NO20240565A1

NO20240565A1 - Riser connection system access tool assembly

Info

Publication number: NO20240565A1
Application number: NO20240565A
Authority: NO
Inventors: Roger Bugge Olsen; Ståle Karlsen; Geir Finnøy; Steinar Heggset; Arnstein Grønås; Kjetil Sundan Grønli
Original assignee: Oceantech Innovation As
Priority date: 2024-05-31
Filing date: 2024-05-31
Publication date: 2025-06-30
Also published as: NO348872B1

Description

Riser connection system access tool assembly

The disclosed embodiments relate to a riser connection system access tool assembly.

The disclosed embodiments especially relate to a riser connection system access tool assembly for maintenance and inspection of a riser connection system on a Floating Production Storage and Offloading Vessel (FPSO) or Floating Storage and Offloading Vessel (FSO).

Background

In the oil and gas exploration and production industry it is common to use Floating Production Storage and Offloading Vessels (FPSO) and Floating Storage and Offloading Vessels (FSO). FPSOs are typically moored at an offshore location and coupled to at least one producing wells, for the temporary storage of produced well fluids, before being transported to shore by tankers. It is common that such FPSOs are connected to a number of producing wells.

An FPSO, in addition to being a storage, may also include facilities for separating received well fluids into different constituents (oil, gas and water) to stabilize the crude oil for later transport by tanker.

FSOs are similarly moored and allow for the storage of received well fluids. In contrast to the FPSO, the FSO may disconnect from its moorings to travel to an offloading location, or the stored fluids may be transferred to a tanker for further transport. Further, the FSOs do not have the facility for separating the well fluids into different constituents as the FPSOs.

For connection directly or indirectly via nodes/buoys to the mentioned wells for receiving the well fluids, different solutions have been used, wherein the FPSOs and FSOs are provided with a riser connection system for direct or indirect connection to the wells, as shown in Fig.1a-c.

The riser connection systems of the FPSOs and FSOs are daily exposed to harsh weather conditions. Due to the harsh weather conditions, the need for inspection and maintenance work on the riser connection systems of the FPSOs and FSOs is a constantly proceeding task.

Over the years, there have been proposed different solutions to avoid the use of divers and ROVs to perform inspections and operations in the splash-zone, such as e.g. NO 346938 B2 (in the name of the applicant), WO2016133402 A1 (in the name of the applicant), NO332220 B1 and NO20130829. Common for the prior art solutions is that they are configured for arrangement to structures of the offshore installation by an attachment device and wherein a tool module is arranged movable along a framework or fundament thereof. The tool module is configured for maintenance and inspection of structures located at difficult available places by comprising a remote arm that can be provided with different work tools, camera etc. enabling the maintenance and inspection.

The prior art solutions are however not suitable/designed to be used on FPSOs and FSOs, due to their use of clamps or similar devices for attachment to the structures. For vessel sides there are no such structures available to clamp onto. Further, due to the requirement for framework or fundament to enable movement of the tool module, the solutions are not usable for FPSOs and FSOs, as there is not space for the framework or fundament in connection with the riser connection system.

Further, they have considerable weight, weight that should not/cannot be added to the riser connection system nor the vessel side.

It is accordingly a need for a riser connection system access tool assembly suitable for arrangement to a riser connection system of FPSOs or FSOs.

It is further a need for a riser connection system access tool assembly that is easier to assemble and disassemble than the prior art solutions, as well as can be deployed and retrieved in a simple and safe manner.

Summary

The disclosed embodiments provide a riser connection access tool assembly partly or entirely solving the above-mentioned disadvantages of prior art.

Provided herein is a riser connection access tool assembly for a riser connection system on a Floating Production Storage and Offloading Vessel or Floating Storage and Offloading Vessel.

Also provided herein is a riser connection access tool assembly enabling maintenance and inspection of the riser connection system.

Provided herein is a riser connection system access tool assembly enabling maintenance and inspection of interconnected risers and external risers connected to a riser connection system.

Also provided herein is a riser connection system access tool assembly enabling maintenance and inspection of connection of external risers to interconnecting risers of the riser connection system.

Provided herein is a riser connection system access tool assembly where one does not need support vessels for performing maintenance and inspection of the riser connection system.

Also provided herein is a riser connection system access tool assembly that is adaptable for work at the different FPSOs or FSOs by that it includes modules or assemblies that are configurable according to the FPSO or FSO vessel in question.

Provided herein is a riser connection system access tool assembly making use of interconnecting risers of the riser connection system for detachable attachment to and controlled movement along.

Also provided herein is a riser connection system access tool assembly providing increased operational stability compared to prior art solutions.

Provided herein is a riser connection system access tool assembly that can be deployed and retrieved rapidly and in a safe manner.

Further features will appear by consideration of the following description, claims and attached drawings.

The invention

A riser connection system access tool assembly for maintenance and inspection of a riser connection system is defined by the technical features of claim 1. Preferable features of the riser connection system access tool assembly are described in the dependent claims.

The present invention is related to a riser connection system access tool assembly (RCSATA) for maintenance and inspection of a riser connection system on a Floating Production Storage and Offloading Vessel or Floating Storage and Offloading Vessel.

The RCSATA according to the present invention comprises a guiding assembly and tool module.

In accordance with the present invention, the guiding assembly is configured for detachable engagement with at least one interconnecting riser of the riser connection system and movement in axial direction thereof, and configured for movement of the tool module in axial direction of the guiding assembly.

According to one embodiment of the RCSATA according to the present invention, the guiding assembly is formed by a tool guide assembly and a riser guide assembly.

In accordance with one embodiment of the RCSATA according to the present invention, the tool guide assembly comprises a guide rail or member or a pair of parallel guide rails or members extending in axial direction of the tool guide assembly.

According to one embodiment of the RCSATA according to the present invention, the riser guide assembly comprises at least one riser guide member arranged in a parallel plane of the guide rail(s) or member(s) by a support structure.

In accordance with one embodiment of the RCSATA according to the present invention, the tool guide assembly is movably arranged to riser guide assembly via a connection interface enabling movement of the tool guide assembly in axial direction of the guiding assembly.

According to one embodiment of the RCSATA according to the present invention, the tool module assembly is provided with a connection interface enabling movement of the tool module in the axial direction of the tool guide assembly.

In accordance with one embodiment of the RCSATA according to the present invention, the guiding assembly further comprises a tool module carrier movably arranged in the axial direction of the tool guide assembly, to which tool module carrier the tool module is arranged, enabling movement of the tool module in axial direction of the tool guide assembly.

According to one embodiment of the RCSATA according to the present invention, the tool module comprises an elongated housing provided with a connection interface at rear side thereof configured for arrangement of the tool module to the tool module carrier or guide rail or member of the tool guide assembly.

In accordance with one embodiment of the RCSATA according to the present invention, the guiding assembly further comprises a landing assembly configured for detachable engagement with the riser connection system and further configured to position the guiding assembly in vicinity of interconnecting risers of the riser connection system.

According to one embodiment of the RCSATA according to the present invention, the guiding assembly is configured for detachable engagement with the landing assembly and movement in axial direction thereof.

In accordance with one embodiment of the RCSATA according to the present invention, the landing assembly comprises an attachment assembly configured for engagement with a platform structure of the riser connection system.

According to one embodiment of the RCSATA according to the present invention, the landing assembly further comprises a guiding assembly connection interface movably arranged to the attachment assembly, between an extended position and collapsed position.

In accordance with one embodiment of the RCSATA according to the present invention, the guiding assembly connection interface is arranged to the attachment assembly by means of hinged connection members.

According to one embodiment of the RCSATA according to the present invention, the landing assembly and guiding assembly are provided with locking means for detachable locking of the two to each other.

