Abstract: A piling-jacket system (10) and method involves a piling jacket (12) having a side, vertically-slit, open port arrangement (14) with an internal flap valve in the shape of a duct (48) attached to a cord (56) which extends externally of the piling jacket to positively force the duct flap valve closed. The piling jacket system includes a steel band (84) at the top of the piling jacket which clamps the piling jacket in a notch (86,88) cut in a piling (80) to be repaired with the piling-jacket system. When the piling jacket is thusly hung from the piling, the lower portion of the piling jacket, pulling down on the vertically-slit open port tends to close the open port. A portable, rigid, access tube (66) is placed through the vertically-slit open port to hold it open for the insertion of a grout-supply hose.

Abstract: An icebreaking buoy system includes an icebreaking buoy connected to clump weight means positioned on the sea floor by a mooring line having minimum extra length sufficient to permit the buoy to ride up over the largest expected wave. Several such buoy systems may be used to form a line along one or more sides of, or a ring entirely around, an offshore structure or rig to break an ice sheet in the direction or directions it is moving. An anchor fixed to the sea floor may be connected to the clump weight means. Each buoy has a downward sloping bottom portion and a cylindrically or spherically formed top portion. The sides or ends and the bottom of the buoy may be beveled, conical or spherical.

Abstract: Precoated corrosion-resistant steel pipe piles, and structures thereof, for driving into the sea bed wherein the waterproofness, corrosion resistance, and scratch resistance of the steel pipe piles are considerably improved by applying a polyethylene resin over the length thereof.

Abstract: The present invention concerns a system for cathodic protection of off-shore structures, by the impressed current method, which system comprises tubular anode assemblies (1, 1') coaxially applied onto power supply cables (4), supported by ropes (5) tensioned between anchoring bodies (15) and the structure to be protected (17) or directly supported by the structure to be protected. The tubular anodes, the relevant hydraulic sealings and electrical connections and the power supply cables (4) are not subjected to the mechanical stresses affecting the support.

Abstract: A method and apparatus for protecting an isolated well conductor of a shallow-water well by installing a reinforcing frame against the well conductor near the water line and another frame on the ocean floor and then driving piles through aligned legs of the two frames and into the ocean floor, and subsequently operatively connecting the frames to the piles and the well conductor.

Abstract: A semi-submersible oil platform comprising two pontoons (1), columns (2) extending up from the pontoons and supporting a deck structure (3), and stays (4) extending transversally of the pontoons between the columns (2), is provided with a plough-like protecting device (8) for diverting drifting objects, e.g. ice bodies which are not sufficiently large to be detected by radar, but which, nevertheless, could cause considerable damage to the horizontal stays (4) of the platform and the drill string.

Abstract: A marine platform comprising a structure composed of a lattice of tubular elements sealingly connected to one another, includes a crack detection system comprising pickups provided on at least some of the elements and adapted to detect the passage of fluid through a wall, each pickup including an autonomous energy source and an acoustic signal transmission means. A signal acquisition unit adapted to receive signals from the pickups is disposed on a non-submerged part of the platform.

Abstract: An apparatus is disclosed for inspecting, cleaning and/or performing other tasks in connection with a welded joint between intersecting tubular members of an offshore platform a substantial distance beneath the water surface. The apparatus includes a support body adapted to be moved onto and removed from one of the tubular members, and a carrier rotatable about the body, when clasped about the one tubular member, and having the task performing devices thereon for traversing the joint as the carrier is so rotated.

Abstract: A floating semisubmersible off-shore drilling platform or the like comprises an upper working level portion and a lower pontoon portion. When the platform is transported from one place to another, it floats on the pontoon portion, but when it is working as a stationary unit in open water, it is submerged deeper, so that the pontoon portion is at a considerable distance below the water surface and the working level portion is at a considerable distance above the water surface. The platform is adapted to withstand ice pressure from ice occurring in the ambient water by giving the pontoon portion of the platform a form particularly advantageous in ice conditions. When ice occurs, the platform is lifted to such a position, that its pontoon portion comes to float at the water surface level.

