Abstract: An intelligent simulation system for jacket towing system includes a distributed collaborative simulation subsystem configured to provide a communication interface for each subsystem, a comprehensive management and evaluation subsystem configured to generate and issue a simulation subject, an operation control simulation subsystem configured to generate operation instructions, a motion simulation subsystem configured to receive parameters of the subject and the operation instructions, simulate a motion state of the jacket, a tugboat and a towrope in real time, and transmit the simulated motion states to the visual simulation subsystem, and a visual simulation subsystem configured to perform a three-dimensional display for the real-time simulation of the motion states of the jacket, the tugboat and the towrope.

Abstract: There provides an auxiliary structure for floating and sinking the whole offshore wind turbine with suction bucket foundation(s), which includes an upper bracket floated on water and a lower bracket sunk synchronously with a support structure. The upper bracket includes upper floating boxes; upper cross-connectors each of which is fixedly connected to the upper hoop and a corresponding upper floating box; and an upper hoop configured to sleeve on an outer side of the support structure. The upper bracket and the support structure are relatively moved in an up and down direction, and are connected in a manner of limiting position. The lower bracket includes lower floating boxes, a bottom of each of which is adjustable in height; lower cross-connectors each of which is fixedly connected to the lower hoop and a corresponding lower floating box; and a lower hoop that holds the support structure tightly.

Abstract: A device for launching and recovering a box sampler includes a suspension coop, a rail assembly, a moving mechanism, a power unit, and a lifting frame. The rail assembly is fixedly arranged on a deck. The moving mechanism is arranged on the rail assembly and can move along the rail assembly. A fixed end of the power unit is articulated with a top end of the moving mechanism, and an extending end of the power unit is articulated with an open end of an upper frame of the lifting frame. A closed end of the upper frame of the lifting frame is articulated with a front end of the moving mechanism. According to the device for launching and recovering a box sampler, the box sampler can be smoothly launched and recovered. The sampler in the suspension coop can be kept horizontal and is prevented from severely shaking.

Abstract: Described herein is a device for upending a tubular element with a longitudinal direction from a support surface at an outer end. The device has a support beam which runs substantially parallel to the support surface and is connected to the support surface at a support point. The support beam guides a coupling tool to which a wall part of an outer end of the tubular element can be coupled. The coupling tool is displaceable relative to the support surface with the support beam, from a clear position to a coupled position in which the tubular element outer end is engaged by the coupling tool. Also described herein, in addition to the device, is a method which makes use of the device.

Abstract: The offshore jack-up has a hull and a plurality of moveable legs engageable with the seafloor. The offshore jack-up is arranged to move the legs with respect to the hull to position the hull out of the water. The method comprises securing the vessel with respect to the hull of the offshore jack-up when the hull is positioned out of the water and the legs engage the seafloor. A lifting mechanism mounted on the offshore jack-up engages with a cargo carrying platform positioned on the vessel. The platform is lifted with the lifting mechanism between a first position on the vessel and a second position clear of the vessel.

Abstract: A pipe-laying vessel including a pipe-laying tower extending upwardly from the vessel, the tower including a first lower section extending upwardly from a proximal end to a distal end above the main deck of the vessel, and a second upper section movably mounted on the first lower section, and the tower having a first pipe-laying configuration for laying pipeline P in which the upper section is positioned above the lower section and pipe is passed from the upper section to the lower section when, in use, it is being laid, and a second stowed configuration in which the second upper section is moved relative to the lower section and the overall height of the tower is reduced.

Abstract: A gravity-based foundation for the installation of offshore wind turbines, manufactured in a floating dock for towing to the final destination thereof, where it is anchored and finally completely submerged below sea level, comprising a concrete floating caisson, in the shape of a prism, with a hexalobular base, divided into several cells by at least one partition with a significantly circular cross section, concentric with a central cell, determining inner vertical cells interconnected with each other and with the exterior, which is closed at the top by a cover or covers that are removed once the foundation is anchored before being filled with a ballast material.

Abstract: A method of assembling and/or disassembling a rotating electric machine of a wind turbine having a vertical structure; a main frame fitted to the top of the vertical structure; a blade assembly fitted to the main frame to rotate about a rotation axis; and a tubular rotating electric machine having a plurality of axial active segments; the method including inserting and/or extracting the active segments axially on the blade assembly side.