In accordance with one embodiment of the RCSATA according to the present invention, the connection interface of the tool module is provided with locking means for detachable locking of the tool module to the tool guide assembly, preventing axial movement of the tool module along the guiding assembly.

According to one embodiment of the RCSATA according to the present invention, the tool module carrier is provided with at least one locking mechanism for detachable locking of the tool module carrier to the guiding assembly, preventing axial movement of the tool module carrier and tool module along the guiding assembly.

In accordance with one embodiment of the RCSATA according to the present invention, the riser guide member is formed by at least two parts enabling the riser guide member to be opened to receive and accommodate the interconnecting riser and closed to enclose the interconnecting riser.

According to one embodiment of the RCSATA according to the present invention, the RCSATA further comprises a scraper assembly configured to accommodate and enclose an external riser, wherein the scraper assembly comprises a scraper blade or disc in engagement with exterior surface of the external riser for cleaning thereof by movement of the scraper assembly in axial direction of the external riser.

In accordance with one embodiment of the RCSATA according to the present invention, the scraper assembly comprises a housing formed by multiple house members configured to be assembled in circumferential direction to accommodate and enclose the external riser in circumferential direction thereof.

According to one embodiment of the RCSATA according to the present invention, the house parts are hinged to each other at one side thereof, enabling the housing to be opened for receiving the external riser and closed for enclosing and engagement with the external riser.

In accordance with one embodiment of the RCSATA according to the present invention, the scraper assembly comprises rigid connection means arranged to the housing enabling operation of the scraper assembly along the external riser by the tool module or a hoisting device or another manipulator system.

According to one embodiment of the RCSATA according to the present invention, the RCSATA further comprises at least one hoisting device configured for operating the riser RCSATA into and out of engagement with the at least one interconnecting riser, controlling the movement of the riser connection system access tool assembly in axial direction of the at least one interconnecting riser, as well controlling movement of the tool guide assembly or tool module carrier in axial direction of the guide assembly.

In accordance with one embodiment of the RCSATA according to the present invention, the at least one hoisting device is further configured for controlling movement of the tool module in axial direction of the tool guide assembly.

In accordance with one embodiment of the tool module according to the present invention, the tool module is provided with a remote arm, to which a desired tool assembly can be arranged.

By the present invention is achieved a RCSATA that is adaptable to the platform structure/vessel in question for enabling arrangement of the RCSATA to the riser connection system.

Due to the guiding assembly is configured to move along the interconnecting risers of the riser connection system, the RCSTA is transported along the vessel side in a controlled and safe manner, as well as this removes the need for using a guiding assembly extending all the way along the vessel side.

When the guiding assembly, after having been moved along the interconnecting risers, is in position at the connection of the external risers, the tool module can be moved in axial direction thereof enabling an operation range in axial direction for the tool module in the splash-zone, as well as the connection area of the external risers that usually is below the water line.

Accordingly, the RCSATA according to the present invention provides a secure and movable arrangement of the tool module with considerably lower weight and smaller parts than would have been the case with the prior art solutions.

The tool module according to the present invention is provided with connection points at upper side thereof for connection to at least one hoisting device for elevating the tool module in longitudinal direction of the guiding assembly, while the present invention according to one embodiment use gravity for lowering the tool module in longitudinal direction of the guiding assembly.

The tool module or tool module carrier will preferably be provided with at least one locking mechanism to precisely secure the tool module and/or tool module carrier at a desired position in longitudinal direction of the guiding assembly where tasks are to be performed by the tool module.

The RCSATA is connected to a control central being arranged on the vessel, typically on deck, where personnel can perform the necessary tasks without danger and without considering the weather by remotely controlling the RCSATA

The installation of the RCSATA can be based on, e.g., advanced rigging and rope techniques (access technique), portable hoisting systems or other types of portable equipment for attaching the RCSATA to a platform structure of the riser connection system. This means that the arrangement of the RCSATA is not dependent of permanent hoisting equipment on the vessel, but if such are available, they can of course be used. This provides a unique flexibility, which provides the RCSATA with the opportunity to be operated independent of other equipment being present on the vessel. This also enables the RCSATA to be used without occupying equipment that could be used for other operations.

Further preferable features and advantageous details of the present invention will appear from the following example description, claims and attached drawings.

Example

The present invention will below be described in further detail with references to the attached drawings, where:

Fig.1a-b are principle drawings of first and second embodiments of a riser connection access tool assembly according to the present invention, arranged to a riser connection system, known per se of a FPSO or FSO vessel,

Fig.1c is a principle drawing showing details of a hoisting device of the riser connection systems in Fig.1a-b,

Fig.2a-b are principle drawings of a riser connection system access tool according to the first embodiment of Fig.1a,

Fig.3a-e are principle drawings of a riser connection access tool assembly according to the second embodiment of the riser connection system access tool of Fig.1b,

Fig.4 is a principle drawing of a locking mechanism according to the present invention,

Fig.5a-b are principle drawings of a tool module according to the first and second embodiments of the riser connection access tool assembly of Fig.1a-b, respectively,

Fig.6a-c are principle drawings of a scraper assembly according to the present invention, and

Fig.7a-b are principle drawings of the tool module according to the first and second embodiment of the riser connection access tool assembly of Fig.1a-b, respectively, positioned in a working area of the riser connection system.

Reference is now made to Fig.1a-b showing principle drawings of first and second embodiments of a riser connection system access tool assembly (RCSATA) 100 according to the present invention, arranged to a riser connection system 500 of a Floating Production Storage and Offloading (FPSO) 600 or Floating Storage and Offloading (FSO) vessel.

Fig.1a-b show examples of a riser connection system 500, known per se, arranged to a side 610 of a FPSO vessel 600. The riser connection system 500 typically comprises a platform 510 arranged at upper part of the vessel side 610 (hull) and a riser connection assembly 520 arranged at a lower part of the vessel side 610, as well as at least one interconnecting riser 530 extending between the platform 510 and riser connection assembly 520.

The riser connection assembly 520 typically comprises a vessel side attachment member 521 attaching the riser connection assembly 520 temporary or permanently to the vessel side 610. The riser connection assembly 520 further comprises connections 522 for connecting external risers 501 from producing wells or other storages to the lower inlet end of the interconnecting risers 530. Accordingly, the riser connection assembly 520 is onboarding the external risers 501 to the vessel side 610.

The platform 510 is provided with connections 511 for connecting the upper outlet ends of the interconnecting risers 530 with interconnecting pipes or manifolds (not shown) of the vessel 600 for further processing.

Accordingly, the interconnecting risers 530 are extending vertically along the vessel side 610 between the fixed platform 510 and fixed riser connection assembly 520.

The vessel 600 will further typically be provided with at least one hoisting device 620, known per se, such as, but not limited to, winch, crane, air hoist, or other hoisting mechanisms, used for retrieving the external risers 501 and connecting them to the riser connection assembly 520, as well as other hoisting operations. The at least one hoisting device 620 may further be arranged movable in axial direction of the platform 510 by rails 621 via a carriage 622, as shown in Fig.1c.

According to one embodiment of the present invention, the least one hoisting device 620 of the vessel 600 or at least one dedicated hoisting device will be used for mounting and dismounting of the RCSATA 100 to the riser connection system 500, as well as operation of the RCSATA 100, further described below.

Reference is now in addition to Fig. 1a-b also made to Fig. 2a-b and 3a-e, respectively, showing principle drawings of different features and components of the RCSATA 100 embodiments according to the present invention. The RCSATA 100 according to the present invention comprises a guiding assembly 200 and a tool module 300.

The guiding assembly 200 according to the present invention is formed by a tool guide assembly 210 and a riser guide assembly 220.

