Abstract: A self-propelled jack-up vessel has a centreline extending from a bow end to a stern end of the vessel along a central longitudinal axis, defining port and starboard sides of the vessel. The vessel comprises a hull, a deck and four retractable legs, which extend through the hull and the deck. The vessel includes a bow leg arranged on the centreline towards the bow, a stern leg arranged on the centreline towards the stern, and a starboard leg arranged at the starboard side. The diagonal placement of the legs, with respect to the centreline gives greater stability and flexibility. Further, a vessel is provided having a cruciform primary structural arrangement.

Abstract: A truss-like hydraulic lifting apparatus with plugs including a pile reinforcing frame, a truss structure extending through and mounted within the pile reinforcing frame and a first number of uniformly disposed support legs, each having a support leg inserting hole. A first number of power source devices each has a plug corresponding to the support leg inserting hole. A detachable mechanism is provided for detachably fixing each of the power source devices to the pile reinforcing frame. The detachable mechanism includes a base plate laterally fixed relative to the pile reinforcing frame and having an opening through which the support leg vertically passes and forms a protective cap above the power source device. The lateral dimension of the protective cap is larger than the lateral dimension of the power source device.

Abstract: A pile guide is provided comprising a base frame and a pile guide member for guiding the pile as it is driven into a substrate when the base frame is resting thereon. The pile guide member comprises plural guide parts each moveable between a operative position and an inoperative position, each guide part being pivotally mounted on the base frame. At least one guide part is operably coupled or couplable with an associated counterweight for opening of the guide member to its inoperative position under gravity, such that, at least in an inoperative position, at least part of the counterweight and the associated guide part are movable with respect to each other. In another aspect, at least one of the guide parts and/or at least one of the counterweights is detachably connected with the base frame and/or with each other. Methods are also provided.

Abstract: An arrangement of floating platforms is provided, including (a) an anchored main platform and (b) one or more outer platforms, each of which being connected to the main platform by at least one connection element. One or more of the main and/or outer platforms are rotatable about a vertical axis by drive units which are fixed thereon. Marine engines having a propeller propulsion system are provided as drive units on the main platform and/or the outer platforms.

Abstract: A method of elevating the deck area of a marine platform (e.g., oil and gas well drilling or production platform) utilizes a specially configured sleeve support to support the platform legs so that they can be cut. Once cut, rams or jacks elevate the platform above the cuts. The sleeve support is then connected (e.g., welded) to the platform leg and becomes part of the structural support for the platform. In one embodiment, two sleeves are employed. In another embodiment, the jacks or rams elevate in two stages including a first stage wherein one sleeve elevates and the other sleeve does not elevate and a second stage wherein both sleeves elevate together.

Abstract: The present invention provides a riser protection structure being suitable to be employed in a Jackup rig. The riser protection structure comprises a plurality of piles, an upper module, wherein the upper module comprises a main protection tubing for receiving a riser, a plurality of sleeves to be installed over the plurality of piles, and a connecting network; wherein the plurality of sleeves are disposed around the main protection tubing; and wherein the main protection tubing and the plurality of sleeves are connected together by the connecting network, and a lower module, wherein the lower module comprises a plurality of tubular guides for guiding and later fixing the piles and a connecting structure, wherein the plurality of piles are securely disposed into the seabed for providing the requisite support for the upper and lower modules when they are assembled.

Abstract: An installation vessel for installing an offshore structure, the installation vessel comprising a hull and a plurality of legs, each leg comprising vertical chords and cross braces, the hull having a plurality of leg openings each configured for passage of a leg therethrough, each leg opening having a number of jack-cases for supporting pinions thereon, each pinion being configured for rotatably engaging a rack disposed on a chord of the leg to move the leg relative to the hull, each jack-case comprising a number of guides for guiding passage of the leg through the leg opening, each guide comprising a plurality of angled surfaces configured for sliding engagement with a corresponding plurality of surfaces of a rack, each of the plurality of angled surfaces comprising a wear plate.