Abstract: The present invention relates to an offshore wind power generator, a lifting jig for transferring the offshore wind power generator, and a method for installing the offshore wind power generator using the lifting jig. The offshore wind power generator according to an embodiment of the present invention includes a blade, a nacelle including a power generator for generating power by the rotation of the blade, and a tower supporting the nacelle and installed on a support structure installed offshore. Also, the offshore wind power generator includes a tower support structure installed on the tower so that the tower is lifted using a predetermined transfer unit in a state where the blade, the nacelle, and the tower are integrally assembled. The tower support structure is disposed above a center of gravity of the wind power generator at which the blade, nacelle, and the tower are integrally assembled.

Abstract: An offshore support system comprises an offshore structure having a platform supported by one or more legs. The system further comprises a mat structure having a mat, and a clamp configured engage at least one leg of the offshore structure. The clamp is movable into and out of engagement with the leg to connect and release the mat to and from the offshore structure.

Abstract: A subsea facility for hydrocarbon recovery in deep waters and methods of installation are provided. More specifically, the subsea facility equipment is on multiple modules equipped with a buoyancy system to allow the modules to sink to the sea floor. The modules can be attached and unattached to each other, thus allowing for a module to be raised to the surface for repairs without affecting the rest of the subsea facility.

Abstract: In a spar-type floating structure comprising a tall, thin floating body 2 and a ballast portion 3 provided to the floating body 2 so that the weight of the ballast portion 3 allows the floating body 2 to float in upright position, the floating body 2 includes a horizontally-extending first extended portion 21 arranged at the bottom, a horizontally-extending second extended portion 22 arranged in the middle, and a column portion connecting the first and second extended portions 21, 22 and extending up to the waterline, the first extended portion 21 forms the ballast portion 3, and the second extended portion 22 constitutes a buoyancy portion giving buoyancy to the floating body 2.

Abstract: A conveyance system and method for delivering at least one component of a windmill to a location is provided. The system is provided with a transporter and a transfer system. The transporter is positionable adjacent a base at the location. The transfer system is provided with a plurality of rails, a support and at least one slider. The rails are positionable on the base and the transporter. The support has a first portion of the rails of the transporter thereon. The support is positionable along a second portion of the rails on a surface of the transporter, and slidably movable between a retracted and an extended position whereby the support is selectively positionable adjacent the base. The slider carries the component(s) of the windmill. The slider is slidably movable along the rails of the transporter and the base whereby the component(s) is/are slidably transferable between the transporter and the base.

Abstract: A new jacket installation method utilizes inflatable buoyancy members for shallow water jacket installation. Two types of inflatable buoyancy members are introduced: 1) the first type is designed to produce a large water plane area in order to improve the jacket floating stability when it is afloat; 2) the second type is designed to produce net buoyancy when they are submerged under water, This new installation method is able to use a small size crane vessel, with lifting capacity less than the weight of the jacket to be installed, for a large and heavy shallow water jacket.

Abstract: The invention relates to a structure for transporting, installing, and dismantling a deck (1) of an off-shore exploitation rig, for installing, and dismantling this deck (1) on at least one supporting column, characterized in that it comprises two transport barges (20) and means (30) for supporting and raising the deck (1), temporarily connected to said deck and to said barges and configured to be supported by these barges for supporting said deck between said barges and a method for transporting, installing, and dismantling the deck (1) using the structure for transporting, installing, and dismantling the deck (1).

Abstract: A subsea platform transporter includes a plurality of pontoon members, a plurality of column members interconnecting select adjacent ones of the plurality of pontoon members forming a support frame having an inner platform receiving area, a plurality of buoyancy members mechanically linked to at least one of the plurality of pontoon members and the plurality of column members, and a plurality of platform retaining members mounted to one or more of the plurality of pontoon members and the plurality of column members about the inner platform receiving area. The plurality of platform retaining members is configured and disposed to selectively retain and release a platform supported by the subsea platform transporter.

Abstract: A method for installation of an offshore wind turbine. The method includes prefabrication of a foundation that provides buoyant force and uprighting force to the foundation so as to keep it upright without external forces. The method further includes installation on a dock that includes assembling the offshore wind turbine into a complete set, and finishing testing in a state of the complete set. The method further includes transporting the complete set to an offshore site in a way of floating on the water, and then offshore installation that includes sinking the complete set onto a sea bed by gravity on the offshore site, and fixing the foundation to finish the installation. The present invention also provides a method for recovery of an offshore wind turbine, which is performed generally in steps reversed to the method for installation.