In the first embodiment of the RCSATA 100 according to the present invention, further shown in detail in Fig.2a-b, the tool guide assembly 210 comprises an axially extending guide rail or member 211, configured for arrangement to the tool module 300 in a sliding manner, further described below. The axially extending guide rail or member 211 has in the shown embodiment a rectangular or quadratic cross-sectional shape. However, it may also have other shapes, such as tubular, elliptic, quadratic or polygonal.

In the second embodiment of the RCSATA 100 according to the present invention, further shown in detail in Fig.3a-d, the tool guide assembly 210 comprises a pair of axially extending parallel guide rails or members 211, spaced apart in transversal direction of the guiding assembly 200 and extending in parallel in axial direction of the tool guide assembly 210. The tool guide assembly 210 further comprises one or more support members 212 extending transversally or diagonally between the guide rails or members 211, wherein at least one such support member 212 is arranged at lower end of the guide rails or members 211. The tool guide assembly 210 may further be provided with reinforcing members or structures 213 extending in longitudinal direction of the mentioned guide rails or members 211. Especially at the lower end of the tool guide assembly 210 it may be favorable to have such reinforcing structures. In accordance with a further embodiment of the tool guide assembly 210, it is further provided with locking means 240 configured for securing the tool guide assembly 210 to the riser connection assembly 520, to maintain the tool guide assembly 210 in position at the riser connection assembly 520, further described below. The mentioned locking means 240 may be electrically or hydraulically operated and remotely controllable from topside or via the tool module 300.

According to one embodiment of the RCSATA 100 according to the present invention, the tool guide assembly 210 at lower end thereof, i.e. at lower end of the guide rail(s) or member(s) 211 comprises a mechanical end stop (not shown) to prevent the tool module 300 or tool module carrier 230, further described below, from leaving/moving beyond the tool guide assembly 210 at lower end.

In accordance with one embodiment of the RCSATA 100 according to the present invention, the tool guide assembly 210 at upper end thereof is provided with a mechanical end stop (not shown) preventing the tool guide assembly 210 from being lowered/moved too far down and out of the riser guide assembly 220.

According to a further embodiment of the RCSATA 100 according to the present invention, the mentioned guide rail(s) or member(s) 211 is/are telescopic enabling extension and retraction of the axial length thereof. In an alternative embodiment the guide rail(s) or member(s) 211 are formed by modules that can be assembled to a desired length.

The riser guide assembly 220 is according to the present invention comprises at least one riser guide member 221 arranged to the tool guide assembly 210 by means of a support structure 222, wherein the support structure 222 is configured to position the at least one riser guide member 221 at a distance from the tool guide assembly 210, in a parallel plane with the guide rail(s) or member(s) 211. The at least one riser guide member 221 is arranged at a rear side thereof, i.e. at the opposite side of where the tool module 300 is to be arranged, further described below. In addition to positioning the at least one riser guide member 221 in vicinity of the interconnecting risers 530, the support structure 222 of the riser guide assembly 220 ensures that the tool guide assembly 210 goes clear of riser connection system 520 and allows the tool module 300 to operate both above and below this area.

In the first embodiment of the RCSTATA 100, as shown in further detail in Fig. 2a-b, the support structure 222 comprises an elongated hollow structure member 223 configured to receive and accommodate the guide rail or member 211 of the tool guide assembly 210, enabling a sliding connection interface between the tool guide assembly 210 and riser guide assembly 220. The support structure 222 further comprises first (lower) 224a and second (upper) 224b structure members extending/protruding perpendicularly from rear side of hollow structure member 223 with a first (proximal) end, the first 224a and second 224b structure member being spaced apart in axial direction of the elongated hollow structure member 223, i.e. space part in the vertical plane. At the second (distal) end of the first 224a and second 224b structure members the riser guide member 221 is arranged, extending in a parallel plane of the elongated hollow structure member 223 and connecting the mentioned first 224a and second 224b structure members. In this manner the riser guide member 221 is positioned a distance from the tool guide assembly 210.

According to a further embodiment of the RCSATA 100, the riser guide assembly 220 further comprises a riser connection guiding member 260 configured to be received in a conically shaped upper part 523 of the connections 522 of the riser connection system 500, which riser connection guiding member 260 being positioned below the riser guide member 221, seen in the vertical plane. The riser connection guide member 260 is, e.g., formed by at least one engaging member 261 arranged at lower end of a support structure 262 extending downwards from the elongated hollow structure member 223 and first (lower) structure member 224a. The support structure 262 is, e.g., formed by a number of stays 263 extending from the mentioned structure members 223-224a. The at least one engaging member 261 is arranged in an angle in relation to the vertical plane corresponding to the angle of the conically shaped upper part 523 for accommodation therein. The riser connection guiding member 260 will thus contribute in guiding the RCSATA 100 in place when arriving at the riser connection assembly 520, as shown in Fig.7a.

In accordance with a further embodiment of the RCSATA 100 according to the present invention, the riser guiding assembly 220 further comprises engaging leg members 270a-b positioned in a plane below the riser engaging member 221. The engaging leg members 270a-b are laterally reversed about a central axial axis of the riser engaging member 221, with a distance therefrom. The engaging leg members 270a-b are, e.g., formed by at least one engaging member 271 arranged at lower end of a support structure 272 extending downwards and outwards from the elongated hollow structure member 223 and first (lower) structure member 224a. The support structure 271 is, e.g., formed by a number of stays 273 extending from the mentioned structure members 223-224a. The at least one engaging member 271 is arranged in an angle in relation to the vertical plane to provide a contact surface against the vessel side attachment member 521/the riser connection assembly 520. The engaging leg members 270a-b will be in contact with the vessel side attachment member 521/the riser connection assembly 520 and prevent rotation of the guide assembly 200 and RCSATA 100 providing as stable and secure platform for the tool module 300 to operate from, as shown in Fig.5a. The engaging members 271 in an alternative embodiment is connected to the lower end of the support structure 272 by a hinged connection (not shown).

In accordance with a further embodiment of the guide assembly 200, the engaging leg members 270a-b and/or riser connection guiding member 260 is/are provided with a locking mechanism (not shown) for detachable fixation to the vessel side attachment member 521/the riser connection assembly 520 for enhanced fixation. The mentioned locking mechanism may be a hydraulically or electrically operated locking mechanism.

The support structures 262, 272 may be provided with one or more cross/diagonally extending stays for reinforcing the support structure 262, 272.

In the second embodiment of the RCSATA 100, as shown in further detail in Fig.3d, the riser guide assembly 220 is fixed to the tool guide assembly 210 via the support structure 222. In this embodiment the riser guide assembly 220 is positioned a distance below the upper end of the guide rails or members 211. In accordance with the second embodiment, the support structure 222 it is formed by first (lower) 224a and second (upper) 224b structure members extending perpendicularly from rear side of each of the respective guide rails or members 211, and spaced apart in axial direction of the guide rails or members 211 with the first structure members 224a arranged at a lower position than second structure members 224b, the seen from the upper end of the guide rails or members 211. The second (upper) structure members 224b further have a larger axial extension than the first structure members 224a and thus protrude farther from the guide rails or members 211 that the first structure members 224b. The support structure 222 further comprises third structure members 225 extending between the first 224a and second 224b structure members, from the distal end of the first structure members 224a and in parallel plane with the respective guide rail or member 211, such that the second structure members 224b have an extension beyond the third structure members 225. At the distal ends of the second structure members 224b is arranged a fourth structure member 226 extending in transversal direction of the riser guide assembly 220, tool guide assembly 210 and guiding assembly 200 forming attachment points for the riser guide member(s) 221, wherein the fourth structure member 226 connects the distal ends of the second structure members 224b.

