Field of the invention

The invention concerns the field of hydrocarbon production and processing, as set out in the preambles of claims 1 and 2.

Background of the invention

Production and treatment of hydrocarbons (e.g. oil, gas) extracted from subterranean wells involve complex equipment and processes, whether the wells are on dry land or subsea. Traditionally, the required work and processes are carried out on large, purpose- built plants associated with one or more wells. Various types of platform substructures exist for producing hydrocarbons from offshore, subsea, wells, e.g. floating, semi- submersible hulls, and fixed structures resting on the resting on the seabed.

The operation (mcluding maintenance, repairs and inspections) of such platforms is labour-intensive, due to the complexity of the equipment and the work performed.

The way process equipment is currently arranged, and has been for over 100 years, is based on allowing personnel access to all process equipment, and requires the physical presence of people in those places where inspection, operation, maintenance and replacements are carried out. Although a certain degree of remote control has been achieved over time, it is still assumed mat the process must be controlled by personnel present at the processing site.

On installations being built today (both offshore and onshore), the arrangement of equipment is related to horizontal planes (i.e. decks and access routes). This is done to allow access for personnel and personnel-operated machines. This is a conventional way of thinking, and one which works, but it imposes conditions on the arrangement of all equipment, pipes, access and lifting and transportation routes. This leads to high construction costs. Access to the entire process plant must be provided in the form of walkways and decks free of obstructions. Equipment must be placed at the correct working height for inspections, operation, maintenance and replacements. This places demands on the working environment in the form of correct lifting height, temperature, maximum wind strength etc. Moreover, the risk of explosions and fire must be taken into consideration. As the operation of conventional lifting and manoeuvring equipment requires a lot of space, the platform (and all the decks) will take up a lot of space. This equals a large volume, which in turn leads to a requirement for large structures and results in high construction costs.

A conventional arrangement is oriented relative to horizontal surfaces where personnel can move around, and everything is set up for manual handling of devices for inspection, operation, maintenance and replacement. This type of arrangement is highly work preserving, i.e. it requires a lot of manpower in the areas where the equipment is located. The operating costs are high because it requires the physical presence of personnel at the equipment to be inspected, maintained and replaced. These operations require skilled personnel, and in many cases the rigging of lifting and transportation equipment. These lifting devices inside the process plant will, in the case of

conventional designs, require the presence of fixed points or rails above the equipment to be lifted. These fixed points or rails will either have rigidly mounted lifting devices or manual lifting devices are mounted prior to each operation. This is time consuming, and the personnel involved are exposed to the risks which the processing of

hydrocarbons normally entails. In some cases it will be necessary to build scaffolding to provide an adequate platform from which the personnel can work. There may also be a requirement for temporary lifting equipment. All these operations entail risks.

Moreover, it is not common for the personnel carrying out the work to be subject to monitoring and quality assurance by other personnel or, for shorter periods, by skilled personnel located remote from the site of the operations. Consequently, the platform operating costs are high.

Over the years, the above disadvantages have motivated operators to develop hydrocarbon-processing equipment that is suitable for subsea use. However, subsea operations are also costly, requiring purpose-built equipment and relying on elaborate systems.

It is therefore a need to simplify the production and processing of hydrocarbons, in order to cut costs and improve operability. Automation of certain hydrocarbon processes on platforms is known in the art. WO 2007/011237 A2 describes an arrangement of process equipment for treatment of hydrocarbons on an offshore surface installation or an onshore installation, said installation comprising a deck having a permanently unmanned area in which the process equipment is located, and to which personnel has no access while the equipment is pressurized and operating, and a manned area to which personnel normally has access. The permanently unmanned area is separated from the manned area by a fire and explosion proof wall which prevents personnel access into the permanently unmanned area while the process equipment is pressurized and operating. The installation comprises at least one deck having a number of racks accommodating the process equipment on one or more levels. Each rack has a corridor on at least one side, and access to the process equipment in the racks being provided via a remotely-controlled or automatic tool introduced into the corridor. While this publications describes a platform with a certain degree of automated operation, it still requires all of the conventional safety measures, due to the fact that personnel are also working on the platform.

Summary of the invention

The invention is set forth and characterized in the main claim, while the dependent claims describe other characteristics of the invention.

It is thus provided a plant for processing of hydrocarbons, comprising a plurality of modules configured for the processing of said hydrocarbons and for controlling such processes, characterized in that

- the modules are enclosed by a sealed housing, whereby the modules are sealed off from the environment surrounding the plant, and

- the plant comprises atmosphere control means for controlling and maintaining an incombustible atmosphere inside the housing.

