NO160736B - UNDERWATER OPERATION SYSTEM. - Google Patents

Description

The invention relates to an underwater operating system including an underwater platform, operating equipment on the platform, mounted as replaceable units, operating means on each equipment unit, a rail on the platform and an operating unit that can move along the rail and assume suitable positions to influence the operating means and replace the equipment units, which operating unit has a manipulator with which an equipment unit can be isolated, grasped and released from the operating unit, and with which a new equipment unit can be retrieved from a warehouse in the operating unit and placed in place on the platform.

Such a system is known from NO-PS 139 323, where an underwater production equipment is described for remote connection to underwater wells and for fluid tapping from boreholes underwater. The underwater production equipment is built so that the components can be easily connected and disconnected and removed and/or replaced. Thus, various sections of the platform and the equipment on it, including manifold equipment, valves, power plants and other control units and the actual rail passage on which the operating unit works, are remotely removable and can be brought to the surface for repair and/or replacement in the underwater production equipment. If maintenance work is to be done on the underwater production equipment, e.g. on a manifold valve, a buoy is released by remote control. The buoy rises from the platform and takes a line with it to the surface. The control unit descends and pulls itself down to the underwater production equipment along the line attached to the buoy. After the operating unit has landed on the rail, the operating unit is secured to the rail. By means of power supply from the surface through an electric cable, the operating unit is supplied with power to a motor that moves the operating unit along the rail. An operating arm on the operating unit can be put into operation, with power supplied through the aforementioned electric cable. After the operating unit has carried out the necessary operations, it returns to the landing point, the anchoring is released and the operating unit returns to the surface along the line. If a maintenance job cannot be done remotely, a man can be lowered into a watch attached to the control unit. The control unit is equipped with its own power supply system which enables it to move along the track should the power supply through the electrical cable that goes up to the surface fail. The man in the possibly used watch can, if necessary, release the operating unit or release the watch from the operating unit so that the watch can float to the surface.

This known system has the disadvantage that one is dependent on a surface attachment. The present invention aims to provide an underwater operating system that is remotely controlled during normal operation and where maintenance, replacement of units etc. can be carried out within the framework of a total underwater system, i.e. that one works without the need for surface contact, so that one in reality has an underwater system that is independent of the conditions on the surface.

According to the invention, it is therefore proposed for an underwater operating system as mentioned at the outset that the equipment units are, to the greatest possible extent, placed as such and/or with their operating organs in typical axes and in typical planes, and that the operating unit is a cargo-carrying, manned autonomous underwater vessel with docking feet for cooperate with the rail gangway and with at least one additional, external manipulator which is mounted on the vessel for positional movement adapted to the mentioned typical axes when the vessel is docked on the rail gangway and occupies one of the mentioned positions.

The invention has primarily been developed for use at so-called production facilities, but the term underwater operation system shall also include other facilities under water, where there is a need for maintenance, replacement of units, etc.

The cargo-carrying, manned autonomous underwater craft is a key factor. As it is load-bearing, it can take with it equipment units and components from a base that can in practice be placed in an appropriate location, for example on land. By having the vessel manned, you gain the advantage that all handling and manipulation can be done "manually", i.e. with direct monitoring (through suitable windows in the vessel). Automatic and automatic and remotely controlled components can also be monitored. By the fact that the underwater vessel is autonomous, i.e. self-sufficient, you gain the advantage that the crew - this can be a larger crew, for example 5-10 people, can stay for several weeks on board, and the vessel is completely independent of external energy supply when the vessel is working on the underwater platform, although it is of course advantageous to provide an energy transfer connection between the vessel and the platform when the vessel is docked on the rail, so that the vessel can receive energy supply from the platform, as it is then assumed that the underwater platform has a cable or wire connection with a suitable energy source located on a remote fixed offshore platform or on land.

The arrangement of the equipment units and/or their operating means (couplings, operating spindles, fixing screws, signal means, etc.) or their axes, if desired, in typical axes and in typical planes simplifies the manipulation operations, and the positionally movable mounting of the manipulators on the vessel adapted the aforementioned typical axes, when the vessel is docked on the rail, further contribute to simplifying the manipulations to be carried out. The operating elements can have an axis which is fixed in relation to the equipment unit or its axes, and the operation can take place by rotating the operating element around and/or shifting it along its axis.