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: A jacking system for jacking a structure, includes a leg having a longitudinal axis and including first engagement parts along the leg, and a guiding frame displaceable along the leg. The guiding frame includes at least a first, second, third and fourth actuator, the actuators each having a first and second actuator part which in operation can displace with respect to one another along the leg, the first actuator part of the actuators coupled to the guiding frame, the second actuator parts of the actuators each coupled to first engagement parts for engaging and disengaging the first engagement parts of the leg for providing abutment in the longitudinal direction of the leg, the second actuator parts of the actuators displaceable along the leg past one another, and the actuators being arranged in pairs opposite one another with respect to a longitudinal plane of the leg.

Abstract: A jack-up platform (1) has a hull (2) and at least three longitudinally movable support legs (3) for the hull (1), at least one of the support legs (3) has at least one variable speed drive (8, 8A1 to 8F2) as a part of a leg driving mechanism, wherein the platform (1) has a closed-loop control unit (7) for the driving mechanism, the closed-loop control unit (7) being connected with the variable speed drive (8, 8A1 to 8F2) via a bi-directional electronic bus (16) for transmitting control parameters (M*,M,N,R).

Abstract: A jacking system (4) is described for a leg (3) of a jack-up platform (1). The jacking system comprises at least three independent yokes (7a-7d). Each independent yoke is connected to a jack-up structure by at least one vertically arranged double acting actuator (8a-8d?) and is equipped with a leg engaging mechanism such as a horizontally arranged movable locking pin (9a-9d), which is configured to engage or to disengage with a hole of the jack-up leg, in order to transfer a load (L) from the jack-up platform (1) to the leg (3), including a controller configured to operate the yokes (7a-7d) in a way that the leg (3) is moved by all the at least three yokes (7a-7d) in an alternating mode, such that at any moment in time during operation all but one of the at least three yokes (7a-7d) take the load (L) via the associated engaging mechanism, while the remaining yoke of the at least three yokes (7a-7d) makes a return stroke with its engagement mechanism in a disengaged position.

Abstract: The invention is directed to a method for increasing the overturning moment resistance of a jack-up drilling rig that includes the step of attaching at least one lateral leg support to at least one jack-up leg, wherein the jack-up leg is secured and has a lattice framework. The invention is also directed to a system and apparatus for increasing the overturning moment resistance of a support member with a lattice framework.

Abstract: A jack-up platform (1) has a hull (2) and at least three longitudinally movable support legs (3) for the hull (1), at least one of the support legs (3) has at least one variable speed drive (8, 8A1 to 8F2) as a part of a leg driving mechanism, wherein the platform (1) has a closed-loop control unit (7) for the driving mechanism, the closed-loop control unit (7) being connected with the variable speed drive (8, 8A1 to 8F2) via a bi-directional electronic bus (16) for transmitting control parameters (M*,M,N,R).

Abstract: Method for assembling a rack portion (1) of a self-raising oil rig, which rack portion (1) is constituted by at least one rectangular plate (3) which comprises teeth (51) at the longitudinal lateral faces (5) thereof, and at least one reinforcement (8) which is in the form of a half-shell and which is welded to a main face (6) of the at least one rectangular plate, along the longitudinal edges (11) of the at least one reinforcement, according to which an internal chamfer and an external chamfer which are separated by a projection of thickness T are produced at each of the longitudinal edges (11) of the at least one reinforcement (8), the at least one reinforcement (8) is provided at a main face (6) of the rectangular plate (3), at least one welding pass is carried out at the internal portion of each of the longitudinal edges (11) of the at least one reinforcement in order to produce an internal weld bead having a connection radius R greater than or equal to 4 mm, and the chamfers are filled at the external po

Abstract: Pre-assembled self installing platforms with improved performance due to additional rotational restraint to supporting legs and methods of installation. The platform includes a hull, legs movable relative to the hull, at least one brace frame movably connected to at least two of the legs. Upon installation, the brace frame may be positioned at a desired elevation and rigidly secured to the legs, providing rotational restraint to significantly reduce leg stress and increase rigidity of the legs. With the increased rigidity, it becomes possible to install platforms in relatively deep waters and harsh environments, and yet preventing large overall platform sway induced by adverse weather or sea conditions. As the brace frame is securable to the legs after the legs or footings are penetrated into or supported on the sea bed, differential penetration of legs or footings into the seabed becomes possible without risking large structural loads in the brace frame.

