Coated pipeline having a joint coating

Abstract

A method for producing a coated pipeline comprising two aligned pipe members (2) which are interconnected. The pipe members comprise an inner pipe (3) configured to convey a hydrocarbon fluid, which inner pipe comprises an inner pipe end (4). The pipe members comprise furthermore a surrounding thermal insulating pipe coating (5) having an embedded pipe conduit (6). The pipe conduits are used to form a duct (11) configured to hold a heating line (12).

Description

[0001] P37126PC00

[0002] Title: Coated pipeline having a joint coating

[0003] FIELD OF THE INVENTION

[0004] The invention relates to a method for producing a coated pipeline comprising two aligned pipe members which are interconnected. In addition, the invention relates to a coated pipeline and to a system for producing a coated pipeline.

[0005] The pipe members comprise an inner pipe configured to convey a hydrocarbon fluid, which inner pipe comprises an inner pipe end. The pipe members comprise furthermore a surrounding thermal insulating pipe coating having an embedded pipe conduit. The pipe conduits are used to form a duct configured to hold a heating line.

[0006] BACKGROUND OF THE INVENTION

[0007] The production of this type of coated pipeline takes in many cases place in the field, such as on a pipelaying vessel at sea using J-lay or S-lay. During the production of the coated pipeline, the two pipe members are interconnected at their inner pipe ends, preferably via a welded connection or a threaded connection. The area of the inner pipes where the inner pipe ends are interconnected forms an inner pipe joint.

[0008] The pipe coating of the pipe members comprises a pipe coating end surface. The pipe coating end surfaces of the interconnected pipe members are located at opposite sides of the inner pipe joint and at a distance from each other. The pipe coating end surfaces extend traverse to a longitudinal axis of the respective pipe member.

[0009] The production of the coated pipeline is completed after a surrounding thermal insulating joint coating is provided and the pipe conduits are interconnected to form the duct configured to hold a heating line.

[0010] US11846378 discloses a method for producing such a coated pipeline. In this known method, the pipe conduits are interconnected while the joint coating is provided.

[0011] SUMMARY OF THE INVENTION

[0012] The known method to produce the coated pipeline has the disadvantage that it is relatively difficult to provide the joint coating and to interconnect the pipe conduits. Due to the environment in which the coated pipeline is typically used, more specifically in sea waterwhile being subjected to tide movements, it is required to provide an accurate interconnection of the pipe conduits and a robust joint coating. Since it is relatively difficult to provide the joint coating and the interconnection of the pipe conduits with the known methods, relatively much time is required to produce the pipeline. The operational costs per hour of a pipelaying vessel are very high due to which the time required to produce the coated pipeline has a significant effect on the production costs. The invention is based on the insight that in the known methods to produce the pipeline, a significant part of the production costs results from the operations required to provide the joint coating and the interconnection of the pipe conduits.

[0013] BRIEF DESCRIPTION OF THE INVENTION

[0014] The invention has the objective to provide an improved, or at least alternative, method for producing a coated pipeline comprising two aligned pipe members which are interconnected, said method comprising the steps of:

[0015] - providing the two interconnected pipe members, wherein:

[0016] -- the pipe members comprise an inner pipe configured to convey a hydrocarbon fluid, which inner pipe comprises an inner pipe end, and a surrounding thermal insulating pipe coating having an embedded pipe conduit,

[0017] -- the inner pipe ends are interconnected, preferably via a welded connection or a threaded connection, at an inner pipe joint,

[0018] -- the pipe coating of the pipe members comprises a pipe coating end surface,

[0019] -- the pipe coating end surfaces of the pipe members are located at opposite sides of the inner pipe joint and at a distance from each other,

[0020] -- the pipe coating end surfaces extend traverse to a longitudinal axis of the respective pipe member,

[0021] - connecting the pipe conduit of one of the two pipe members to the pipe conduit of the other of the two pipe members to form a duct configured to hold a heating line, which duct comprises a joint coating duct section extending between the pipe coating end surfaces of the two pipe members, and

[0022] - providing, after the duct is formed, a thermal insulating joint coating between the pipe coating end surfaces, which joint coating surrounds the inner pipe joint, therewith embedding the joint coating duct section of the duct in the joint coating.

[0023] Providing the joint coating after the pipe conduits are connected to form the duct for a heating line facilitates the forming of an accurate connection of the pipe conduits. In addition, this tends to allow a more time efficient way of interconnecting the pipe conduits.In the situation that the joint coating is, one way or the other, present during the establishment of the connection of the pipe conduits, the joint coating will hinder the person making said connection of the pipe conduits. This negatively affects the accuracy of the established connection of the pipe conduits. In addition, more time tends to be required for establishing the connection of the pipe conduits, which will result in higher production costs.

[0024] The pipe coating end surfaces may extend under an angle a being smaller than 90 degrees and larger than 15 degrees with respect to the longitudinal axis of the respective pipe member.

[0025] In an embodiment of said method, the method comprises placing at least one joint conduit between the pipe conduits of the two pipe members to form the duct, aligning, preferably with an aligner, the pipe conduits and the at least one joint conduit, and connecting the pipe conduits to the aligned at least one joint conduit. Aligning the pipe conduits and the at least one joint conduit, preferably with an aligner, facilitates the forming of an accurate connection between the pipe conduits and the at least one joint conduit. In addition, it facilitates the production of smooth transition between the interconnected pipe conduits and the at least one joint conduit.

[0026] In an embodiment of said method, the pipe conduits have a pipe conduit wall having an inner pipe conduit wall surface, the at least one joint conduit has a joint conduit wall having an inner joint conduit wall surface, the pipe conduit wall and the joint conduit wall have a same inner diameter, and the method comprises aligning the inner pipe conduit wall surface of the pipe conduits with the inner joint conduit wall surface of the at least one joint conduit in order to form a flush inner duct wall surface of the duct. Creating the flush inner duct wall facilitates the placing of the heating line in the duct.

[0027] In an embodiment of said method, the pipe conduits comprise a pipe conduit connection surface which extends traverse, preferably perpendicular, to the longitudinal axis of the respective pipe member, the at least one joint conduit comprises two joint conduit connection surfaces, the two joint conduit connection surfaces and the two pipe conduit connection surfaces are preferably complementary formed surfaces, and the method comprises connecting the pipe conduits to the at least one joint conduit such that the two joint conduit connection surfaces are positioned adjacent to the two pipe conduit connection surfaces. Positioning the joint conduit connection surfaces adjacent to the pipe conduit connection surfaces facilitates the production of a smooth transition between the interconnected pipe conduits and the at least one joint conduit.In an embodiment of said method, the method comprises connecting the pipe conduits to the at least one joint conduit by connecting, such as by welding or gluing, the two joint conduit connection surfaces to the two pipe conduit connection surfaces. Connecting the joint conduit connection surfaces to the pipe conduit connection surfaces facilitates to forming of an accurate connection between the pipe conduits and the at least one joint conduit.

