Traction member and inspection system

Abstract

This invention provides a traction member that allows for the verification of the integrity of a pipeline after its installation. It also provides an inspection system equipped with this traction member. [Solution] A towed member 10 is attached to the end of a pipeline 1 laid by a pipeline laying ship and is towed when the pipeline 1 is towed, and comprises a pig 50 that can pass inside the pipeline 1.

Description

Technical Field

[0001] The present disclosure relates to a towed member and an inspection system.

Background Art

[0002] Pipelines are used for transporting natural gas, oil, etc. in water or the like. Patent Document 1 discloses a flexible hose used in an offshore oil storage base or the like.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Here, after laying the pipeline, it is necessary to confirm the soundness of the pipeline. However, Patent Document 1 does not disclose how to confirm the soundness of the pipeline.

[0005] The present disclosure has been made in view of the above, and an object thereof is to provide a towed member capable of confirming the soundness of a pipeline after laying the pipeline. Another object is to provide an inspection system provided with this towed member.

Means for Solving the Problems

[0006] A towed member according to an aspect of the present disclosure is a towed member that is attached to an end of a pipeline laid by a laying vessel and is towed when towing the pipeline, and includes a pig that can pass through the inside of the pipeline.

Effects of the Invention

[0007] According to this disclosure, it is possible to provide a traction member that can verify the integrity of a pipeline after its installation. Furthermore, it is possible to provide an inspection system equipped with this traction member. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a schematic diagram showing a pipeline inspection system equipped with a traction member according to one embodiment of the present disclosure. [Figure 2] Figure 2 is a partial cross-sectional view of a traction member according to one embodiment of the present disclosure. [Figure 3] Figure 3 is a view of the tractioned member as shown by arrow A in Figure 2. [Modes for carrying out the invention]

[0009] An example of a traction member 10 according to one embodiment of this disclosure will be described using the drawings. Note that the drawings are schematic in order to facilitate understanding, and the dimensions and proportions of each component may differ as appropriate.

[0010] Figure 1 is a schematic diagram showing a pipeline inspection system 100 equipped with a traction member 10 according to this embodiment. Figure 2 is a partial cross-sectional view of a tractioned member 10 according to one embodiment of the present disclosure. In Figure 2, the pipeline 1 is not included in the tractioned member 10, and is therefore shown by dashed lines. Figure 3 is a view of the tractioned member 10 as shown by arrow A in Figure 2.

[0011] <Towed member> The towed member 10 according to this embodiment is a member that is towed when the pipeline 1 is towed at the start of laying the pipeline 1. The towed member is also called a "pulling head". The towed member is attached to the end 2 of the pipeline 1 being laid by a pipeline laying vessel (not shown). As the pipeline laying vessel moves forward, the towed member 10 is sent out from the stern of the pipeline laying vessel, thereby sending the pipeline 1 into the sea. The towed member 10 according to this embodiment is an example of being attached to a pipeline 1 laid on the seabed G. The towed member 10 may be used not only in the sea, but also in rivers, lakes, etc. The pipeline 1 is used, for example, for transporting oil or gas (carbon dioxide, etc.). Note that carbon dioxide may also be transported in the liquid phase by increasing the pressure, rather than in the gas phase. Figure 1 shows a pipeline laid on the seabed G between two platforms (first platform 110, second platform 120). A towed member 10 is attached to end 2 of pipeline 1.

[0012] The towed member 10 primarily has a water-stopping function to prevent water (seawater) from entering the inside of the pipeline 1, a water-injection function to inject water (seawater) into the inside of the pipeline 1, a towing function to pull the pipeline 1, and a health confirmation function to confirm the health of the pipeline 1. This disclosure primarily describes the integrity verification function among the functions of the traction member 10. Integrity verification involves checking for flattening or buckling of the pipeline 1, and is performed, for example, after the pipeline 1 has been laid but before it is handed over to the customer.

[0013] As shown in Figure 2, the tractioned member 10 comprises a joint 20, a connecting portion 40, and a main body portion 60. Here, the longitudinal direction (direction of the central axis O1) of the tractioned member 10 is defined as the X direction. Also, as shown in Figure 2, the direction perpendicular to the X direction and the direction in which the guard 85 (described later) extends is defined as the Z direction. Furthermore, the direction perpendicular to both the X and Z directions is defined as the Y direction. The central axis O1 of the tractioned member 10 and the central axes of the main body 60 and the joint 20 are coaxial (O1). In Figure 2, the main body 60, the pig 50 (described later), and the positioning member 55 are shown as cross-sectional views including the central axis O1.