Abstract: The instant disclosure relates to a system and method of constructing drilling and production platforms that are particularly useful in remote, inaccessible and/or environmentally sensitive operating environments. According to one aspect of the invention, an arctic drilling platform is provided wherein various methods and means of interlocking neighboring platform modules are provided. Methods and means for sealing the intersections formed between a plurality of interlocked platform modules are also disclosed. According to further aspects of the invention, improved platform floor plans are provided, and various wellhead cellar layouts and sealing means are also described. Methods and means of enhancing the usefulness of modular storage platforms are disclosed, and a number of support post installation and removal techniques are also provided.

Abstract: A complementary locking system for locking legs to the deck of a jack-up offshore drilling platform is disabled. The system includes at each leg, at least one assembly comprising plates forming two counter-racks that engage with a leg rack and, on one side of the plates, at least one internal element for connecting the internal edges of the plates, at least one external element for connecting the external edges of the plates and at least one intermediate member for connecting said at least one internal element to said at least one external element. Methods of installing said complementary locking system on the legs of a jack-up offshore drilling platform are also disclosed.

Abstract: The instant disclosure relates to a system and method of constructing drilling and production platforms that are particularly useful in remote, inaccessible and/or environmentally sensitive operating environments. According to one aspect of the invention, an arctic drilling platform is provided wherein various methods and means of interlocking neighboring platform modules are provided. Methods and means for sealing the intersections formed between a plurality of interlocked platform modules are also disclosed. According to further aspects of the invention, improved platform floor plans are provided, and various wellhead cellar layouts and sealing means are also described. Methods and means of enhancing the usefulness of modular storage platforms are disclosed, and a number of support post installation and removal techniques are also provided.

Abstract: A jackup rig having a built-in capability of driving and extracting piles without need for dedicated pile drivers or extractors. The jackup rig provides an ice breaking functional capability, supplied by a jacking system, for operating in icy waters.

Abstract: A vessel is provided that is an improvement over previously disclosed jack-up rigs and lift boats. The vessel has at least three thrusters and is self-propelled. The vessel additionally has a raised and hollow crane support on which a crane may be mounted. The crane support is preferably affixed to tracks, which permit the crane to slide along the deck of the vessel. The raised and hollowed feature of the crane support permits the storage of equipment and things beneath the crane support without hindering the movement of the crane along the tracks. Optionally, the vessel further has an extension assembly atop which may be deployed a workover rig assembly. The crane may be used to assemble the extension assembly and thus aid in the construction, remediation, and demolition of offshore oil and gas platforms and wells.

Abstract: A jacking system (4) is described for a leg (3) of a jack-up platform (1). The jacking system comprises at least three independent yokes (7a-7d). Each independent yoke is connected to a jack-up structure by at least one vertically arranged double acting actuator (8a-8d?) and is equipped with a leg engaging mechanism such as a horizontally arranged movable locking pin (9a-9d), which is configured to engage or to disengage with a hole of the jack-up leg, in order to transfer a load (L) from the jack-up platform (1) to the leg (3), including a controller configured to operate the yokes (7a-7d) in a way that the leg (3) is moved by all the at least three yokes (7a-7d) in an alternating mode, such that at any moment in time during operation all but one of the at least three yokes (7a-7d) take the load (L) via the associated engaging mechanism, while the remaining yoke of the at least three yokes (7a-7d) makes a return stroke with its engagement mechanism in a disengaged position.

Abstract: A leg guide for use in a leg of a jack up unit adapted to provide sliding guidance of the leg during vertical movement of the leg. The leg guide has a first portion contacting an edge of a leg chord and a second portion contacting a face of the leg chord along a longitudinal plane opposite the contact plane of the first portion. The edge contacting guide has a deflecting guide unit, which uses a compressible member sandwiched between two rigid plates. As the leg moves, the teeth of the leg chord contact the edge guide unit, with the compressible member absorbing compressible loads acting on the leg chord. The second portion provides for a face plate mounted transversely to the edge contacting guide for reducing the build-up of horizontal moment acting on the leg chord during the vertical movement of the leg and for reducing bending moments acting on the leg.