[0028] In an embodiment of said method, the pipe conduits comprise an outer pipe conduit wall surface near or at the pipe conduit connection surface, the at least one joint conduit comprises outer joint conduit wall surfaces near or at the joint conduit connection surfaces, and the method comprises connecting the pipe conduits to the at least one joint conduit by coupling the outer pipe conduit wall surfaces to the outer joint conduit wall surfaces.

[0029] In an embodiment of said method, the method comprises coupling the outer pipe conduit wall surfaces to the outer joint conduit wall surfaces with an aligner, such as alignment sleeve, configured to align the pipe conduit and the at least one joint conduit. The use of an aligner facilitates the forming of an accurate connection between the pipe conduits and the at least one joint conduit.

[0030] In an embodiment of said method, the at least one joint conduit comprises two extension conduits being provided with the two joint conduit connection surfaces, the pipe conduit connection surfaces are preferably at least partly located within the pipe coating of the respective pipe member, and the method comprises connecting, preferably by welding or gluing, the two joint conduit connection surfaces of the extension conduits to the two pipe conduit connection surfaces of the pipe conduits. The use of two extension conduits allows that a connection between the pipe conduits and the at least one joint conduit is formed in an accurate and efficient manner, especially in the situation that the pipe conduit connection surfaces are at least partly located within the pipe coating.

[0031] In an embodiment of said method, the pipe coatings comprise a cavity, such as a bore hole, extending from the pipe conduit connection surface to the pipe coating end surface, and the method comprises placing part of the extension conduits in the cavities to connect the two joint conduit connection surfaces of the extension conduits to the two pipe conduit connection surfaces of the pipe conduits.

[0032] In an embodiment of said method, the method comprises drilling the pipe coatings and / or pipe conduits at the pipe coating end surfaces to form the cavities, more specifically bore holes, and the pipe conduit connection surfaces. This provides an efficient manner to form thecavities and the pipe conduit connection surfaces.

[0033] In an embodiment of said method, the pipe conduits comprise a pipe conduit wall thickness and the extension conduits comprise an extension conduit wall thickness which is smaller than the pipe conduit wall thickness, and the method comprises drilling only the pipe conduits at the pipe coating end surfaces to form the cavities, more specifically bore holes, and the pipe conduit connection surfaces. This way relatively robust cavities are formed.

[0034] In an embodiment of said method, the cavities comprise a cavity wall which forms an aligner configured to align the extension conduit with the pipe conduit, and the method comprises aligning the extension conduits with the pipe conduits by placing the extension conduits in the cavities of the pipe conduits. The cavity wall allows that the aligners are provided in an efficient manner.

[0035] In an embodiment of said method, the method comprises holding the extension conduits in a connection position in which the joint conduit connection surface is in contact the pipe conduit connection surface, and wherein the joint conduit connection surface is preferably at least partly located within the pipe coating of the respective pipe member. Holding the extension conduits in the connection position facilitates the forming of the connection between the joint conduit connection surface and pipe conduit connection surface.

[0036] In an embodiment of said method, the method comprises pushing the joint conduit connection surface of the extension conduits against the pipe conduit connection surface of the pipe conduits while the extension conduits are held in the connection position and during said connecting of the extension conduits to the pipe conduits. Said pushing tends to facilitate the forming of a strong connection between the joint conduit connection surface and pipe conduit connection surface.

[0037] In an embodiment of said method, the at least one joint conduit comprises at least one intermediate conduit, and the method comprises connecting the extension conduit of one of the two pipe members to the extension conduit of the other of the two pipe members via the at least one intermediate conduit to form the duct. The at least one intermediate conduit allow that the extension conduits are connected in an efficient manner.

[0038] In an embodiment of said method, the method comprises heating the joint conduit connection surfaces of the at least one joint conduit and the pipe conduit connection surfaces of the pipe conduits to connect the at least one joint conduit to the pipe conduits, wherein the methodpreferably comprises pushing the joint conduit connection surfaces against the pipe conduit connection surfaces during said connecting of the at least one joint conduit to the pipe conduits. Said heating facilitates that the joint conduit connection surfaces are connected to the pipe conduit connection surfaces in an accurate manner.

[0039] In an embodiment of said method, the method comprises placing a joint coating mould around the pipe coating end surfaces and the inner pipe joint and filling the mould with joint coating material to provide the joint coating.

[0040] In an embodiment of said method, the pipe coating end surfaces extend under an angle a being smaller than 90 degrees and larger than 20 degrees with respect to the longitudinal axis of the respective pipe member.

[0041] In an embodiment of said method, the method comprises placing a heating line in the duct.

[0042] In an embodiment of said method, the method comprises placing a heating line in the duct after said duct is formed.

[0043] In an embodiment of said method, the pipe coating and / or the joint coating is formed by one or more layers of coating material.

[0044] In an embodiment of said method, the joint coating extends between the pipe coating end surfaces, and the joint coating is preferably in contact with the pipe coating end surfaces.

[0045] In an embodiment of said method, the pipe members comprises multiple pipe conduits embedded in the pipe coating, and the method comprises connecting the pipe conduits of one of the two pipe members to the pipe conduits of the other of the two pipe members to form multiple ducts configured to hold a heating line, which ducts comprise joint coating duct sections extending between the pipe coating end surfaces of the two pipe members, and providing, after the ducts are formed, the thermal insulating joint coating between the pipe coating end surfaces, which joint coating surrounds the inner pipe joint, therewith embedding the joint coating duct sections of the ducts in the joint coating.

[0046] In an embodiment of said method, the method pipeline comprises any combination of any number of the above indicated embodiments of said method.The invention further relates to a coated pipeline comprising two aligned pipe members which are interconnected, wherein:

[0047] - the pipe members comprise an inner pipe configured to convey a hydrocarbon fluid, which inner pipe comprises an inner pipe end, and a surrounding thermal insulating pipe coating having an embedded pipe conduit,

[0048] - the inner pipe ends are interconnected, preferably via a welded connection or a threaded connection, at an inner pipe joint,

[0049] - the pipe coating of the pipe members comprises a pipe coating end surface,

[0050] - the pipe coating end surfaces of the pipe members are located at opposite sides of the inner pipe joint and at a distance from each other,

[0051] - the pipe coating end surfaces extend traverse to a longitudinal axis of the respective pipe member,

[0052] - the pipe conduit of one of the two pipe members is connected to the pipe conduit of the other of the two pipe members,

[0053] - the interconnected pipe conduits form a duct configured to hold a heating line,

[0054] - the duct comprises a joint coating duct section extending between the pipe coating end surfaces of the two pipe members,

[0055] - a thermal insulating joint coating is provided between the pipe coating end surfaces, which joint coating surrounds the inner pipe joint, and

[0056] - the joint coating duct section of the duct is embedded in the joint coating.

[0057] The same positive technical effects are achieved as explained above in relation to the method for producing a coated pipeline.

[0058] In an embodiment of said coated pipeline, the pipe conduits are connected to each other via at least one joint conduit to form the duct, the at least one joint conduit and the pipe conduits are aligned, and the coated pipeline preferably comprises at least one aligner configured to align the pipe conduits and the at least one joint conduit.