By "typical axes" and "typical planes" is meant here such axes and planes that repeat themselves in, i.e. are typical for, all the equipment units arranged in the operating system.

The components that are to be operated by the manipulator(s) on the underwater vessel are fitted into a coordinate system which, in addition to the aforementioned simplification of the manipulation operations, allows for matching components, tools and manipulators and also enables defined operations, particularly with the utilization of a DAK system

(the drawing of the equipment entered on a CAD system in the control, so that the control system itself "sees" the equipment and any obstacles):. The manipulator/tool will receive reference data in its data-assisted control by "sensing" reference points on the equipment (e.g. a production tree). Addressing can then take place based on the known location of tools in relation to the equipment. The location in typical axes and plan will also facilitate the use of a television camera or "acoustic camera" to send close-up images to the operator aboard the underwater vessel. At greater depths poor visibility and light conditions must be expected and therefore cannot be based on purely manual (visual) control.

The use of a cargo-carrying, manned autonomous underwater vessel allows for the placement of underwater operational systems also at greater depths, i.e. depths beyond normal diving range, and a particular advantage is seen in the fact that the new system will be excellently suited for efforts in arctic waters (under the ice).

Today, great demands are placed on underwater operational systems for safety reasons. Thus, equipment units and components are required to have a very long service life and be extra operationally reliable, precisely because these are facilities that are difficult to access, and where failure or errors could have catastrophic consequences. The new underwater operation system provides the possibility of shortening the "warranty time" of equipment units and components, i.e. that you can abandon the long-term concept required today because, by using the underwater vessel, you can quickly and relatively easily replace and repair/ overhaul units and components. Overall, you thus achieve a system where, in a wet environment, you approach the working and operating conditions you have in a dry environment.

The use of the underwater vessel, which will be relatively large, will make it possible to "spread" the equipment more. For example, a manifold area can be designed larger, i.e. placed over a larger area, which is covered by the underwater vessel's manipulators, and individual components can be dimensioned and placed in more easily accessible places. A so-called barbed lock can, for example, be transported with the underwater vessel and put in place in the pipeline system if necessary, whereby this can take place without the currently necessary surface connection with a vessel.

Certain components can be simplified, as they only need to be made for direct operation. This applies, for example, to valves for shutting off sections where work/manipulations/replacements are to be carried out.

In an underwater operating system where the equipment includes production trees and associated manifold equipment, the production trees can advantageously be arranged in line, with the manifold equipment placed along this line, as the railway then extends over the manifold.

When the vessel is docked on the rail, the manipulators will be able to operate both the production trees and the underlying manifold equipment.

Preferably, the rail is laid parallel to the aforementioned line. The underwater vessel can then be docked so that its longitudinal axis is at right angles to the rail passage and on the aforementioned line, and the underwater vessel can then be shifted laterally along the rail passage. With manipulators in the front, the production trees can be operated, while one or more manipulators below the vessel can operate the manifold equipment, as the vessel is docked on the rail with the axis of the vessel parallel to the typical axes in the manifold.

Appropriately, the rail passage can include a section outside the platform's equipment area, so that the vessel can dock without risk of collision with equipment units on the platform. This provides additional security.

Advantageously, rails and underwater vessels include mutually form-locking propellants, for example rack and pinion. This will often be advantageous, often even necessary, as the slime coating will be able to prevent the necessary friction between the rail and support wheel. The underwater vessel will also be close to a floating state, with associated low surface pressure against the rail.

Advantageously, the underwater vessel can include locking means, for example claws, for locking to the rail.

The invention will be explained in more detail below with reference to the drawings, where

fig. 1 shows a plan view of an underwater platform, with a docked underwater vessel,

fig. 2 shows the platform in fig. 1, seen from the left side,

fig. 3 shows the underwater platform, seen from the one in fig. 1 lower end, on a larger scale,

fig. 4 shows a section through the partially shown underwater vessel in fig. 3,

fig. 5 shows a more schematic section of an underwater plate form as in fig. 1, where the rail passage is extended to outside the platform's equipment area,

fig. 6 shows a schematic side view of the front part of an underwater vessel with manipulators, together with a product line,

fig. 7 and 8 show respectively an end view and a ground view of the underwater vessel and the production tree in fig. 6,

fig. 9 shows an equipment unit hanging from a lifting yoke, and

fig. 10 and 11 show an example of locking an equipment unit in the hold.