The riser guide assembly 220 according to the second embodiment of the RCSATA 100 comprises at least one riser guide member 221 arranged to the support structure 222 via a fifth structure member 227 extending perpendicularly from the fourth structure member 226. In an embodiment with only one riser guide member 221, the riser guide member 221 will be positioned centered in transversal direction of the riser guide assembly 220. In the shown embodiment with two riser guide members 221, the fourth structure member 226 will have an axial extension that is adapted the distance between two adjoining interconnecting risers 530 to position a respective riser guide member 221 in vicinity of the respective interconnecting riser 530 for engagement therewith.

In accordance with one embodiment of the riser guide member 221 according to the present invention it is formed by first and second sleeve members 228a-b hinged to each other, enabling opening thereof to receive and closing thereof to enclose and accommodate the respective interconnecting riser 530 and enabling sliding movement thereon. The riser guide member 221 further comprises locking means (not shown) for securing/fixation of the sleeve members 228a-b to each other after enclosing and engaging the interconnecting riser 530. Alternatively, at least one of the mentioned sleeve members 228a-b are associated with a controllable actuator (not shown) enabling controlled opening and closing thereof.

In accordance with the second embodiment of the RCSATA 100, the riser guide member 221 at lower end thereof is provided with a conical exterior shape adapted for being received in a conically shaped upper part 523 of the connections 522 of the riser connection system 500, having a similar function as the riser connection guide member 260 discussed above.

In accordance with a further embodiment of the riser guide member 221, the sleeve members 228ab are provided with interior bushing parts 229 that are configured to form engaging and sliding surface against the interconnecting risers 530.

The second embodiment of the RCSATA 100 according to the present invention, as shown Fig.3a-c, further comprises a landing assembly 400.

An embodiment of the landing assembly 400 according to the present invention is shown in more detail in Fig.3c. The landing assembly 400 according to one embodiment of the present invention is formed by an attachment assembly 410 and a guiding assembly connection interface 420.

The attachment assembly 410 is formed by first frame members 411, spaced apart in transversal direction of the attachment assembly 410/landing assembly 400 and parallel to each other, and engaging members 412 protruding from an upper part of the first frame members 411, the engaging members 412 being configured for engagement with the riser connection system 500.

In the shown embodiment, the engaging (L-shaped) members 412 are configured (adapted) for engagement with a platform structure 512 of the platform 510. In the shown example, the engaging members 412 and the first frame members 411 form a U-shape or claw configured to receive and accommodate a flange or similar vertically extending platform structure 512, i.e. configured to be hung on the platform structure 512. The engaging members 412 may also be provided with securing/locking means (not shown) for fixation of the attachment assembly 210/landing assembly 400 to the platform 510.

The guiding assembly connection interface 420 is according to one embodiment formed by first frame members 421, extending in axial direction of and the landing assembly 400. The first frame members 421 are spaced apart in transversal direction of the landing assembly 400 and parallel to each other, and further arranged to each other by at least one second frame member 422 extending in transversal direction of the guiding assembly connection interface 420. The mentioned axially extending frame members 421 are spaced apart with a similar distance as the first frame members 411 of the attachment assembly 410, and thus aligned with the respective first frame member 411. The guiding assembly connection interface 420 is movably arranged to the attachment assembly 410 by that the respective first frame members 411, 421 are connected by means of hinged connection members 430 at facing sides thereof, arranged at the upper and lower ends of the respective first frame members 411, 421.

By the hinged connection members 430 the guiding assembly connection interface 420 is movable from an extended position, for attachment of the attachment assembly 410 to the platform 510/platform structure 512, and a collapsed position, wherein the guiding assembly connection interface 420 is displaced downwards and towards the attachment assembly 410, for positioning the guiding assembly 200/guiding assembly connection interface 420 in vicinity of the interconnecting risers 530, further described below.

For making the guiding assembly connection inference 420 stronger, additional second frame members 422 may be arranged extending transversally or diagonally between the first frame members 411.

The first frame members 411 of the attachment assembly 410 may also be connected by transversally or diagonally extending support members (not shown) for strengthening the attachment assembly 410.

The first frame members 421 of the guiding assembly connection interface 420 are further at the side facing away from the attachment assembly 410 provided with respective axially extending tracks 423 configured to receive the respective guide rails or members 211 of the guide assembly 200, further described below, enabling sliding movement of the guide assembly 200 in relation to the landing assembly 400, as well as detachable arrangement thereto.

The respective axially extending track 423 may further be provided with locking means (not shown) for securing the guide assembly 200 to the landing assembly 400 and/or the guide assembly 200 is provided with locking means 250 for securing the guide assembly 200 to the landing assembly 400, further described below. An example of a suitable lock mechanism 250 that can be integrated in the mentioned tracks 423 is shown in Fig.4 and further described below.

The length of the hinged connection members 430 will be adapted to enable the guide assembly 200 to slide past the platform 510/platform structure 512, with the landing assembly 400 in extended position, and at the same time enable positioning of the guide assembly 200 in vicinity of the interconnecting risers 530, further described below.

The guide assembly 200 in the embodiment of Fig. 1b and 3a-e further comprises a tool module carrier 230 formed by axially extending carrier structure members 231 spaced apart in transversal direction of the guide assembly 200, arranged in parallel and aligned with respective guide rail or member 211. The tool module carrier 230 further comprises transversally extending carrier structure members 232 extending in transversal direction of the tool module carrier 230 and connecting the axially extending carrier structure members 231 at upper and lower end thereof to form a rigid elongated (rectangular) frame for the tool module carrier 230 to be mounted to. The tool module carrier 230 may further comprise additional support structure members (not shown) extending transversally or diagonally between the axially extending carrier structure members 231 and/or transversally extending carrier structure members 232.

The axially extending carrier structure members 231 are at the respective rear side provided with guide tracks 233 configured to receive and accommodate the respective guide rails or members 211 for sliding movement thereon.

The tool module 300 is provided with a connection interface 311, further described below, at rear side thereof for fastening of the tool module 300 to the tool module carrier 230 via the transversally extending structure members 232.

Reference is now made to Fig.4 showing a principle drawing of a lock mechanism 250 suitable for use in different applications/positions in the present invention. In accordance with one embodiment of the RCSATA 100 according to the present invention, the tool module carrier 230 further comprises lock mechanisms 250 (Fig. 4) for locking the tool module carrier 230 and the tool module 300 arranged thereto to the guiding assembly 200.

In accordance with the second embodiment of the RCSATA 100 as shown in Fig. 1b and 3a-d, the lock mechanism 250 is integrated in the bottom of the tracks 233 arranging the tool module carrier 230 to the guide rails or members 211.

In the first embodiment of the RCSATA 100, as shown in Fig. 1a and 2a-b, the mentioned lock mechanisms 250 may integrated in the elongated hollow structure member 223 providing the possibility to lock the tool guide assembly 210 to the riser guide assembly 220. The mentioned lock mechanism 250 may also be integrated in the tool module 300 for locking the position of the tool module 300 in relation to the tool guide assembly 210, further described below.

In accordance with one embodiment of the RCSATA 100 according to the present invention, the lock mechanism 250, as shown in Fig. 4, comprises at least one movable lock member 251 and an actuator 252 enabling the movable lock member 251 to move between a locking position, wherein the lock member 251 is in engagement with the guide rail or member 211 of the tool guide assembly 210, and a releasing position, wherein the lock member 251 is retracted from engagement with the guide rail or member 211 of the tool guide assembly 210.

In the locking position, the tool module carrier 230 and/or tool module 300 is secured to the guiding assembly 200/tool guide assembly 210 and in a stable position resulting in that the wear and tear will be reduced which again is resulting in that the operating time of the RCSATA 100 will be longer.

