 2A, the ring 2 is first forcibly inserted inside the pipe 4 by means of a pushing tool (not shown), typically a hydraulic piston, coming to bear against the bearing surface 14a of the collar 14 of the ring.

[0044] When the ring 2 is correctly positioned, the crown 18 made of polymer material is in turn inserted inside the pipe 4 by means of another tool (not shown).

[0045] When the crown 18 reaches the edge 20 of the cavity of the ring (figure 2B), it deforms locally in order to be able to cross this obstacle and pass beyond.

[0046] Once it has passed the edge 20, the crown resumes its initial shape and is housed inside the cavity 16 (FIG. 2C). Given its truncated cone-shaped part 18a, the compression member thus has a truncated cone shape at its two longitudinal ends, thereby facilitating the passage of scrapers inside the pipe (in both directions of advance).

[0047] It will be noted that to facilitate its local deformation and its insertion into the cavity of the ring, the crown 18 can advantageously be deformed by heating prior to its insertion inside the cavity of the ring. Once the crown is installed in the cavity and cooled, it regains its initial rigidity.

[0048] Figures 3A to 3C show a second possible embodiment for the filling element.

[0049] In this embodiment, the filling element is composed of a material 18' which is injected into a mold 22 of truncated cone shape previously positioned around the cavity 16.

[0050] More precisely, once the ring 2 is correctly positioned inside the pipe 4, a mold 22 having a truncated cone shape is inserted inside the pipe to come and position itself around the cavity to close it (FIG. 3A).

[0051] The mold 22 comprises at least one injection orifice 22a, and at least one air exhaust orifice 22b.

[0052] The empty volume of the cavity 16 thus closed is then filled by the injection (via the injection orifice 22a) of resin materials of the epoxy type, polyurethane foam or polyethylene foam (FIG. 3B). During the filling, the air is gradually replaced by the injected materials and escapes from the cavity through the air evacuation orifice 22b.

[0053] Once the volume of the cavity is completely filled by the injected materials, the mold is removed from the pipe. The cavity 16 is then filled with a filling element 18' and the compression member thus has a truncated cone shape at its two longitudinal ends (FIG. 3C).

[0054] Figure 4 shows a third possible embodiment for the filling element.

[0055] In this embodiment, the filling element is a ring 22 of truncated cone shape which is made of polymer material and which is split so as to allow a reduction in its diameter during its forceful insertion into the cavity of the ring.

[0056]As shown in FIG. 4, the ring 22 has a slot 24 which allows its diameter to be slightly reduced in order to facilitate its forced insertion inside the cavity of the ring.

[0057] Once the ring 2 is correctly positioned inside the pipe 4, the ring 22 is deformed by reducing its diameter to facilitate its insertion inside the cavity of the ring. When the ring is correctly positioned inside the cavity, the deformation stops and it resumes its initial diameter.

[0058] Advantageously, the ring 22 further comprises a retaining ring 26 (circlip type) which is housed in an annular groove so as to ensure retention of the ring in the cavity of the ring.

[0059] It will be noted that whatever the embodiment of the compression member, the upstream end 10 of the ring 2 is preferably welded to the internal wall of the pipe.

[0060] It will also be noted that the truncated cone shape of the insertion end 8 of the ring 2 is flared downstream, while the truncated cone shape of the filling element 18, 18', 18 is flared upstream.

Claims (13)

[Claim 1] Compression member for a fluid transport pipe (4) provided with an internal protective lining (6), comprising an annular ring (2) which is intended to be inserted by force inside the pipe and which comprises a downstream insertion end (8) having a truncated cone shape, an upstream thrust end (10) opposite the insertion end, and a substantially cylindrical central part (12) connecting the upstream and downstream ends together and intended to compress one end of the internal protective lining against an internal wall of the pipe, characterized in that the thrust end (10) comprises: - an annular collar (14) projecting radially outwards and forming a support surface (14a) for a tool for pushing the ring inside the pipe; - an annular cavity (16) formed upstream of the collar; and - an annular filling element (18; 18'; 18) of the cavity which is intended to be inserted inside the cavity of the ring, the filling element being a part independent of the ring which has a truncated cone shape so as to facilitate the passage of scrapers inside the pipe once the filling element is inserted inside the cavity of the ring. [Claim 2] A member according to claim 1, in which the cavity (16) of the ring (2) comprises at an upstream end a rim (20) projecting inwards to ensure axial blocking of the filling element once the latter is inserted inside the cavity. [Claim 3] Organ according to one of claims 1 and 2, in which the filling element is a crown (18) of truncated cone shape made of polymer material which is capable of deforming to be inserted by force into the cavity (16) of the ring. [Claim 4] A member according to one of claims 1 and 2, in which the filling element is composed of a material (189) injected into a mold (22) of truncated cone shape previously positioned around the cavity (16) of the ring. [Claim 5] A member according to either of claims 1 and 2, in which the filling element is a ring (18) of truncated cone shape which is made of polymer material and which is split so as to allow a reduction in its diameter when it is forcibly inserted into the cavity (16) of the ring. [Claim 6] A member according to claim 5, wherein the ring (18) further comprises a retaining ring (26) housed in an annular groove so as to ensure retention of the ring in the cavity of the ring. [Claim 7] A member according to any one of claims 1 to 6, in which the upstream end of the ring is welded to the internal wall of the pipe. [Claim 8] A member according to any one of claims 1 to 7, wherein the frustoconical shape of the insertion end of the ring is flared downstream and the frustoconical shape of the filling element is flared upstream. [Claim 9] Method for mounting the compression member according to any one of claims 1 to 8 inside a fluid transport pipe (4) provided with an internal protective liner (6), comprising the forceful insertion of the ring (2) inside the pipe using a pushing tool bearing against the collar (14) of the pushing end (10), the welding of an upstream end of the ring to an internal wall of the pipe, and the insertion of the filling element (18; 18'; 18) inside the cavity (16) of the ring. [Claim 10] A method according to claim 9 when dependent on claim 3, in which the crown (18) forming the filling element is deformed by heating prior to its insertion inside the cavity of the ring. [Claim 11] A method according to claim 9 when dependent on claim 4, wherein the step of inserting the filling element comprises placing the frustoconical-shaped mold (22) around the cavity of the ring, injecting a material (183) into the mold for the 5 filling, cooling of the injected material, and removal from the mold. [Claim 12] The method of claim 11, wherein the material injected into the mold is an epoxy resin, a polyurethane foam or a polyethylene foam. [Claim 13] A method according to claim 9 when dependent on claim 5, in which the ring (18) forming the filling element is deformed by reducing its diameter prior to its insertion inside the cavity of the ring.