[0014] The joint 20 is joined to the end 2 of the pipeline 1, for example, by welding or flange joint. The joint 20 is provided at a location (first location) 11 of the towed member 10 in the longitudinal direction of the towed member 10. The joint 20 has a cylindrical shape and is configured such that water (seawater) flows through its interior 23. The material of the joint 20 is, for example, steel.

[0015] When towing the pipeline 1, a tensile force from the pipeline 1 is applied to the towed member 10. Therefore, it is desirable that the towed member 10 is securely joined to the pipeline 1. The towed member 10 and the pipeline 1 are, for example, flange - joined. Figs. 2 and 3 show an example of a flange - joint type towed member 10 in which the joint 20 is joined to the end 2 of the pipeline 1 by flange joint. The joint 20 includes a flange portion 21 for flange joint and a plurality of through - holes (not shown) penetrating the flange portion 21 in its thickness direction. When using the flange - joint type towed member 10, the pipeline 1 has a pipeline (hereinafter also referred to as "PL") joint portion 4 for joining with the joint 20. The PL joint portion 4 of the pipeline 1 includes a pipeline (PL) flange portion 5 and a plurality of PL through - holes (not shown) penetrating the PL flange portion 5 in its thickness direction. Bolts are inserted through the through - holes formed in the flange portion 21 and the PL through - holes formed in the PL flange portion 5, and are fastened using nuts. In this way, the flange - joint type towed member 10 and the pipeline 1 are joined. With such a configuration, the towed member 10 (joint 20) can be firmly attached to the end 2 of the pipeline 1.

[0016] The towed member 10 and the pipeline 1 may be joined by welding. Although not shown in the figure, the joint 20 is joined to the end 2 of the pipeline 1 by welding. For the welding between the joint 20 and the joint surface of the end 2 in the pipeline 1, well - known welding methods such as arc welding, TIG welding, etc. can be adopted. With such a configuration, the towed member 10 (joint portion 20) can be firmly attached to the end portion 2 of the pipeline 1.

[0017] The connecting portion 40 may be, for example, a pad eye. As shown in FIG. 2, the connecting portion 40 is connected to a cable-like body 70 for towing the pipeline 1 (see FIG. 1). The connecting portion 40 is disposed at a location (second location) 12 on the opposite side of the joint portion 20 in the longitudinal direction of the towed member 10. The towed member 10 includes the joint portion 20 at the first location 11 and the connecting portion 40 at the second location 12 in the longitudinal direction. The cable-like body 70 is, for example, a wire. The connecting portion 40 is configured such that the cable-like body 70 can be connected thereto. The material of the connecting portion 40 is, for example, a steel material. As shown in FIG. 1, one end of the cable-like body 70 is connected to the connecting portion 40, and the other end is connected to, for example, the first platform 110. The other end of the cable-like body 70 may be connected to an anchor driven into the seabed G, for example.

[0018] The main body portion 60 is disposed between the joint portion 20 and the connecting portion 40 in the longitudinal direction of the towed member 10. The main body portion 60 has, for example, a cylindrical shape and is configured such that water (seawater) flows through the interior 63. The main body portion 60 and the joint portion 20 are firmly connected, for example, by welding.

[0019] As shown in FIG. 2, the towed member 10 includes a pig 50 that can pass through the interior of the pipeline 1. The pig 50 is a member for passing through the interior of the pipeline 1 together with a fluid (for example, seawater, water) to check for flattening or buckling of the pipeline 1. Further, the pig 50 can remove scale or the like adhering to the inner wall of the pipeline 1 and inspect the internal damage state. In FIG. 2, since the main body portion 60 is shown in a cross-sectional view, a cross-sectional view of the pig 50 and the like is displayed. Pig 50 is formed from, for example, an elastic material, a resin material, or a metallic material, and is bullet-shaped, cylindrical, or spherical. Pig 50 is shaped to contact (e.g., adhere tightly) the inner wall of pipeline 1. For example, by making the outer diameter of Pig 50, which is formed from an elastic material (e.g., a silicon disk), slightly larger than the inner diameter of pipeline 1, Pig 50 adheres tightly to the inner wall of pipeline 1 as it passes through the inside of pipeline 1.