In addition to the mentioned lock mechanisms 250, the tool carrier module 230 may be provided with one or more guide pads (not shown) in axial direction of the mentioned tracks 233 to pick up loads and slack, as well as reduce friction forces between the tool module carrier 230 and the tool guide assembly 210 and prevent jamming.

Similarly, the elongated hollow structure member 223 may be provided with one or more guide pads (not shown) pick up loads and slack, as well as reduce friction forces between the tool guide assembly 210/guide rail or member 211 and riser guide assembly 220 and prevent jamming.

Reference is also made to Fig. 5a-b showing principle drawings of different embodiments of a suitable tool module 300 for integration in the present invention. In accordance with the first embodiment, as shown in Fig. 1a and 5a, the tool module 300 is configured for being arranged directly to the tool guide assembly 210 and configured to be movable in axial direction thereof. In accordance with the second embodiment, as shown in Fig. 1b and 5b, the tool module 300 is arranged to the tool guide assembly 210 via the tool module carrier 230 that is configured to be movable in axial direction thereof.

The tool module 300 according to the present invention comprises an elongated housing 310, in the example mainly rectangular, which at its rear end, which is to face the tool guide assembly 210, is provided with a connection interface 311 for arrangement to the guide rail or member 211 or tool module carrier 230, respectively. In the first embodiment the connection interface 311, e.g., is formed by at least one clamp 311a-b comprising fixed or movable arms. When using only one clamp 311a-b, the clamp 311a-b will be centered at the rear side of the tool module 300. In the shown embodiment of Fig.1a and 5a, the tool module 300 is provided with upper 311a and lower 311b clamps arranging the tool module 300 to the tool guide assembly 210. If the clamps 311a-b are formed by fixed arms, the tool module 300 is arranged to the tool guide assembly 210 from one of the ends thereof. The mentioned movable arms of the mentioned clamps 311a-b are e.g. controllable by hydraulic or electric operation.

In accordance with a further embodiment of the tool module 300, one or more of the arms of the at least one clamp 311a-b have a lock mechanism 250 integrated, or the tool module 300 is at a rear side facing the tool guide assembly 210 provided with at least one lock mechanism 250, enabling locking of the tool module 300 in a desired position in axial direction of the tool guide assembly 210 by engagement with the guide rail or member 211. A non-limiting example of a suitable lock mechanism 250 is shown in Fig.4. There may be arranged numerous such lock mechanisms 250. In addition, the lock member 251 may be shaped for improved friction force with the guide rail or member 211.

In the embodiment of Fig.1b and 5b, the connection interface 311, e.g., is formed by one or more attachment adapters, mountings, fittings or plates, configured for attachment to the transversally extending carrier structure members 232 via suitable fixation means.

The elongated housing 310 is further at upper side provided with an attachment device 320 provided with at least one lifting point 321 providing a connection point for arrangement to the mentioned at least one hoisting device 620 via wire, cable or chain (not shown), wherein the at least one hoisting device 620 is arranged topside of the vessel 600 or in connection with the mentioned platform 510 for controlled movement of the tool module 300 in longitudinal direction of the guiding assembly 200 either directly, as in the embodiment of Fig.1a and 5a, or via the tool module carrier 230, as in the embodiment of Fig.1b and 5b.

In accordance with one embodiment of the RCSATA 100 according to the present invention, the attachment device 320 comprises two attachment points 321 (as shown in Fig.5b), wherein one of the attachment points 321 is used for performing the hoisting or lowering movement, while the other may be arranged to an anti-falling device (not shown) with a wire, typically an anti-falling block of known type provided with automatic rewind of the wire, securing the tool module 300 from falling if there arises an error with the main hoisting device 620 or for arrangement to a redundant hoisting device for the same purpose.

The tool module 300 further includes a remote arm 330, which is arranged at lower part of the elongated housing 310 or arranged to the lower part of the tool module carrier 230 separately as shown in Fig.3a, 3e. In the embodiment shown in Fig.5a, the remote arm 430 is arranged at a lower end of the housing 310, while in the embodiment of Fig. 5b, the remote arm 330 is arranged in a horizontal opening 313 in the front side of the elongated housing 310. The latter embodiment provides some protection of the rotation arrangement of the remote arm 330. The remote arm 330 according to the present invention is formed by at least one horizontal arm 331, 332 rotatably arranged to the elongated housing 310 by one end thereof. To the other end of the mentioned horizontal arm 331 a desired tool assembly 350, as shown in Fig.5a, or a second horizontal arm 332 is arranged via a rotational joint or interface 333, as shown in Fig. 5b. In the embodiment with a second horizontal arm 332 arranged to the first horizontal arm 331, as shown in Fig.5b, the desired tool assembly 350 is arranged to the other end of the second horizontal arm 332.

According to a further embodiment of the tool module 300 according to the present invention, the tool module 300 comprises a hoisting unit 340 arranged to the remote arm 330, providing a connection interface for camera, light, tool assembly 350 etc. that is movable in the vertical direction of the mentioned remote arm 330.

In Fig.5a is shown a tool assembly 350 arranged to the free end of the first horizontal arm 331 by a rotational interface 351 and in Fig.5b is shown a tool assembly 350 arranged to the free end of the second horizontal arm 332 by a rotational interface 351. The tool assembly 350, e.g., further comprises a remote tool arm 360 formed by a first 361 and second 362 tool arm arranged to each other by a rotational joint or interface 363 and wherein at the free end of the second tool arm 362 is arranged a tool or at least one manipulator arm 370 for holding a desired tool.

The mentioned first 331 and second 332horizontal arms of the tool module 300 may be arranged to operate in the same horizontal plane or displaced in vertical direction to operate in two parallel horizontal planes.

The rotation of the first horizontal arm 331 in relation to the elongated housing 310 is powered by driving means 334, such as an electric, hydraulic or pneumatic motor connected to a slew drive, and capable of rotating from 210 to 360 degrees in relation to the elongated housing 310 depending on how it is rotationally arranged to the housing 310. The rotation of the second horizontal arm 332, if present, about the free end of the first horizontal arm 331 is provided by driving means 335, such as an electric, hydraulic or pneumatic motor connected to a slew drive, and capable of rotating the second horizontal arm 332 about the end of the first horizontal arm 331, in the same horizontal plane or a horizontal plane located above or below the plane of the first horizontal arm 331. The length of the horizontal arm(s) 331, 332 can be adapted to the area of use. In addition, the horizontal arm(s) 331, 332 may be telescopic such that the axial length thereof can be changed during an operation. As shown in Fig.5b, the respective horizontal arm 331, 332 can further be formed by arm modules or sections, such that the length of the respective arm 331, 332 as well as the properties of the remote arm 330 can easily be changed/altered by replacing, adding or removing arm modules or sections.

By that the remote arm 330 and/or tool assembly 350 includes independently controllable arms 331, 332, 361, 362, respectively, the working area of the tool module 300 is easy to manipulate, such that the tool assembly 350 can reach all positions within the working range of the tool module 300. Further, by using multiple arms 331, 332, 361, 362, rotatable in relation to each other, the arms can be folded together such that the tool module 300 occupies minimum space and thus makes the tool module 300 easy to transport without requiring detaching the arms 331, 332, 361, 362.

The tool module 300 further comprises a control unit (not shown). The tool module 300 can further be provided with one or more of: batteries or electricity supply from the offshore installation, valves/valve control unit, hydraulics (tanks for hydraulic oil, hydraulic pump), pneumatics (compressor, air tanks), compensators, sensors or similar, which will be known for a skilled person and is thus not shown explicit in the figures or described herein. In this manner the tool module 300 is capable of driving/powering any equipment which is arranged on the remote arm 330/tool assembly 350, either it is electric, pneumatic or hydraulic.