Abstract: An anti-scour apparatus and method for preventing, reducing or repairing scour in the vicinity of a structure extending vertically from the floor beneath a body of moving water. The anti-scour apparatus comprises one or more deflectors, a spacer for maintaining the positional relationship of the deflectors and for maintaining the positional relationship of the deflectors and the floor beneath the body of water, and a plurality of hydraulic trips operatively associated with the structure. The method for preventing scour including the steps of deflecting a downwash at a location adjacent the structure and above the floor, deflecting a downwash at a location adjacent the structure and adjacent the floor, inducing the turbulent flow of water adjacent the structure, and capturing the suspended sediment for filling prior scour.

Abstract: This invention relates to an offshore unit structure. When the sea bottom ground on which an offshore structure is to be built is weak, in order to prevent the structure from being deformed by gravitational load of the structure or by horizontal load applied thereto, a cement type solidifying agent is impregnated into and mixed with subsoil in such weak ground to construct a unit-volume reformed ground, and a unit structure body is built upon such reformed ground. The structure according to this invention can be advantageously used for prospecting or producing oil in the sea.

Abstract: A method of reinforcing a hollow underwater member of an offshore platform which includes drilling and tapping holes at substantially opposite ends of the member, injecting air into the member to determine leak holes, cleaning the outside of the member near the holes, patching the holes on the outside of the member, and injecting grout into the patched member.

Abstract: This invention relates to a reinforced concrete structure of enhanced corrosion resistance. The invention structure finds particular utility in service in brackish or saline water. The reinforced concrete of the structure is, on its surface, in contact with a low resistivity grout. Anode elements are in contact with the grout, such as at the surface of the reinforced concrete or by partial or full embedment in the grout. Together with this combination, a high resistivity material is provided as a covering over the low resistivity grout and anode elements. The resulting structure is especially useful when in contact with seawater, and most particularly seawater subject to tidal action.

Abstract: In a corrosion monitoring system for an offshore marine platform which includes a deck positioned above the water's surface and a jacket fixed to the ocean floor to support said deck, said monitoring system including cable means extending from the deck to the ocean floor and carrying corrosion monitoring instruments for generating an electrical signal, said carriage being fabricated of such a material to allow generation of said electrical signals without interference or distortion of the latter.

Abstract: For use with a subsea well incorporating an external conductor pipe extending upwardly above the seabed, a well support miniplatform is set forth. In the preferred and illustrated embodiments, the preferred embodiment describes a longitudinally split, flange equipped, bolt joined elongate conductor clamp supported on a frame at the bottom thereof and having a plurality of appended upstanding braces. The support frame is adapted to be rested on a seabed and held in place by a number of anchors driven into the seabed at corners. The support frame is selectively installed after completion of a well wherein the conductor pipe extends above the seabed. The support frame may subsequently be removed after installation of a permanent platform. In alternate embodiments, the support frame may be installed as a permanent structure. A boat landing and miniplatform may be mounted on the conductor pipe or the conductor clamp supported by the support frame.

Abstract: To inhibit marine growth on a submerged framework, one or more collars are placed loosely around each member of the framework, the collars having outwardly projecting vanes so that ambient water movement causes movement around or along the member. The vanes (5; 25; 45; 55; 65) are preferably hinged to the collar for limited pivotation and may be twisted or provided with extension portions to ensure axial movement.

Abstract: A protective device protects a platform installed in the open sea against the impact of floating objects such as icebergs, ice formations, or ships. A massive protective body surrounds the platform to be protected and has a bottom with inclined bearing surfaces. The body is movably supported on large bearings having inclined bearing areas that slidingly engage the bearing surfaces. When the protective body is struck by a floating object the kinetic energy of the impact pushes the protective body upwards on a portion of the inclined bearing areas and is transformed into potential energy of the elevated body. The protective body is able to thrust the floating object away from the platform as the body moves downwardly to its original position as its potential energy is reconverted to kinetic energy.