[0020] The towed member 10 according to this embodiment is configured to include a pig 50 that can pass through the inside of the pipeline 1. With this configuration, there is no need to prepare a separate pig 50 in addition to the towed member 10 when checking the integrity of the inside of the pipeline 1. Therefore, according to the towed member 10 according to this embodiment, it is possible to check the integrity of the pipeline 1 after it has been laid.

[0021] The pig 50 may be housed in the main body 60, as shown in Figure 2. The main body 60 of the towed member 10 is, for example, cylindrical in shape, and the pig 50 can be housed inside the main body 63. The pig 50 is positioned along the longitudinal direction (X direction) inside the main body 63 and is movable in the longitudinal direction inside the towed member 10.

[0022] With this configuration, the pig 50 can be accommodated using the main body 60 of the traction member 10.

[0023] The tractioned member 10 may also include a positioning member 55. The positioning member 55 is a member that positions the pig 50 in a predetermined position within the main body 60. The positioning member 55 may also function as a stopper for the pig 50. The pig 50 is positioned in the predetermined position with reference to the positioning member 55. The positioning member 55 is, for example, cylindrical in shape and is made of, for example, an elastic material, a resin material, or a metal material. The positioning member 55 is, for example, positioned inside 63 of the main body 60 such that its longitudinal direction is aligned with the central axis O1. The positioning member 55 (first positioning member 55-1) used when positioning the pig 50, for example, with respect to the end portion 65 of the second location 12, will be described below. As shown in Figure 2, the end portion 56 of the first positioning member 55-1 is positioned inside the main body portion 60 63 so as to extend from the end portion 65 toward the center of the main body portion 60 in the direction of the central axis O1. By positioning the second positioning member 55-2, which will be described later, in contact with the first positioning member 55-1 inside the main body portion 63, the pig 50 (first pig 50-1) can be positioned. The positioning member 55 does not have to be positioned with respect to the end portion 65. The positioning member 55 does not have to be cylindrical in shape; for example, it may be prism-shaped, cylindrical, or have a flange portion at its top. Furthermore, the positioning member 55 does not have to be positioned so that its longitudinal direction aligns with the central axis O1 inside the main body portion 63.

[0024] This configuration allows the Pig 50 to be positioned precisely on the main body 60.

[0025] The traction member 10 may have multiple pigs 50. Figure 2 shows a case where there are four pigs 50 (first pig 50-1, second pig 50-2, third pig 50-3, and fourth pig 50-4). The number of pigs 50 is not limited to four; for example, there may be one, two, three, or five or more. The multiple pigs 50 are arranged inside the main body 60 63 with their longitudinal direction aligned along the central axis O1. By providing multiple pigs 50, the integrity check of the pipeline 1 can be performed more effectively by the multiple pigs 50.

[0026] Positioning members 55 may be provided at both ends of the pig 50 on the central axis O1. However, the positioning member 55 may be provided at only one end of the pig 50. In Figure 2, second positioning members 55-2 are positioned at both ends of the first pig 50-1 on the central axis O1. One of the second positioning members 55-2 abuts against the first positioning member 55-1. Also, third positioning members 55-3 are positioned at both ends of the second pig 50-2 on the central axis O1. One of the third positioning members 55-3 abuts against the other second positioning member 55-2. The second pig 50-2 can be positioned by one of the third positioning members 55-3 abutting against the other second positioning member 55-2. Also, fourth positioning members 55-4 are positioned at both ends of the third pig 50-3 on the central axis O1. One of the fourth positioning members 55-4 abuts against the other third positioning member 55-3. The third pig 50-3 can be positioned by one of the fourth positioning members 55-4 abutting against the other third positioning member 55-3. Furthermore, fifth positioning members 55-5 are positioned at both ends of the fourth pig 50-4 on the central axis O1. One of the fifth positioning members 55-5 abuts against the other fourth positioning member 55-4. The fourth pig 50-4 can be positioned by the abutment of one fifth positioning member 55-5 against the other fourth positioning member 55-4. These first pigs 50-1, second pig 50-2, third pig 50-3, and fourth pig 50-4 are positioned with their longitudinal directions on the central axis O1 inside the main body 60 63. In this way, by providing positioning members 55 between adjacent pigs 50 on the central axis O1, each pig 50 can be positioned precisely.

