Inspection platform and method for inspection of riser pipes on a drilling rig

Abstract

A method of inspecting vertically arranged riser pipes (10) on a drilling rig, comprising: providing an inspection platform (20) having an inspection tool (21), lifting the inspection platform (20) onto an upper end (11) of a riser pipe (10), supporting the inspection platform (20) on the riser pipe (10) via a support structure (22), and operating the inspection tool (21) whilst moving the inspection tool (21) in the riser pipe (10). There is also provided an inspection platform (20) comprising an inspection tool (21) and a support structure (22) configured to be arranged on the upper end (11) of a riser pipe (10), wherein the inspection platform (20) comprises a riser interface (23) projecting from the support structure (22) and being configured to dock to the riser pipe (10).

Description

[0001] INSPECTION PLATFORM AND METHOD FOR INSPECTION OF RISER PIPES ON A DRILLING RIG

[0002] The present disclosure relates to tools and methods for inspecting riser pipes on a drilling rig.

[0003] BACKGROUND

[0004] In offshore drilling operations, risers are commonly used to provide a temporary extension of a subsea well to a surface facility, for example for drilling, intervention work or production. There are several types of risers that are commonly utilized in petroleum operations. One type of riser is a marine drilling riser where a subsea blowout preventer is used and generally deployed from floating drilling vessels. Another riser type is a tie-back drilling riser where a surface blowout preventer is utilized and generally deployed from fixed platforms. WO 2015 / 071411 A2 describes, generally, the use of a riser in an offshore drilling operation. (See Fig. 1 of that document and the associated description.)

[0005] Common to most such risers are that they are made up of sections which are connected together in an end-flange to end-flange fashion. The riser pipes and these connections are then in the primary load path while running, operating and retrieving the riser. As a safety-critical component, the structural integrity of the riser is essential. For this reason, riser sections are commonly inspected between deployments in order to identify weaknesses or damage in the riser pipe(s) or other components of the riser. An example of a method and inspection unit for this purpose is described in WO 03 / 087733 A2.

[0006] Other documents which may be useful for understanding the background include WO 2021 / 0150615 A1 ; KR 2013 / 0046634 A; WO 2006 / 068497 A1 ; GB 2150962 A; and US 4708563 A

[0007] There is a continuous need for improved technology to make drilling rig operations more efficient, safe and reliable. It is an aim of the present disclosure to provide improvements in one or more of these areas, or at least alternatives, to known technology. SUMMARY

[0008] In an embodiment, there is provided a method of inspecting vertically arranged riser pipes on a drilling rig, the method comprising: providing an inspection platform having an inspection tool, lifting the inspection platform onto an upper end of a riser pipe of the vertically arranged riser pipes, supporting the inspection platform on the upper end of the riser pipe via a support structure of the inspection platform, and operating the inspection tool whilst moving the inspection tool in the riser pipe.

[0009] In an embodiment, there is provided an inspection platform for inspecting vertically arranged riser pipes on a drilling rig, the inspection platform comprising an inspection tool and a support structure configured to be arranged on the upper end of a riser pipe, wherein the inspection platform further comprises a riser interface projecting from the support structure and being configured to dock to the riser pipe.

[0010] The detailed description below and appended claims outline further inventive aspects and embodiments.

[0011] BRIEF DESCRIPTION OF THE DRAWINGS

[0012] These and other characteristics will become clear from the following description of illustrative embodiments, given as non-restrictive examples, with reference to the attached drawings.

[0013] Figure 1 is a perspective view of a drilling rig with riser pipes vertically arranged in a riser pipe storage and with an inspection platform according to a first embodiment in a vertical use orientation.

[0014] Figure 2 is a perspective front view of the inspection platform in the vertical use orientation.

[0015] Figure 3 is a perspective back view of the inspection platform in the vertical use orientation.

[0016] Figure 4 is a perspective front view of the inspection platform in a horizontal transport orientation. Figure 5 is a perspective back view of the inspection platform in the horizontal transport orientation.

[0017] Figure 6 is a perspective exploded view of the inspection platform according to figure 4.

[0018] Figure 7 is a perspective side view of the inspection platform in the vertical use orientation provided with an interface protector.

[0019] Figure 8 is a side view of the inspection platform attached to a shipping skid in the horizontal transport orientation.

[0020] Figure 9 is a side view of the inspection platform during an uprighting operation from the horizontal transport orientation to the vertical use orientation.

