Abstract: A development and production facility for an offshore oil or gas field is constructed and drilling of wells is performed using a jack-up drilling platform in an improved manner. The facility is composed of a development well platform and a production platform, each of which is composed of a modular prefabricated unitary deck assembly of substantially turn-key completeness and of a prefabricated jacket or leg assembly to which the deck assembly is matable. Crane or derrick barges are used only to position the deck assemblies on the leg or jacket assemblies after the latter assemblies have been placed erect on and secured to the sea floor by use of the jack-up platform. The development well platform is constructed first so that drilling of development wells can be performed from the jack-up platform through the former platform concurrently with the placement and completion of the production platform.

Abstract: A modular and floatable offshore exploration and production platform system for use in shallow arctic waters is disclosed. A concrete base member is floated to the exploration or production site, and ballated into a predredged cavity. The cavity and base are sized to provide a stable horizontal base 30 feet below the mean water/ice plane. An exploration or production platform having a massive steel base is floated to the site and ballasted into position on the base. Together, the platform, base and ballast provide a massive gravity structure that is capable of resisting large ice and wave forces that impinge on the structure. The steel platform has a sloping hourglass profile to deflect horizontal ice loads vertically, and convert the horizontal load to a vertical tensile stress, which assists in breaking the ice as it advances toward the structure.

Abstract: An earthquake-resistant off-shore gravity structure which can stand on the sea bed under its own weight and the weight of any ballast carried by the structure has coupled to its undersurface a separately formed substantially flat concrete foundation grid which underlies at least a major part of the area of the undersurface of the structure, which is of a thickness substantially less than the height of the base and which has a downwardly extending projection for penetrating the sea bed. The coupling between the structure and the foundation grid is such that vertical loads on the structure are transferred through the foundation grid to the sea bed and is such that, for horizontal forces on the structure less than a predetermined maximum value, relative movement between the foundation grid and the structure is substantially prevented and, for a horizontal force equal to or in excess of said maximum value, limited relative movement between the foundation grid and the structure is permitted.

Abstract: The structure is made in several "storeys" (D1, D2, D3). These are floated away from their construction site in conventional manner. Once in sufficiently deep water, the storeys are tilted over so that they float on their side, and they are then joined together end-to-end. With tilting and rotating operations performed by suitable ballasting and unballasting of compartments in the storeys, the joining operations can all be performed on members at or near (just above or just below) the surface of the water. Once the storeys are assembled together, the entire structure may be towed on its side to a point of use, and then immersed so that it stands vertically on the sea bed.

Abstract: A device for positioning an off-shore platform (1) on a previously-installed support structure. Said platform has support piles (6) designed to rest on legs (4) of the support structure.The device includes means for bringing said support piles towards said legs which are provided with centering cones (5). Each pile is constituted by a tube containing a rod (13) associated with a damping unit (8). The lower portion of the rod (13) has a centering pin (16) and extends below the lower end of the pile in the damping unit rest position.

Abstract: A method of assembling or testing a large-load, marine working platform structure, comprising the steps of laying sand on the bottom surface of a dock, and placing on the layer of sand spud cans attached to the lower ends of support frames of the working platform structure so as to scatter a load applied to the dock bed.

Abstract: An apparatus and method are disclosed for aligning equipment lowered from the ocean surface with a fixed subsea structure without the use of guidelines. The apparatus comprises a guide frame including primary and secondary members, a mating guide base including primary and secondary members, vertical channeling means and rotational engagement means. In the practice of the method, the frame is generally positioned above the base using known means of limited precision. Using remote means, the frame is first lowered to vertically channel the primary members into alignment, then rotated until the secondary members are engaged and finally lowered further to fully land the frame on the base.

Abstract: A lightweight drilling structure for use in offshore arctic waters comprising a lower frustoconical section and upper section wherein the lower section is towed to location, ballasted to sink in place on the sea floor and anchored in position by flooding the stability compartments. The upper section containing the drilling rig and equipment is then floated into place over the lower section, ballasted to rest on the lower section and the two sections sealed and fastened together. The assembled structure is firmly anchored in place by dewatering chambers located in the bottom of the lower section to create a suction between the bottom of the lower section and the ocean floor.

Abstract: A concrete offshore structure located in a body of water of selected depth and extending from a bed defining the bottom of the water body to above the water surface comprises at least two similar prefabricated concrete modular subassemblies interconnected in a vertical arrangement in such manner to define a horizontal interface between each such pair of subassemblies. vertically disposed shear resistant pin means between the subassemblies and cement at the interface secure them together.A method for deploying such a structure includes towing the subassemblies offshore, mating them, and towing the assembled structure to the selected offshore installation site.