[0027] The multiple pigs 50 may be similar or different. If the multiple pigs 50 are different, for example, by varying the shape or material of the pigs 50, the tractioned member 10 can have pigs 50 with different performance characteristics. For example, as shown in Figure 2, the multiple pigs 50 may include a cleaning pig 50D, a batch pig 50C, and a gauge pig 50B. In this embodiment, the second pig 50-2 is an example of a gauge pig 50B, the third pig 50-3 is an example of a batch pig 50C, and the fourth pig 50-4 is an example of a cleaning pig 50D.

[0028] The cleaning pig (first cleaning pig) 50D is a pig for cleaning the inside of pipeline 1. The cleaning pig 50D moves while cleaning the inside of pipeline 1. Part of the cleaning pig 50D (at least the outer periphery) is formed of, for example, a metal material. The cleaning pig 50D may also be, for example, a metal scouring pad. This configuration makes it possible to remove (scrape off) scale and other substances adhering to the inner wall of pipeline 1.

[0029] The batch pig (first batch pig) 50C is a pig for scale recovery. The batch pig 50C moves while recovering scale inside pipeline 1. Part of the batch pig 50C (at least the outer periphery) is formed of, for example, silicon (silicon disk). This configuration allows for the recovery of residual scale within pipeline 1.

[0030] The gauge pig (first gauge pig) 50B is a pig used to inspect for damage inside pipeline 1. The gauge pig 50B moves while inspecting for damage inside pipeline 1. Part of the gauge pig 50B (at least the outer periphery) is made of, for example, aluminum (aluminum plate). By moving the gauge pig 50B inside pipeline 1, it is possible to inspect for damage inside pipeline 1. For example, if the aluminum plate deforms when the gauge pig 50B is moved inside pipeline 1, there is a possibility that the inside of pipeline 1 is damaged.

[0031] Multiple Pig 50s may include spare Pig 50X. In this embodiment, the first Pig 50-1 is an example of a spare Pig 50X. A spare pig 50X is, for example, a spare gauge pig 50B. Having multiple pigs 50 including spare gauge pigs 50BX allows, for example, if gauge pig 50B is damaged, the spare gauge pig 50BX can be used to move the pigs through pipeline 1. There may be one spare pig 50X, two or more spare pigs 50X, or there may be no spare pigs 50X at all.

[0032] Multiple pigs 50 may include spare cleaning pigs. By including spare cleaning pigs in the multiple pigs 50, if cleaning pig 50D is damaged, the spare cleaning pig can be used to remove (scrape off) scale and other debris adhering to the inner wall of pipeline 1. Multiple pigs 50 may include spare batch pigs. Having multiple pigs 50 with spare batch pigs allows for the recovery of remaining scale inside pipeline 1 if batch pig 50C is damaged.

[0033] By providing the traction member 10 with multiple types of pigs 50, the integrity of the pipeline 1 can be checked more effectively. The multiple pigs 50 may include two different pigs 50 from among cleaning pigs 50D, batch pigs 50C, and gauge pigs 50B (for example, cleaning pig 50D and batch pig 50C). The multiple pigs 50 may also include two or three or more identical pigs 50 from among cleaning pigs 50D, batch pigs 50C, and gauge pigs 50B. Multiple Pig 50s may include a second cleaning pig. This allows for more effective cleaning of the pipeline. Multiple Pig 50s may include a second batch of Pigs. This allows for more effective scaling. Multiple Pig 50s may include a second gauge pig. This allows for more effective inspection of damage inside the pipeline. Note that there does not need to be multiple Pig 50s. For example, Pig 50 may include only Cleaning Pig 50D, or only Gauge Pig 50B.

[0034] The pig 50, housed in the main body 60 of the towed member 10, is launched from the main body 60 toward the joint 20 and moves inside the pipeline 1. If the towed member 10 includes multiple pigs 50, the pigs 50 positioned closer to the pipeline 1 are launched first. In Figure 2, the pigs are arranged in the order of cleaning pig 50D, batch pig 50C, and gauge pig 50B from the side closest to the pipeline 1. In this case, the cleaning pig 50D, batch pig 50C, and gauge pig 50B are launched in this order. First, cleaning pig 50D is moved into the interior of pipeline 1 to remove scale and other debris adhering to the inner wall of pipeline 1. Next, batch pig 50C is moved to collect the scale and other debris removed by cleaning pig 50D. Then, gauge pig 50B is moved to inspect the interior of pipeline 1 for damage.