Abstract: Pressurized liquid filled tubular tendons provide a means for detecting leaks therein. Filling the tendon with a liquid having a specific gravity less than that of sea water provides increased buoyancy and reduces the weight supported by the buoyant structure. The use of a corrosion inhibiting liquid reduces the corrosion of the interior tendon wall.

Abstract: Disclosed in a method of and apparatus for lowering pipe strings and other objects, particularly pipe strings carrying anodes for cathotic protection, into and through the support structure of an offshore plateform. Skid beams are inserted into the support structure of the offshore platform below the top deck of the platform and above the water level, preferably at the plus twelve level of the structure. Mounted to the skid beams are winch and derrick means. The skid beams are inserted into the structure such that the winch and derrick means are positioned over the point at which the pipe string is to be lowered through the structure. The skid beams cantilever out from the structure such that they extend well beyond the outside perimeter of the top deck. The skid beams also serve as track for a trolley. Pipe string sections can be delivered to the trolley either from the top deck of the platform or directly from a barge.

Abstract: An arrestor for reducing the velocity of moving icebergs and the like or large drifting objects relative to an off-shore fixed structure is disclosed. In use, the device extends outwardly from a fixed structure in at least one direction. A frame is adapted to be mounted to the structure in a manner which will allow an extending end thereof to move toward the structure. Nylon ropes or any other suitable elastic members are attached to the frame and to the structure and are utilized to provide an increasingly greater resistive force on the frame as the extending end of the frame is pushed toward the structure by an iceberg. Various embodiments of the general concept are disclosed.

Abstract: An improved mechanism for cushioning shocks imparted to a stationary body from various sizes of vessels, including a resiliently retarded telescoping member having a first movement versus thrust characteristic with a relatively high rate of movement versus thrust over a first predetermined range of thrusts, and an abruptly lower rate of movement versus thrust for thrusts exceeding said first predetermined range.

Abstract: A marine structure comprising steel pipe piles in which the top head, splash zone and tidal zone of each steel pipe pile driven into the sea bed are covered with a polyethylene resinous covering material, and the top head of the steel pipe pile is inserted inside a slab concrete structure, whereby is realized a considerably improvement in the water imperviousness, corrosion resistance, and scratch resistance of the steel pipe piles.

Abstract: A structure having a polygonal base and sloping sides forming a frustrum includes a load bearing outer skin which contains an inner assembly and an outer assembly. Both the inner and outer assemblies include a skin plate member which is stiffened by stiffeners welded to one side of the skin plate member. The stiffeners are located at spaced intervals from each other and are disposed substantially perpendicular to the skin plate member. The inner and outer assembly are placed substantially parallel to each other to form a composite structure having an internal cavity defined by the inner and outer plates. The stiffeners of the inner assembly and the outer assembly are disposed in the cavity at a spaced relation to each other and extend partly into the cavity. A cementitious material substantially fills the cavity thereby completing the load bearing outer skin structure. The stiffeners may be flat steel plates or may have the profile of structural shapes such as angles or T's among others.

Abstract: An emergency aircraft landing device is shown of the type having a base with a concave upper surface for receiving and supporting the fuselage of an aircraft. A plurality of resilient, elongate members are arranged in rows at spaced intervals along the upper surface and the rows are oriented normal to the upper surface for stopping the forward progress of an aircraft landing on the upper surface. An inflatable bag on either side of each of the rows supports the elongate members normal to the plane of the upper surface. The base is mounted on wheels and is powered by an electric motor for moving down a runway. A second electric motor is remotely controlled by a radio signal and operates a worm gear to position the front wheel of the device control the direction of travel.