[0059] In an embodiment of said coated pipeline, the pipe conduits have a pipe conduit wall having an inner pipe conduit wall surface, the at least one joint conduit has a joint conduit wall having an inner joint conduit wall surface, the pipe conduit wall and the joint conduit wall have a same diameter, and the inner pipe conduit wall surface of the pipe conduits is aligned with the inner joint conduit wall surface of the at least one joint conduit and form a flush inner duct wall surface of the duct.In an embodiment of said coated pipeline, the pipe conduits comprise a pipe conduit connection surface which extends traverse, preferably perpendicular, to the longitudinal axis of the respective pipe members, the at least one joint conduit of the duct comprises two joint conduit connection surfaces, the two joint conduit connection surfaces and the two pipe conduit connection surfaces are preferably complementary formed surfaces, and the pipe conduits are connected to the at least one joint conduit such that the two joint conduit connection surfaces are positioned adjacent to the two pipe conduit connection surfaces.

[0060] In an embodiment of said coated pipeline, the two joint conduit connection surfaces of the at least one joint conduit are connected, such as welded or glued, to the two pipe conduit connection surfaces of the pipe conduits.

[0061] In an embodiment of said coated pipeline, the pipe conduits comprise an outer pipe conduit wall surface near or at the pipe conduit connection surface, the at least one joint conduit comprises outer joint conduit wall surfaces near or at the joint conduit connection surfaces, and the pipe conduits are connected to the at least one joint conduit by coupling members which couple the outer pipe conduit wall surfaces to the outer joint conduit wall surfaces.

[0062] In an embodiment of said coated pipeline, the coupling members are aligners, such as alignment sleeves, configured to align the pipe conduits and the at least one joint conduit.

[0063] In an embodiment of said coated pipeline, the at least one joint conduit comprises two extension conduits being provided with the two joint conduit connection surfaces, the pipe conduit connection surfaces and the two joint conduit connection surfaces are preferably at least partly located within the pipe coating of the respective pipe member, and the two joint conduit connection surfaces of the extension conduits are connected, preferably welded or glued, to the two pipe conduit connection surfaces of the pipe conduits.

[0064] In an embodiment of said coated pipeline, the pipe coatings comprise a cavity, such as a bore hole, extending from the pipe conduit connection surface to the pipe coating end surface, and the extension conduits are partly located in the cavities.

[0065] In an embodiment of said coated pipeline, the pipe coatings and / or pipe conduits are drilled at the pipe coating end surfaces to form the cavities, more specifically bore holes, and the pipe conduit connection surfaces.In an embodiment of said coated pipeline, the pipe conduits comprise a pipe conduit wall thickness, the extension conduits comprise an extension conduit wall thickness which is smaller than the pipe conduit wall thickness, and only the pipe conduits are drilled at the pipe coating end surfaces to form the cavities, more specifically bore holes, and the pipe conduit connection surfaces.

[0066] In an embodiment of said coated pipeline, the cavities comprise a cavity wall which forms an aligner which aligns the extension conduit with the pipe conduit.

[0067] In an embodiment of said coated pipeline, the at least one joint conduit comprises at least one intermediate conduit, and the extension conduit of one of the two pipe members is connected to the extension conduit of the other of the two pipe members via the at least one intermediate conduit to form the duct.

[0068] In an embodiment of said coated pipeline, a heating line is located in the duct.

[0069] In an embodiment of said coated pipeline, the pipe coating end surfaces extend under an angle a being smaller than 90 degrees and larger than 20 degrees with respect to the longitudinal axis of the respective pipe member.

[0070] In an embodiment of said coated pipeline, the pipe coating and / or the joint coating is formed by one or more layers of coating material.

[0071] In an embodiment of said coated pipeline, the joint coating extends between the pipe coating end surfaces, and the joint coating is preferably in contact with the pipe coating end surfaces.

[0072] In an embodiment of said coated pipeline, the pipe members comprises multiple pipe conduits embedded in the pipe coating, the pipe conduits of one of the two pipe members to the pipe conduits of the other of the two pipe members to form multiple ducts configured to hold a heating line, which ducts comprise joint coating duct sections extending between the pipe coating end surfaces of the two pipe members, and the joint coating duct sections of the ducts are embedded in the joint coating.

[0073] In an embodiment of said coated pipeline, the coated pipeline comprises any combination of any number of the above indicated embodiments of said coated pipeline.System for producing a coated pipeline comprising two aligned pipe members which are interconnected, wherein:

[0074] - the system comprises a connection device configured to be attached to the two interconnected pipe members, wherein the pipe members comprise an inner pipe configured to convey a hydrocarbon fluid, which inner pipe comprises an inner pipe end, and a surrounding thermal insulating pipe coating having an embedded pipe conduit, the inner pipe ends are interconnected, preferably via a welded connection or a threaded connection, at an inner pipe joint, the pipe coating of the pipe members comprises a pipe coating end surface, the pipe coating end surfaces of the pipe members are located at opposite sides of the inner pipe joint and at a distance from each other, the pipe coating end surfaces extend traverse to a longitudinal axis of the respective pipe member, the pipe conduits comprise a pipe conduit connection surface, which pipe conduit connection surface is preferably at least partly located within the pipe coating of the respective pipe member, and the pipe conduit connection surfaces extend traverse, preferably perpendicular, to the longitudinal axis of the respective pipe member,

[0075] - the connection device comprises an attachment unit configured to be attached to the interconnected pipe members in a fixed position relative to the interconnected pipe members, - the system comprises a conduit holder configured to hold an extension conduit of at least one joint conduit configured to interconnect the pipe conduits to form a duct for holding a heating line,

[0076] - the connection device comprises at least one support member extending from the attachment unit and supporting the conduit holder, and

[0077] - the conduit holder is configured to hold the extension conduit in a connection position in which a joint conduit connection surface of the extension conduit is positioned in contact with the pipe conduit connection surface of one of the pipe members, and wherein the joint conduit connection surface is preferably at least partly located within the pipe coating of said one of the pipe members, and

[0078] - the connection device optionally comprises a push unit configured to push the joint conduit connection surface of the extension conduit against the pipe conduit connection surface while the conduit holder holds the extension conduit in the connection position.

[0079] Said system facilitates the forming of an accurate connection between the pipe conduits and the extension conduits. In addition, the same positive technical effects are achieved as explained above in relation to the method for producing a coated pipeline.

[0080] In an embodiment of the system, the conduit holder is configured to align the extension conduit with pipe conduit.In an embodiment of the system, the system comprises a first heating unit configured to heat the pipe conduit connection surface of the pipe conduit and a second heating unit configured to heat the joint conduit connection surface of the extension conduit.

[0081] In an embodiment of the system, the first heating unit comprises a first heating member having a first heating contact surface, and the first heating unit is configured to be supported by the at least one support member and positioned in a heating position in which the first heating contact surface is in contact with the pipe conduit connection surface.

[0082] In an embodiment of the system, the push unit is configured to push the first heating contact surface of the first heating unit against the pipe conduit connection surface of the pipe conduit.

[0083] In an embodiment of the system, push unit is controlled by a control unit configured to control a push force with which the joint conduit connection surface or the first heating contact surface is pushed against the pipe conduit connection surface.

