NO344729B1 - Multipurpose jackup rig and use of such a rig for fish farming - Google Patents

Description

MULTIPURPOSE JACKUP RIG AND USE OF SUCH A RIG FOR FISH FARMING

The invention relates to the use of a jackup rig for use in fish farming. More specifically, the invention relates to a jackup rig that has been modified to be a multipurpose jackup rig. In a first operating state, the multi-purpose jackup rig can be provided with an exchangeable equipment package comprising a displaceable outrigger (cantilever) with a derrick according to known technology. In a second operating state, the jackup rig can be provided with an exchangeable equipment package comprising a facility for operating a marine fish farming facility. The jackup rig can in a third operating state be provided with an exchangeable equipment package adapted for a different purpose than in the first and second operating states.

Background for the invention

It is known from the marine petroleum industry to use a platform that can be jacked up, referred to in the technical language as a jackup rig. A jackup rig comprises a floating hull with a rig deck and several legs that can be moved up or down relative to the hull. By raising the legs, the jackup rig can be moved with the help of a tugboat. In a use position, the legs are lowered to a seabed. When the legs are anchored to the seabed, the hull can be raised clear of a water surface. For use in the petroleum industry, the jackup rigs are typically equipped with a cantilever that includes a derrick. The jackup rigs can also include a deck arranged on the outside of the hull, known in the technical language as a Texas deck.

Because the jackup rigs can be moved and can be docked to a quay, they can be rebuilt at the quay to adapt to alternative operations. It is desirable that a possibly converted jackup rig can be returned to an ordinary petroleum rig in the simplest possible way.

There is a need within the aquaculture industry to develop fish farming facilities that can be positioned in locations more exposed to the weather than the locations that have been in use until now. There is also a desire to position such localities as rooms offshore, as there is, among other things, more space than inland, good current conditions and less infection pressure from pathogenic organisms.

Exposed localities are exposed to larger waves and more wind than the more sheltered localities inland. There is a need to develop equipment for farming fish that can withstand storms and large waves without the equipment being damaged. Examples of such equipment are the ocean cages "Ocean Farm 1" and "Havfarm".

Well-known jackup rigs are designed for, and certified for, operation in deep sea. Used jackup rigs can be a reasonable alternative to building sea cages that are only intended for fish farming.

Patent US 5628279 shows how closed and abandoned offshore oil platforms can be converted for aquaculture purposes. A feeding station with a feed silo and other necessary equipment is placed in a standard transport container.

The purpose of the invention is to remedy or to reduce at least one of the disadvantages of known technology, or at least to provide a useful alternative to known technology.

The purpose is achieved by the features indicated in the description below and in the subsequent patent claims.

The invention is defined by the independent patent claims. The independent claims define advantageous embodiments of the invention.

Description of the invention

A multi-purpose jackup rig according to the invention has the advantage that it can be positioned on an exposed location both inside and outside. A jackup rig, when the cantilever module is removed, has plenty of space for the necessary equipment to run fish farming. Such necessary equipment includes silos for storing fish feed, feeding equipment, equipment for treating fish in case of disease and parasite infestation, and equipment for collecting and storing dead fish. Furthermore, such a jackup rig has living space for a crew and good opportunities to transport the crew to and from, either by helicopter or by boat.

The jackup rig includes space and facilities for large feed stores, fresh water and living quarters. This can reduce logistics from shore. Existing support systems and safety systems on the jackup rig will also be able to be used, including certification in accordance with maritime regulations.

The jackup rig stands firmly on the seabed with its displaceable legs. The jackup rig is therefore a stable rig and vessels can lie close to the jackup rig to transfer feed, supplies, fish and crew. Similarly, fish can be transferred from the jackup rig to a vessel.

The jackup rig according to the invention has the further advantage that in the event of a forecasted storm, the rig can be raised to increase the so-called air gap (eng. air gap) between the water surface and the jackup rig's hull. The rig and the equipment on the rig will thereby not be exposed to waves. The jackup rig as such is designed to withstand storms.

Breeding cages of a known type are positioned around the jackup rig. The breeding cages can be moored in a known way with individual anchoring systems, or with an anchoring system that includes two or more cages. In one embodiment, the cages can be lowered. This has the advantage that the cages can be lowered in the event of a predicted storm. This prevents the cages from being exposed to large waves with the risk of the cages being destroyed. The cages can be raised again when the storm is over. The cages can be supplied with feed from a feeding facility on the jackup rig's fish farming equipment package. Such a feeding system is known in the art, and is not mentioned.