[0021] Figures 10a and 10b provide a side view and a detail view of the inspection platform in a further uprighted state compared to figure 9.

[0022] Figures 1 1 a and 11 b provide a side view and a detail view of the inspection platform fully uprighted to the vertical use orientation.

[0023] Figure 12 is a perspective front view of an inspection platform according to a second embodiment.

[0024] Figure 13 is a perspective back view of the inspection platform according to the second embodiment.

[0025] Figure 14 is a perspective side view of the inspection platform according to the second embodiment supported on the upper end of a riser pipe.

[0026] Figure 15 is a perspective side view of the inspection platform according to the first embodiment prepared for crane transport.

[0027] Figure 16 is a perspective side view of the inspection platform according to the second embodiment prepared for crane transport.

[0028] DETAILED DESCRIPTION

[0029] The present description provides an improved inspection method and an advantageous inspection platform allowing for the inspection of vertically arranged riser pipes. Drilling riser pipes require periodic inspection in order to discover weaknesses or damages that may result in leakage. In the past, inspection has been primarily performed by transporting the rise pipers to onshore service sites, disassembling the riser pipes, inspecting the riser pipe sections and reassembling the riser pipes for reuse on the drilling rig, which is to a time-consuming and expensive inspection procedure. The described invention enables to conduct inspections on-site at the drilling rig. Drilling rigs commonly comprise riser pipe storages in which the riser pipes may be arranged in a vertical manner. By providing an inspection method and an inspection platform allowing for the inspection of vertically arranged riser pipes, the inspection may be facilitated locally, accelerated and performed at lower cost.

[0030] Figure 1 shows an offshore drilling rig with riser pipes 10 vertically arranged in a riser pipe storage. “Vertically arranged riser pipes” may imply that the generally tubular riser pipes 10 are set up with a predominantly vertical extension and e.g. standing on a lower end with a first opening on the bottom of the riser pipe storage. An upper end 11 with a second opening of the riser pipe 10 may be arranged on the opposite side of the riser pipe 10 and may form at least one accessible inspection opening 14. The lower end and the upper end 11 are usually connected via a tubular shell of the riser pipe 10. In order to allow for on-site inspection of the vertically arranged riser pipes 10, an inspection platform 20 as well as an inspection method using the inspection platform 20 are provided according to the invention. Nevertheless, the inventive method and inspection platform may be implemented anywhere, both on offshore sites and onshore sites.

[0031] For further description of the inspection platform 20, reference is now made to Figs. 2 and 3 providing front and back views of the inspection platform 20 oriented in a vertical use orientation. As illustrated, the inspection platform 20 comprises an inspection tool 21 arranged in a launch unit 25, wherein the inspection tool 21 is configured to be moved downwardly and upwardly in a riser pipe 10 to be inspected. The launch unit 25 may comprise a protective frame in order to protect the inspection components from mechanical impacts, e.g. caused by a swinging crane hook. In the figures, the inspection tool 21 is not directly visible as it is covered by a protective shell. The inspection tool 21 may use magnetic or camera imaging techniques, ultrasonic transducers or other suitable methods in order to provide inspection results to an operator. For instance, the inspection tool 21 may record or send inspection data to a platform control (not illustrated). The inspection tool 21 is configured to be operated upon movement in the riser pipe 10 and may be activated continuously or at discrete intervals during movement. According to advantageous embodiments, the inspection platform 20 comprises a winch unit 24 for moving the inspection tool 21 downwardly and upwardly inside the riser pipe 10 in a controlled manner. The winch unit 24 provides enhanced cable management and assists beneficially in securing the inspection tool 21 in the riser pipe 10. The winch unit 24 may be controlled electronically and may operate fully automatized according to some embodiments. The winch unit 24 may inter alia comprise a cable drum, a winch motor, a manual spooling device, a rotary unit, a drum support and at least one lifting point 31 for the releasable attachment of lifting means as ropes or hooks. The launch unit 25 may further comprise additional components as e.g. an electrical enclosure for an electrical energy supply unit and a control unit, a hand wheel for manual rotation of the inspection tool 21 , a drive bar for motorized tool rotation, and lifting points 32 for the releasable attachment of lifting means and / or fork lift pockets for facilitated transport.