[0084] In an embodiment of the system, the connection device is configured to move the at least one support member, optionally also the conduit holder or the first heating unit, in longitudinal direction with respect to the longitudinal axis of the respective pipe member.

[0085] In an embodiment of the system, the connection device is configured to move the at least one support member, optionally also the conduit holders or the first heating unit, in tangential direction with respect to the longitudinal axis of the respective pipe member.

[0086] In an embodiment of the system, the connection device is configured to move the at least one support member, optionally also the conduit holders or the first heating unit, in radial direction with respect to the longitudinal axis of the respective pipe member.

[0087] In an embodiment of the system, the system comprises a drilling unit for drilling the pipe coating and / or the pipe conduits at the pipe coating end surfaces to form a cavity, more specifically a bore hole, and the pipe coating end surface.

[0088] In an embodiment of the system, the pipe members comprise multiple pipe conduits embedded in the pipe coating, and the conduit holder is configured to hold multiple extension conduits in the connection position.In an embodiment of the system, the first heating unit is configured to heat multiple configured to heat the pipe conduit connection surfaces of the pipe conduits and the second heating unit is configured to heat the joint conduit connection surfaces of the extension conduits.

[0089] In an embodiment of said system, the pipe coating end surfaces extend under an angle a being smaller than 90 degrees and larger than 20 degrees with respect to the longitudinal axis of the respective pipe member.

[0090] In an embodiment of said system, the pipe coating and / or the joint coating is formed by one or more layers of coating material.

[0091] In an embodiment of said system, the system comprises a joint coating device comprising a joint coating mould configured to surround the pipe coating end surfaces and the inner pipe joint and a joint coating material supplier configured to fill the joint coating mould with joint coating material.

[0092] In an embodiment of said system, the system comprises any combination of any number of the above indicated embodiments of said system.

[0093] The invention further relates to an assembly comprising any one of the above indicated embodiments of the system and the two interconnected pipe members, wherein the pipe members comprise an inner pipe configured to convey a hydrocarbon fluid, which inner pipe comprises an inner pipe end, and a surrounding thermal insulating pipe coating having an embedded pipe conduit, the inner pipe ends are interconnected, preferably via a welded connection or a threaded connection, at an inner pipe joint, the pipe coating of the pipe members comprises a pipe coating end surface, the pipe coating end surfaces of the pipe members are located at opposite sides of the inner pipe joint and at a distance from each other, the pipe coating end surfaces extend traverse to a longitudinal axis of the respective pipe member, the pipe conduits comprise a pipe conduit connection surface, which pipe conduit connection surface is preferably at least partly located within the pipe coating of the respective pipe member, and the pipe conduit connection surfaces extend traverse, preferably perpendicular, to the longitudinal axis of the respective pipe member.

[0094] BRIEF DESCRIPTION OF THE DRAWINGS

[0095] Embodiments of the method according to the invention, the coated pipeline according to the invention, the system according to the invention, and the assembly according to the invention will be described by way of example only, with reference to the accompanying schematicdrawings in which corresponding reference symbols indicate corresponding parts, and in which:

[0096] the Figures 1 A and 1 B schematically show a first step of an embodiment of said method, the Figures 2A, 2B and 2C schematically show a second step of said method of the figures 1A and 1B,

[0097] the Figures 3 and 4 schematically show a third step of the method of the figures 1A and 1B, the Figures 5A, 5B and 5C schematically show a fourth step of the method of the figures 1 A and 1B,

[0098] Figure 6 schematically shows an enlarged view of part VI of figure 5B,

[0099] Figure 7 schematically shows an alternative embodiment of said method,

[0100] Figure 8 schematically shows a view in perspective of an embodiment of said system provided with an extension conduit holder,

[0101] Figure 9 schematically shows a view in perspective of said extension conduit holder of figure 8,

[0102] Figure 10 schematically shows a view in perspective of the extension conduit holder of figure 9 and a second heating unit,

[0103] Figure 11 schematically shows a view in perspective of said system of figure 8 provided with a first heating unit which is heating the pipe conduits,

[0104] Figure 12 schematically shows a view in perspective of said first heating unit of figure 9, and Figure 13 schematically shows a view in perspective of the first heating unit of figure 10 and a preheating device, and

[0105] Figure 14 schematically shows a view in perspective of part of said system of figure 8.

[0106] DETAILED DESCRIPTION OF THE DRAWINGS

[0107] The figures 1 A and 1 B show a first step of an embodiment of the method according to the invention. Figure 1A shows a side view of two aligned pipe members 2 which are interconnected. Figure 1 B shows a cross-sectional view of the two pipe members 2 of figure 1A.

[0108] Said method comprises the step in which the two interconnected pipe members 2 are provided as shown in the figures 1A and 1B. The pipe members 2 comprise an inner pipe 3 configured to convey a hydrocarbon fluid and a surrounding thermal insulating pipe coating 5 having embedded pipe conduits 6. The inner pipe 3 comprises an inner pipe end 4. The inner pipe ends 4 of the two pipe members 2 are interconnected at an inner pipe joint 8 via a welded connection 7. In other embodiments of the coated pipeline 1 , the inner pipe ends 4 are interconnected via a threaded connection or another type of pipe connection.The pipe coating 5 of the pipe members 2 comprises a pipe coating end surface 9. The pipe coating end surfaces 9 of the pipe members 2 are located at opposite sides of the inner pipe joint 8 and at a distance from each other. The pipe coating end surfaces 9 extend traverse to a longitudinal axis 10 of the respective pipe member 2. The pipe coating end surfaces 9 extend preferably under an angle a being smaller than 90 degrees and larger than 15 degrees with respect to the longitudinal axis 10 of the respective pipe member 2.

[0109] Said method comprises the step of connecting the pipe conduits 6 of one of the two pipe members 2 to the pipe conduits 6 of the other of the two pipe members 2 to form ducts 11 configured to hold a heating line 12. The ducts 11 comprise a joint coating duct section 13 extending between the pipe coating end surfaces 9 of the two pipe members 2. This will be discussed more in detail with reference to the figures 2A, 2B, 2C, 3, and 4.

[0110] Said method comprises the subsequent step of providing, after the ducts 11 are formed, a thermal insulating joint coating 14 between the pipe coating end surfaces 9. The joint coating 14 extends between the pipe coating end surfaces 9 and surrounds the inner pipe joint 8. By providing the joint coating 14, the joint coating duct sections 13 of the ducts 11 are embedded in the joint coating 14. This will be discussed more in detail with reference to the figures 5A, 5B, 5C and 6.

[0111] Providing the joint coating 14 after the pipe conduits 6 are connected and form the ducts 11 facilitates the forming of an accurate interconnection of the pipe conduits 6. In addition, this tends to allow a more time efficient way of interconnecting the pipe conduits 6.

[0112] In the situation that the joint coating 14 is, one way or the other, present during the establishment of the connection of the pipe conduits 6, the joint coating 14 will hinder the person making said connection of the pipe conduits 6. This negatively affects the accuracy of the established connection of the pipe conduits 6. In addition, more time tends to be required for providing the connection of the pipe conduits 6, which will result in higher production costs.