Abstract: The invention relates to a method for erecting at sea a large slender body, such as the monopile of a wind turbine. The method comprises bringing the large slender body in a substantially horizontal floating condition at least partly underneath the work deck of a platform, attaching a tension cable to the slender body, and pulling on the tension cable using fixations means and guiding means that are provided at an edge of the work deck and are connected to it to gradually bring the slender body in an erected position along the edge of the work deck. The slender body is optionally driven into the under water bottom. The invention also relates to a device for performing the method. The method is reliable and obviates the use of large cranes.

Abstract: According to one or more embodiments disclosed herein is a method of transporting equipment between sea-surface and seafloor by providing a structure with equipment mounted thereon. The equipment may be liquid storage tanks, pumps, compressors, separators, metering systems, energy sources, communication systems, buoyancy tanks, and the like. The structure is used for disposal and installation in a subsea environment by changing the volume of buoyancy material within at least one buoyancy tank.

Abstract: A catamaran-type boat suitable for handling, assembling, and/or transporting off-shore wind turbines, the boat having two side floats constituting a U-shaped floating structure, the open space between the two branches of the U-shape constituted by the two side floats being suitable for receiving a base, the floats being fitted with grippers suitable for gripping the base between the two side floats, and the grippers being suitable for gripping the base and at least two grip levels of different heights.

Abstract: A device for transporting and placing a bridge (1) of an offshore oil rig onto a floating or stationary mounting structure (3). The device has two parallel floating barges (10) for mounting the bridge (1). Each barge has a set of vertical movement rams (11) that move the bridge between a position of bearing on the barges (10) and a position of bearing on the structure (3). Each barge (10) has at least one assembly (15) for controlling the roll of each barge (10) in relation to the bridge (1) during the placement of the bridge onto the mounting structure (3). The assembly includes at least two rams (16) that are carried by the barge (10) and are located on both sides of the longitudinal axis of the barge (10). Each ram (16) is connected to the bridge (1) by a connecting member (17) that has rigid pull and flexible compression.

Abstract: A structure for transport and offshore installation of at least one wind turbine or underwater generator includes a U-shaped floating hull having lateral arms. Each lateral arm has at least one leg vertically movable by the hull in flotation, and at least one assembly for supporting a wind turbine or underwater generator. The assembly includes two shuttles opposite each other and each combined with a leg and each having higher and lower pairs of arms which are pivotably movable between a retracted position and an active position tilted against a mast of the wind turbine or underwater generator.

Abstract: An offshore wind turbine installation vessel, wherein the wind turbine is of the type to be installed on a foundation that is installed on the seabed prior to the installation of the wind turbine on the foundation, wherein the wind turbine is of the type with a vertical mast to be fitted with its lower end onto the foundation, wherein the vessel includes a non-jack-up type floating hull; and a crane structure extending upward from said hull. The crane structure is provided with a hoisting device having one or more wind turbine suspension elements and a wind turbine engagement device supported by the suspension elements and adapted to engage with said wind turbine. The hoisting device is adapted to support and to raise and lower in controllable manner at least the mast of the wind turbine while in vertical orientation.

Abstract: A deployment method and system for ocean bottom seismometers (OBS) includes providing a plurality of circular shaped, wireless, self-contained OBS units. The circular shaped OBS units are loaded into a carrier and transported from a surface vessel to the ocean floor where a remotely operated vehicle (ROV) is utilized to individually place the plurality of circular OBS units on the ocean floor. Placement of each OBS unit is accomplished by utilizing suction mechanism attached to a robotic arm. The suction mechanism is defined about an axis and employs a suction cup to individually engage each circular shaped OBS unit so that the suction mechanism is coaxially aligned with the OBS unit, and move the OBS unit from a first location to the ocean floor.

Abstract: An offshore windpower plant (OWP) including a wind turbine and foundation and a new method of installing them that exclude the use of a jack up crane vessel. By this system and method, named OWP technology, the completely assembled wind turbines are lifted from the shore stand, using the buoyancy force of a catamaran wind installer (CWTI), transported to the preinstalled foundation, engaged with it in a manner that would exclude CWTI from rolling and pitching and by this allow to use the installed foundation as the base for stability for safely placing a wind turbine on it allowing placement of wind turbines on foundations regardless of the depth of their installation. The CWTI does not need a heavy lift revolving heavy lift crane and also does not need legs, thus making the system and method simpler, smaller and drastically less expensive than jack up crane vessles.