[0032] Referring back to Fig. 1 , the inspection platform 20 is shown as being lifted onto an upper end 11 of a first riser pipe 10 of the vertically arranged riser pipes 10. By a support structure 22, the inspection platform 20 is supported on the upper end 11 of the first riser pipe 10. Although not necessarily the case, the support structure 22 may be a bottom plate of the inspection platform 20 as best illustrated in Fig. 4. Other embodiments may comprise a grid or other suitable mechanical abutment structures configured to support the inspection platform 20 on the upper end 11 of a riser pipe 10. The support structure 22 may comprise an inspection tool opening for enabling the inspection tool 21 to be lowered vertically through the support structure 22 into the riser pipe 10. According to other embodiments, the inspection tool 21 may be guided along the outer contour of the inspection platform 20 without the need to be guided through the support structure 22.

[0033] According to the embodiment depicted in Figs. 2 and 3, the inspection platform 20 further comprises an operator platform 40. The operator platform 40 may provide access to the inspection platform 20 and to the inspection tool 21 for a human operator 41 . Nevertheless, it is also possible to provide completely automatic inspection systems that do not require a human operator 41 to be present. Accordingly, other embodiments may use inspection platforms 20 without any operator platform 40. Nevertheless, by providing an operator platform 40, the inspection process may be beneficially operated, assisted or just monitored by the human operator 41 . For instance, the human operator 41 may rotate the inspection tool 21 by means of a manual hand wheel between inspection cycles. In addition, maintenance work on the launch unit 25 or on the inspection tool 21 may be facilitated by providing the operator platform 40. The operator platform 40 may be releasably attachable to the inspection platform 20. Furthermore, the operator platform 40 may be configured as a vertical operator platform 40 with a higher vertical than horizontal extension, as for instance depicted in Fig. 2, or it may be configured as a horizontal operator platform 40 with a higher horizontal than vertical extension, as for instance depicted in Fig. 12. The operator platform 40 may comprise a bottom plate and a frame to secure the operator 41 working on the operator platform 40. It may furthermore preferably comprise doors and a foldable ladder 42 for accessing the operator platform 40. According to some embodiments, the operator platform 40 may be entered from more than on side, e.g. as illustrated in 14.

[0034] With the inspection platform 20 depicted in Figs. 2 and 3, the following method steps of inspecting vertically arranged riser pipes 10 on a drilling rig may be performed:

[0035] - providing the inspection platform 20 with the inspection tool 21 ,

[0036] - lifting the inspection platform 20 onto an upper end 11 of a first riser pipe 10 of the vertically arranged riser pipes 10,

[0037] - supporting the inspection platform 20 on the upper end 11 of the first riser pipe 10 via a support structure 22 of the inspection platform 20,

[0038] - operating the inspection tool 21 whilst moving the inspection tool 21 in the first riser pipe 10.

[0039] By performing these method steps, a secure, time-efficient and accurate inspection of vertically arranged riser pipes 10 is achieved.

[0040] The inspection platform 20 may be moved between riser pipes 10 in order to apply the inspection method to a plurality of riser pipes 10. With regard to the described method, the step of operating the inspection tool 21 may thus be followed by: retrieving the inspection tool 21 from the first riser pipe 10, and lifting the inspection platform 20 off the first riser pipe 10 and lifting it onto the upper end 11 of a second riser pipe 10.

[0041] According to advantageous embodiments, the inspection platform 20 may be releasably attached to an overhead crane 30 as illustrated in Fig. 1 . The inspection platform 20 may comprise one or more lifting points 31 , 32 for attachment to the overhead crane 30. For instance, the inspection platform 20 may comprise at least one lifting point 31 for vertical lifting and e.g. three or four further lifting points 32 for horizontal lifting. By means of the overhead crane 30, the inspection platform 20 may be moved in a time-efficient manner between riser pipes 10. Preferably, the inspection platform 20 may be transported between riser pipes 10 via the overhead crane 30 in the vertical use orientation of the inspection platform 20. However, other embodiments may comprise moving the inspection platform 20 between riser pipes 10 in a rather horizontal transport orientation. During the method steps of supporting the inspection platform 20 and operating the inspection tool 21 it is preferred that the overhead crane 30 holds the inspection platform 20 to provide additional support and to ensure a high safety level for the operator 41 and ground staff on the drilling rig. According to some embodiments, the overhead crane 30 may be implemented as a gantry crane which provides high flexibility and mobility thus accelerating the inspection process. The gantry crane may traverse the riser pipe storage and may additionally be configured to move the riser pipes 10. Nevertheless, also other crane types as e.g. tower cranes or deck cranes may be utilized. Furthermore, initial placement of the inspection platform 20 on the drilling rig may be accomplished by means of a separate crane.