The tool module 300 will further be provided with communication means for communicating with a control central arranged on the vessel 600 or platform 510, where personnel can perform the necessary tasks without danger and consideration of the weather by remote controlling of the RCSATA 100. The mentioned control central has full control and manipulation possibilities of the RCSATA 100 via monitors and control devices, and a computer or control device for controlling the equipment. The control central may further be configured for controlling the at least one hoisting devices 620 or the at least one hoisting device 620 may be arranged to a dedicated control unit. This is well known for a skilled person and does not need to be elaborated further herein.

According to a further embodiment of the present invention, the driving means 334, 335 for the horizontal arm(s) 331, 332 are provided with or associated with means for reading or measuring the rotational position, such as an encoder, to provide a measure of the angle of the horizontal arm 331, 332 in relation to an initial position. Similar means may also be associated with all rotational joints or interfaces 351, 363 of the tool assembly 350. In this manner, the tool module 300 and/or tool assembly 350 can be arranged to operate the arm(s) 331, 332 in preprogrammed operational paths or movements.

In this manner the tool module 300 can be controlled from the control central and operate both above the sea surface and under the sea surface, and be driven under bad weather conditions and wave loads considerably larger than conventional techniques can handle.

By the present invention a desired tool can easily be arranged to the remote arm 330 via the tool assembly 350 and be exchanged for performing different types of operations related to the riser connection system 500.

It should also be mentioned that the tool module 300 preferably is provided with at least one vision system, such as a CCTV system, and one or more light sources, e.g. arranged to the hoisting unit 340, which is well known for a skilled person and does not need to be described in further detail herein.

With the present invention, it is accordingly provided a RCSATA 100 that easily can be guided along interconnecting risers 530 down to the connections 522 of the riser connection assembly 520 for inspection and maintenance of the connection of external risers 501 and maintenance work on the connections 522, external risers 501, interconnection risers 530 and the riser connection system 500 per se.

It is further provided a RCSATA 100 having low weight and that can be separated into assemblies (modules) for easy transport and assembly/disassembly at the location, as well as enables arrangement to the riser connection system 500 with simple access technique and low weight rigs or hoisting systems.

As the RCSATA 100 according to the present invention is formed by separate assemblies, this enables the separate assemblies/modules 200, 300, 400 of the RCSATA 100 to be adapted to the riser connection system 500 and vessel 600 in question without the requiring redesigning the entire system.

By the present invention is provided a RCSATA 100 with a stiff, strong and compact construction, that makes the RCSATA 100 suitable for work in the splash-zone, as well as above and below this, as it will not be highly affected to waves.

By the described embodiments of the RCSATA 100, solutions are provided that is suitable for standalone/single interconnecting risers 530, as shown by the first embodiment in Fig. 1a, 2a-b, 5a, 7a and a solution suitable for multiple interconnecting risers 530, as shown in Fig. 1b, 3a-e, 5b, 7b utilizing the properties of the riser connection system 530 to enable a stable working platform for the RCSATA 100.

It is further achieved a RCSATA 100 that is cheap to produce and arrange by the design of the guide assembly 200, tool module 300 and landing assembly 400, if present, as well as the mutual movability of the tool guide assembly 210 and riser guide assembly 220 and landing assembly 400, if present, in relation to the riser connection system 500 and vessel 600.

Examples of the assembly and arrangement of the RCSATA 100 will now be described.

The guiding assembly 200 is assembled topside and the tool module 300 is arranged to the guiding assembly 200 either directly or via the tool module carrier 230. In embodiments including the landing assembly 400 this is assembled and secured to the guiding assembly 200. In this manner the entire RCSATA 100 is ready to be arranged to the riser connection system 500. The assembled RCSATA 100 is next lifted into position of the riser connection system 500 at the vessel side 610. In the first embodiment, the RCSATA 100 is lifted and positioned with the riser guiding assembly 220 in vicinity and facing the interconnecting riser 530 below the platform 510 of the riser connection system 500. The riser guide member 321 is set in open position and moved into engagement with the interconnecting riser 530 and the riser guide member 321 is next closed to enclose and ensure safe engagement with the interconnecting riser 530, as shown in Fig. 1a. In an alternative embodiment, the tool module 300 is arranged to the guiding assembly 200 after the riser guiding assembly 220 is arranged to the riser connection system 500, by sliding the tool module 300 onto the tool guide assembly 210 or using movable arms of the connection interface 311 to attach the tool module 300 to the tool guide assembly 210. In this position the RCSATA 100 is ready to be lowered along the interconnecting riser 530, as described further below.

In the second embodiment, comprising the landing assembly 400, the assembled RCSATA 100 is lifted into a position where the landing assembly 400 via the at least one engaging member 412 of the attachment assembly 410 comes into engagement with the platform structure 512 with the landing assembly 400 in extended position. The RCSATA 100 is next lowered further and wherein the landing assembly 400 moves from extended position to collapsed position, wherein the at least one riser guide member 321 is moved past the platform structure 512 and into vicinity of the interconnection risers 530. The at least one riser guide member 321 is set in open position and moved into engagement with the interconnecting riser 530 and the at least one riser guide member 321 is next closed to enclose and ensure safe engagement with the interconnecting riser 530, and is thus in the position as shown in Fig.1b.

The guiding assembly 200 is next released from the attachment to the landing assembly 400 by releasing the locking means 250, enabling sliding movement of the guiding assembly 200 and tool module 300 in relation to the landing assembly 400. In an alternative embodiment, the tool module 300 is arranged to the guiding assembly 200 after the landing assembly 400 and guiding assembly 200 is arranged to the riser connection system 500, but before the landing assembly 400 and guiding assembly 200 are released from the landing assembly 400, by sliding the tool module carrier 230 with the attached tool module 300 onto the upper end of the guiding assembly 200 and securing the tool module carrier 230 to the guiding assembly 200. In this position the RCSATA 100 is ready to be lowered along the interconnecting riser 530, as described further below.

The guiding assembly 200 and the tool module 300 is next lowered along the interconnecting riser(s) 530, wherein the guiding assembly 200 slides along the interconnecting riser(s) 530. In the embodiment of Fig.1b, 3a-e, the guiding assembly 200 is detached from the landing assembly 400 as the guiding assembly 200 is lowered.

The RCSATA 100 is lowered until the guiding assembly 200 comes into engagement with the riser connection assembly 520. In the first embodiment of the RCSATA 100, as shown in Fig.1a, the riser connection guide member 260 is received and rests in the upper part 523 of the connection 522, and the engaging leg members 270a-b rests on the vessel side attachment member 521, as shown in Fig. 7a. In the second embodiment of the RCSATA 100, as shown in Fig. 1b, the riser guide members 221 are received and rest in the upper parts 523 of the connections 522, as shown in Fig. 7b.

In embodiments with only one riser guide member 221, the movement of the guiding assembly 200 and tool module 300 along the interconnecting risers 530 can be assisted by additional hoisting devices 620 or ropes to avoid the guiding assembly 200 and tool module 300 from rotating around the interconnecting riser 530 and connection 522.

The guiding assembly 200 and tool module 300 are now positioned in vicinity of the connections 522 of the external risers 501 for inspection and maintenance thereof, as shown in Fig.7a-b.

In the first embodiment, as shown in Fig.7a, the lock mechanism 250, if present, retaining the tool guide assembly 210 to the riser guide assembly 220 is released enabling the guide rail or member 211 to move axially in the elongated hollow structure member 223 of the riser guide assembly 220., enabling movement of the tool module 300 in longitudinal direction. In addition, the tool module 300 may itself be movable in relation to the tool guide assembly 210 for movement in longitudinal direction thereof. In this manner is enabled two different movement possibilities for the adjustment of the position of the tool module 300.