It is also provided a plant for processing of hydrocarbons, comprising a plurality of modules configured for the processing of said hydrocarbons and for controlling such processes, characterized in that

- the modules are enclosed by a sealed housing, whereby the modules are sealed off from the environment surrounding the plant, - the plant comprises atmosphere control means for controlling and maintaining an incombustible atmosphere inside the housing, and

- robotic means are arranged in the housing and configured for automated or remotely controlled operations within the housing.

In one embodiment, the robotic means comprise a plurality of work robots, configured for controlled relocation within the housing.

The atmosphere control means may comprise means for generating an incombustible atmosphere inside the housing.

The atmosphere control means may be configured to maintain a controlled atmosphere with respect to pressure, gas composition, temperature.

In one embodiment, the atmosphere control means may comprise means for generating a nitrogen-rich atmosphere inside the housing, and the gas is maintained at a pressure above the pressure outside the housing. The atmosphere control means may comprise a nitrogen generator. In another embodiment, the atmosphere control means comprises an inert gas generator, configured to produce the inert gas from cleaned combustion gases. Alternatively, the inert gas may be supplied from a source external to the plant, such as a nearby platform.

In one embodiment of the plant, the modules are arranged in racks, and the racks are arranged on a main deck and separated by access corridors. The robotic means (e.g. work robots) are configured for automated or remotely controlled movement and relocation within the housing, via robot transportation means, said robotic means being configured for, individually or collectively, performing one or more of inspections, maintenance, repair on the modules, relocating modules, and operating members in the housing.

The plant may comprise module movement means for releasable connection to the module.

The plant may comprise a remotely operated liquid drainage system. The plant may comprise a remotely operated cable pulling system, having a plurality of cable traction means and controllable cable diversion means, whereby the cable may be remotely guided in a desired direction.

The plant may comprise a remotely controlled cleaning device, configured for operation by a robot.

The plant may comprise a remotely controlled flange connection device, comprising actuation members and an abutment member, and the actuation members are configured to be operated by one or more robots.

In one embodiment, the main deck is arranged a distance above a lower deck of the housing, and piping and cables between the modules are disconnectably routed between the main deck and the lower deck.

In one embodiment, the housing comprises at least one removable and sealable panel through which a rack may be passed. In one embodiment the plant comprises a lock chamber which is connected to the housing via a sealable first door, and which also comprises a sealable second door facing the environment surrounding the plant.

In one embodiment, the plant comprises a substructure configured for supporting the housing above water.

The robotic means may thus be used for automated or remotely controlled inspection and mechanical handling tasks within said housing.

It is also provided a method of operating the invented plant, wherein the robot means operate based on pre-defined information of the shapes of all objects in the plant. The robot means may also be configured to operate based on pre-defined information of the locations of all objects in the plant.

With the invention, the entire topsides facility (e.g. processing equipment, power generators, control modules) is enclosed in an incombustible environment, inside a housing. The modules inside the housing are fully I/O compatible. The invention relies entirely on condition-based maintenance and the use of robotics. No cranes are required inside the housing, as all equipment handling inside the housing is performed using a system of robots and associated transportation systems, trolleys, rails and tracks. With the invention, it is thus possible to move relatively large objects in comparatively narrow passages, which means that the plant may be considerably more compact than conventional platforms.

Compared to existing platforms for hydrocarbon processing, the invented plant does not require living quarters, helideck, lifeboats and rafts. Nor are cranes, firewater pumps, fire barriers, heating and ventilation required. As the atmosphere inside the housing is inert and controlled, the electrical equipment does not need to be of standard, and the steel quality need not be corrosion resistant. Neither need electrical equipment be protected for safety reasons since personnel will not be present on the installation when platform is live. The invented plant therefore offers considerable weight and cost savings compared to plant of the prior art.

Brief description of the drawings

These and other characteristics of the invention will become clear from the following description of a preferential form of embodiment, given as a non-restrictive example, with reference to the attached schematic drawings, wherein:

Figure 1 is a perspective view of the invented plant, in the form of a platform for production and processing of hydrocarbons;

Figure 2 is a side view of the platform shown in figure 1, and illustrates a module being lifted with respect to the platform; Figure 3 is a side view of the platform shown in figure 2, and illustrates a rack being lifted with respect to the platform;

Figure 4 is a perspective see-through drawing of the platform illustrated in figure

1;

Figure 5 is a perspective see-through drawing of the platform illustrated in figures 2 and 3;

Figure 6 is a sectional side view of a section of the platform roof structure, in a closed state;