Abstract: This invention describes a scheme for absorbing the energy of floating bodies such as ships approaching the coastal wall by providing the coastal wall with fenders made of spring materials along with dash-pots that absorb the energy of the approaching floating body due to liquid resistance so that the energy is first absorbed by the springs of the fender in the form of displacement energy and is then dissipated by the dash-pots.

Abstract: A mechanism for positioning on a dock vertical wall a fender including spaced openings, the mechanism comprising a movable support, a first arm pivotally attached to the movable support, a first hydraulic cylinder piston rod assembly for pivoting the first arm, a second arm pivotally attached to the first arm, means for pivoting said second arm, a plurality of spaced projections attached to and extending from the second arm, and pins for releasably securing the projections in the spaced openings in the fender. And a method for positioning on a dock vertical wall fenders including spaced openings opposite an attaching surface, the method comprising the steps of positioning the fender so the spaced openings are accessible, releasably fastening a fender moving mechanism in the openings, locating the fender so the attaching surface is generally vertical, locating the fender on the dock vertical wall, attaching the fender attaching surface to the dock vertical wall, and releasing the fender moving mechanism.

Abstract: This invention is directed to a novel method and apparatus for constructing artificial islands in relatively shallow bodies of water such as lakes, seas and oceans for use in drilling oil and gas wells and installing storage and production platforms. The method of building an artificial island in a Water-bound area comprises converting a conventionally designed oil tanker, oil/bulk/ore, or oil/ore (O, O/B/O, O/O) hull so that it can be partially submerged by liquid or solid ballast; transporting the hull to the water-bound area where the artificial island is to be created; and partially submerging the hull with liquid or solid ballast so that the bottom of the hull is founded on the bottom of the water body, while a portion of the hull remains above the water level.

Abstract: A method is provided for producing usable hydrocarbon product from an offshore reservoir. The method includes the economically desirable step of producing a valuable hydrocarbon product from the formation, soon after its being discovered. The product is then extracted from its reservoir, long prior to, and during the period when a marine structure is being fabricated and installed to more fully develop the reservoir and to receive a flow of the product.

Abstract: A movable fixed-type semi-submerged construction includes a plurality of legs each having a spat tank attached to its lower end and sunken to rest on the bottom of the sea and a superstructure supported on the legs. A scouring preventing structure including a cylindrical circumferential wall formed with a large number of holes therethrough is arranged at the lower part of each of the legs so as to encircle the spat tank.

Abstract: Inclined plane protection boards are provided in a manner to cover an inclined plane of an artificial island whereby the inclined plane may be protected from ice force of growing or drifting ice bodies or wind and wave force.

Abstract: A marine structure adapted to be at least partially submerged at an offshore body of water to drill wells into the ocean floor and to produce fluids therefrom. A corrosion deterrent system for protecting the submerged members of the structure comprises sacrificial anodes which are disposed about the structure's jacket.A drilling template carried on the jacket comprises means to a plurality of drilling conductors therein. At least one upright column incorporated into said drilling template is provided with discretely placed sacrificial anodes arranged to best protect the drill conductors.

Abstract: A method and means for storing a marine riser is disclosed for relocating an offshore mobile unit from a drilling or production site. The riser is disconnected from a subsea port and lowered into an auxiliary borehole. Means are provided for the lowering and raising of the marine riser and positioning of same.

Abstract: A method and apparatus is disclosed for moving a large mass of ice by anchoring a two line thereto. The tow line is connected to a marine vessel which tows the ice mass to a remote location distant from threatened equipment and personnel.

Abstract: A flame sprayed aluminum coating of high strength steel components offers excellent seawater corrosion protection, increased fatigue life and uniform low level cathodic protection that avoids hydrogen embrittlement. Marine mooring and riser elements fabricated from such components are superior in the above respects to steel components protected from corrosion by common sacrificial anode cathodic protection systems. In addition, the need of welding a stud to the steel to insure electrical continuity between the steel and the sacrificial anodes is eliminated.