[0035] If multiple pigs 50 include a cleaning pig 50D, a batch pig 50C, and a gauge pig 50B, launching the cleaning pig 50D, batch pig 50C, and gauge pig 50B in that order allows for more effective verification of the health of pipeline 1.

[0036] The pig 50 is launched from the towed member 10 by the pressure of a fluid (e.g., water, seawater) and moves inside the pipeline 1. The pig 50 can move inside the pipeline 1 when pressure is applied in the direction of movement. The towed member 10 may be equipped with a valve 80 for injecting water into the interior 63 of the main body 60. During the laying of the pipeline 1, for example, when connecting the riser pipe to the offshore platform to the pipeline 1, water can be injected into the interior 63 of the main body 60 (inside the pipeline 1) using the valve 80. The valve 80 is provided on the outside of the main body 60. The inside of the valve 80 and the interior 63 of the main body 60 are in communication, and water can move between the inside of the valve 80 and the interior 63 of the main body 60.

[0037] When water is injected into the main body 60 from the valve 80, the pig 50 housed in the main body 60 is subjected to water pressure. Upon receiving water pressure, the pig 50 is launched from the main body 60 toward the interior of the pipeline 1. In this way, in order to launch the pig 50 toward the interior of the pipeline 1, the valve 80 is positioned on the opposite side of the pig 50 from the pipeline 1. For example, as shown in Figure 2, in the X direction, the first valve 80-1 (80) is positioned on the opposite side of the pipeline 1 from the cleaning pig 50D (or the fourth pig 50-4). When water is injected into the main body 60 from the first valve 80-1, the cleaning pig 50D receives water pressure from the opposite side of the pipeline 1, causing it to launch toward the interior of the pipeline 1.

[0038] Thus, the Pig 50 is launched from the main body 60 towards the inside of the pipeline 1 by water injection from the valve 80. This configuration allows the Pig 50 to be launched towards the pipeline 1.

[0039] The traction member 10 may be equipped with multiple valves 80. For example, as shown in Figure 2, in addition to the first valve 80-1(80), it may be equipped with a second valve 80-2(80), a third valve 80-3(80), and a fourth valve 80-4(80). In this case, the second valve 80-2 is positioned on the opposite side of pipeline 1 to batch pig 50C (or third pig 50-3), the third valve 80-3 is positioned on the opposite side of pipeline 1 to gauge pig 50B (or second pig 50-2), and the fourth valve 80-4 is positioned on the opposite side of pipeline 1 to spare gauge pig 50BX (or first pig 50-1).

[0040] With this arrangement of multiple valves 80 (e.g., 80-1, 80-2, 80-3, 80-4), each valve 80 (e.g., 80-1, 80-2, 80-3, 80-4) can launch a pig 50 (e.g., 50-1, 50-2, 50-3, 50-4) toward pipeline 1 by injecting water from each valve 80. Specifically, the fourth pig 50-4 is launched first by injecting water from the first valve 80-1, then the third pig 50-3 is launched by injecting water from the second valve 80-2, then the second pig 50-2 is launched by injecting water from the third valve 80-3, and finally the first pig 50-1 is launched by injecting water from the fourth valve 80-4. The multiple valves 80 may or may not be the same size. When multiple different valves 80 are provided on the main body 60 of the tractioned member 10, for example, valves 80 with different allowable flow rates may be provided. Furthermore, the first valve 80-1, the second valve 80-2, the third valve 80-3, and the fourth valve 80-4 are connected by piping 82, as shown in Figure 2. Water is injected into piping 82 via the fifth valve 80-5(80). One end of a hose (not shown) is connected to the fifth valve 80-5(80), and the other end of the hose is connected to a pump on the laying vessel. The water is then injected into the interior 63 of the main body 60 via the first valve 80-1, the second valve 80-2, the third valve 80-3, and the fourth valve 80-4. If only water is to be injected into the interior of pipeline 1 without launching the pig 50, the water is injected into the interior 63 of the main body 60 using the fifth valve 80-5 and the sixth valve 80-6(80).