Abstract: A jack-up platform (1) has a hull (2) and at least three longitudinally movable support legs (3) for the hull (1), at least one of the support legs (3) has at least one variable speed drive (8, 8A1 to 8F2) as a part of a leg driving mechanism, wherein the platform (1) has a closed-loop control unit (7) for the driving mechanism, the closed-loop control unit (7) being connected with the variable speed drive (8, 8A1 to 8F2) via a bi-directional electronic bus (16) for transmitting control parameters (M*,M,N,R).

Abstract: The instant disclosure relates to a system and method of constructing drilling and production platforms that are particularly useful in remote, inaccessible and/or environmentally sensitive operating environments. According to one aspect of the invention, an arctic drilling platform is provided wherein various methods and means of interlocking neighboring platform modules are provided. Methods and means for sealing the intersections formed between a plurality of interlocked platform modules are also disclosed. According to further aspects of the invention, improved platform floor plans are provided, and various wellhead cellar layouts and sealing means are also described. Methods and means of enhancing the usefulness of modular storage platforms are disclosed, and a number of support post installation and removal techniques are also provided.

Abstract: An improved jack up vessel includes a hull, a plurality of legs, each leg having a pad, and a jacking mechanism for moving the hull upward and downward. Each leg is a generally triangular leg that is a closed wall, buoyant structure.

Abstract: A leg guide for use in a leg of a jack up unit adapted to provide sliding guidance of the leg during vertical movement of the leg. The leg guide has a first portion contacting an edge of a leg chord and a second portion contacting a face of the leg chord along a longitudinal plane opposite the contact plane of the first portion. The edge contacting guide has a deflecting guide unit, which uses a compressible member sandwiched between two rigid plates. As the leg moves, the teeth of the leg chord contact the edge guide unit, with the compressible member absorbing compressible loads acting on the leg chord. The second portion provides for a face plate mounted transversely to the edge contacting guide for reducing the build-up of horizontal moment acting on the leg chord during the vertical movement of the leg and for reducing bending moments acting on the leg.

Abstract: The invention concerns a method for making a section of a support strut member of an offshore oil-drilling rig comprising steps which consist in: a) machining each longitudinal edge of a semi-cylindrical stiffener (13) to provide along the longitudinal edge, a lip (18) for support on a main surface (12A) of a main plate (12), by producing along the longitudinal edge an outer bevel (20) on the side opposite the conduit (17) defined by the stiffener (13); b) applying a base plate (22) of the support lip (18) to weld it with main surface (12A) of the plate (12); heating the support lip (18) to weld it with the plate (12) and constitute a support weld joint; and d) forming a weld bead with filler metal from outside the conduit (17) in the space delimited between the support weld joint, the outer bevel (20) and the main surface (12A) of the main plate (12).

Abstract: A leg guide for use in a leg of a jack up unit adapted to provide sliding guidance of the leg during vertical movement of the leg. The leg guide has a first portion contacting an edge of a leg chord and a second portion contacting a face of the leg chord along a longitudinal plane opposite the contact plane of the first portion. The edge contacting guide has a deflecting guide unit, which uses a compressible member sandwiched between two rigid plates. As the leg moves, the teeth of the leg chord contact the edge guide unit, with the compressible member absorbing compressible loads acting on the leg chord. The second portion provides for a face plate mounted transversely to the edge contacting guide for reducing the build-up of horizontal moment acting on the leg chord during the vertical movement of the leg and for reducing bending moments acting on the leg.