Figure 7 is a sectional side view of a pair of roof panel support assemblies; Figures 8a-e are sectional side views of the platform roof structure, and illustrate a sequence for removing a roof panel;

Figure 9 is a see-through drawing of the platform according to the invention, schematically illustrating hydrocarbon-processing racks;

Figures 10a,b are a side view and a top view, respectively, of two process racks and work robots;

Figures 1 la,b are a side view and a top view, respectively, of three process racks and work robots, and illustrate i.a. how piping is connected transversely between the racks, above the top of the racks and below a main deck (in a separate void for piping);

Figure 12a is a perspective view of three process racks, and illustrate i.a. how work robots are in the process of retrieving a process module;

Figures 12b,c are perspective views of the racks shown in figure 12a, and illustrate two steps in the process of retrieving a module and placing it onto tracks;

Figures 13a-c are perspective views of a process module, and illustrate steps in the retrieval of a module from a rack and placing it in a laydown area located in a lock chamber;

Figures 14a,b are perspective views of a process module, and illustrate how work robots may travel inside a module, for example to perform x-ray computed tomography on equipment and structures to reveal e.g. sub-surface cracks;

Figure 15 is a perspective view of an arrangement for retrieving a module from a rack;

Figure 16 is principle sketch of a device for connecting a connector rail to a horizontal rail;

Figures 17 and 18 are principle sketches for arranging a top rail junction making the vertical access bars supporting the robots to shift trail between two or more process racks; Figures 19 and 20 illustrate an embodiment of pre-installed brackets in a module;

Figure 21 illustrates an embodiment of a structure for moving a robot internally in a rack, using an internal robot rail system making it possible for robots to reach locations inside the module/skid that otherwise would not be possible;

Figures 22a and 22b illustrate the operation of a system for transporting a module out of and into a rack, and a transport elevator, in such manner that the module/skid is not lifted up and the horizontal movement is controlled with high precision;

Figure 23 illustrates another embodiment of a transport elevator;

Figure 24 illustrates an alternative arrangement for moving a heavy object into and out of a rack, in confined spaces inside the module/skid;

Figures 25a and 25b show an alternative arrangement for an access and transport system for robots and equipment to be used in maintenance and inspection operation of one or several modules/skids;

Figures 26 and 27 illustrate a remotely operated drainage system, making it possible to remove liquids from any one module/skid and dispose the liquid in a central disposal tank on the facility,

Figure 28 shows, in plan view and side view, respectively, a remotely operated device for pulling a cable, using the power of robots to pull or push the cable through the cable ducts;

Figure 29 shows an alternative embodiment of a remotely operated device for pulling a cable;

Figures 30 and 31 show alternative embodiments of a remotely operated cleaning device; and

Figures 32a, 32b, 32c, 32d show a device for connecting flanges, and various stages of the connection process, using the torque of robots to align the flanges, pull them together and install the bolts constituting the completed flange connection. Detailed description of preferential embodiments

The following description may use terms such as "horizontal", "vertical", "lateral", "back and forth", "up and down", "upper", "lower", "inner", "outer", "forward", "rear", etc. These terms generally refer to the views and orientations as shown in the drawings and that are associated with a normal use of the invention. The terms are used for the reader's convenience only and shall not be limiting.

Referring initially to figure 1, the invented plant comprises in the illustrated

embodiment of an offshore platform 1, comprising a substructure 2 and a topsides facility 3. In should be understood that the substructure 2 could be any suitable substructure known in the art, such as a steel jacket (as illustrated), concrete gravity- base structure, a semi-submersible hull or a ship-shaped vessel. The topsides facility 3 comprises in the illustrated embodiment a flare stack 4 and carries process equipment for hydrocarbons (described below), as well as power generation systems, control modules, etc. (not shown). A housing 5 encloses the process equipment and the ancillary equipment and modules, and access into the housing is provided only through removable roof panels 6 (optional) and a lock chamber 10, all of which will be described below.

Figure 2 shows the platform 1 placed in a body of water W, and a lifting vessel 7 with a lifting wire 8 is in the process of lifting a process module 9 out of (or into) the lock chamber 10. In figure 3, the lifting vessel 7 is in the process of lifting a process rack 11 out of (or into) one of the roof openings; which will be described below. Although not illustrated, the platform may for example be connected to a remote power hub and to one or more remotely located wells.