Abstract: An off-shore platform (1) is floated on a barge (2). A support structure is fixed to the sea bed and including a plurality of upstanding piles with at least two of said piles (4) having platform-receiving guide means (5) at their upper ends. The platform includes a plurality of legs for fixing to corresponding ones of the piles with at least two of the legs (6) being hollow and being provided with respective plungers (8) slideably mounted therein for co-operating with said platform-receiving guide means. Each plunger is associated with a releasable fastening (10, 11) capable of holding the plunger fixed in its leg, and of releasing it suddenly on command to drop into engagement with said platform-receiving guide means. The releasable fastenings of at least two of the plungers are arranged to release simultaneously on a common command.

Abstract: A device for damping impacts between a load (1) and a floating support (70) while the load is being removed from said support which includes at least one housing (10) on which the load rests. The device includes means (11, 15, 18) for automatically and irreversibly inserting a damping unit (14) between the load and its bearing point on the floating support as soon as the weight of the load is removed from the bearing point.

Abstract: A placement and retrieval modular barge arrangement for off-shore well drilling equipment comprising at least two separable barge sections having an arrangement for being joined together, each barge section being made of a floatable hull having a deck capable of carrying thereon sections of a blow-out collar or other equipment, the barge having a central opening formed therein for surrounding a well drilling derrick when the barge sections are joined together, each barge section being provided with a radially movable platform arrangement slidably supported in the hull thereof, and an arrangement for actuating the platform arrangement to retract it to the confines of the central opening or extend it therefrom a distance sufficient to support a blow-out collar or other equipment during assembly or disassembly thereof.

Abstract: A vertically movable, offshore working platform structure is disclosed, which includes a working platform vertically movably mounted on parallel arranged support frames individually comprising a plurality of parallel disposed vertically elongate cords connected altogether to a support frame assemblage by horizontal members and diagonal members having their ends secured to the cords at panel point portions of the cords, and which also includes guides for the vertical movement thereof which individually have a length at least great enough to extend between two longitudinally adjacent panel point portions of respective cords.

Abstract: A bearing assembly for structures composed of two main elements each of which forms a portion of either the supported structure or the supporting structure or foundation. One of these main elements is formed in a "U" type shape and provided with flutings on the interior sides facing each other. The other main element is formed to fit into the interior of the other "U" type main element and is provided with flutings on opposing sides of said element. As one main element is inserted into the other, the flutings of both elements can be aligned to face each other, and complementary cores inserted. Two or more of such cores inserted at opposing sides of the inserted element, would position the inserted main element securely into the other main element, the cores filling the flutings of the "U" type main element and thus providing a secure positioning to the supported structure.

Abstract: A method for installing an electric power plant comprises preparing a plant yard in the form of a shallow pool connected to a water area. The electric power plant is in a package form comprising a floatable base, and is mounted on a submersible barge and towed. Near the plant yard, the package is unloaded and moved into the plant yard when the water is at a high level. Water is then introduced into a ballast tank of the base of the package to cause the package to sink onto the foundation forming the bottom of the pool.

Abstract: Methods and apparatus for offshore operations including individually significant aspects comprising:1. Methods and apparatus for providing lateral force transmitting arch means extending across a vessel passageway which is laterally bounded by upwardly projecting portions of a substructure and bounded on the top by an integrated deck:2. Methods and apparatus for assembling an integrated deck with a substructure wherein there are effected horizontal and vertical shock absorbing action, motion dampening, and desired alignment; and3. Methods and apparatus for assembling an integrated deck with a substructure wherein, at a relatively slower rate, an integrated deck is lowered into engagement with a substructure and, at a subsequent more rapid rate, a vessel initially supporting the integrated deck is vertically separated therefrom.

Abstract: Methods and apparatus for offshore operations including individually significant aspects comprising:1. Methods and apparatus for providing lateral force transmitting arch means extending across a vessel passageway which is laterally bounded by upwardly projecting portions of a substructure and bounded on the top by an integrated deck:2. Methods and apparatus for assembling an integrated deck with a substructure wherein there are effected horizontal and vertical shock absorbing action, motion dampening, and desired alignment; and3. Methods and apparatus for assemblying an integrated deck with a substructure wherein, at a relatively slower rate, an integrated deck is lowered into engagement with a substructure and, at a subsequent more rapid rate, a vessel initially supporting the integrated deck is vertically separated therefrom.

Abstract: A method of working an underwater deposit comprises the following stages:(a) constructing and positioning a platform structure, equipped before or after positioning with drilling devices and installations,(b) executing drilling using these devices and installations,(c) constructing and equipping, during stages (a) and (b), a production bridge fitted with devices and installations required for production,(d) transporting the production bridge to, and positioning it on, said platform structure, and(e) commencing production from deposit.The drilling bridge may remain in position on the platform structure during stages (d) and (e), or it may be removed to make way for the production bridge.