[0113] In the embodiments of the method shown in figures 1 - 7, at least one joint conduit 15 is placed between the pipe conduits 6 of the two pipe members 2 to form the ducts 11. The pipe conduits 6 and the at least one joint conduit 15 are aligned with an aligner 16. The pipe conduits 6 are subsequently connected to the aligned at least one joint conduit 15. Aligning the pipe conduits 6 and the at least one joint conduit 15, preferably with an aligner 16, facilitates the forming of an accurate connection between the pipe conduits 6 and the at leastone joint conduit 15. In addition, it facilitates the production of a smooth transition between the interconnected pipe conduits 6 and the at least one joint conduit 15.

[0114] The pipe conduits 6 comprise a pipe conduit connection surface 23 which extends traverse, preferably perpendicular, to the longitudinal axis 10 of the respective pipe member 2. As shown in the figures 1 A and 1 B, the pipe coatings 5 comprise a cavity 29, more specifically a bore hole 30, extending from the pipe conduit connection surface 23 to the pipe coating end surface 9. The pipe coatings 5 and / or pipe conduits 6 may be drilled at the pipe coating end surfaces 9 to form the cavities 29, more specifically bore holes 30, and the pipe conduit connection surfaces 23. This provides an efficient manner to form the cavities 29 and the pipe conduit connection surfaces 23.

[0115] The pipe conduits 6 comprise a pipe conduit wall thickness 53 (see figure 2C). In the shown embodiment, only the pipe conduits 6 are drilled at the pipe coating end surfaces 9 to form the cavities 29, more specifically bore holes 30, and the pipe conduit connection surfaces 23. This way relatively robust cavities 29 are formed.

[0116] The figures 2A, 2B and 2C show a second step of said method. Figure 2A shows a side view of the interconnected pipe members 2. Figure 2B shows a cross-sectional view of the two pipe members 2 of figure 2A. Figure 2C shows an enlarged view of part II of figure 2B.

[0117] The at least one joint conduit 15 used to interconnect the pipe conduits 6 comprises two joint conduit connection surfaces 24. The two joint conduit connection surfaces 24 of the at least one joint conduit 15 and the two pipe conduit connection surfaces 23 of the pipe conduits 6 are preferably complementary formed surfaces. This means the form of the joint conduit connection surfaces and the pipe conduit connection surfaces correspond to each other to allow an accurate surface contact.

[0118] The pipe conduits 6 are connected to the at least one joint conduit 15 such that the two joint conduit connection surfaces 24 are positioned adjacent to the two pipe conduit connection surfaces 23. Positioning the joint conduit connection surfaces 24 adjacent to the pipe conduit connection surfaces 23 facilitates the production of a smooth transition between the interconnected pipe conduits 6 and the at least one joint conduit 15.

[0119] The pipe conduits 6 have a pipe conduit wall 17 having an inner pipe conduit wall surface 18. The at least one joint conduit 15 has a joint conduit wall 19 having an inner joint conduit wall surface 20, the pipe conduit wall 17 and the joint conduit wall 19 have a same inner diameter21. The inner pipe conduit wall surface 18 of the pipe conduits 6 is aligned with the inner joint conduit wall surface 20 of the at least one joint conduit 15 in order to form a flush inner duct wall surface 22 of the duct 11 (see figures 6 and 7). Creating the flush inner duct wall surface 22 facilitates the placing of the heating line 12 in the duct 11.

[0120] In the embodiment shown in the figures 1 -6, the at least one joint conduit 15 used to interconnect the pipe conduits 6 comprises two extension conduits 28 being provided with the two joint conduit connection surfaces 24. The extension conduits 28 comprise an extension conduit wall thickness 54 which is smaller than the pipe conduit wall thickness 53. Due to the drilled cavities 29, the pipe conduit connection surfaces 23 of the pipe conduits 6 are located within the pipe coating 5 of the respective pipe member 2.

[0121] Part of the extension conduits 28 are placed in the cavities 29 to connect the two joint conduit connection surfaces 24 of the extension conduits 28 to the two pipe conduit connection surfaces 23 of the pipe conduits 6. The cavities 29 comprise a cavity wall 31 which forms an aligner 16 configured to align the extension conduit 28 with the pipe conduit 6. Hence, the extension conduits 28 are aligned with the pipe conduits 6 by placing the extension conduits 28 in the cavities 29 of the pipe conduits 6. The cavity wall 31 allows that the aligners 16 are provided in an efficient manner.

[0122] The two joint conduit connection surfaces 24 of the extension conduits 28 are connected by welding to the two pipe conduit connection surfaces 23 of the pipe conduits 6. In other embodiments of said method, other ways of connecting may be used, such as gluing. The use of two extension conduits 28 allows that a connection between the pipe conduits 6 and the at least one joint conduit 15 is formed in an accurate and efficient manner, especially in the situation that the pipe conduit connection surfaces 23 are at least partly located within the pipe coating 5.

[0123] During the connection of the extension conduits 28 to the pipe conduits 6, the extension conduits 28 are held in a connection position 32 in which the joint conduit connection surface 24 is in contact the pipe conduit connection surface 23. The joint conduit connection surface 24 is preferably at least partly located within the pipe coating 5 of the respective pipe member 2. Holding the extension conduits 28 in the connection position 32 facilitates the forming of the connection between the joint conduit connection surface 24 and pipe conduit connection surface 23. As will be explained in detail with reference to figure 9, the system 35 according to invention is configured to hold the extension conduits 28 in the connection position 32 in an efficient and accurate manner.The joint conduit connection surfaces 24 of extension conduits 28 and the pipe conduit connection surfaces 23 of the pipe conduits 6 are heated in order to connect the extension conduits 28 to the pipe conduits 6. Said heating facilitates that the joint conduit connection surfaces 24 are connected by welding to the pipe conduit connection surfaces 23 in an accurate manner.

[0124] The joint conduit connection surface 24 of the extension conduits 28 is pushed against the pipe conduit connection surface 23 of the pipe conduits 6 while the extension conduits 28 are held in the connection position 32 and during the connecting of the extension conduits 28 to the pipe conduits 6. Said pushing tends to facilitate the forming of a strong connection between the joint conduit connection surface 24 and pipe conduit connection surface 23.

[0125] The figures 3 and 4 show a third step of said method. The figures 3 and 4 show a side view of the interconnected pipe members 2.

[0126] The at least one joint conduit 15 comprises an intermediate conduit 55 and the extension conduits 28 of one of the two pipe members 2 are connected to the extension conduit 28 of the other of the two pipe members 2 via the intermediate conduit 55 to form the ducts 11. The intermediate conduit 55 allows that the extension conduits 28 are connected in an efficient manner. In other embodiments of said method, more than one intermediate conduit 55 may be used to connect the extension conduits 28.

[0127] The intermediate conduit 55 is aligned with and connected to the extension conduits 28 via two aligners 16, more specifically alignment sleeves 27, configured to couple the outer wall surfaces of the intermediate conduit 55 and the extension conduit 28.