Figure 4 illustrates a central feature of the invention, namely that the housing S completely encloses the process modules 9. The housing S may thus be defined by its external walls and roof and the lower deck 13, and as such in effect form a pressure vessel within which the atmosphere may be controlled. Reference number 26 denotes an atmosphere control module, i.e. an apparatus that is configured to maintain a controlled atmosphere with respect to pressure, gas composition, temperature, etc. It should be understood that the atmosphere control module 26 is a schematic representation of systems and equipment that per se are known in the art (e.g. for generating inert gases from combustion of hydrocarbons), and need therefore not be discussed in more detail here. The atmosphere control module 26 thus comprises means for controlling and maintaining an incombustible (i.e. incapable of burning) atmosphere inside the housing. The atmosphere control module 26 may also comprise means for generating such incombustible atmosphere. However, inert gas(es) may additionally or alternatively be supplied from an external source (not illustrated in the figures). In one embodiment, the housing 5 comprises a nitrogen-rich atmosphere, and the gas is maintained at a pressure above the ambient pressure (i.e. outside the housing), for example 5mm water gauge, to prevent ingress of oxygen and/or moist air. Specifically, the gaseous atmosphere inside the housing may be provided by inert gas generators (e.g. combusting hydrocarbons) and contain only CO, CO ₂ and ΝΟ _x . The use of other inert gases are also conceivable. Soot, water and corrosive substances are removed. In one embodiment, the atmosphere inside the housing contains nitrogen with less than 15% O ₂ . This allows personnel to work inside the housing, e.g. in order to perform maintenance for limited periods of time, but there is no risk of fire or explosion, as the atmosphere is still incombustible. The ability to control the atmosphere inside the housing also makes it possible to maintain the humidity at such low levels that corrosion does not occur. The housing walls, roof and lower deck may also be insulated to make the platform suitable for extreme temperatures (e.g. arctic and tropical). In arctic regions, surplus heat from the process may be used to heat the topsides facility (i.e. the housing interior) sufficiently such that the use of special steel qualities are not required.

Figure 4 also illustrates how a main deck 14 is arranged a distance above the lower deck 13, thereby creating compartment in which piping, lines and cables between the racks 11 may be routed. Figure 4 also illustrates support beams 12 for use in removing one or more of the roof panels 6. These features are also shown in figure 5, which also shows work robots 15 inside a rack 11 , supported by rails 27 by means of which the robots are movable in a vertical plane. Figure 5 also illustrates braces 28, that may be removed by the work robots in order to access the rack interior.

The housing roof comprises openings covered by removable panels 6 (see e.g. figure 4). These openings are dimensioned such that entire process racks may be lifted into and out of the housing (lifting illustrated in figure 3). Figure 6 is a sectional drawing of a part of the housing roof, and shows how each roof panel 6 is supported by support members 19 and sealed by seal assemblies 17, and arranged between fixed roof segments 16. The support members 19 are in turn supported by the housing wall (not shown in figure 6). The dimensions of the rack 11 underneath the roof panel 6 may typically be height 1 = 15 to 25 m and a width w = 4 to 8 m. The rack typically spans almost the entire width of the platform. Figure 6 also shows support jacks 18, that are movably supported (e.g. on wheels) by the support beams 12.

The design and operation of the seal assemblies 17 will now be described in more detail, with reference to figure 7. Figure 7 shows two seal assemblies 17 on both sides of a roof panel 6. Each seal assembly 17 comprises a first plate 20 which is pivotally connected to the fixed roof segment (indicated by reference number 16' in figure 7) at a first hinge 21. The seal assembly also comprises a second plate 22 which is pivotally connected to the roof panel 6 at a second hinge 23. The free end 30 of the first plate 20 extends into a recess 29 on the roof panel 6. A first gasket 24 is arranged in the recess 29 and is clamped in place by the first plate free end 30. The free end 31 of the second plate 22 abuts against a portion of the first plate 20 and clamps a second gasket 25 against a portion of the recess 29 and the first plate free end 30. The seal assembly 17 thus provides a double barrier seal, by virtue of the first and second gaskets 24, 25. These may be inflatable and activated when first and second plates 20, 22 are in place. The gas used for the activation of the gaskets is the same as that used for inerting the housing interior. The gaskets may be inflatable. The first and second hinges 21 , 23 are conveniently operated by work robots (not shown in figure 7), e.g. via conventional torque tools. Alternatively, if required, the work robots used for this application may be mounted on conventional telescopic cranes.

It should be understood that figure 7 is a sectional drawing, and that the plates, recesses, gaskets, etc., extend the entire length of the roof panel.

The removal of a roof panel 6 will now be described with reference to figures 8a-e: ● Figure 8a: Roof panel 6 in closed and sealed position. Supported by support members 19 and seal assemblies 17 in the closed position. Movable support jacks 18 have been positioned (on the beams 12) underneath roof panel 6.