Abstract: The tendons of a tension leg platform (TLP) used for producing petroleum offshore at a depth of 400-1000 m are protected against fatigue corrosion which mainly determines the life of the tendons.The straight steel pipes (1) have an insulative, corrosion-protection coating (8) having good damage resistance. The screw couplings (2) have a sprayed aluminum layer (9) having the ends contiguous to the ends of the insulative, corrosion-protection, and a galvanic current anode (5) is electrically connected to the screw coupling (2).

Abstract: The present invention is a method and an apparatus for reducing marine growth on an offshore oil platform member. The device uses a buoyant member coupled with a sleeve to scrape the exterior surface of the platform members. The buoyant component floats on the surface of the water and takes advantage of the ocean energy (i.e., the variation of the water's surface height due to the tidal and surge responses) to move the device up and down on the member. The liner and the buoyant member are adjusted for size and buoyancy to ensure that scraping occurs in the areas of the members that are most vulnerable to attachment of marine organisms.

Abstract: An ice-breaking structure having a platform member adapted to be flexibly connected to an off-shore fixed well shaft in a manner which allows the platform to lift and/or tilt relative to the shaft is disclosed. The platform member has at least one lower surface which slopes upwardly toward an outer edge thereof and is adapted to be positioned on the shaft so that the sloping surface extends both above and below sea level. As oncoming ice approaches and contacts the structure, the sloping surface lifts a portion of the platform upwardly onto the ice so that part of the weight of the platform is carried by the ice. This weight on the ice aids in breaking-up the same. Various embodiments of the general concept are disclosed.

Abstract: An anode pod system for cathodically protecting offshore structures and method of installing the system in which a set of anode pod units are individually placed on the ocean floor adjacent an offshore structure. Each anode pod unit comprises a plurality of anodes attached to a top tubular ring and a base tubular ring larger than the top tubular ring to form a conically-shaped unit. An electrical conductor cable connects each anode pod unit to the offshore structure.

Abstract: An off-shore drilling platform or the like supported by support legs standing on the bottom of the sea is converted to withstand ice pressure occurring in ice filled waters by providing those portions of said drilling platform, which are to be protected against ice pressure, with protective structures below the platform. The drilling platform and/or the protective structures are then, when ice occurs, lowered along the support legs to a level where the protective structures partly extend below the surface of the ambient water.

Abstract: A shield for protecting a well head and functional modules in an under sea station comprising a composite cushion formed from a floor 6 made from a material less dense than water, such as a plastic material or treated wood, and resting on a perforated metal sheet or grid 7, removably fixed by means of deformable feet 4 to a horizontal plate 1 mounted at the top of the module to be protected and having at the position where the guide column 2 passes an opening in which is welded a sleeve 14 capable of sliding along said guide columns 2.In a shield for protecting a module provided with a central connector, said plate has a central cage with vertical lateral wall for housing said connector, radial arms being fixed to the bodies of several shock absorbers spaced apart on said plate and to said wall of the cage for transmitting shock absorbing forces.

Abstract: A floating semisubmersible off-shore drilling platform or the like comprises an upper working level portion and a lower pontoon portion. When the platform is transported from one place to another, it floats on the pontoon portion, but when it is working as a stationary unit in open water, it is submerged deeper, so that the pontoon portion is at a considerable distance below the water surface and the working level portion is at a considerable distance above the water surface. The platform is adapted to withstand ice pressure from ice occurring in the ambient water by giving the pontoon portion of the platform a form particularly advantageous in ice conditions. When ice occurs, the platform is lifted to such a position, that its pontoon portion comes to float at the water surface level.

Abstract: A method for protecting stationary constructions, located in water and surrounded by water, against strain caused by a moving ice field in said water. A protective structure is arranged around said stationary construction. Said protective structure has a cross-section considerably greater than the cross-section of said stationary construction and it comprises, at the water surface level and below this level, an outer surface which slopes downwards in a direction against the stationary construction to form an ice breaking surface bending downwards ice, which move against said protective structure.