Abstract: The invention relates to a structure for transporting, installing and dismantling a fixed oil platform provided with framework elements which are substantially formed by a bridge and at least one supporting pillar. The inventive structure comprises a floating U-shaped shell provided with at least three lifting legs adapted for resting upon the bottom of the sea and a shuttle movable along the lifting legs for displacing a platform element. Said shuttle consists of at least three elements each of which is associated with the lifting leg and is provided with mechanical means for driving on the corresponding lifting leg in a manner independent of the shell of the structure and with means for connecting to displaceable framework element. Methods for transporting, installing and dismantling the bridge or the supporting pillar of a fixed offshore oil platform are also disclosed.

Abstract: An operating includes a rack cut on both sides, sandwiched between two pinions with horizontal axes and arranged in the same horizontal plane or substantially in the same horizontal plane, driven into opposite directions by the same motorized system. The outlet shaft of the motorized system transmits the driving motion to a primary reducing system whose outlet shaft corresponds to the inlet shaft of a secondary reducing gear of planetary differential type including a solar pinion, satellite pinions and an outer ring. The satellite holder of the secondary differential reducing gear drives one of the pinions on one of the sides of the double rack, and the outer ring of the planetary reducing gear drives, by appropriate mechanical elements, a toothed wheel in charge of driving the second pinion on the other side of the double rack.

Abstract: Disclosed is a system useful in stabilizing a vessel. The vessel includes, but is not limited to, a first leg, a second leg, a third leg, and a platform coupled to the first, second, and third legs. The system can include a first brace coupled to the first leg at a first location along the first brace. The first brace can form an acute angle with the first leg. The system can also include an anchoring structure coupled to the first brace at a second location along the first brace. The first and second locations along the first brace can define a first brace length between them. At least a portion of the first brace length can be located beneath the platform. Also disclosed is a system useful in stabilizing a vessel, where the vessel includes, but is not limited to, a first leg having an upper end and a lower end, a second leg having an upper end and a lower end, a third leg having an upper end and a lower end, and a platform coupled to the first, second, and third legs.

Abstract: The invention relates to mobile offshore jack-up structures and provides for a self-regulating jacking system for elevating and lowering of the legs and the hull. A central controller assembly regulates movement of each of the legs, depending on the relative speed of movement of each leg and inclination of the hull along two independent axes: forward-aft and starboard-port. Each chord of the supporting legs is inverter driven to ensure a bi-directional full rated torque control of the associated pinion assemblies at very low speeds. By regulating the relative speed of the leg vertical movement, the system monitors the hull inclination within allowable limits and prevents an excessive differential vertical travel of any of the leg chords, thereby minimizing a possibility of leg bending or jamming of the screw jacks of the jacking assemblies 30.

Abstract: A wind-driven source of electricity can be located and oriented to take advantage of winds traveling over water. A structure is provided that can be transported over water and carry one or more wind-driven sources of electricity and structure-supporting means for engaging the earth's surface under water. The structure is transported to an advantageous location for operation of the wind-driven sources of electricity; the structure supporting means is engaged with the earth's surface under water at the advantageous location; and the one or more wind-driven sources of electricity can be elevated to take advantage of the winds traveling over the water.

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.

Abstract: A jacking method and apparatus for a heavily loaded platform includes hydraulic continuous linear motion motors, preferably comprising a plurality of phased hydraulic piston/cylinder units, that are engaged to drive the heavily loaded platform to provide relative motion of the platform with respect to a platform support, and to also hold the platform in a selected stationary position. In the preferred jack-up system, the number of hydraulic piston/cylinder units and the number and design of the teeth that are engaged in providing relative motion may be combined to substantially reduce material stresses on the system.

Abstract: In a jacking system for a marine platform, a plurality of hydraulic continuous linear motion motors are engageable with a plurality of marine platform supporting logs to provide relative motion between the platform and its supporting legs, and to also maintain the platform and its supporting legs locked in a stationary relationship. In the jacking system, the number of hydraulic piston/cylinder units and the number and design of the teeth that are engaged in providing relative motion may be selected to substantially reduce material stresses on the system.