Abstract: A deployment and retrieval apparatus for ocean bottom seismic receivers, the apparatus being a remotely operated vehicle (ROV) having a carrier attached thereto and carrying a plurality of receivers. The carrier comprises a frame in which is mounted a structure for seating and releasing said receivers. The structure may comprise a movable carousel or a movable conveyor or fixed parallel rails or a barrel. The structure includes a discharge port on said frame and a discharge mechanism for removing and retrieving said receivers. A method for deployment and retrieval of ocean bottom seismic receivers comprises the steps of loading a carrier with a plurality of receivers, attaching said carrier to an ROV, utilizing said ROV to transport the carrier from a surface vessel to a position adjacent the seabed and thereafter utilizing said ROV to remove receivers from said carrier and place the receivers on the seabed.

Abstract: The invention relates to a structure for the transport, installation and dismantling of an oil rig deck, of the type comprising a floating hull provided with legs which can move vertically in relation to the buoyant hull and a shuttle associated with each of said legs and intended to be applied against the lower face of the deck, whereby said shuttle can be moved by the corresponding leg between a low position on the buoyant hull and a high rig deck lifting position.

Abstract: Method for installing a topside module on an offshore support structure that in use comprises at least one support leg that extends a height above the water level. The method comprises the steps of supporting said topside module on a barge in a position adjacent to said at least one support leg and de-ballasting the barge to lift the topside module a height above water level.

Abstract: The present invention reduces loads and saves steel on topsides and grillage of a catamaran system by creating a lifting force from a barge to the topsides to offset a sagging bending moment of the self-weight on the topsides during transportation. The present invention can reduce the span of the supports on the topsides on the catamaran float-over barges and move the reaction forces toward inner edges of the float-over barges. The lifting force can cause a reduction of stress on the topsides' and grillage's members caused during the topside offloading and transportation. The stress reduction can result in the members withstanding the additional dynamic load caused by a catamaran system without increasing member sizes adequate for an offloading operation. The reduction results in a significant savings, given the size of a typical topsides for a Spar hull or other offshore structure.

Abstract: The invention relates to a method for the installation of a tidal power plant having a water turbine, which is mounted so it is rotatable on a nacelle, the nacelle being assigned to a coupling device for placing the tidal power plant on a coupling counterpart on a tower, which carries the tidal power plant during operation, comprising the following method steps: a floating device is coupled to the tidal power plant to form an installation unit, the buoyancy force and the buoyancy point of the floating device being adjustable and being selected so that the installation unit has a positive buoyancy; the installation is connected by means of a traction cable arrangement to the tower, the traction cable arrangement being connected to at least one motorized winch on the floating device and linkage points of the traction cable connection being arranged on the floating device and the tower so that during hauling in of the traction cable arrangement, the coupling device is guided to the coupling counterpart against t

Abstract: A vessel for transporting and hoisting offshore wind turbine includes a hull, fixing brackets, first sliding rails, second sliding rails, a buffer device, rotary cranes and winch devices. A U-shaped opening is provided at the stern of the hull for a wind turbine to pass through. The fixing brackets are arranged in two rows in parallel, and their bottoms are fixed onto the deck in the hull. The second sliding rails are in parallel with the first sliding rails. A hanging beam slidably matched with the first sliding rails is installed on the body of the wind turbine. The buffer device is fixed to the bottom of the wind turbine. The rotary cranes are fixed on the top of two sides of the U-shaped opening. The winch devices are installed on the stern of the hull. An offshore wind turbine transporting and hoisting method using the vessel is also disclosed.

Abstract: A device for transporting structures on water, as well as dismounting or installation of the structure(s) includes an elongated tilting frame (8) hingedly connected at a pivoting point (10) to a water vessel (6). The tilting frame (8) holds one or more support cribs (5) designed for being displaceable relative to the tilting frame and possibly relative to each other, the tilting frame further being designed to be able to assume an essentially horizontal or slightly tilted position, corresponding to a transport position, and being designed for being able to be tilted about the hinge connection to an essentially vertical position by suitable means, the vertical position corresponding to a lifting or operating position wherein the structure(s) carried by the support crib(s) may be lifted or lowered up from or down into the water, respectively, or up or down above water level.

Abstract: A quick-release system for coupling a topside for a fixed or floating platform and a barge for float-over installation of the topside is disclosed. The quick-release system comprises one or more releasable connections, each releasable connection configured to support at least a fraction of the weight of the barge and to be remotely actuated to allow the barge to decouple from the topside. In some embodiments, the quick-release system comprises two plates, one coupled to the topside and the other coupled to the barge, and a plurality of bolts extending therebetween. A frangible nut is coupled to each bolt. The quick-release system is actuatable by an electric signal that causes the frangible nuts to fracture and the barge to subsequently be released from the topside.