[0128] Figure 3 shows the intermediate conduits 55 being aligned with the extension conduits 28. Figure 4 shows also the aligners 16. The aligners 16 at the left side are positioned in their final position in which the intermediate conduits 55 are aligned with and connected to the left extension conduits 28. The aligners 16 at the right side still need to be moved to right into their final position to ensure that the intermediate conduits 55 are aligned with and connected to the right extension conduits 28.

[0129] After that, the pipe conduits 6 are connected and the ducts 11 for holding a heating line 12 are completed. The ducts 11 comprise a joint coating duct section 13 extending between the pipe coating end surfaces 9 of the two pipe members 2 (see figure 5A).The figures 5A, 5B and 5C show a fourth step of said method. Figure 5A shows a side view of the interconnected pipe members 2. Figure 5B shows a cross-sectional view of the two pipe members 2 of figure 5A with a joint coating 14. Figure 5C shows a cross-sectional view of the two pipe members 2 of figure 5A with a joint coating 14 and a joint coating mould 51. Figure 6 shows an enlarged view of part VI of figure 5B.

[0130] As shown in figure 5C, a joint coating mould 51 is placed around the pipe coating end surfaces 9 and the inner pipe joint 8. The joint coating mould 51 is subsequently filled with joint coating material supplied by a joint coating material supplier 52 to provide the joint coating 14. The joint coating duct sections 13 of the ducts 11 are embedded in the joint coating 14. The joint coating 14 extends between the pipe coating end surfaces 9 and is in contact with the pipe coating end surfaces 9.

[0131] The joint coating mould 51 is subsequently removed as shown in figure 5B. After that, a heating line 12 is placed in the ducts 11 as shown in the lower duct 11. Alternatively, a communication line can be placed in one of the ducts 11.

[0132] This way a coated pipeline 1 comprising two aligned pipe members 2 which are interconnected is produced by said method. In the produced coated pipeline 1 shown in the figures 5A, 5B and 6, the pipe members 2 comprise an inner pipe 3 configured to convey a hydrocarbon fluid and a surrounding thermal insulating pipe coating 5 having multiple embedded pipe conduits 6.

[0133] The inner pipe 3 comprises an inner pipe end 4. The inner pipe ends 4 of the two pipe members 2 are interconnected, more specifically via a welded connection 7, at an inner pipe joint 8. The pipe coating 5 of the pipe members 2 comprises a pipe coating end surface 9. The pipe coating end surfaces 9 of the pipe members 2 are located at opposite sides of the inner pipe joint 8 and at a distance from each other. The pipe coating end surfaces 9 extend traverse to a longitudinal axis 10 of the respective pipe member 2.

[0134] The pipe conduits 6 of one of the two pipe members 2 are connected to the pipe conduits 6 of the other of the two pipe members 2. The interconnected pipe conduits 6 form ducts 11 configured to hold a heating line 12. The ducts 11 comprise a joint coating duct section 13 extending between the pipe coating end surfaces 9 of the two pipe members 2. A thermal insulating joint coating 14 is provided between the pipe coating end surfaces 9. The joint coating 14 surrounds the inner pipe joint 8. The joint coating duct sections 13 of the ducts 11 are embedded in the joint coating 14.Figure 7 shows an alternative embodiment of said method. Only one joint conduit 15 is used to connect the pipe conduits 6 of the two pipe members 2. The pipe conduit connection surfaces 23 are located outside the pipe coating 5. The joint conduit 15 is placed between the pipe conduits 6. Hence, the two joint conduit connection surfaces 24 of the joint conduit 15 are also located outside the pipe coating 5. The joint conduit connection surfaces 24 of the joint conduit 15 are positioned adjacent to the pipe conduit connection surfaces 23 of the pipe conduits 6.

[0135] The joint conduit 15 is aligned with and connected to the pipe conduits 6 via two aligners 16. The used aligners 16 are alignment sleeves 27. In other embodiments of said method, other types of aligners 16 may be used. The pipe conduits 6 comprise an outer pipe conduit wall surface 25 near or at the pipe conduit connection surface 23. The joint conduit 15 comprises outer joint conduit wall surfaces 26 near or at the joint conduit connection surfaces 24. The pipe conduits 6 are connected to the joint conduit 15 by coupling the outer pipe conduit wall surfaces 25 to the outer joint conduit wall surfaces 26s with two aligners 16, more specifically alignment sleeves 27.

[0136] The above-described embodiments of said method show that different types of aligners 16 may be used in different manners to facilitate the connection of the pipe conduits 6. The aligner 16 may be formed by a cavity wall 31 of a cavity 29, such as a bore hole 30, provided in the pipe coating 5. The aligner 16 may be formed by an alignment sleeve 27 which for example couples the outer wall surfaces of the pipe conduit 6 and the at least one joint conduit 15. The aligner 16 may be formed by an insert which for example is inserted in the pipe conduit 6 and the at least one joint conduit 15. Such an insert may also be configured to prevent a flow radially inward into the duct 11 when the pipe conduit 6 and the at least one conduit are heated to create a welded connection. Furthermore, other types of aligners 16 may be used.

[0137] Figure 8 shows a view in perspective of an embodiment of said system 35 for producing a coated pipeline 1 comprising the two interconnected pipe members 2. The system 35 comprises a connection device 36 configured to be attached to the two interconnected pipe members 2.

[0138] The connection device 36 comprises an attachment unit 37 configured to be attached to the interconnected pipe members 2 in a fixed position relative to the interconnected pipe members 2. The shown attachment unit 37 has screw holes 56 for attaching the connection device 36 to the pipe coating 5 via screws. In other embodiments of the system 35, othertypes of attachment unit 37s may be used, such as a band which surrounds and engages the pipe coating 5.

[0139] The system 35 comprises a conduit holder 38 configured to hold extension conduits 28 of at least one joint conduit 15 configured to interconnect the pipe conduits 6 to form the ducts 11 for holding the heating line 12. The connection device 36 comprises support members 39 extending from the attachment unit 37 and supporting the conduit holder 38. The conduit holder 38 is attached to the support member 39 in a fixed position relative to the support members 39.

[0140] The conduit holder 38 is configured to hold the extension conduits 28 in a connection position 32 in which joint conduit connection surfaces 24 of the extension conduits 28 are positioned in contact with the pipe conduit connection surfaces 23 of one of the pipe members 2. The joint conduit connection surfaces 24 are preferably at least partly located within the pipe coating 5 of said one of the pipe members 2.

[0141] The connection device 36 comprises a push unit 40 configured to push the joint conduit connection surfaces 24 of the extension conduits 28 against the pipe conduit connection surfaces 23 while the conduit holder 38 holds the extension conduits 28 in the connection position 32. The conduit holder 38 is configured to align the extension conduits 28 with the pipe conduits 6.

[0142] In figure 8, the system 35 holds the extension conduits 28 as shown in figure 2A and 2B in order to connect the extension conduits 28 to the pipe conduits 6. The system 35 facilitates the forming of an accurate connection between the pipe conduits 6 and the extension conduits 28.

[0143] Figure 9 shows a view in perspective of the extension conduit 28 holder of figure 8. The extension holder comprises clamps 57 configured to hold the extension conduits 28 in a fixed position relative to the extension holder.