Abstract: A taut mooring system for use on a mobile offshore jack-up platform while it is in an elevated operating condition. The elevated operating condition is with the hull jacked up a safe distance above the highest anticipated wave crests, on vertically movable legs which extend to the ocean floor. The mooring system consists of: radially spaced mooring line attachment means on the structure of the platform; suction piles that are radially spaced around the platform, consistent with the radial spacing of the mooring line attachment means; and taut mooring lines which radially connect the suction piles to the attachment means. The flexibility of the taut mooring system provides the ability to coact with the platform's free standing storm resistance capabilities, yielding enhanced capabilities that will enable the platform to safely resist storm induced forces that the platform would not normally be capable of withstanding, and to enable the platform to be used with longer legs in deeper water.

Abstract: A support device is used to facilitate maintenance of a jacking system of a self-elevating drilling or maintenance platform having a plurality of legs supporting the platform in an operating orientation. The platform includes jacking mechanisms associated with the legs to raise and lower the platform using jacking racks on each leg chord. Support devices temporarily support the platform independent of the jacking mechanisms using a rack chock removably clamped in place on each leg with locking teeth on the rack chock meshed with jacking teeth on the leg's jacking rack. In this manner the platform can be temporarily supported by using removable fasteners to secure a rack chock to each leg chord beneath the platform hull, lowering the platform relative to the legs so that the hull rests on a support seat on each support device, and then disengaging the jacking mechanism from the jacking teeth on the legs for maintenance of the jacking system.

Abstract: A mobile offshore drilling unit (MODU) jacking system includes a plurality of hydraulic continuous linear motion motors, preferably comprising a plurality of phased hydraulic piston/cylinder units, that are engaged with a plurality of MODU supporting legs to provide continuous relative motion between the MODU platform and its supporting legs, and to also maintain the MODU platform and MODU supporting legs locked in a stationary relationship. In the preferred jack-up system, the number of hydraulic piston/cylinder units and the number and design of the teeth that are engaged in providing relative motion may be combined to substantially reduce material stresses on the system.

Abstract: A “frozen” rack chock of a jack-up rig is released by a moving force imparted on the rack chock by a worm gear assembly. The worm gear assembly has a tooth wheel with a plurality of teeth and a worm gear member provided with a worm thread that engages the teeth for transmitting rotational force from a drive motor to the tooth wheel. A shaft of the tooth wheel is operationally connected to the rack chock to cause disengagement of the rack chock from the contact surface of a leg chord when the tooth wheel is rotated.

Abstract: An arrangement of a jackup platform's elevating system, leg guides, hull-to-legs load transfer device, and method of operation of the load transfer device for an offshore jackup platform's hull to be supported by legs which have one or more vertical toothed gear racks attached. An apparatus consisting of rectangular blocks with protruding lugs that are shaped for efficient engagement with a portion of the upper faces of the gear rack teeth, that extend vertically on the leg chords of the jackup platform. The rectangular blocks are movable in a direction perpendicular to one side of the gear rack. Powered guide assemblies control movement of the rectangular blocks such that their protruding lugs can move into the spaces in between the gear rack teeth.

Abstract: The present invention has at least one rack chock which is supported pivotally and tiltably at one end by a pin and cross head assembly located at a position between at least one leg rack and the hull of the platform. The other end of the rack chock is connected to the jack foundation with an actuator assembly. The pin and cross head assembly is disposed slidably within a guide for permitting the teeth of the rack chock to engage the leg rack teeth without visual monitoring and manual control. The actuator assembly connected to the other end of the rack chock controls the swinging movement of the rack chock and its engagement and disengagement with the leg rack. A pair of jacks urges upper and lower wedges with tiltable surfaces converging onto the rack chord's upper and lower surfaces, thus obtaining a optimal surface to arrest the relative movement between the rack chock and the leg rack.

Abstract: An elevating unit for a jack-up rig provides a pinion gear that rotates upon a support frame for engaging a toothed rack of each leg of the jack-up rig. Each pinion gear is mounted on a gear shaft that extends in opposite directions from a plane of rotation of the gear. First and second roller bearings are mounted upon the frame for supporting the pinion gear at first and second pinion gear shaft end portions. On one shaft end portion, a planetary gear box engages the shaft, the gear box being motor driven. On the opposite side of the shaft end portion a brake hub is attached to the pinion gear shaft and carries a brake drum. A brake band extends about the drum, the band being operable to frictionally engage the brake drum to retard movement of the drum, hub and pinion gear shaft relative to the frame.