● Figure 8b: Seal assemblies 17 have been opened by pivoting the first and second plate members (e.g. by means of work robots), exposing the housing interior atmosphere to the ambient atmosphere.

● Figure 8c: Support jacks 18 extended to support roof panel 6 and relieve the panel support members 19 (The support members are subsequently removed or retracted so as not to obstruct the lowering of the roof panel).

● Figure 8d: Panel support members 19 have been removed. Support jacks 18 lowered, thereby also lowering roof panel 6, into the housing.

● Figure 8e: Movable support jacks 18 have been moved (skidding or rolled) along support beams 12 to underneath remaining roof structure, thereby providing access into the housing.

Installation of the roof panel is performed in a reverse manner. The above procedure of removing one or more roof panels is only used when it is necessary to move large equipment, such as an entire rack, into or out of the housing. This could in particular be relevant when large pumps and/or compressors with associated motors are to be maintained. These operations could be complex and not necessarily suitable for robotic operations. The rack will then be lifted off and replaced by a new rack containing the same type of equipment and ready overhauled.

Opening the roof panel will allow influx of ambient air and thus contaminate the controlled atmosphere inside the housing. The invention also comprises means for moving smaller equipment, such as process modules (typically weighing between 5 and 300 tonnes), into and out of the housing without compromising the controlled atmosphere. This will be explained in more detail below, with reference to figures 16a- c.

Figure 9 is yet another schematic representation of how process racks 11 are arranged in a side-by-side relationship on the main deck 14 inside the housing 5 (roof panels and lock chamber are not shown in this figure), spaced apart by access corridors 32. Inside each rack 11 are modules 9, for example process equipment and control devices required to process hydrocarbons. The process modules and racks will require a series of different currents, like 12V, 24V, 230V and 440V in addition to 11kV and 16kV. All this power distribution is made as an integral part of the main support frame of the process racks. When installing a process module in a rack, these different power connections are connected by "stab-in connections". All these connections can be designed without the need for considering corrosion, explosion risk and insulation for personnel protection. All the control signalling between the process modules and between process modules and the control centre (being typically on-shore) are to be based on wire-less transmissions within the topside facility. In order to remove and reinstall a process module (and a complete rack) a large number of pipes need to be disconnected (and re-connected). These operation need to be performed by robotics and the pipe connections are the same or similar to that used in sub-sea installations.

Referring also to figures 10a,b, the robots 15 are supported by a network of vertical rails 27 (also referred to as "robot access bar") and horizontal rails 35. The rails 27, 35 are interconnected in a network and supported by the racks, thus allowing the robots to travel around each rack 11, and between racks, in order to perform work operations. The interface between each robot and the rails is not disclosed here. The horizontal rails 35 are furnished with electric servo motors (not shown) and are connected at both ends to respective vertical rails 27 via a rack-and-pinion assembly (not shown). The horizontal rails may thus travel up and down on a pair of vertical rails 27, via the rack-and-pinion assembly.

In general, work robots 15 may work in pairs, typically providing a lifting capacity of 1000 kg using readily available work robots. Each robot is battery powered and controlled by wireless transmission, in a manner which per se in known in the art and therefore not explained in further detail here. Docking stations for charging (not shown) are provided in a holding area 34, as shown in figures 11 a,b. Figure 11a also shows how piping and electrical cables (schematically illustrated and designated by reference number 33) are routed below the main deck 14 and above each of the racks 11. The piping/cables 33 are modularized, whereby they may be disconnected and reconnected (by the robots) as needed. Movement of a module 9 will now be described in more detail, with reference to figures 12a-c:

• Figure 12a: Four robots 15 (only three shown) are positioned on horizontal rail pieces 35' that are aligned at an elevation suitable for retrieving a module 9 inside a rack 11. The rail pieces 35' are furnished with electric servo motors (not shown) and are connected at both ends to respective vertical rails (robot access bars) 27 via a rack-and-pinion assembly (not shown). The horizontal pieces 35' rails may thus travel up and down on a pair of vertical rails 27, via the rack-and- pinion assembly. Typically, there is one vertical rail per robot. A trolley 36 supported by tracks 37 is in position on the main deck below the robots. The trolley 36 comprises wheels and is powered by servo motors (not shown) in a manners which is known in the art.

• Figure 12b: The module 9 has been retrieved (e.g. by skidding on rails or tracks) from the rack by the robots and is fully supported by the interconnected rail pieces 35'.

The interconnected rails pieces 35', carrying the module, are being lowered along the vertical rails 27, by means of the servo motor and the rack-and-pinion assembly.