Abstract: An underwater backfilling apparatus which can be used by undersea divers provides a sediment intake which is randomly movable by a diver over the ocean floor for removing sediment material from the seabed which is to be used in underwater backfilling. A handheld discharge dispenses the sediment material into a selected void space to be backfilled with the sediment which is removed by the intake from the seabed. A conduit connects the intake and the discharge with a bore so that sediment can be transmitted from the intake to the outlet. A fluid drive is positioned in the conduit between the inlet and the outlet for moving a mixture of sediment and seawater through the conduit.

Abstract: For use with a subsea well incorporating an external conductor pipe extending upwardly above the seabed, a protector apparatus is set forth. In the preferred and illustrated embodiment, the preferred embodiment describes a longitudinally split, flange equipped, bolt joined elongate conductor clamp supported on a frame at the bottom thereof and having a plurality of appended upstanding braces. The bottom frame is adapted to be rested on a seabed and held in place by a number of anchors driven into the seabed at corners. This apparatus is selectively installed after completion of a well wherein the conductor pipe extends above the bottom, and the apparatus is subsequently removed after protecting the pipe after drilling but before installation of a platform.

Abstract: An installation 18 is protected by a circular array of drag elements 2. Each drag element is anchored to the seabed and has teeth on its upper surface which penetrate, and decelerate, moving ice structures. Ice structures which move over the drag elements and enter the protection area have insufficient momentum to damage the installation.

Abstract: The load bearing outer skin contains an inner assembly and an outer assembly. Both the inner and outer assemblies include a skin plate member which is stiffened by stiffeners welded to one side of the skin plate member. The stiffeners are located at spaced intervals from each other and are disposed substantially perpendicular to the skin plate member. The inner and outer assembly are placed substantially parallel to each other to form a composite structure having an internal cavity defined by the inner and outer plates. The stiffeners of the inner assembly and the outer assembly are disposed in the cavity at a spaced relation to each other and extend partly into the cavity. A cementitious material substantially fills the cavity thereby completing the load bearing outer skin structure. The stiffeners may be flat steel plates or may have the profile of structural shapes such as angles or T's among others.

Abstract: A protective sleeve for fitting about the periphery of the leg of an offshore structure. The sleeve comprises means for carrying and enclosing a plurality of conductors. It further includes one or more inner rings; an outer jacket is fixedly spaced from the rings to define longitudinal passages within which the respective conductors are fixedly positioned. The sleeve is capable of deflecting packed ice and floating objects which represent possible sources of damage to the structure or to conductors.

Abstract: Pressurized gas filled tubular tendons provide a means for detecting leaks therein. Filling the tendon with a gaseous fluid provides increased buoyancy and reduces the weight supported by the buoyant structure. The use of a corrosion inhibiting gaseous fluid reduces the corrosion of the interior tendon wall.

Abstract: A well head protector for a well which is located at the floor of an offshore body of water. The protector includes a plurality of discrete sub-assemblies which, for installation purposes, are initially transported to a drilling vessel and positioned above the well head. The sub-assemblies are sequentially lowered from the vessel deck and assembled above the water surface into a composite unit. The completed unit is guidably lowered by the vessel's drilling derrick to its position surrounding the well head. The deflecting elements are then lowered into place.

Abstract: A sleeve adapted to float in water and to surround a piling to protect the same from being lifted by ice includes an outer corrugated casing which can be easily gripped by ice forming therearound. Within the casing is a layer of waterproof cementitious material followed by a layer of closed cell foam plastic. The innermost surface of the sleeve, which faces the piling, is a smooth even layer of polyethylene film. Should ice form in the annular space between the piling and the sleeve, the sleeve can easily slide up or down across the outer surface of the ice without moving the piling.