Abstract: Methods and apparatus for offshore operations including individually significant aspects comprising:1. Methods and apparatus for providing lateral force transmitting arch means extending across a vessel passageway which is laterally bounded by upwardly projecting portions of a substructure and bounded on the top by an integrated deck:2. Methods and apparatus for assemblying an integrated deck with a substructure wherein there are effected horizontal and vertical shock absorbing action, motion dampening, and desired alignment; and3. Methods and apparatus for assemblying an integrated deck with a substructure wherein, at a relatively slower rate, an integrated deck is lowered into engagement with a substructure and, at a subsequent more rapid rate, a vessel initially supporting the integrated deck is vertically separated therefrom.

Abstract: The present invention provides methods and apparatus for mooring a tension leg platform. The platform is positioned over an anchor means attached to the ocean floor. A plurality of guidelines or cables, attached to the anchor means, are called to the surface by means of acoustic recall buoys which are attached to a free end of the guide cables. The guide cables are then connected to the floating platform. Tension legs, each including a plurality of tubular leg elements threaded at each end, with threaded couplings connecting adjacent leg elements, are then lowered from the floating platform. Guide means connected between the tension legs and the guide cables direct the tension legs toward the anchor means on the ocean floor. A hydraulically actuated wellhead connector is connected to a lower end of the tension leg. The wellhead connector engages a wellhead body attached to the anchor means, and is locked thereto upon the sending of a hydraulic signal to the wellhead connector.

Abstract: An offshore construction arrangement in which a platform is provided with raisable and lowerable support legs which engage a substructure resting on the sea bed. The parts lie on one another in a solid support surface and engage over one another while maintaining a funnel-shaped gap. Spring elements are located between side walls of the substructure and end portions of the legs, and the spring elements are supported on one of the side walls. The spring elements are displaceable in horizontal and vertical directions, and they are constructed as leaf springs arranged in a funnel. The leaf springs protrude beyond the rim of the funnel and are pre-bent inwardly. The leaf springs, furthermore, may be supported by lateral springs, and an auxiliary funnel may be used to receive the spring elements while being exchangeably arranged in the first-mentioned funnel. The spring elements may be in the form of several blocks of elastic material and spaced from each other.

Abstract: A device for coupling and uncoupling an emerging articulated column to or from its base installed on the bottom of a body of water, the said column and the said base being provided with piping portions, wherein quick operated connecting-disconnecting means are provided for rapidly interconnecting corresponding portions of the said base pipings and column pipings, respectively, connectable and disconnectable concomitantly with the use or operation of the means of connection and disconnection of the said column to or from the said base.According to one aspect of the invention, the column is provided with a connecting pedestal substantially cylindrical in shape and adapted to be fitted into an annular socket of the pedestal, and the bundle of pipes pertaining to the column can be connected by screwing to corresponding piping portions converging towards the center of the socket.

Abstract: Containers for storing crude oil or other liquids at offshore locations are formed preferably of reinforced concrete, though prestressed concrete can be used. The containers can be floated into position and sunk onto the ocean floor. Each container is bottle-shaped and consists of a lower storage section and an upper or neck section. The lower section is located below water and the neck section extends upwardly to a point above the water level. The maximum diameter of the lower section is considerably greater than the maximum diameter of the upper section. A platform or platform section can be provided on the upper end of the upper section. A number of containers can be grouped together and interconnected at their upper ends by a platform.

Abstract: A method is provided for mounting a deck superstructure, comprising at least one concrete girder and/or beam, on a supporting structure intended to operate in marine surroundings. The supporting structure comprises at least one column which extends above sea level and the method comprises the steps of bringing the deck superstructure, either as a unit or in sections, in position relative to the column, hoisting the deck superstructure up to the final position thereof using cables and a jacking system, and tensioning the cables upon the arrival of the deck superstructure in its final position. The lower ends of the cables are permanently anchored to the deck superstructure while the upper ends of the cables are connected to hoisting and tensioning devices arranged on top of the column.

Abstract: A method of, and equipment for, providing at the sea bed at a deep water site an installation for extracting oil or gas and comprising an anchored base structure and a column extending from the base structure to above the surface and made up of telescopically arranged column sections.

Abstract: A subfloor comprising leg-supported modules and drop in panels adapted to be installed in and around a grid of Christmas trees in the well bay area of a production platform.