Abstract: A method and apparatus of raising or lowering an oil drilling rig mounted on a platform is provided. The rig is mounted on the platform hull, which is supported by a plurality of legs. Each leg has a plurality of jacking chords. The legs are raised or lowered relative to the hull to lower or raise the rig. The elevation of each chord of a leg is measured during the raising or lowering action, and the measured elevations are used to determine the deformation of the leg. In this manner, a corrective action is instituted according to the determined deformation by acting individually on each chord of the leg.

Abstract: The invention concerns a method of assembling sections (20) of support legs (2) of an oil platform in which an opening (11) is formed in the hull and in the lower part of the drive mechanism support framework (10) for each leg (2) to pass through, the sections (20) are engaged successively in the lateral opening (11) and the sections (20) are assembled to form each leg (2).

Abstract: A device for releasing of a frozen screw pressed against a contact surface uses a compression disc pre-loaded to an anticipated amount of deflection prior to mounting between the contact surface and the screw. The disc has an insert formed from a granulated material mixed with a water soluble binder, allowing to wash out the insert and cause collapse of the disc, so as to break the connection between the contact surface and the screw.

Abstract: A locking mechanism is disclosed for use on the legs of a jack-up offshore platform. Each chord of the legs includes a rack for cooperation with pinions used in raising and lowering the legs. The locking mechanism of the invention includes a rigid frame attached to the hull of the platform and housing a plurality of vertically aligned toothed chock segments adapted to engage the teeth of the rack on a leg. The chock segments have upper and lower inclined surfaces which cooperate with upper and lower movable wedges for supporting the chock segments. The design makes the chock segments sufficiently adjustable for independent alignment and engagement of the teeth of each chock segment with the corresponding teeth of the rack. Dimensional variances in the rack teeth spacing, resulting from manufacturing tolerances, thereby are accommodated and force concentrations between the rack teeth and chock teeth are minimized.

Abstract: An arrangement of a jackup platform's elevating system, leg guides, hull-to-legs load transfer device, and method of operation of the load transfer device for an offshore jackup platform's hull to be supported by legs which have one or more vertical toothed gear racks attached.An apparatus consisting of rectangular blocks with protruding lugs that are shaped for efficient engagement with a portion of the upper faces of the gear rack teeth, that extend vertically on the leg chords of the jackup platform. The rectangular blocks are movable in a direction perpendicular to one side of the gear rack. Powered guide assemblies control movement of the rectangular blocks such that their protruding lugs can move into the spaces in between the gear rack teeth.

Abstract: A jack-up offshore drilling or production oil platform of the type including a barge (1) mounted so that it can be moved between a position for floating and a position for production out of the water. The barge is moved along bearing legs (2) by means of drive mechanisms (10) which each include at least two opposed sets (11). Each set is formed of a motor (12) associated with at least one set of reduction gears (13) driving, via a shaft, an output pinion (15) interacting with opposed racks (16) mounted on the bearing legs (2). Each rack (16) is provided along a length of the corresponding leg (2) necessary for moving the barge (1) between the position for floating and the production position. Also provided are devices for controlling the lowering of each leg (2) as far as a bearing structure (6) or as far as a seabed (7).

Abstract: An elevating unit for a jack-up rig provides a pinion gear that rotates upon a support frame for engaging a toothed rack of each leg of the jack-up rig. Each pinion gear is mounted on a gear shaft that extends in opposite directions from a plane of rotation of the gear. First and second roller bearings are mounted upon the frame for supporting the pinion gear at first and second pinion gear shaft end portions. On one shaft end portion, a planetary gear box engages the shaft, the gear box being motor driven. On the opposite side of the shaft end portion a brake hub is attached to the pinion gear shaft and carries a brake drum. A brake band extends about the drum, the band being operable to frictionally engage the brake drum to retard movement of the drum, hub and pinion gear shaft relative to the frame.