The one in fig. The underwater platform shown in 1 - 3 is a production platform which is placed on the seabed 1. The production platform 2 is in itself built up in a conventional manner from strong pipe elements 3 and beams 4 which are welded together so that a framework is created. The production platform shown includes four production trees 5, 6, 7 and 8. Each production tree is connected to a well in a manner known in and of itself. The number of production trees is here chosen completely at random, and an underwater platform can naturally include a larger or smaller number of production trees.

The production trees 5 - 8 are, as can be seen from fig. 1 - 3, arranged on a line Y-Y. Each production tree has a vertical axis Z-Z which represents a so-called typical axis. From fig. 2 and 3, it appears that each production tree, see production tree 5 in fig. 2 and the production tree 7 in fig. 3, has its operating organs 9, 10 respectively. 11 arranged in the typical axis and in typical planes A, B, C, D, E (fig. 3). In fig. 2, the drawing plane can also be regarded as a typical plane where the operating elements 9 and 10 are located.

Another typical axis is X-X, see fig. 1. The manifold equipment and other equipment units are arranged according to such axes X-X in the ground plan in fig. 1. In fig. 3, the axis X-X lies in the paper plane and the paper plane also represents a typical plan for placing equipment units.

The underwater platform 2 is along the line Y-Y, which

the production trees 5 - 8 are lined up lengthwise, provided with a manifold equipment area 12. The equipment is here, in the same way as the production trees, in and of itself known equipment that does not require further explanation.

Above the manifold equipment area 12 there is a rail passage in the form of two rails 13 and 14. The rail passage 13, 14 here extends parallel to the alignment of the product ion trees 5-8. An underwater vessel 15 is shown docked on the rails 13, 14, in a position outside the production tree 7. This underwater vessel 15 is a cargo-carrying, manned autonomous underwater vessel which is dimensioned and equipped to provide space for a larger crew, for example 5-10 people, and for longer stays in a submerged state (up to several weeks).

The underwater vessel 15 is designed with a pressure hull 16 (see fig. 3 and 4). Below the pressure hull 16, the underwater vessel has a cargo space 17, which is limited externally by swing-out side walls 18, 19. In the front part, in front of the forward end of the pressure hull 16, there is a room 20 which is closed with bow ports 21.

Along the belly of the pressure hull 16 run two rails 22, 23 which form a rail guide for a running carriage 24. This running carriage 24 carries a belly manipulator 25. Furthermore, two rails 26, 27 are arranged under the belly for one or more running cats 28 with a suspended therein lifting yoke 29.

The manipulator 25 is in fig. 3 and 4 shown in a rest/transport position swung into the hold. A working position is shown with dashed lines in fig. 4. The running cat 28 and the lifting yoke 29 are used for handling equipment units which are suspended in the cargo space 17. The manipulator 25 is used for carrying out necessary work on the platform.

Two bow manipulators 30, 31 are arranged in the room 20 (see fig. 6-8). These manipulators can travel on vertical rails 32, 33. The rails 32, 33 can be displaced horizontally, as indicated by the double arrows in fig. 6, in suitable guides 34, 35. At the front of the pressure hull 16, there is a large acrylic window 36 which provides a good overview for the operator 37 who controls the manipulators from within the pressure hull's living space. Correspondingly large windows (not shown) are arranged in the belly of the pressure hull, so that the operator also has visual control with the belly manipulator 25 and the lifting yoke 29.

In the cargo space 17, in fig. 3 with dotted lines indicated equipment units which are designed as modules in a containerization system, i.e. that each module lies within a parallelepiped "frame". Each such "container" module 38 can advantageously include a frame structure (not shown in detail) with at least one top frame with attack points for the lifting yoke 29 and with attachment-suspension points for cooperation with corresponding points in the cargo space 17. One can here advantageously utilize known locking and fastening techniques from ordinary containers. Thus, the frame structure can be provided with protruding locking lugs intended for interlocking with suitable hook fasteners in the cargo compartment where the modules can be suspended during transport.