Abstract: An Offshore Windpower Plant (OWP) includes wind turbine and foundation with the means that allow installing them by a new method that exclude the use of Jack up Crane Vessel. By this method, named OWP Technology, the completely assembled wind turbines would be lifted from the shore stand, using buoyancy force of Catamaran Wind Installer (CWTI), transported to the preinstalled foundation, engaged with it in a manner that would exclude CWTI from rolling and pitching and by this allow to use installed foundation as the base for stability for safe placing wind turbine on it. Thus would allow placing wind turbines on foundations regardless the depth of their installation. The CWTI does not need heavy lift revolving heavy lift crane it also does not need legs, thus makes it simpler, smaller and drastically less expensive that Jack up Crane Vessels.

Abstract: The present disclosure provides an improved method and system for loading a topsides onto an offshore structure by functional modules. A module support frame forms a supporting structure to which production modules can be assembled. The production modules are adapted to extract or process hydrocarbons from a hydrocarbon well in an offshore location. One production module is a well bay production module to which other production modules can be coupled, including a drilling support production module, separation production module, export module, and utility module. The module support frame can be loaded onto floating barges and other modules assembled thereto to allow the barges to provide incremental and controlled support during the loading process and for the floatover installation. The barges can be floated out to the offshore structure and loaded onto the offshore structure by methods including a floatover method or with a heavy-lift crane vessel.

Abstract: A method and system for transporting an offshore structure such as a wind turbine generator includes a supporting frame in which the offshore structure is assembled on land in an upright configuration. The frame is used for lifting the structure onto a transport vessel, on which it is retained in the upright configuration. At its location of use, the offshore structure is transferred to a pre-prepared foundation. The foundation is provided with a frame which cooperates with the supporting frame. The supporting frame includes a plurality of legs having hydraulically controlled feet. The frame of the foundation includes an equal number of supporting formations on which the feet ultimately rest. The feet are moveable in response to the hydraulic control along a nominally vertical line of action and provide a damping arrangement for the mounting of the offshore structure.

Abstract: The present disclosure relates to a structure (10) for transport and offshore installation of at least one wind turbine or underwater generator. Said structure (10) includes a U-shaped floating hull (11) having lateral arms (11a), each having at least one leg (20) vertically movable by the hull (11) in flotation, and at least one assembly for supporting a wind turbine or underwater generator, consisting of two shuttles (30) opposite each other and each combined with a leg (20) and each having two pairs (60, 70) of arms that are higher and lower, respectively, and pivotably movable around a horizontal axis between a retracted position and an active position tilted against the mast (2) of the wind turbine or underwater generator.

Abstract: The present invention refers to a process to permit descent to sea bottom, with the use of two conventional tug boats, of equipment used in submarine field oil field exploration, especially descent of equipment of large size and mass in deep water fields. Equipment is being suspended by a sling, attached to an auxiliary component. This, on its turn, is attached to two cables, each one activated by one of the two tug boats. Connection of the auxiliary component to cables is being made by means of connectors, which are trespassed thru cable openings and attached to auxiliary component by screws, forming a connection, in which connectors may carry out a pivotal movement around holes of auxiliary component. This movement of said connectors almost entirely absorbs oscillations of tug boats caused by waves, without transmitting same to equipment. In this way, both tug boats may lower equipment and cross the so-called resonance area without risk of its occurrence.

Abstract: The invention provides a method for the transport of a civil engineering structure in an aquatic medium. According to this method: at least one float is associated with the civil engineering structure in such a way as to ensure that the said civil engineering structure floats stably in an aquatic medium, the said float surrounding the civil engineering structure and a bottom portion of the civil engineering structure extending below the said float, and the civil engineering structure and the associated float are caused to move in the aquatic medium to a desired position.

Abstract: The invention relates to a method for installing an offshore wind turbine (5) comprising the steps of preparing an offshore foundation (5) for receiving and retaining a part of said wind turbine, moving said wind turbine in substantially vertical (erected) position from an onshore position to a transit position on a barge system (2), transporting said barge system to the site of said offshore foundation (5), moving said wind turbine from said transit position to an installation position on said barge system, positioning said part of the wind turbine in relation to said foundation, and lowering the barge system in relation to the water level so that said part of the wind turbine engages with said prepared offshore foundation (5).