• Figure 12c: The module 9 is placed on the trolley 36 and may be moved to its destination on the tracks 37.

In order to achieve a versatile utilization of the robots that are operating within the plant, it is of relevance that all robots can be placed along all outer surfaces of the process rack, such that any robot can be in any position along the outer surfaces of the racks in addition to any combination of robots. To achieve this, connector rails 43 are arranged for removable connection between the rails 35. The connector rails 43 are structurally supported to that they can be moved in a controlled manner to serve its intended function. Figures 12b and 12c show the connector rails 43 in an open

(disconnected) position, while figure 15 shows the connector rails 43 in the closed (connected) position.

A robot 15, when connected to a robot access bar 27, will be able to be moved such that it can be adjacent to all areas on the outside of the process racks 11 , rails 35 are arranged at both top and bottom, around each process rack. The aforementioned connector rails 43 provide connection between the rails 35 (see figure 15).

The horizontal rail 35 around the process rack 11 comprises movable comer pieces 44, of which one is shown in figure 16. Each corner piece 44 is connected to the rail 35 via a hinge 47 such that it can be lifted up. The robot access bar may be hung off a respective support structure 45 on the rail 35. The connector rail 43 comprises a straight rail segment that may be moved horizontally, as indicated by the arrows in figure 16. Supports 46 are provided for the corner rail and connector rail 43. When the connector rail 43 is in position (see figure 15), the robot access 27 bar can move between adjacent process racks 11.

In order for the corner piece 44 to be moved up and down, the connector rail 43 is provided with a bar system 48 (see figure 17) being such that when the connector rail 43 is approaching the rail 35 it will be lifted up. The powering of the connector rail can be electric or hydraulic. Referring to figure 18, the robot access bar 27 can then move along the connector rail. The movement of the robot access bar is by one motor 49 at the top and a similar one (not shown) at the bottom.

Figures 13a-c are a schematic illustration of a procedure for removing a module 9 from the platform without compromising the controlled atmosphere inside the housing. The lock chamber 10, which in itself is an air-tight pressure vessel, is placed outside the housing 5 (see e.g. figure 5) but a first sealable door 38 provides access between the housing interior and the lock chamber. A second sealable door 39 and a sealable cover 40 are facing the outside.

● Figure 13 a: The first door 38 is closed and sealed; hence isolating the lock

chamber 10 from the housing 5 interior.

● Figure 13b: The first door 38 is open and the second door 39 is closed, such that the atmosphere in the housing interior also extends into the lock chamber 10. The module 9 is moved into the lock chamber 10.

● Figure 13c: The first door is closed, thus sealing the housing interior from the lock chamber 10. Lock chamber 10 is opened (second door 39 and sealable cover 40 are open), whereby the module may be lifted out of the lock chamber 10, by e.g. a lifting wire 8 (The inert generator provides the necessary inert gas for the lock chamber 10 and the opening and closing of the doors are performed when the monitoring instruments for the locked atmosphere indicated that the acceptance criteria are fulfilled). A lay-down area (not shown) may be arranged outside the lock chamber 10, in order to provide an intermediate storage facility;

Figures 14a,b illustrate how a work robot 15 supported by a telescopic arm 41 may extend into a rack 11, e.g. for performing verification and inspection tasks. For example, the robot may carry equipment for performing x-ray computed tomography of welds and other structural components, m figure 14b, a horizontal rail segment 35" is used to bridge the span between a vertical rail 27 and a network of rack-internal rails 42, thereby allowing a work robot 15 to move inside individual racks and process modules.

Referring now to figure 19, the processes may be set to operate in a pre-defined manner. The basis for defining the required equipment for a given task, operation or process may be based on for example reservoir data (and e.g. influx of oil, gas, water and sand into the processing plant. However, if the change in the flow of fluids from the reservoir differs from that forming the basis for the process design, it may be required to add equipment and instruments in the plant. Consequently, during the initial design of the plant, the amount of equipment and the sizes of these will not be known. Hence the topography of the plant needs to have a significant built-in flexibility to accommodate future equipment and instruments. The arrangement is illustrated in figures 19 and 20, showing a series of pre-installed brackets 50 in a rack 11. Rack-internal support module beams 51 may be removably connected to the bracket 50.

The areas where the equipment (e.g. modules 9) is located may be congested. However, from time to time there will be a need for inspection and preventive maintenance of equipment and instruments. The mobility of the robots 15 is therefore essential. Figure 21 illustrates how a robot 15 may be entering an equipment area inside a rack. The robot may be turned upside down just by twisting the rack-internal rail 52 along which the robot is travelling (and which also provides electric power) Figure 21 shows that the rail 52 is rotated 180°. However, it special cases the rail 52 may be only rotated 90°, clockwise or counter-clockwise. Referring to figure 21, the following operations may be envisaged: ● Pos.1 : The robot 15 is located in the correct position for entering the equipment area.