In fig. 9 shows an example of a frame structure with associated equipment unit. The frame structure is denoted by 41 and the equipment unit by 42. The frame 41 and the thus assembled equipment unit 42 hang in the lifting yoke 29, which in turn is suspended from the running cat 28 with line 43 in a way that can be raised and lowered. The manipulator 25 is used for steering and position orientation of the equipment unit 42.

Fig. 10 and 11 show purely schematically how a containerized unit 38 can be suspended and locked in a transport position in suitable hooks 44 in the cargo space, the unit 38 being provided with projecting locking ears 45, designed as shown in fig. 10 and 11. The locking eye 45 has a hole 46 into which a locking pin 47 can engage. The locking pin 47 is driven by a small working cylinder 48. Corresponding hooks, possibly without a lock, can be used at a lower level, for "parking" the equipment units.

Fig. 5 shows a variant of the platform in fig. 1. The difference is that the rail passage 13, 14 in fig. 1, at the platform in fig. 5 is extended by the rail sections 13', 14', so that the underwater vessel 15 can dock outside the equipment area on the platform, i.e. the area where the production ion trees and the manifold equipment etc. are located. The vessel 15 can thus dock without risk of collision with equipment units on the platform, and can then drive in along the rail passage.

The underwater vessel is provided with four telescopic legs 39, which at their respective ends have impellers 40 for contact with the rails 13, 14. After docking, the position of the underwater vessel can be regulated with the help of the two telescopic legs 39, and with the help of propulsion means not shown which act on the wheel sets 40, the underwater vessel can move along the rails 13, 14. In the desired position outside a production tree 7, the underwater vessel can optionally be locked to the rail passage by means not shown, which will be well known to the person skilled in the art.

In the foregoing, an underwater platform that rests on the seabed is discussed. The invention is naturally not limited to such an underwater platform. The underwater platform may well be the upper end of a tower-like construction that stands on the seabed, whereby the working depth of the platform and the underwater vessel can be reduced.

For example, you can also imagine a curved rail track for the underwater vessel. A possible embodiment is also one where the underwater vessel is docked on a turntable-like rail that is centrally located in an underwater platform.

Claims (7)

1. Underwater operation system including an underwater platform (2), operating equipment (5 - 8) on the platform, mounted as interchangeable units, operating means (9 - 11) on each equipment unit, a rail passage (13, 14) on the platform and an operating unit (15) which can move along the rail and assume suitable positions to influence the operating means and replace the equipment units, which operating unit has a manipulator (25) with which an equipment unit can be isolated, grasped and released from the operating unit, and with which a new equipment unit can be retrieved from a warehouse in the operating unit and placed in place on the platform, characterized by the fact that the equipment units (5 - 8) are placed as such and/or with their operating elements (9 - 11) in typical axes (X, Y, Z) and in typical planes (A-F, X-Z, Y-Z), and that the operating unit is a cargo-carrying, manned autonomous underwater vessel (15) with docking feet (39, 40) for cooperation with the rail passage (13, 14) and with at least one outer gere, external manipulator (30; 31) which is movably mounted on the vessel adapted to the aforementioned typical axes when the vessel is docked on the rail and occupies one of the aforementioned positions. 2. Underwater operation system according to claim 1, where the equipment includes production trees (5 - 8) and associated manifold equipment (12), characterized in that the production trees (5 - 8) are arranged on a line (Y - Y), that the manifold equipment (12) is placed along the line and that the rail runs over the manifold equipment. 3. Underwater operating system according to claim 2, characterized in that the rail passage (13, 14) runs parallel to the aforementioned line (Y-Y). 4. Underwater operating system according to claim 2 or 3, characterized in that the vessel (15) and its docking feet (39, 40) are designed for docking on the rail passage (13, 14) with the longitudinal axis of the vessel parallel to the typical axis (X-X) in the manifold equipment . 5. Underwater operation system according to one of the preceding claims, characterized in that the rail passage (13, 14) includes a part (13', 14') outside the platform's equipment area, so that the vessel can dock without risk of collision with equipment units on the platform. 6. Underwater operating system according to one of the preceding claims, characterized in that the underwater vessel includes form-locking propellants, for example rack and pinion. 7. Underwater operating system according to one of the preceding claims, characterized in that the underwater vessel includes locking means, for example claws, for locking to the rail passage.