[0041] As shown in Figure 2, the multiple valves 80 are aligned in the direction of the central axis O1 of the main body 60 (the central axis of the tractioned member 10). Also, as shown in Figure 3, the multiple valves 80 (for example, 80-1, 80-2, 80-3, 80-4) are arranged such that the central axes O2 of each valve 80 in the longitudinal direction (Z direction) overlap when viewed from the X direction. In this way, the multiple valves 80 are arranged so that the central axis O2 of each valve 80 is in the same direction with respect to the main body 60 of the tractioned member 10. In this embodiment, in the view along the X-direction, the side on which the valve 80 is positioned relative to the main body 60 of the towed member 10 is defined as the upper side. As shown in Figure 3, the multiple valves 80 are positioned on the upper part (upper side) of the main body 60 of the towed member 10. When the pipeline 1 is towed, the towed member 10 is attached to the pipeline 1 so that the valves 80 are positioned on the upper side. In this way, since the multiple valves 80 are arranged in the same direction with respect to the main body 60 of the towed member 10, it is possible to position the valves 80 so that they do not come into contact with the seabed G or the laying vessel when laying the pipeline 1.

[0042] Since the valve 80 protrudes from the outer circumferential surface 64a of the main body 60, there is a risk that the valve 80 may be damaged if it comes into contact with an object. For this reason, a guard 85 may be provided on the outside of the valve 80 to protect it. The guard 85 is shaped to surround the valve 80 from the outside.

[0043] The guard 85 is a three-dimensional frame structure, as shown in Figures 2 and 3, for example. The valve 80 is surrounded by the guard 85, which has a three-dimensional frame structure. For example, guard 85 is composed of frame 86. Specifically, for example, guard 85 includes a first frame 86-1 and a second frame 86-2. As shown in Figure 3, the first frame 86-1 and the second frame 86-2 are frames that are approximately trapezoidal (specifically, approximately trapezoidal with a widening top) when viewed from the X direction. However, the first frame 86-1 and the second frame 86-2 may also be frames that are approximately rectangular and approximately circular when viewed from the X direction. As shown in Figure 2, the first frame 86-1 and the second frame 86-2 are arranged with a gap between them in the longitudinal direction of the tractioned member 10. The first frame 86-1 and the second frame 86-2 are positioned such that the valve 80 is located between the first frame 86-1 and the second frame 86-2 in the longitudinal direction. Furthermore, the upper ends of the first frame 86-1 and the second frame 86-2 may be connected by a transverse frame 87. The transverse frame 87 comprises, for example, two members extending in the longitudinal direction and two members extending in the Y direction across the two members. The material of the guard 85 is, for example, steel plate.

[0044] Thus, the valve 80 is enclosed by a guard 85 having a three-dimensional frame structure. This configuration allows the guard 85 to protect the valve 80. As shown in Figure 2, the guard 85 may also include a third frame 86-3 positioned between the first frame 86-1 and the second frame 86-2 in the longitudinal direction. In Figure 2, the guard 85 has a configuration that includes three frames (first frame 86-1, second frame 86-2, and third frame 86-3) in the longitudinal direction. The frame 86 constituting the guard 85 may be four or more.

[0045] The main body 60 of the traction member 10 may have a hole 88 for confirming the position of the pig 50 inside the main body 60 from outside the main body 60. The hole 88 is a through hole that penetrates the outer peripheral wall of the main body 60. The hole 88 is formed, for example, by threading. The holes 88 are positioned in a location where the position of the pigs 50 can be confirmed. For example, the holes 88 are located on the outer circumferential wall of the main body 60 at the position where each pig 50 is placed. For example, as shown in Figure 2, the holes 88 are positioned above each pig 50. Through the holes 88, for example, a worker can confirm the position of the pigs 50 by visual inspection or by pressing a rod-shaped member against the pig. After confirming the position of the pigs 50 through the holes 88, the holes 88 are sealed with bolts to prevent water leakage.

[0046] The traction member 10 has a hole 88 in its main body 60. This configuration allows for confirmation that the pig 50 is positioned correctly.

[0047] <Pipeline Inspection System> A pipeline inspection system 100 equipped with the traction member 10 described above will now be explained. The pipeline inspection system 100 according to this embodiment comprises a first platform 110, a second platform 120, a pipeline 1, and a traction member 10. As shown in Figure 1, pipeline 1 is installed between the first platform 110 and the second platform 120. Figure 1 shows pipeline 1 laid on the seabed G using a towed member 10. The towed member 10 is removed from pipeline 1 after it has been laid on the seabed G. Figure 1 shows the case where both the first platform 110 and the second platform 120 are offshore platforms. At least one of the first platform 110 and the second platform 120 is an offshore platform. One of the first platform 110 and the second platform 120 may be a land-based platform (not shown). Both the first platform 110 and the second platform 120 may be offshore platforms.