Abstract: A semi-submersible floating apparatus for operating at sea and a method of assembling the same are disclosed. The apparatus comprises two or more submerged or bottom hulls supporting, by pillars, one or more working platforms or top hulls all of which are elongate floating bodies adapted to be individually constructed. The top hull is arranged transversely of the bottom hulls and is affixed by lateral connections adjacent the tops of the pillars. In assembling the apparatus, the bottom hulls are interconnected and fitted with the pillars and then ballasted until the bottom hulls are submerged. The top hull is floated until centered transversely of the bottom hulls and raised to a position for the lateral connection thereof. Alternately, the top hull is connected to the pillars and the bottom hulls are deballasted to raise the top hull above the level of the sea.

Abstract: Disclosed is an improved fixed offshore platform and method of erecting the same. The platform has an open truss structure with upper and lower deck levels. The upper deck has removable floor sections to allow installation of equipment down through the truss structure. The platform is provided with pads for mounting equipment and housing in modules on the deck. No flotation is provided in the platform and means are provided for supporting the platform on the deck of a simple barge. The platform is generally triangular in shape having three caisson legs with one leg enlarged to allow drilling therethrough. Jacks are provided for gripping the legs and a crane is mounted on the deck to move along tracks provided thereon. In erecting the platform, the platform is first barged to the location of installation on a simple barge with the legs in a vertically-extending position and the platform in its normal operating position with the crane thereon. The barge is moored in position over a well site.

Abstract: A platform comprises a base structure designed to rest on the bottom of the sea for supporting an industrial or scientific installation above the surface of the water. The base structure comprises a floatable device capable of keeping afloat and means for ballasting the base structure to install the structure on the bottom of the sea. The base structure also includes a shaft in which a hollow element with a water-tight peripheral wall and a water-tight lower end wall, can slide vertically. The element can be temporarily fixed to the shaft. The element forms a float capable of supporting a deck which carries the installations, but is capable of being immersed over at least the greater part of its height. The deck is capable of floating until it is over the top of the element when the element is immersed and has means for fixing it to the top of the element.

Abstract: An apparatus for erecting a bridge structure which is adapted to be disposed above a body of water includes an elongated bridge member and a support tower pivotably mounted upon the bridge member. The support tower includes a caisson which has a jacking member telescopically mounted therein at its upper end and the support tower is further provided with a plurality of pile sleeves mounted upon its lower end, such that the support tower may be anchored to the surface underlying the body of water. The bridge structure has a gas flare line and a gas flare tip associated therewith.

Abstract: An upper deck structure which contains the equipment necessary for operation of an oil rig is positioned on top of the main deck of the rig, the main deck being supported by vertical pilings or columns. The upper deck is not rigidly connected to the main deck but is held in place by frictional engagement therebetween. Such engagement can be enhanced by the placement of a rubber layer between the two decks. The oil rig is consequently made much lighter in weight and is easier to put together.

Abstract: Apparatus for constructing an island in a body of water including a plurality of caissons and means for connecting the caissons in an end-to-end configuration to form a ring. Once the caissons have been connected together to form a ring and ballasted to set the caissons upon the bottom of the body of water, sufficient fill material is placed inside the ring of caissons to construct an island in the body of water.

Abstract: A marine platform comprises a caisson unit adapted to be placed onto the submarine ground at a desired offshore site. A tower-like tubular structure comprising a plurality of columns extends vertically upwardly from said caisson unit and with their lower ends integrally fixed to said caisson unit. A deck unit adapted to be provided with petroleum drilling equipment or the like is integrally fixed to the upper ends of said columns. A floating unit is adapted to be displaceably and removably fixed to said columns.

Abstract: A method for joining two or more jacket or substructure components of an offshore platform in the water to form a single jacket unit. An offshore platform is located in deep water by dividing a jacket or support of extensive length therefor into at least two sections which have only sufficient buoyancy to float at water surface when the sections are launched from at least a vessel at a selected location. The sections are aligned and connected together. Guide means ensure proper alignment of the legs of the sections. Access tubes from the surface of the water to the hollow legs permit direct internal welding in securing the legs of the sections together. The sections are then sunk at the selected location until the jacket is in an upright position at which point it is anchored by driving piling through the jacket's hollow legs into the sea floor, following which the deck of the platform is placed or stabbed on the anchored jacket.

Abstract: A method for joining two or more jacket or substructure components of an offshore platform in the water to form a single jacket unit. An offshore platform is located in deep water by dividing a jacket or support of extensive length therefor into at least two sections which have only sufficient buoyancy to float at water surface when the sections are launched from at least a vessel at a selected location. The sections are aligned and connected together. Guide means ensure proper alignment of the legs of the sections. Access tubes from the surface of the water to the hollow legs permit direct internal welding in securing the legs of the sections together. The sections are then sunk at the selected location until the jacket is in an upright position at which point it is anchored by driving piling through the jacket's hollow legs into the sea floor, following which the deck of the platform is placed or stabbed on the anchored jacket.