In a first aspect, the invention relates more specifically to a multi-purpose jackup rig, where the jackup rig is arranged to be provided in a first operating state with a first exchangeable equipment package comprising a cantilever with a derrick. The jackup rig is, in a second operational state, adapted to be provided with a second exchangeable equipment package comprising a facility for operating a marine fish farm, the second equipment package being placed on a carrier, the second equipment package being arranged for positioning on a rig deck on the jack-up rig such that the second replaceable equipment package replaces the first replaceable equipment package, the second equipment package includes at least one silo for feed and a feeding facility, and the jack-up rig is adapted to selectively assume the first operational state and the second operational state such that the jackup rig in operation houses one of the first or the second equipment package.

The second equipment package can be placed on a frame or a carrying device arranged for movement by means of a transport trolley. The second equipment package can, in an alternative design, be arranged for movement with a crane. The frame or the carrying device can be modularly constructed so that parts of the second equipment package can be replaced independently of each other.

The second equipment package may comprise a superstructure, comprising a feed warehouse and a control module according to known technology.

A modular structure and the use of known components can contribute to a shorter and simpler conversion and thereby provide a cost-effective construction.

The jackup rig can optionally be supplied with at least one additional module designed for installation on the outside of the hull. The additional module can include one of means for processing fish and means for distributing feed to a breeding pen.

The additional module can comprise a level control according to known technology, for example a hydraulic lifting device or a toothed rack with a toothed drive. The add-on module may comprise an automatic vertical level control adapted to keep the add-on module at a constant height above the water surface depending on wave height and tide height.

The hull of the jackup rig and the auxiliary module may be connected by at least one telescopic tube or at least one flexible hose.

There is also described a procedure for changing from a first equipment package to a second equipment package for a multipurpose jackup rig, where the method includes the steps of: a) bringing the multipurpose jackup rig up to a quay;

b) displacing a first equipment package from the jackup rig and to a first position on the dock; c) carry a second equipment package from a second position on the quay to the jackup rig; d) sliding the second equipment package onto the jackup rig; and

e) lead the multipurpose jackup rig from the dock.

The first equipment package may include a cantilever with a derrick. The second equipment package may include a facility for operating a marine fish farming facility.

In what follows, an example of a preferred embodiment is described which is illustrated in the accompanying drawings, where:

Fig. 1 shows a jackup rig according to known technology designed for petroleum operations;

Fig. 2 shows a jackup rig according to the invention modified for marine fish farming;

Fig. 3 shows the movement of a first equipment package from the jackup rig to a quay;

Fig. 4 shows the first equipment package in a first position on the dock, and a second equipment package in a second position on the dock;

Fig. 5 shows the movement of the second equipment package up to the jackup rig;

Fig. 6 shows the second equipment package positioned on the jackup rig;

Fig. 7 shows the jackup rig fitted with an additional module;

Fig. 8 shows guiding the jackup rig from the quay;

Fig. 9 shows the jackup rig jacked up in a desired operational position;

Fig. 10 shows a plurality of marine breeding cages around the jackup rig;

Fig. 11 shows the additional module provided with a de-lice module in operative position;

Fig. 12 shows the jackup rig with an increased air gap in anticipation of storms; and

Fig. 13 shows a walkway arranged between the jackup rig and a cage.

It should be noted that the drawings initially have different scales.

Figure 1 shows a jackup rig 1) according to known technology arranged for petroleum operations, comprising a first equipment package 10) provided with a cantilever module 11) comprising a derrick, a housing module 16), a helicopter deck 17) and a crane 15).

Figure 2 shows from another angle a jackup rig 1 according to the invention, where the first equipment package 10 and other petroleum-related equipment (not shown) have been replaced by a second equipment package 20 designed for fish farming. As figures 1 and 2 show, only the equipment packages 10, 20 distinguish the jackup rig 1 in the two very different areas of use. The housing module 16, the helicopter deck 17 and the crane 15 are intact.

Figure 3 shows the jackup rig 1 placed at a quay 9, where the first equipment package 10 is moved from the jackup rig 1 to a first position 91 on the quay 9 to make room for the second equipment package 20, which in the figure is placed in a second position 92. The movement of the first equipment package 10 and the second equipment package 20 takes place using a cart 3 according to known technology, where the cart 3 is designed to raise and lower a load. The movement of the first and second equipment package 10, 20 can alternatively take place with a crane (not shown).

Figure 4 shows the first equipment package 10 placed in the first position 91 on the dock 9. The elevating and lowering carriage 3 is positioned in front of the second equipment package 20. The second equipment package 20 is shown in the figure as one unit comprising a first feed store 21, a second feed storage 22, a control room 23 and a feeding facility according to known technique (not shown).

Figure 5 shows the second equipment package 20 placed on the carriage 3 and being moved from the second position 92 on the quay 9 and to a rig deck 12 on the jackup rig 1.

Figure 6 shows the second equipment package 20 in operational position on the jackup rig 1. The second equipment package 20 is lowered onto a plurality of supports (not shown) according to known technology arranged on the rig deck 12 of the jackup rig 1. The figure also shows an additional module 30 belonging to it second equipment package 20.