[0048] The towed member 10 is provided at the end 2 of the pipeline 1 on the first platform 110 side. As described above, the towed member 10 is equipped with a pig 50 that can pass through the inside of the pipeline 1. The pig 50 launched from the towed member 10 moves through the inside of the pipeline 1 and reaches the end 3 of the pipeline 1 on the second platform 120 side.

[0049] According to the pipeline inspection system 100 of this embodiment, the integrity of the pipeline 1 installed between the first platform 110 and the second platform 120 can be confirmed by the pig 50.

[0050] The pipeline inspection system 100 may include a recovery member 130. The recovery member 130 is provided at the end 3 of the pipeline 1 on the second platform 120 side and is a member that recovers the pigs 50 launched from the towed member. The recovery member 130 is also called a "receiver". If the towed member 10 has multiple pigs 50, the recovery member 130 recovers the multiple pigs 50 launched from the towed member 10.

[0051] When the pig 50, launched from the towed member 10, moves inside the pipeline 1 and reaches the end 3 on the second platform 120 side of the pipeline 1, the pig 50 can be recovered by the recovery member 130.

[0052] The technical scope of this disclosure is not limited to the embodiments described above, and various modifications can be made without departing from the spirit of this disclosure. For example, the Pig 50 does not necessarily have to be housed in the main body 60. The traction member 10 does not necessarily need to include a positioning member 55 for positioning the pig 50 at a predetermined position within the main body 60. The traction member 10 does not necessarily need to be equipped with a guard 85 to protect the valve 80. One valve 80 is sufficient. The main body 60 does not necessarily have to have a hole 88 for checking the position of the pig 50 inside the main body 60 from outside the main body 60. The pipeline inspection system 100 does not necessarily have to include a recovery member 130 for recovering the pig 50 launched from the towed member 10.

[0053] (Note) The above embodiment can be understood, for example, as follows:

[0054] <1> A towed member according to one aspect of the present disclosure is a towed member that is attached to the end of a pipeline laid by a pipeline laying vessel and is towed when the pipeline is towed, The pipeline includes a pig capable of passing through the interior of the pipeline.

[0055] With this configuration, there is no need to prepare a separate pig in addition to the towed member for checking the integrity of the inside of the pipeline. Therefore, with the towed member according to this embodiment, it is possible to check the integrity of the pipeline after the pipeline 1 has been laid.

[0056] <2> the above <1> The traction member may be configured to include a main body, and the pig may be housed within the main body.

[0057] With this configuration, the pig can be housed using the main body of the towed member.

[0058] <3> the above <2> The traction member may be configured to include a positioning member that positions the pig at a predetermined position within the main body.

[0059] This configuration allows the Pig to be positioned precisely on the main body.

[0060] <4> the above <1> from <3> The traction member relating to any one of the above may be configured to include multiple pigs.

[0061] This configuration allows for more effective pipeline health checks using multiple pigs.

[0062] <5> the above <4> The traction member may employ a configuration in which a plurality of pigs include a cleaning pig, a batch pig, and a first gauge pig.

[0063] This configuration allows for more effective pipeline health checks by using multiple types of pigs.

[0064] <6> the above <5> The traction member may be configured such that the cleaning pig, the batch pig, and the first gauge pig are launched in that order.

[0065] This configuration allows for more effective verification of pipeline health.

[0066] <7> the above <4> from <6> The traction member relating to any one of the above may employ a configuration in which the multiple pigs include a second gauge pig.

[0067] With this configuration, for example, if the first gauge pig is damaged, the second gauge pig can be used to move it through the inside of the pipeline.

[0068] <8> the above <1> from <7> The traction member relating to any one of the items is the main body and, A valve for injecting water into the main body, A configuration that includes this feature may be adopted.

[0069] With this configuration, water can be injected into the main body (inside the pipeline) using a valve.

[0070] <9> the above <8> The towed member may be configured such that the pig is launched from the main body toward the interior of the pipeline by water injection from the valve.

[0071] This configuration allows the pig to be launched into the pipeline.

[0072] <10> the above <8> or <9> The traction member may be provided on the outside of the valve and may be configured to include a guard that protects the valve.

[0073] This configuration allows the valve to be protected by the guard.