[0042] According to the embodiment illustrated in Figs. 2 and 3, the inspection platform 20 comprises a riser interface 23 projecting from the support structure 22. The riser interface 23 is configured to dock to the riser pipe 10, which may be accomplished by a pipe section as depicted which is configured to be inserted into the riser pipe 10. For instance, the pipe section of the riser interface 23 may have a smaller diameter than the riser pipe 10 to be inspected. Nevertheless, further embodiments may comprise a pipe section with a higher diameter than the riser pipe 10 to be inspected. Although it is advantageous if the inspection platform 20 comprises a riser interface 23 with a pipe section, other guiding structures for the alignment of the inspection platform 20 with the riser pipe 10 may be provided according to further embodiments. By providing a riser interface 23, accurate alignment of the inspection platform 20 and the inspection tool 21 with the inspection opening 14 is highly facilitated. Furthermore, the riser interface 23 may contribute to a stable support of the inspection platform 20 on the riser pipe 10. Thus, with regard to the suggested method steps for inspecting vertically arranged riser pipes 10, the method step of lifting the inspection platform 20 onto an upper end 11 of the riser pipe 10 may include docking the riser interface 23 to the first riser pipe 10. According to an advantageous embodiment, the riser interface 23 may comprise additional guiding means as e.g. guiding bars corresponding to a suitable guidance structure of the riser pipe 10 in order to facilitate precise and safe docking of the riser interface 23 to the riser pipe 10.

[0043] For further description of the transport of the inspection platform 20, reference is now made to Figs. 4 and 5 providing front and back views of the inspection platform 20 oriented in a horizontal transport orientation. The horizontal transport orientation may be beneficial for the transport of the inspection platform 20 to the drilling rig, e.g. by shipment. The horizontal transport may ensure secure and compact transport conditions with facilitated lifting e.g. by 4-point lifting. The horizontal transport orientation may also provide an advantageous storing orientation of the inspection platform 20 when it is not in use. As depicted, the inspection platform 20 may be releasably attached to a shipping skid 50 according to an advantageous embodiment. The shipping skid 50 may provide a stable support for the inspection platform 20 and facilitate handling of the inspection platform 20. For instance, the shipping skid 50 may comprise a frame structure with support legs for easy attachment of the inspection platform 20. Furthermore, the shipping skid 50 may provide a mounting base for mounting the several components of the inspection platform 20. In addition, maintenance may be facilitated by providing the inspection platform 20 in the horizontal transport orientation on the shipping skid 50. In the horizontal transport orientation, movable or foldable components as the ladder 42 and the doors of the operator platform 40 may be fixed to the inspection platform 20 in order to provide a compact transport unit. As illustrated in the exploded view of Fig. 6, the transport unit may comprise preassembled sub-units as the shipping skid 50, the launch unit 25, the winch unit 24, the operator platform 40 and the ladder 42. The sub-units may be mounted and fixed to each other on the shipping skid 50. Alternatively, they may be pre-assembled to form the inspection platform 20 and the shipping skid 50. For transport, the riser interface 23 may be protected by a suitable interface protector 33 as depicted in Fig. 7. The interface protector 33 may prevent damages on the riser interface 23 which protrudes from the launch unit 25 in an exposed manner. The interface protector 33 is to be removed before use of the inspection platform 20. According to embodiments, it may remain attached to the riser interface 23 during an uprighting step of the inspection platform 20 from the horizontal transport orientation to the vertical transport orientation.

[0044] According to a preferred embodiment, the inspection platform 20 is selectively orientable in the vertical use orientation and the horizontal transport orientation. The orientation of the inspection platform 20 may be changed by means of a lifting device, for instance by means of the crane 30.

[0045] Preferably, the aforementioned method step of providing an inspection platform 20 for the described inspection method comprises:

[0046] - transporting the inspection platform 20 oriented in a horizontal transport orientation on a shipping skid 50,

[0047] - uprighting the inspection platform 20 to a vertical use orientation, and

[0048] - detaching the inspection platform 20 from the shipping skid 50.

