The present invention relates to a deployment system, and in particular to a system for use in deploying and retrieving equipment from and to an offshore vessel.
In the oil and gas industry there is a requirement to deploy and retrieve equipment and components into and from the sea from floating vessels, such as supply boats and anchor handling vessels. Subsea equipment may include Christmas trees for coupling to a subsea wellhead, BOP stacks, intervention systems, subsea processing equipment including pumps, separators, injectors, meters, valves, chokes, manifolds and the like. In many cases the subsea equipment is very heavy, typically from a few tons up to around 200 tons, and very long, for example between 5 to 40 metres in length. This makes handling such equipment very difficult. For example, where very long components are to be deployed and installed vertically, these must be transported in a horizontal position, and subsequently moved to a vertical orientation upon deployment. The reverse is true when the equipment is to be retrieved. This therefore requires specialised handling equipment to be provided in order to properly and safely deploy the subsea equipment.
In many cases vessels are fitted with large handling cranes. However, these often have a significant footprint, using valuable deck space. Alternatively, a dedicated lifting vessel may be required to lift the subsea equipment to and/or from a suitable transport vessel. Where lifting cranes are utilised, significant human interaction may be required, for example to couple lifting components, monitor movement of the equipment and relay commands to a crane operator or the like. Accordingly, personnel may be required to operate in a hazardous environment.
When deploying equipment from a floating vessel, it is difficult to retain proper control through the splash zone. Additionally, conventional lifting and handling equipment may not adequately accommodate for the movement of the vessel as a result of waves and wind. As such, proper control of the equipment may be difficult, particularly when attempting to land the equipment on the seabed or on subsea apparatus to prevent causing damage to the equipment or subsea apparatus.
According to a first aspect of the present invention, there is provided a deployment system for deploying equipment from a vessel, said system comprising:
The carriage may be translatable relative to the cradle in any plane.
Preferably, the system is adapted to retrieve equipment to a vessel upon which the system is mounted.
The cradle is adapted to be translated relative to the support structure between retracted and extended positions. Preferably, when in the retracted position all or at least a major portion of the cradle is located over the deck of the vessel. Preferably also, when in the extended position at least a portion of the cradle extends beyond the edge of the deck of the vessel.
Preferably, at least a portion of the cradle is adapted to be pivoted relative to the support structure towards a tilted position. More preferably, at least a portion of the cradle is adapted to be pivoted relative to the support structure when said cradle is located in its extended position. Advantageously, the cradle is reconfigured into the deployment configuration by a combination of being translated towards the extended position and then pivoted towards the tilted position.
In use, the cradle may be translated to the extended position and then pivoted to tilt a portion of the cradle over the edge of the deck of the vessel and preferably into the sea. Once the cradle is positioned within this deployment configuration the equipment to be deployed may be moved by the carriage from the stored position to the deployed position. Tilting a portion of the cradle into the sea provides a fixed transition through the splash zone of the sea, permitting controlled deployment of equipment by the carriage through this hazardous zone.
In one embodiment the cradle comprises a frame mounted on a translatable support, wherein the translatable support is mounted on the support structure. Preferably, the carriage of the deployment system is mounted on the frame of the cradle and is translatable relative thereto. Preferably also, in use, the frame is adapted to contain at least a portion of equipment to be deployed.
The translatable support may be slidably mounted on the support structure. Alternatively, and in a preferred embodiment, the translatable support is mounted on the support structure via friction reducing means. The friction reducing means may comprise at least one and preferably a plurality of rolling bodies, which may be freely positioned between the translatable support and support structure, or alternatively may be fixed to at least one of the supports, or any suitable combination thereof. The rolling bodies may comprise rollers, wheels, balls or the like.
The support structure may comprise at least one and preferably a plurality of rails upon which the translatable support is mounted. The translatable support may comprise a dolly or cart, for example.
Advantageously, the translatable support may be coupled to the support structure in a manner to prevent inadvertent separation thereof. For example, the support structure may comprise one or more channels within which at least a portion of the translatable support is adapted to be received and moved. Alternatively, or additionally, the translatable support may comprise a plurality of rolling members rotatably coupled thereto, wherein said rolling members are adapted to be received within the channels of the support structure.
In a preferred embodiment the frame of the cradle is pivotally mounted on the translatable support, preferably in the region of one end of the translatable support.
Preferably, the system comprises drive means adapted to translate the cradle relative to the support structure. In one embodiment the drive means comprises hydraulic drive means such as a piston or ram arrangement. A single stage piston arrangement may be provided, or alternatively a multiple stage piston arrangement may be provided which advantageously permits a greater degree of translation to be achieved. This is beneficial where long equipment is to be transported and deployed. Alternatively, or additionally, a gearing arrangement may be utilised, such as a rack and pinion gear arrangement adapted to be driven by a motor, such as an electric motor.
The drive means may be mounted between the deck of the vessel and the translatable support, or alternatively between the support structure and the translatable support. Alternatively further, the drive means may be mounted directly on the translatable support. In this arrangement the drive means may comprise a motor adapted to drive the translatable support, for example via a friction or geared connection with one or both of the support structure and deck of the vessel.
Preferably, the system further comprises drive means adapted to pivot the frame of the cradle relative to the support structure and the translatable support. In one embodiment the pivot drive means comprises hydraulic drive means, such as a hydraulic piston arrangement or the like. Alternatively, the pivot drive means may comprise an electric motor or the like adapted to drive a gearing arrangement, for example. Alternatively further, the pivot drive means may comprise a winch arrangement. The pivot drive means may be provided between the frame and the translatable support. Alternatively, the pivot drive means may be provided between the frame of the cradle and the support structure, or alternatively the deck of the vessel.