In the second embodiment, as shown in Fig.7b, the tool module carrier 230 in this lower position is released from engagement with the guide rails or members 211 by releasing the lock mechanisms 250 enabling movement of the tool module carrier 230 and tool module 300 along the guide rails or members 211. In addition, the locking means 240 are operated to secure the tool module assembly 210 to the riser connection assembly 520.

During an operation, the tool module 300 can easily be moved in longitudinal direction along the vessel side 610 by means of the tool guide assembly 210 being movable in relation to the riser guide assembly 220 and/or tool module 300 being movable in relation to the tool guide assembly 210 for the first embodiment, and by means of the tool module carrier 230 being movable in relation to the guide rails or members 211, the movement being assisted by hoisting devices 620 to elevate the tool module 300/tool guide assembly 210 and gravity to lower the tool module 300/tool guide assembly 210 and secured at desired positions by activating the lock mechanisms 250, if present.

As mentioned above, there is preferably also arranged safety stops at the bottom/lower end of the guiding assembly 200 to avoid the tool module carrier 230 and/or tool module 300 from sliding out of the lower end of the guiding assembly 200.

Due to the guiding assembly 200 according to the present invention is arranged to the interconnecting risers 530 and configured to move along the interconnecting risers 530, this provides a larger operational (weather) window for an operation. If required, the guiding assembly 200 and tool module 300 can rapidly be retrieved to the platform 510 and out of the waves without requiring the entire RCSATA 100 to be disassembled. Accordingly, if required, the guiding assembly 200 and tool module 300 is retrieved to the platform 510 while remaining arranged to the interconnecting risers 530 and ready for use, and can rapidly be lowered again to the connections 522. This will considerably reduce the costs and time of an operation due to the guiding assembly 200 and the tool module 300 will not have to be disassembled from the riser connection system 500, only elevated, if bad weather is coming during an operation.

Even though the guide rail(s) or member(s) 211 are shown with a mainly rectangular cross-section, these may be tubular, elliptic, quadratic or any other shape. Similarly, the tracks 233 and 423 are provided with a corresponding shape.

The guide rail(s) or members 211, axially extending tracks 233 and/or tracks 423 may be provided with a coating, bushings or similar reducing the friction between the engaging the surfaces thereof.

According to a further embodiment of the present invention, the RCSATA 100 comprises a docking station (not shown) for the tool module 300, that can be used to secure the tool module 300 on the deck of the vessel 600 in an upright position. In a further embodiment of the present invention, the docking station can further be used for lifting the tool module 300 for assembly to the tool module carrier 240/guiding assembly 200 and used for removing the tool module 300 from the tool module carrier 240/guiding assembly 200. The docking station may further be arranged for landing on the upper end of the guide rail(s) or member(s) 211 of the guiding assembly 200 such that the tool module carrier 240 and/or tool module 300 may slide onto or off the guiding assembly 200 in connection with assembly and disassembly of the tool module carrier 240 and/or tool module 300 in the alternative embodiments discussed above.

According to a further embodiment of the present invention, the tool module 300 is adapted for arrangement of a tool or equipment at other positions than the remote arm 330.

By means of the degrees of freedom of movement of the remote arm 330 and/or the tool assembly 350 it is provided a tool module 300 capable of performing any desired operation.

The tool module 300 according to the present invention is designed to operate both above the sea surface and under the sea surface if required, and thus operate during bad weather conditions and wave loads considerably larger than conventional techniques can handle.

Due to the degrees of freedom of movement of the remote arm 330 and tool assembly 350 both the remote arm 330 and tool assembly 350 are easy to manipulate, such that it reaches all locations within reach of the remote arm 330 and tool assembly 350.

An advantage by using a remote arm 330 comprising first 331 and second 332 horizontal arms being arranged to each other by a rotational interface 333 is that it will be possible to fold the remote arm 330 together such that minimum of space is required to make transport of the tool module 300 less space-demanding as well as having few protruding parts.

The tool assembly 350 according to the present invention typically comprises exchangeable manipulator arms 370 capable of performing different types of operations. The fact that they are exchangeable means that it in a simple manner can be mounted a mechanical unit at the end thereof for performing maintenance as grinding, cutting and drilling, etc., and which in addition can be rotated such that the equipment does not need to be brought to the surface for changing direction/position. This makes the tool module 300 also capable of performing advanced inspection work by arranging inspection equipment to the tool assembly 350 which includes, but is not limited to, equipment for, e.g., visual inspection, X-ray and eddy current equipment, painting, washing, etc.

The tool module 300 and/or tool assembly 350 is further preferably provided with a vision system, such as a CCTV system, for full video surveillance of the work being performed such that all operations can be performed from a remote location. The tool module 300 and/or tool assembly 350 is preferably also provided with one or more light sources for illumination of the work area for operations by night or under water.

The tool module 300 and tool assembly 350 are provided with energy and control signals from topside of the vessel 600, e.g. via hoses and umbilical. The tool module 300 is further preferably provided with driving means (motor/gear/pneumatic/batteries/electricity etc.) for powering and operation of the tool assembly 350 and locking mechanisms 250, if present, of the tool module carrier 230 and/or tool module 300. In an alternative embodiment, the communication is performed by wireless communication means.

Reference is now made to Fig.6a-c. In accordance with a further embodiment of the RCSATA 100 according to the present invention, it comprises a scraper assembly 700 configured for cleaning of exterior surface of the external risers 501 and/or interconnecting risers 530. The scraper assembly 700 according to the present invention comprises a scraper housing 710 and rigid connection means 720 for operation of the scraper assembly 700 by means of the tool module 300, or a hoisting device 620 or another manipulator system. In accordance with one embodiment of the scraper assembly 700 according to the present invention, the scraper housing 710 is cylinder-shaped and formed by multiple house members 711 and 712 configured to be assembled in circumferential direction to accommodate and enclose an external riser 501 in circumferential direction thereof. In the shown embodiment, the housing 710 is formed by two corresponding house members 711, 712, each constituting half of the housing 710. In alternative embodiments, the housing 710 may comprise more than two house members 711, 712. In accordance with one embodiment of the present invention, the house members 711-712 at engaging sides thereof are provided with corresponding attachment means 713, 714 for mutual attachment thereof. In accordance with one embodiment of the scraper assembly 700, the house members 711 are hinged 713 to each other at one respective side thereof, enabling the housing 710 to be opened for receiving an external riser 501 therein and closed for enclosing and engagement with the external riser 701, and wherein the house members 711-712 at the other respective sides thereof are provided with corresponding fixation means 714 for securing the house members 711-712 together.

The house members 711-712 are further provided with scraper blade or disc members 715 arranged at the distal axial ends of the house members 711-712 by interior attachment flanges 716 (Fig.6c) and attachment members 717 securing the scraper blade or disc members 715 to the house members 711-12. When the house members 711-712 are arranged together and fixed to form the scraper housing 710 enclosing the external riser 501, a complete scraper blade or disc 718 is formed that enclose the external riser 501 and in engagement with the exterior surface thereof, and configured to clean the exterior surface of the external riser 501 when operated in axial direction thereof by the tool module 300, hoisting device 620 or another manipulator system.

The rigid connection means 720 are, e.g., formed by at least two first rigid bars or rods 721 connected with a proximal end thereof to the scraper housing 710 via appropriate connection points 722, e.g., laterally reversed about a center axis thereof, and connected with their distal ends to an elongated rigid second bar or rod 723 for connection to the tool module 300, e.g. via the remote arm 330, or by a hoisting device 620 or another manipulator system. The second bar or rod 723 may be assembled by multiple parts or be telescopic for adjusting the length thereof.