[0049] The uprighting step is now further described with reference to Figs. 8 to 11b. In Fig. 8, the inspection platform 20 is shown in the horizontal transport orientation, in which it is laid up on the shipping skid 50 and optionally secured to it by fastening elements. If so, the fastening elements should be released at the beginning of the uprighting process. Furthermore, a lifting means as a crane hook provided by the crane 30 may be connected to the vertical lifting point 31 , which may be provided close to the winch unit 24. As soon as the lifting means starts to lift the inspection platform 20, the inspection platform 20 begins to pivot around a given pivot point 34 as best illustrated in the detail view of Fig. 10b. The pivoting movement may be guided by pivot supports 51 provided by the shipping skid 50, as likewise best illustrated in Fig. 10b. In the order of Fig. 8, 9, 10a and 11 a the inspection platform 20 is increasingly pivoted from the horizontal transport orientation depicted in Fig. 8 to the vertical use orientation depicted in Fig. 11a. In this position, the inspection platform 20 may be detached from the shipping skid 50, e.g. via the crane 30, and lifted to a first riser pipe 10 in order to start the inspection process. Referring back to Fig. 1 , the riser pipe 10 to be inspected may comprise a main pipe section 12 and at least one auxiliary pipe section 13. The main pipe section 12 is commonly used to convey drilling fluid, while auxiliary pipe sections 13 may be used for circulating fluids between the drilling vessel and a blow-out preventer, for instance. The main pipe section 12 generally comprises a higher diameter compared to the diameter of auxiliary pipe sections 13. Furthermore, the main pipe section 12 is commonly arranged more centrally in the riser pipe 10, while the auxiliary pipe sections 13 may be arranged rather eccentrically.

[0050] According to an advantageous embodiment, the inspection tool 21 is configured for inspection of a main pipe section 12 of the riser pipe 10. For this, the inspection tool 21 may be designed with appropriate dimensions in order to move smoothly in the main pipe section 12 of the riser pipe 10 without tilting. Alternatively, the inspection tool 21 may be configured for inspection of an auxiliary pipe section 13 of the riser pipe 10. For this, the inspection tool 21 may be designed with different appropriate dimensions in order to move smoothly in the auxiliary pipe section 13 of the riser pipe 10 without tilting. Typically, as the main pipe section 12 will usually comprise a higher diameter, an inspection tool 21 configured for inspecting a main pipe section 12 will not be suitable for the inspection of auxiliary pipe sections 13. Furthermore, the inspection tools 21 configured for the inspection of the main pipe section 12 or of the auxiliary pipe section 13 may comprise different components, a different structure or they may be based on different inspection techniques. According to advantageous embodiments, the inspection tool 21 may be releasably attached to the launch unit 25 in order to be interchangeable with a different inspection tool 21 . In addition or alternatively, the inspection platform 20 may provide at least two different or equal inspection tools 21 arranged in the launch unit 25.

[0051] According to a further advantageous embodiment which is illustrated in the figures, there may be provided separate inspection platforms 20 each providing an inspection tool 21 either configured for the inspection of the main pipe section 12 or configured for the inspection of an auxiliary pipe section 13. Whereas Figs. 1 to 11 b and 15 depict an inspection platform 20 according to a first embodiment according to which the inspection tool 21 is configured for the inspection of a main pipe section 12, Figs. 12 to 14 and 16 illustrate an inspection platform 20 according to a second embodiment according to which the in comparison narrower inspection tools 21 are configured for the inspection of an auxiliary pipe section 13. As can be taken from the figures, the inspection platform 20 according to the second embodiment is also provided with smaller riser interfaces 23 compared to the riser interface 23 of the inspection platform 20 according to the first embodiment. By distributing the different inspection tools 21 to separate inspection platforms 20, the handling of the inspection platforms 20 on the drilling rig may be facilitated and the inspection platforms 20 may be perfectly tailored to the intended inspection procedures.

[0052] As illustrated in Figs. 12 and 13, the inspection platform 20 according to the second embodiment comprises two inspection tools 21 configured for the inspection of auxiliary pipe sections 13. The inspection tools 21 comprise different diameters and different riser interfaces 23 in order to enable inspection of different types of auxiliary pipe sections 13. The inspection tools 21 project through openings in the support structure 22 of the inspection platform 20 and may be easily inserted in auxiliary pipe sections 13 by means of the connected winch unit 24. The inspection tools 21 are arranged in a launch unit 25, which may comprise a protective frame. The inspection platform 20 further comprises an operator platform 40 with two opposite entry points for a more flexible entry direction as it may be needed in a common riser pipe storage.