The carriage may be slidably mounted on the cradle. Alternatively, the carriage may be mounted on the cradle via friction reducing means such as at least one and preferably a plurality of rolling bodies, such as rollers, wheels, balls or the like. At least a portion of the carriage may be received within one or more channels formed in or on the cradle to prevent inadvertent separation of the carriage and cradle.
In one embodiment the carriage may be translated by hydraulic drive means, such as by a piston arrangement or the like. Alternatively, the carriage may be translated by a motor driving a gear arrangement or the like. Alternatively further, the carriage may be translated by a cable or chain drive system or the like.
Preferably, the carriage is adapted to engage and couple to equipment to be deployed by a latching arrangement, such as a male-to-female engaging and latching arrangement. Preferably, the system further comprises an adaptor to be secured to the equipment and to be engaged and coupled to the carriage. The adaptor may form part of a protective structure adapted to surround the equipment to be deployed.
Preferably, the system comprises a winch arrangement adapted to be secured to the equipment and to deploy the equipment to the required depth within the sea once released from the carriage. The winch arrangement preferably comprises a winch drum and a reelable medium, such as steel rope, chain, wireline or the like. The winch drum may be mounted on the support structure, or may alternatively be mounted on the cradle, on the deck or other portion of the vessel. Preferably, the winch arrangement comprises means for securing the reelable medium to the equipment to be deployed.
In a preferred embodiment the carriage comprises a guide adapted to engage and direct the reelable medium in the required direction. The guide may comprise a gooseneck arrangement mounted on the carriage, preferably the upper end of the carriage when in use.
The cradle may define a slot adapted to accommodate the reelable medium when the carriage is translated along the cradle.
Preferably, the system comprises a compensator system adapted to compensate for heave of the vessel. Preferably, the compensator system is adapted to minimise undulation movement of the equipment when being moved through the sea as a result of heave of the vessel upon which the system is mounted. This arrangement advantageously minimises impulse loading on the reelable medium and permits the equipment to be accurately and carefully landed at the target destination, such as a Christmas tree, thus preventing damage to the equipment or target destination. In a preferred embodiment, the compensator system is coupled to the winch arrangement, and more preferably coupled between the equipment to be deployed/retrieved and the reelable medium of the winch arrangement. The compensator system may therefore provide means for securing the reelable medium to the equipment. Advantageously, the compensator system is secured to a protective structure surrounding the equipment. The compensator system may surround a portion of the equipment and adapted to provide protection to said portion of the equipment.
Preferably, the compensator system comprises first and second portions, the first portion being adapted to be secured to the equipment and the second portion being adapted to be secured to the reelable medium, wherein the first and second portions are coupled together via a piston arrangement. The piston arrangement is preferably adapted to adjust the separation of the first and second portions to accommodate for heave of the vessel. The compensator system may be activated/de-activated by hydrostatic pressure and adjustment may be initiated and achieved by monitoring and accommodating changes in hydraulic load.
Preferably, the system comprises alignment means adapted to align equipment to be retrieved with the carriage to permit the equipment to become correctly secured to the carriage. In a preferred embodiment the alignment means comprises a profile on one of the carriage and equipment and a slot in the other of the carriage and equipment, wherein, in use, the profile is guided and aligned to be received within the slot. The alignment means may comprise a mule shoe arrangement. One of the carriage and equipment may comprise a cage defining a cam surface and a slot, wherein a profile on the other of the carriage and equipment is adapted to engage the cam surface to cause rotation of the equipment when the carriage and equipment are brought together, such that the profile may be received within the slot. The compensator system may form part of the alignment means.
The system of the present invention may be adapted to be mounted on a seagoing vessel, such as a ship or floating platform or the like. Alternatively, in aspects of the invention the system may be adapted to be mounted onshore, adjacent a body of water, such as on a pier, harbour or the like.
Preferably, the system of the present invention may be adapted for use in deploying/retrieving a rigless intervention system to be mounted on a Christmas tree. Such a rigless intervention system is disclosed in applicant's international patent publication no. WO 2004/065757.
According to a second aspect of the present invention, there is provided a vessel comprising a deployment system for deploying equipment from the vessel, said system comprising:
The vessel may be a seagoing vessel, such as a ship or floating platform or the like.
These and other aspects of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which:
Reference is first made to
An enlarged view of the system 12 is shown in
A carriage 22 is mounted on the cradle 20 and is adapted to engage the equipment 16, said carriage 22 being translatable relative to the cradle 20 to move the equipment 16 between a stored position, as shown in
Referring to
A detailed description of the cradle 20 will now be given with reference to
Reference is now made to
A perspective view of the equipment 16, removed from the system 12, is shown in
The carriage 22 and equipment 16 are shown secured together and located on the frame 30 in
The compensator system 58 will now be described in detail with reference to
Reference is now made to
As noted above, the equipment 16 is of a modular construction. Advantageously, the frame 30 of the cradle 20 permits the equipment 16 to be separated when supported thereon, as shown in
It should be understood that the embodiment described is merely exemplary of the present invention at that modifications may be made thereto without departing from the scope of the invention. For example, the deployment system may be utilised to deploy/retrieve any subsea equipment. Additionally, the system may be secured onshore adjacent a body of water, and as such is not entirely limited for use offshore.
Number | Date | Country | Kind |
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0610268.5 | May 2006 | GB | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/GB2007/001860 | 5/21/2007 | WO | 00 | 9/22/2009 |