In accordance with a further embodiment of the scraper assembly 700, the scraper housing 710 is provided further external connection points 719 for arrangement of additional hoisting devices or similar for handling of the house members 711-712 during transport or assembly and disassembly.

The scraper assembly 700 according to the present invention is arranged to the external riser 501 by arranging the house members 711-712 in open position for receiving the external riser 501, and closing the house members 711-712 to enclose the external riser 501 in circumferential direction thereof, and securing the house members 711-712 to each other by the fixation means 714. The scraper blade or disc 718 then engages and enclose the exterior surface of the external riser 501 in circumferential direction.

Cleaning of the splash-zone of the external risers 501 can then be performed by operating the scraper assembly 700 in axial direction of the external riser 501 by the remote arm 330 of the tool module 300, as well as moving the tool module 200 in axial direction of the guide rail(s) or member(s) 211, or by operating a hoisting device 620 or another manipulator system.

The scraper assembly 700 is preferably provided with at multiple cameras and illumination sources 730 for inspection and monitoring of the cleaning process.

In an alternative embodiment, the scraper assembly 700 is connected to a dedicated hoisting mechanism (not shown) and is free to move independently of the tool module 300. In this embodiment, the scraper assembly 700 is placed in clamping position of the external riser 501 using the remote arm 330.

In a further alternative embodiment, the scraper assembly 700 is provided with one or more thrusters (not) shown assisting in or enabling maneuvering in the water.

In accordance with a further embodiment of the scraper assembly it is provided with independent energy and control signals from topside of the vessel 600, e.g. via hoses and umbilical.

The technical features of the above described embodiments may be combined to form modified embodiments within the scope of the attached claims.

Claims

1. Riser connection system access tool assembly (100) for maintenance and inspection of a riser connection system (500) on a Floating Production Storage and Offloading Vessel (600) or Floating Storage and Offloading Vessel, wherein the riser connection system access tool assembly (100) comprises a guiding assembly (200) and a tool module (300),

wherein the guiding assembly (200) is configured for detachable engagement with at least one interconnecting riser (530) of the riser connection system (500) and movement in axial direction thereof, and configured for movement of the tool module (300) in axial direction of the guiding assembly (200).

2. Riser connection system access tool assembly (100) according to claim 1, wherein the guiding assembly (200) is formed by a tool guide assembly (210) and a riser guide assembly (220).

3. Riser connection system access tool assembly (100) according to claim 2, wherein the tool guide assembly (210) comprises a guide rail or member (211) or a pair of parallel guide rails or members (211) extending in axial direction of the tool guide assembly (210).

4. Riser connection system access tool assembly (100) according to claim 3, wherein the riser guide assembly (220) comprises at least one riser guide member (221) arranged in a parallel plane of the guide rail(s) or member(s) (211) by a support structure (222).

5. Riser connection system access tool assembly (100) according to claim 2, wherein the tool guide assembly (210) is movably arranged to riser guide assembly (220) via a connection interface (223) enabling movement of the tool guide assembly (210) in axial direction of the guiding assembly (200).

6. Riser connection system access tool assembly (100) according to claim 2, wherein the tool module assembly (300) is provided with a connection interface (311) enabling movement of the tool module (300) in the axial direction of the tool guide assembly (210).

7. Riser connection system access tool assembly (100) according to claim 2, wherein the guiding assembly (200) further comprises a tool module carrier (230) movably arranged in the axial direction of the tool guide assembly (210), to which tool module carrier (230) the tool module (300) is arranged, enabling movement of the tool module (300) in axial direction of the tool guide assembly (200).

8. Riser connection system access tool assembly (100) according to claim 3 or 7, wherein the tool module (300) comprises an elongated housing (310) provided with a connection interface (311) at rear side thereof configured for arrangement of the tool module (300) to the tool module carrier (330) or guide rail or member (211) of the tool guide assembly (210).

9. Riser connection system access tool assembly (100) according to claim 2, wherein the guiding assembly further comprises a landing assembly (400) configured for detachable engagement with the riser connection system (500) and further configured to position the guiding assembly (200) in vicinity of interconnecting risers (530) of the riser connection system (500).

10. Riser connection system access tool assembly (100) according to claim 9, wherein the guiding assembly (200) is configured for detachable engagement with the landing assembly (400) and movement in axial direction thereof.

11. Riser connection system access tool assembly (100) according to claim 9, wherein the landing assembly (400) comprises an attachment assembly (410) configured for engagement with a platform structure (512) of the riser connection system (500).

12. Riser connection system access tool assembly (100) according to claim 11, wherein the landing assembly (400) further comprising a guiding assembly connection interface (420) movably arranged to the attachment assembly (410), between an extended position and collapsed position.

13. Riser connection system access tool assembly (100) according to claim 12, wherein the guiding assembly connection interface (420) is arranged to the attachment assembly (410) by means of hinged connection members (430).

14. Riser connection system access tool assembly (100) according to claim 10, wherein the landing assembly (400) and guiding assembly (300) are provided with locking means (250) for detachable locking of the two to each other.

15. Riser connection system access tool assembly (100) according to claim 6, wherein the connection interface (311) of the tool module (300) is provided with locking means (250) for detachable locking of the tool module (300) to the tool guide assembly (210), preventing axial movement of the tool module (300) along the guiding assembly (200).

16. Riser connection system access tool assembly (100) according to claim 7, wherein the tool module carrier (230) is provided with at least one locking mechanism (250) for detachable locking of the tool module carrier (230) to the guiding assembly (200), preventing axial movement of the tool module carrier (230) and tool module (300) along the guiding assembly (200).

17. Riser connection system access tool assembly (100) according to claim 7, wherein the riser guide member (221) is formed by at least two parts (228a-b) enabling the riser guide member (221) to be opened to receive and accommodate the interconnecting riser (530) and closed to enclose the interconnecting riser (530).

18. Riser connection system access tool assembly (100) according to claim 1, wherein further comprising a scraper assembly (700) configured to accommodate and enclose an external riser (501), wherein the scraper assembly (700) comprises a scraper blade or disc (718) in engagement with exterior surface of the external riser (501) for cleaning thereof by movement of the scraper assembly (700) in axial direction of the external riser (501).

19. Riser connection system access tool assembly (100) according to claim 18, wherein the scraper assembly (700) comprising a housing (710) formed by multiple house members (711-712) configured to be assembled in circumferential direction to accommodate and enclose the external riser (501) in circumferential direction thereof.

20. Riser connection system access tool assembly (100) according to claim 14, wherein the house parts (711-712) are hinged (713) to each other at one side thereof, enabling the housing (710) to be opened for receiving the external riser (501) and closed for enclosing and engagement with the external riser (501).

21. Riser connection system access tool assembly (100) according to claim 18, wherein the scraper assembly (700) comprises rigid connection means (720) arranged to the housing (710) enabling operation of the scraper assembly (700) along the external riser (501) by the tool module (300) or a hoisting device (620) or another manipulator system.

22. Riser connection system access tool assembly (100) according to any preceding claim, wherein further comprising at least one hoisting device (620) configured for operating the riser connection system tool assembly (100) into and out of engagement with the at least one interconnecting riser (530), controlling the movement of the riser connection system access tool assembly (100) in axial direction of the at least one interconnecting riser (530), as well controlling movement of the tool guide assembly (210) or tool module carrier (230) in axial direction of the guide assembly (200).

23. Riser connection system access tool assembly (100) according to any preceding claim, wherein the at least one hoisting device (620) is further configured for controlling movement of the tool module (300) in axial direction of the tool guide assembly (210).