● Pos.2: The robot has left the transport platform mat is attached to the robot access bar.

● Pos. 3 : A section of the rail 52 is rotated 180°.

● Pos. 4: The robot is has left the rotated segment, hanging upside down, and climbing to the correct level.

● Pos.5: The robot has arrived at its end position to inspect an instrument at the inner part of the equipment area in question.

The plant concept is designed to transport large constellations of equipment from the position in which it is functioning in the process, and to a position where manual inspection and repair can be performed; for example on an onshore factory. Figures 22a,b illustrate an embodiment of how this may be performed. Transport screws S3 (preferably four; only one shown) are connected to the robot access bars 27 and used to drag/pull the module 9 onto the transport elevator 54. The transport screws are powered by four robots 15 in synchronous operation. The robots may be equipped with cameras and light (not shown), allowing an operator (e.g. at an onshore base) to monitor parameters such as the alignment of the transport screws (in particular region "R" in figure 22a) before the operation is started. A position "R" exists also on the other side of the module/skid. The transport screws (four in number) are powered by four robots exerting is torque in four points - two on each side. Figure 22b shows a module 9, having been moved onto the transport elevator 54, and the elevator is being lowered.

The ability to move of process equipment vertically inside the plant is essential. After the equipment has been skidded onto the transport elevator 54, four robot access bars 27 function as support pillars for the transport elevator. An embodiment is illustrated in figure 23, where the lifting and lowering mechanism comprises:

- Four wheels for the chains 55; two on each side of each of the robot access bars 27;

- 16 motors 49' powering the wheels 56, two on each side of each of the four robot access bars. The 16 motors are located such: two at the top and two at the bottom on each of the four robot access bars; - One support bracket on each robot access bar, four in total for the four robot access bars;

- Support rails 57, with motor, on one each of the four robot access bars; two at the top and two at the bottom.

When the equipment has been skidded onto the beams, as explained above, the 16 motors are operated synchronously to lower the equipment down to the predetermined position.

Referring to figure 24, in some instances, when heavy equipment 58 is to be moved from inside a process rack 11 , it will not be possible to lift the equipment by the use of a robot, as described above. In that case, the heavy equipment 58 may be permanently mounted on an undercarriage 59 (e.g. a trolley) which is connected to, and powered via, the rack-internal rail 52'. As the undercarriage is clamped to the rail 52', it can follow the rail even if moving upwards and downwards. In the event that the rail is steep, the rail can be fitted with rack-and-pinion facilities to provide the sufficient traction. This is important when the equipment is located in confined spaces. A typical path is indicated by Pos.1, Pos.2 and Pos.3 in figure 24. When the equipment is located at its end position (Pos.3), it can be moved both horizontally and vertically to its final destination. This could either a storage area inside the facility or be moved onto a sea going vessel to be shipped to shore for repair.

Figures 25a and 25 b illustrate an alternative to the robot access bars discussed above. In this embodiment, the robot access bars are replaced by one or several carts 60. The carts 60 are suspended between support brackets 50' placed on adjacent process racks 11. The carts 60 are rolling on wheels or skidding along on the support brackets. A trolley supports a frame 61 acting as a support for handling tools, robots, robot tools, and equipment to be changed out inside the process racks, for example during predetermined inspection and(or maintenance tasks. These could be located in buckets 62 that have the same type of horizontal traction and rail interface system as the robots. The frame 61 has a function to move the robot 15 both in the vertical and horizontal plane such that it can be aligned with the top surface of the rack-internal rail 52. In addition, the frame can be moved from between process racks 11 , as indicated by the arrows in figure 25a. The frame 61 can also be rotated 180° along its longitudinal axis L so that the robot handling structure 62 can face towards the other process rack. When the robot leaves the handling tool and enters the rails 52, it is of importance that the surfaces on which the robot rolls are aligned. This is done by using the cameras and lights located on the front part (indicated by "T" in figure 25b) of the robot to move from the frame and onto the rail in the process rack.

As all the processing equipment is located in multiple levels and there are no personnel that require any decks to step on, the need for ordinary decks (as in prior art platforms) does not exist. However, when opening up equipment, for example breaking up flanges, liquids may spill out. In addition, when performing the operation of dismantling equipment the liquids inside will normally be drained out prior to opening up the flanges.