Figure 7 shows the jackup rig 1 in a raised position and with the additional module 30 placed on the outside of the jackup rig's 1 hull 11. The additional module 30 comprises a displacement device 31 so that the additional module 30 can be raised and lowered vertically and shifted horizontally on the outside of the jackup rig 1 hull 11. The displacement device may comprise a toothed rack with a toothed gear. The additional module 30 can be lifted into place by means of a crane 15 on the jackup rig 1. The additional module 30 is shown in the figure in a middle position.

Figure 8 shows a fully rebuilt jackup rig 1 under tow by two towboats TB. Before towing, the legs 13 of the jackup rig 1 are raised so that the hull 11 floats on a water surface 4 and can thereby be towed from the quay to a working position. During towing, the additional module 30 is advantageously raised to an upper position to clear the water surface 4.

Figure 9 shows the jackup rig 1 in a jacked-up and operational position, where part of the legs 13 extends visibly between the hull 11 and the water surface 4. In the operative position, the legs 13 are brought down and rest on a seabed (not shown) so that The jackup rig 1 is stable on the seabed. The three legs 13 can be moved independently of each other so that the jackup rig 1 can stand level even if the seabed has differences in height, as is known in the art.

Figure 10 shows the jackup rig 1 in operational position with a plurality of rearing cages 40 positioned around the jackup rig 1. The additional module 30 is shown lowered to a lower operational position. The cages 40 are anchored to the seabed (not shown) according to known techniques. The feed is fed from the feed store 21 out to the cages 40 by means of the feed system not shown. The feeding system comprises a plurality of distribution hoses 41 which lead the feed from the jackup rig 1 and to the cages 40. A portion of the distribution hoses 41 is submerged and not shown in the figure.

Figure 11 shows the additional module 30 in an operational position close to the water surface 4 and arranged for de-liceing fish (not shown) in the rearing cage 40. The fish are led from the rearing cage 40 into a de-lice module 31 on the additional module 30 via an inlet hose 32. The module's 30 position of use near the water surface 4 provides a minimal lifting height for the fish. A low lifting height is energy efficient and contributes to less stress on the fish during the de-lice process. After the fish has been treated in the de-lice module 31, it is returned to the cage 40 via an outlet hose 33. A flexible groove wall 42 in the cage 40 separates the treated and the untreated fish from each other. In the figure, the untreated fish is in cage section 40U, while the treated fish is in cage section 40T. A rotor spreader 45 for feed is arranged in the cage 40.

Figure 12 shows the jackup rig 1 in a raised position in anticipation of a storm. By raising the rig 1, the hull 11 and the additional module 30 avoid being hit by any high waves. At the same time, the cages 40 can be lowered below the water surface 4 for protection (not shown).

Figure 13 shows the additional module 30 in the operative position. A walkway 14 from the rig deck 12 of the jackup rig 1 to the rearing cage 40 provides a safe movement of personnel between the jackup rig 1 and the rearing cages 40. The walkway 14 can be positioned using the crane 15. The walkway 14 can be telescopic to compensate for different height differences between the water surface 4 and the rig deck 12. Furthermore, the figure shows walkways 44 between the rearing cages 40.

It should be noted that all of the above embodiments illustrate the invention, but do not limit it, and those skilled in the art will be able to devise many alternative embodiments without departing from the scope of the appended claims. It should also be noted that the drawings initially have different scales.

The use of the verb "to comprise" and its various forms does not exclude the presence of elements or steps not mentioned in the claims. The indefinite articles "an", "ei" or "et" before an element do not exclude the presence of several such elements.

The fact that certain features are listed in mutually different dependent claims does not indicate that a combination of these features cannot be advantageously used.

Claims (2)

Patent claims 1. Multi-purpose jackup rig (1), where the jackup rig (1) is arranged in a first operating state to be provided with a first replaceable equipment package (10) comprising a cantilever with a derrick, characterized in that the jackup rig (1) in a second operating condition is arranged to be provided with a second replaceable equipment package (20) comprising a facility for operating a marine fish farming facility, the second equipment package (20) is placed on a carrier device, the second equipment package (20) is arranged for positioning on a rig deck (12) on the jack-up rig (1) so that the second exchangeable equipment package (20) replaces the first exchangeable equipment package (10), the second equipment package (20) comprises at least one silo for feed and a feeding facility, and the jackup rig is arranged to selectively assume the first operating state and the second operating state so that the jackup rig (1) in operation houses one of the first or the second equipment package (10, 20). 2. Multipurpose jackup rig (1) according to claim 1, where an additional module (30) is arranged on the outside of the jackup rig's (1) hull (11), and the additional module comprises one of means for treating fish and means for distribution of feed to a breeding pen (40).