[0144] The system 35 comprises a first heating unit 41 configured to heat the pipe conduit connection surfaces 23 of the pipe conduits 6 (see figure 11) and a second heating unit 44 configured to heat the joint conduit connection surfaces 24 of the extension conduits 28 (see figure 10).Figure 10 shows a view in perspective of the extension conduit 28 holder of figure 9 and the second heating unit 44. The second heating unit 44 comprises second heating members 45 configured to produce heat. The joint conduit connection surfaces 24 of the extension conduits 28 are placed in the second heating members 45 in order to be heated.

[0145] The extension conduits 28 are placed in contact with the pipe conduits 6 as shown in figure 8 after the joint conduit connection surfaces 24 are heated. In addition, also the pipe conduit connection surfaces 23 of the pipe conduits 6 are heated (see figure 11) before said contact between the extension conduits 28 and the pipe conduits 6 is established.

[0146] Figure 11 shows a view in perspective of said system 35 of figure 8 provided with a first heating unit 41 which is heating the pipe conduits 6. Figure 12 shows a view in perspective of said first heating unit 41 of figure 11.

[0147] The first heating unit 41 comprises first heating members 42 having a first heating contact surface 43. The first heating unit 41 is configured to be supported by the support members 39 and positioned in a heating position 49 in which the first heating contact surfaces 43 are in contact with the pipe conduit connection surfaces 23. The first heating unit 41 is attached the support members 39 in a fixed position relative to the support members 39. The push unit 40 is configured to push the first heating contact surfaces 43 of the first heating unit 41 against the pipe conduit connection surfaces 23 of the pipe conduits 6.

[0148] Figure 13 shows a view in perspective of the first heating unit 41 of figure 10 and a preheating device 46. The preheating device 46 comprises preheating members 47 configured to produce heat. The first heating members 42 of the first heating unit 41 are placed in the preheating members 47 in order to be preheated. The first heating members 42 are placed in contact with the pipe conduits 6 as shown in figure 11 after the first heating contact surfaces 43 are preheated.

[0149] Figure 14 shows a view in perspective of part of said system 35 of the figures 8 and 11. The connection device 36 is configured to be moved relative to the pipe member 2 in order to accurately position the connection holder and the first heating device.

[0150] As indicted by arrow L, the connection device 36 is configured to move the at least one support member 39, and in use also the conduit holder 38 or the first heating unit 41, in longitudinal direction with respect to the longitudinal axis 10 of the respective pipe member 2.The push unit 40 is integrated in connection device 36 due to which it is possible not only possible to move in the longitudinal direction, but also to apply a push force in the longitudinal direction. The push unit 40, and therefore also the connection device 26, is controlled by a control unit 48 configured to control the push force with which the joint conduit connection surfaces 24 or the first heating contact surfaces 43 are pushed against the pipe conduit connection surface.

[0151] As indicated by arrow T, the connection device 36 is configured to move the at least one support member 39, and in use also the conduit holders 38 or the first heating unit 41 , in tangential direction with respect to the longitudinal axis 10 of the respective pipe member 2.

[0152] As indicted by arrow R, the connection device 36 is configured to move the at least one support member 39, and in use also the conduit holders 38 or the first heating unit 41 , in radial direction with respect to the longitudinal axis 10 of the respective pipe member 2.

[0153] The system 35 comprises a joint coating device 50 (see figure 5C). The joint coating device 50 comprises a joint coating mould 51 configured to surround the pipe coating end surfaces 9 and the inner pipe joint 8. The joint coating device 50 further comprises a joint coating material supplier 52 configured to fill the joint coating mould 51 with joint coating material. The makes it possible to provide the joint coating 14 discussed above in relation with the figures 5A, 5B, 5C and 6 in an efficient manner.

[0154] In addition, the system 35 may be provided with a drilling unit for drilling the pipe coating 5 and / or the pipe conduits 6 at the pipe coating end surfaces 9 to form the cavities 29, more specifically the bore holes 30, and the pipe coating end surfaces 9. The drilling unit is supported by and attached to the support members 39 in a fixed position relative to the support members 39. This allows that the cavities 29 discussed above in relation with the figures 1A, 1B, 2A and 2B are drilled in an accurate manner.

[0155] As required, detailed embodiments of the present invention are disclosed in the figures; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention, which can be embodied in various forms. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present invention in virtually any appropriately detailed structure.The terms "a" or "an", as used herein, are defined as one or more than one. The terms multiple and plurality, as used herein, are defined as two or more than two. The term another, as used herein, is defined as at least a second or more. The terms including and / or having, as used herein, are defined as comprising (i.e., open language, not excluding other elements or steps). Any reference signs in the claims should not be construed as limiting the scope of the claims or the invention.

[0156] It will be apparent to those skilled in the art that various modifications can be made to said method, said coated pipeline, said system, and said assembly as shown in the figures without departing from the scope as defined in the claims.

Claims

- 24 -CLAIMS1. Method for producing a coated pipeline comprising two aligned pipe members which are interconnected, said method comprising the steps of:providing the two interconnected pipe members, wherein:-- the pipe members comprise an inner pipe configured to convey a hydrocarbon fluid, which inner pipe comprises an inner pipe end, and a surrounding thermal insulating pipe coating having an embedded pipe conduit,-- the inner pipe ends are interconnected, preferably via a welded connection or a threaded connection, at an inner pipe joint,-- the pipe coating of the pipe members comprises a pipe coating end surface, -- the pipe coating end surfaces of the pipe members are located at opposite sides of the inner pipe joint and at a distance from each other,-- the pipe coating end surfaces extend traverse to a longitudinal axis of the respective pipe member,connecting the pipe conduit of one of the two pipe members to the pipe conduit of the other of the two pipe members to form a duct configured to hold a heating line, which duct comprises a joint coating duct section extending between the pipe coating end surfaces of the two pipe members, andproviding, after the duct is formed, a thermal insulating joint coating between the pipe coating end surfaces, which joint coating surrounds the inner pipe joint, therewith embedding the joint coating duct section of the duct in the joint coating.

2. Method according to claim 1, wherein the method comprises:- placing at least one joint conduit between the pipe conduits of the two pipe members to form the duct,- aligning, preferably with an aligner, the pipe conduits and the at least one joint conduit, and- connecting the pipe conduits to the aligned at least one joint conduit.

3. Method according to claim 2, wherein:- the pipe conduits comprise a pipe conduit wall having an inner pipe conduit wall surface, - the at least one joint conduit comprise a joint conduit wall having an inner joint conduit wall surface,- the pipe conduit wall and the joint conduit wall have a same inner diameter, and- the method comprises aligning the inner pipe conduit wall surface of the pipe conduits with the inner joint conduit wall surface of the at least one joint conduit in order to form aflush inner duct wall surface of the duct.

4. Method according to claim 2 and 3, wherein:- the pipe conduits comprise a pipe conduit connection surface which extends traverse, preferably perpendicular, to the longitudinal axis of the respective pipe member,- the at least one joint conduit comprises two joint conduit connection surfaces,- the two joint conduit connection surfaces and the two pipe conduit connection surfaces are preferably complementary formed surfaces, and- the method comprises connecting the pipe conduits to the at least one joint conduit such that the two joint conduit connection surfaces are positioned adjacent to the two pipe conduit connection surfaces.