Figure 26 illustrates an embodiment of an atmospheric drainage system. The system comprises a complete atmospheric drain sump 64, covering the entire area below the equipment module 9, or covering the entire bottom area of the module/skid. A robot 15 is equipped with suction facilities and a portable drain tank 65 is accompanying the robot on the robot access bar 27. The robot is configured to suck up liquids from the sump 64. Since the robot access bar can move to any position along the process rack 11, the robot and associated portable drain tank can reach any relevant place in the plant for removing liquids. The drain tank 65 can be transported to a larger collection tank (not shown) and pumped into this tank. One advantage of performing drainage in this manner is that a conventional open drain system including several pipes and valves will not be required.

Referring to figure 27, a similar procedure can be used for sucking out a combination of liquids and solid particles S from open drain trays 64 or tanks as fully enclosed vessels (like a hydrocarbon separator). However, for fully enclosed vessels like pressure vessels, a man-hole has to be opened in order for the robot to get access with its suction hose. The base plates on which the portable drain tanks (both figures 26 and 27) are resting on are in itself powered by servo motors (not shown) in a manner similar to that of the robots - and are hence movable to the correct position assisted by an operator in the central control room onshore. Another aspect of the invented unmanned plant is the possibility to utilize the power and manoeuvrability of the robots to both push and drag cables through the cable racks. It is not possible at design stage of the plant to fully anticipate the future need for cables. The cable installation system must therefore be adjustable to accommodate for various cable diameters.

One embodiment of a cable installation system is illustrated in figures 28 and 29 and show a cable 67 in a cable rack 66. A plurality of rollers 68, which may be powered by a robot (not shown in figures 28, 29) at a robot access point 69, in the form of for example a conventional nut. Spacing between rollers can be adjusted by robots at regular intervals along the cable rack at adjustment points 70, which could be a conventional nut and screw. The cable may thus be moved in the cable rack by operation of the powered rollers.

Figure 29 shows an embodiment where the cable installation system is set up to diverge the cable 67 into a diverging cable rack 66'. The set-up is similar to that shown in figure 28, but the rollers 68 are adjusted set to force the cable into the diverging cable rack.

Within the unmanned plant, where processes are taking place over a long period of time, for example 20 to 30 years, it will be necessary to clean all, or most, surfaces inside the plant. This is an activity that can be executed by robots. Figure 30 shows an

embodiment of a cleaning device that will both stir up the solid particles and liquids and suck these into the robot. The robot (not shown in figure 30) may be equipped with both a gas compressor delivering high pressure gas to ejection nozzles 73 and suction to suction nozzles 74. The robot may thus be equipped with a collection tank for the particles and liquids. The illustrated cleaning device comprises an end piece 71 which is connectable to a robot arm (not shown) that rotates, for example at 200 rpm. The illustrated rotating cleaning device is circular in shape and a flexible skirt 72 which is fixed to the periphery of the device. The ejection nozzles 73 are delivering high pressure gas, typically 3 bar above the surrounding atmosphere. The suction nozzles 74 may operate at typically 200 milli bar absolute. The compressed air zone inside the rotating skirt may be replaced by a conventional, flexible, mechanical brush 75, as shown in figure 31. The equipment in an unmanned production plant, remotely operated via robots (in the plant) by personnel on shore land, may benefit from a remotely operated device for mating flanges. An embodiment of such device is described below, with reference to figures 32a-d.

The mating device comprises two portions 76a,b, each connected to its respective pipe portion 77a,b in the vicinity of its respective flange 78a,b. The first device portion 76a comprises a plurality of guide pins 79 (three guide pins are preferred), and the second device portion 76b comprises guide sockets 80, configured for receiving a

corresponding guide pin. A plurality of tension bars 81 (preferably three) are rotatably connected to the second device portion 76b, and are each configured for operation by a robot (not shown in figures 32a-d). Each tension bar comprises a corresponding robot- operated nut 82. Figure 32a shows the flanges in a disengaged position.

In figure 32b, the tension bars 81 have been moved (by rotation) such that a distal tip, which comprises a lug 83 engages a portion of the first flange 78a.

In figure 32c, the nuts 82 have been turned, whereby the guide pins have entered the corresponding guide socket, and the tension bars have pulled the flange halves 78a,b together.

In figure 32d, bolts 84 have been inserted and tightened (by a robot), and the flange connection is made up. The lugs 83 have been disconnected.

In operation of the plant, the robots may be configured to operate based on pre-defined information of the shapes of all objects in the plant.

Although the invention has been described above with reference to a hydrocarbon processing plant located on an offshore platform, it should be understood that the invention is equally applicable for plants located at inshore locations and on land.