[0074] <11> the above <8> from <10> The traction member relating to any one of the above may be configured to include a plurality of the aforementioned valves.

[0075] This configuration allows multiple pigs to be launched into the pipeline by injecting water from multiple valves.

[0076] <12> the above <2> from <11> The traction member relating to any one of the above may have a configuration in which the main body portion has a hole portion for confirming the position of the pig within the main body portion from the outside of the main body portion.

[0077] This configuration allows you to verify that the Pigg avatar is positioned correctly.

[0078] <13> A pipeline inspection system relating to one aspect of this disclosure is the above <1> from <12> A pipeline inspection system comprising a traction member as described in any one of the following items, Platform 1 and The second platform and A pipeline provided between the first platform and the second platform, The towed member provided at the end of the pipeline on the first platform side, Equipped with, Of the first and second platforms, at least one is an offshore platform. The pig, launched from the towed member, moves inside the pipeline and reaches the end of the pipeline on the second platform side.

[0079] With this configuration, the health of the pipeline established between the first platform and the second platform can be verified by pigging.

[0080] <14> the above <13> The pipeline inspection system relating to the above is provided at the end of the pipeline on the second platform side and includes a recovery member for recovering the pig launched from the towed member, A configuration may be adopted in which the pig launched from the towed member moves inside the pipeline and is collected by the recovery member.

[0081] With this configuration, the pig launched from the towed member moves through the inside of the pipeline, and when it reaches the end of the pipeline on the second platform side, the pig can be recovered by the recovery member. [Explanation of symbols]

[0082] 1 Pipeline 10 Towed member 20 Joint 40 Connection part 50 Pigg 50B Gauge Pig 50C Batch Pig 50D Cleaning Pig 50X Spare Pigg 55 Positioning member 60 Main body 80 valves 85 Guard 88 Hole 100 Pipeline Inspection System 110 Platform 1 120 Platform 2 130 Recovery component G Undersea

Claims

1. A towed member attached to the end of a pipeline laid by a pipeline laying vessel, which is towed when the pipeline is towed, A pig capable of passing through the inside of the pipeline, It comprises a main body and, The aforementioned pig is a traction member housed in the main body.

2. A towed member attached to the end of a pipeline laid by a pipeline laying vessel, which is towed when the pipeline is towed, The pipeline includes a pig capable of passing through the interior of the pipeline, The pig is a towed member that is towed together with the towed member.

3. A towed member attached to the end of a pipeline laid by a pipeline laying vessel, which is towed when the pipeline is towed, The pipeline includes a pig capable of passing through the interior of the pipeline, The aforementioned pipeline is a towed member that is a single pipe.

4. The traction member according to claim 1, further comprising a positioning member for positioning the pig at a predetermined position within the main body.

5. A traction member according to any one of claims 1 to 4, comprising a plurality of the aforementioned pigs.

6. The traction member according to any one of claims 1 to 4, wherein the plurality of pigs include a cleaning pig, a batch pig, and a first gauge pig.

7. The towed member according to claim 6, wherein the cleaning pig, the batch pig, and the first gauge pig are launched in this order.

8. The traction member according to claim 6, wherein the plurality of pigs include a second gauge pig.

9. The main body and A valve for injecting water into the main body, A traction member according to any one of claims 1 to 4, comprising:

10. The towed member according to claim 9, wherein the pig is launched from the main body toward the interior of the pipeline by water injection from the valve.

11. The traction member according to claim 9, further comprising a guard provided on the outside of the valve to protect the valve.

12. The traction member according to claim 9, comprising a plurality of the valves.

13. The traction member according to claim 1, wherein the main body portion has a hole portion for confirming the position of the pig within the main body portion from the outside of the main body portion.

14. A pipeline inspection system comprising a traction member according to any one of claims 1 to 4, The first platform and The second platform and A pipeline provided between the first platform and the second platform, The towed member provided at the end of the pipeline on the first platform side, Equipped with, Of the first platform and the second platform, at least one is an offshore platform. A pipeline inspection system in which the pig, launched from the towed member, moves inside the pipeline and reaches the end of the pipeline on the second platform side.

15. The pipeline is provided at the end on the second platform side and includes a recovery member for recovering the pig launched from the towed member, The pipeline inspection system according to claim 14, wherein the pig launched from the towed member moves inside the pipeline and is collected by the recovery member.

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