5. Method according to claim 4, wherein the method comprises connecting the pipe conduits to the at least one joint conduit by connecting, such as by welding or gluing, the two joint conduit connection surfaces to the two pipe conduit connection surfaces.

6. Method according to claim 4 or 5, wherein:- the pipe conduits comprise an outer pipe conduit wall surface near or at the pipe conduit connection surface,- the at least one joint conduit comprises outer joint conduit wall surfaces near or at the joint conduit connection surfaces, and- the method comprises connecting the pipe conduits to the at least one joint conduit by coupling the outer pipe conduit wall surfaces to the outer joint conduit wall surfaces.

7. Method according to claim 6, wherein the method comprises coupling the outer pipe conduit wall surfaces to the outer joint conduit wall surfaces with an aligner, such as alignment sleeve, configured to align the pipe conduit and the at least one joint conduit.

8. Method according to any one of the claims 2 -7, wherein:- the at least one joint conduit comprises two extension conduits being provided with the two joint conduit connection surfaces,- the pipe conduit connection surfaces are preferably at least partly located within the pipe coating of the respective pipe member, and- the method comprises connecting, preferably by welding or gluing, the two joint conduit connection surfaces of the extension conduits to the two pipe conduit connection surfaces of the pipe conduits.

9. Method according to claim 8, wherein:- the pipe coatings comprise a cavity, such as a bore hole, extending from the pipe conduit connection surface to the pipe coating end surface, and- the method comprises placing part of the extension conduits in the cavities to connect the two joint conduit connection surfaces of the extension conduits to the two pipe conduit connection surfaces of the pipe conduits.

10. Method according to claim 9, wherein the method comprises drilling the pipe coatings and / or pipe conduits at the pipe coating end surfaces to form the cavities, more specifically bore holes, and the pipe conduit connection surfaces.

11. Method according to claim 9 and 10, wherein:- the cavities comprise a cavity wall which forms an aligner configured to align the extension conduit with the pipe conduit, and- the method comprises aligning the extension conduits with the pipe conduits by placing the extension conduits in the cavities of the pipe conduits.

12. Method according to any one of the claims 8- 11, wherein the method comprises holding the extension conduits in a connection position in which the joint conduit connection surface is in contact the pipe conduit connection surface, and wherein the joint conduit connection surface is preferably at least partly located within the pipe coating of the respective pipe member.

13. Method according to claim 12, wherein the method comprises pushing the joint conduit connection surface of the extension conduits against the pipe conduit connection surface of the pipe conduits while the extension conduits are held in the connection position and during said connecting of the extension conduits to the pipe conduits.

14. Method according to any one of the claims 8- 13, wherein:- the at least one joint conduit comprises at least one intermediate conduit, and- the method comprises connecting the extension conduit of one of the two pipe members to the extension conduit of the other of the two pipe members via the at least one intermediate conduit to form the duct.

15. Method according to any one of the claims 5 - 14, wherein the method comprises heating the joint conduit connection surfaces of the at least one joint conduit and the pipe conduit connection surfaces of the pipe conduits to connect the at least one joint conduit- 27 -to the pipe conduits, wherein the method preferably comprises pushing the joint conduit connection surfaces against the pipe conduit connection surfaces during said connecting of the at least one joint conduit to the pipe conduits.

16. Method according to any one of the preceding claims, wherein the method comprises placing a joint coating mould around the pipe coating end surfaces and the inner pipe joint and filling the joint coating mould with joint coating material to provide the joint coating.

17. Method according to any one of the preceding claims, wherein the method comprises placing a heating line in the duct.

18. Method according to any one of the preceding claims, wherein the pipe members comprises multiple pipe conduits embedded in the pipe coating, and the method comprises:- connecting the pipe conduits of one of the two pipe members to the pipe conduits of the other of the two pipe members to form multiple ducts configured to hold a heating line, which ducts comprise joint coating duct sections extending between the pipe coating end surfaces of the two pipe members, and- providing, after the ducts are formed, the thermal insulating joint coating between the pipe coating end surfaces, which joint coating surrounds the inner pipe joint, therewith embedding the joint coating duct sections of the ducts in the joint coating.

19. Coated pipeline comprising two aligned pipe members which are interconnected, wherein:the pipe members comprise an inner pipe configured to convey a hydrocarbon fluid, which inner pipe comprises an inner pipe end, and a surrounding thermal insulating pipe coating having an embedded pipe conduit,the inner pipe ends are interconnected, preferably via a welded connection or a threaded connection, at an inner pipe joint,the pipe coating of the pipe members comprises a pipe coating end surface, the pipe coating end surfaces of the pipe members are located at opposite sides of the inner pipe joint and at a distance from each other,the pipe coating end surfaces extend traverse to a longitudinal axis of the respective pipe member,the pipe conduit of one of the two pipe members is connected to the pipe conduit of the other of the two pipe members,the interconnected pipe conduits form a duct configured to hold a heating line,- 28 -the duct comprises a joint coating duct section extending between the pipe coating end surfaces of the two pipe members,a thermal insulating joint coating is provided between the pipe coating end surfaces, which joint coating surrounds the inner pipe joint, andthe joint coating duct sections of the duct are embedded in the joint coating.

20. System for producing a coated pipeline comprising two aligned pipe members which are interconnected, wherein:- the system comprises a connection device configured to be attached to the two interconnected pipe members, wherein the pipe members comprise an inner pipe configured to convey a hydrocarbon fluid, which inner pipe comprises an inner pipe end, and a surrounding thermal insulating pipe coating having an embedded pipe conduit, the inner pipe ends are interconnected, preferably via a welded connection or a threaded connection, at an inner pipe joint, the pipe coating of the pipe members comprises a pipe coating end surface, the pipe coating end surfaces of the pipe members are located at opposite sides of the inner pipe joint and at a distance from each other, the pipe coating end surfaces extend traverse to a longitudinal axis of the respective pipe member, the pipe conduits comprise a pipe conduit connection surface, which pipe conduit connection surface is preferably at least partly located within the pipe coating of the respective pipe member, and the pipe conduit connection surfaces extend traverse, preferably perpendicular, to the longitudinal axis of the respective pipe member,- the connection device comprises an attachment unit configured to be attached to the interconnected pipe members in a fixed position relative to the interconnected pipe members,- the system comprises a conduit holder configured to hold an extension conduit of at least one joint conduit configured to interconnect the pipe conduits to form a duct for holding a heating line,- the connection device comprises at least one support member extending from the attachment unit and supporting the conduit holder, and- the conduit holder is configured to hold the extension conduit in a connection position in which a joint conduit connection surface of the extension conduit is positioned in contact with the pipe conduit connection surface of one of the pipe members, and wherein the joint conduit connection surface is preferably at least partly located within the pipe coating of said one of the pipe members, and- the connection device optionally comprises a push unit configured to push the joint conduit connection surface of the extension conduit against the pipe conduit connection- 29 -surface while the conduit holder holds the extension conduit in the connection position.

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