Abstract: A method of mating of a buoyant hull with a truss structure while at the installation site of the completed offshore structure. The buoyant hull is moored in place. The truss structure is placed in the water, self upends, and maneuvered near the buoyant hull. The buoyant hull and truss structure are rigged with lines to allow the truss structure to be pulled into engagement with the buoyant hull. The truss structure is lowered to a predetermined depth below the water surface but above the sea floor and the weight is transferred to the lines from the buoyant hull. The truss structure is aligned with the buoyant hull and lines from the buoyant hull are used to pull the truss structure into engagement with the buoyant hull. The truss structure and buoyant hull are rigidly attached together as is customary using grouting and welding.

Abstract: A method and vessel for removing or installing an offshore jacket structure in a body of water, the vessel having a generally planar main buoyancy section having the outline of a delta with an extension at the apex and auxiliary buoyancy sections extending transversely of the main buoyancy section at the ends of the base of the delta. The bottom parts of the auxiliary buoyancy sections have a rounded outer surface and contain heavy fixed ballast. The vessel may be rotated as it is brought close to the jacket structure with the auxiliary sections straddling the jacket structure. The vessel is rotated towards the jacket structure while its rounded bottom portion rolls on the seabed. Once the jacket structure is connected securely to the vessel, the vessel is rotated back to the initial position de-ballasting the auxiliary sections before it is brought to the surface.

Abstract: The present invention is concerned with a system and method for the deployment of a hydroelectric turbine, and comprises a base and vessel beneath which the base can be secured, and to which base, from above deck, a hydroelectric turbine can be secured to the base and subsequently released with the base from the vessel.

Abstract: The present invention relates to a device for transporting structures on water, as well as dismounting or installation of the structure(s). The invention is characterized in that an elongated tilting frame (8) is hingedly connected at a pivoting point (10) to a water vessel (6), the tilting frame (8) holding one or more support cribs (5) designed for being displaceable relative to the tilting frame and possibly relative to each other, the tilting frame further being designed to be able to assume an essentially horizontal or slightly tilted position, corresponding to a transport position, and being designed for being able to be tilted about the hinge connection to an essentially vertical position by suitable means, the vertical position corresponding to a lifting or operating position wherein the structure(s) carried by the support crib(s) may be lifted or lowered up from or down into the water, respectively, or up or down above water level.

Abstract: The invention relates to a structure for the transport, installation and dismantling of an oil rig deck, of the type comprising a floating hull provided with legs which can move vertically in relation to the buoyant hull and a shuttle associated with each of said legs and intended to be applied against the lower face of the deck, whereby said shuttle can be moved by the corresponding leg between a low position on the buoyant hull and a high rig deck lifting position.

Abstract: The invention provides a method for the transport of a civil engineering structure in an aquatic medium. According to this method: at least one float is associated with the civil engineering structure in such a way as to ensure that the said civil engineering structure floats stably in an aquatic medium, the said float surrounding the civil engineering structure and a bottom portion of the civil engineering structure extending below the said float, and the civil engineering structure and the associated float are caused to move in the aquatic medium to a desired position.

Abstract: There is disclosed a support means, especially for mounting or dismounting an offshore platform, comprising an articulated bracket which is movable horizontally swinging its two articulated arms. In the case of a rather rough sea a compensating movement in the horizontal direction can be effected by appropriately controlling the articulated arms, wherein the reaction forces acting in the horizontal direction are minimal.

Abstract: An apparatus and method for protecting wellheads of a fixed-leg drilling and production platform which provide an alternative from the shutting in of producing wells as currently required. The apparatus provides a structural barrier for the production process systems of the platform, shielding such systems from heavy objects which may be dropped in the course of rig mobilization and skidding procedures. A method of installing an embodiment of the apparatus allows the barrier to be installed without shutting in the production wells.

Abstract: This invention relates to a method for installation of an elongate process unit (4)on the seabed, said process unit (4) to be handled comprising a first process unit end and a second process unit end. A method of retrieving an elongate process unit (4) from the seabed is also provided. Further, this invention relates to a receptor apparatus for use in a process unit handling operation, such as a process unit installation or retrieval operation.

Abstract: A self-elevating offshore structure supports a deck for production operations at sea in the absence of an elevating hull. A non-buoyant deck is supported by braces and truss legs above wave action. The legs move in relation to the legs and the braces, elevating the deck and the braces supporting the deck. The offshore structure is transported to a deployment site by a buoyant vessel and then released from the vessel once the legs are embedded into the sea bottom.