[0053] Fig. 14 depicts the inspection platform 20 according to the second embodiment in a ready-for-inspection state, as it is lifted onto an upper end 11 of a riser pipe 10. The ladders 42 are unfolded and the operator platform 40 is illustrated as ready for entry by a human operator 41 . As shown, the inspection platform 20 is supported on the riser pipe 10 by means of the support structure 22 arranged on the upper end 11 of the riser pipe 10. Although not depicted, the inspection platform 20 may be further hold by the crane 30 in order to secure the inspection platform 20 on the riser pipe 10.

[0054] Figs. 15 and 16 show suitable horizontal lifting points 32 which enable horizontal crane transport of the inspection platforms 20 according to the first and second embodiment. Again, the inspection platforms 20 are releasably attached to shipping skids 50. As illustrated, the horizontal lifting points 32 may preferably be arranged at the launch unit 25 in order to take the platform’s approximate center of gravity into account. Whereas Fig. 15 illustrates an advantageous 4-point lifting arrangement, Fig. 16 depicts an also possible 3-point lifting arrangement. With the described inspection method and the associated inspection platform 20 allowing for the inspection of vertically arranged riser pipes 10, the inspection may be highly facilitated, accelerated and performed at lower cost.

[0055] The invention is not limited by the embodiments described above; reference should be had to the appended claims.

Claims

CLAIMS1 . A method of inspecting vertically arranged riser pipes (10) on a drilling rig, the method comprising: providing an inspection platform (20) having an inspection tool (21), lifting the inspection platform (20) onto an upper end (11) of a riser pipe (10) of the vertically arranged riser pipes (10), supporting the inspection platform (20) on the upper end (11) of the riser pipe (10) via a support structure (22) of the inspection platform (20), and operating the inspection tool (21) whilst moving the inspection tool (21 ) in the riser pipe (10).

2. The method according to claim 1 , wherein the method comprises releasably attaching the inspection platform (20) to an overhead crane (30) to secure the inspection platform (20) during inspection of a riser pipe (10) and to move the inspection platform (20) between riser pipes (10).

3. The method according to claim 1 or 2, wherein the inspection platform (20) comprises a riser interface (23) projecting from the support structure (22) and configured to dock to the riser pipe (10), and the method step of lifting the inspection platform (20) onto an upper end (11 ) of the riser pipe (10) includes docking the riser interface (23) to the riser pipe (10).

4. The method according to any preceding claim, wherein the inspection tool (21 ) is configured for the inspection of a main pipe section (12) or of an auxiliary pipe section (13) of the riser pipe (10), and the method step of operating the inspection tool (21) comprises moving the inspection tool (21 ) in the main pipe section (12) or in the auxiliary pipe section (13) of the riser pipe (10).

5. The method according to any preceding claim, wherein the method step of operating the inspection tool (21) comprises moving the inspection tool (21 ) by means of a winch (24).

6. The method according to any preceding claim, wherein the inspection platform (20) comprises an operator platform (40) configured to be enteredby a human operator (41), and the method step of operating the inspection tool (21) comprises operating the inspection tool (21) by a human operator (41 ) present on the operator platform (40).

7. The method according to any preceding claim, wherein the inspection platform (20) is selectively orientable in a vertical use orientation and a horizontal transport orientation, and the method step of providing an inspection platform (20) comprises- transporting the inspection platform (20) oriented in a horizontal transport orientation on a shipping skid (50),- uprighting the inspection platform (20) to a vertical use orientation, and- detaching the inspection platform (20) from the shipping skid (50).

8. The method according to any preceding claim, wherein the riser pipe (10) is a first riser pipe (10) and the step of operating the inspection tool (21 ) is followed by the steps of- retrieving the inspection tool (21 ) from the first riser pipe (10), and- lifting the inspection platform (20) off the first riser pipe (10) and lifting it onto the upper end (11 ) of a second riser pipe (10).

9. An inspection platform (20) for inspecting vertically arranged riser pipes (10) on a drilling rig, comprising an inspection tool (21) and a support structure (22) configured to be arranged on the upper end (11) of a riser pipe (10), wherein the inspection platform (20) further comprises a riser interface (23) projecting from the support structure (22) and being configured to dock to the riser pipe (10).

10. The inspection platform according to claim 9, wherein the inspection platform (20) further comprises an operator platform (40) configured to be entered by a human operator (41).11 . The inspection platform according to claim 9 or 10, wherein the inspection tool (21) is configured for inspection of a main pipe section (12) or of an auxiliary pipe section (13) of the riser pipe (10).

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