Abstract: Disclosed is a vessel comprising at least two parallel hulls at a predetermined mutual distance. A deck structure is supported on the hulls. Fluid storage tanks are placed in the at least two hulls, at least partly below the deck structure. The deck structure carries fluid processing and/or production equipment. The fluid is a hydrocarbon. The ratio of length to width of the vessel being at least 3, preferably at least 4. The length of the vessel being at least 150 m, preferably at least 250 m, more preferably at least 350 m.

Abstract: An apparatus for use in offshore oil or gas production in which a plurality of vertical stabilizing columns are supported on a submerged horizontal water entrapment plate is provided to support minimum offshore oil and gas production facilities above a subsea wellhead, or subsea processing facilities, or a submarine pipeline, and whose main function is to provide power or chemicals or to perform other operations such as compression, injection, or separation of water, oil and gas. The apparatus is maintained in the desired location by a plurality of mooring lines anchored to the sea-bed. The respective size and shape of the columns and water entrapment plate are designed to provide sufficient buoyancy to carry the weight of all equipment on the minimum floating platform and mooring lines, umbilical and risers attached to it, and to minimize the platform motion during normal operations.

Abstract: A process for the conversion of natural gas to higher hydrocarbons in a system comprising (1) a synthesis gas production unit and (2) a Fischer-Tropsch synthesis unit comprising at least one high shear mixing zone and a reactor vessel wherein the units are located abroad a floatable structure. The process comprises the steps of: (a) converting the natural gas to synthesis gas in the synthesis gas production unit; and (b) converting the synthesis gas to higher hydrocarbons, at an elevated temperature and pressure, in the Fischer-Tropsch synthesis unit by (i) passing synthesis gas and a suspension comprising a particulate Fischer-Tropsch catalyst suspended in a liquid medium through the high shear mixing zone(s) wherein the synthesis gas is broken down into gas bubbles and/or irregularly shaped gas voids which are dispersed in the suspension, and (ii) discharging suspension containing the dispersed gas bubbles and/or irregularly shaped gas voids from the high shear mixing zone(s) into the reactor vessel.

Abstract: Method for transport and installation of objects at sea, particularly relating to transport and installation of obs jects that are part of the infrastructure in oil and gas fields offshore, the object (4) is put in the sea at a suitable location near the shore or in sheltered waters, then towed to the installation site while being suspended in a slender buoyancy unit (5) acting much like a heave compensating unit. Upon arrival at the installation site, the suspension of the object (4) is transferred from the buoyancy unit (5) to a heave compensated winch (3) on a surface vessel (2), preferably the same vessel as used for the preceding towing operation. The winch is used to lower is the object (4) to its destination on the sea bottom or a predetermined location above the sea bottom.

Abstract: A bottom-supported jack-up rig has a hollow ring mat with a central opening for accommodating a lower portion of a hull nested therein when the rig is in transit. The ring mat has a predetermined surface footprint sufficient to provide stability to the rig when embedded in the sea bottom. The mat buoyancy helps support the hull and the legs in a floating position when the rig is in transit, while allowing lowering of the mat to the sea bottom without assistance of a ballasting/de-ballasting means.

Abstract: A system for offloading LNG (liquified natural gas) from a tanker (26) in shallow waters, for regasing, or heating the offloaded LNG to produce gaseous hydrocarbons, or gas, for pressurizing the gas, and for flowing the gas to an onshore station (56), includes a structure that is fixed to the sea floor and projects above the sea surface and aids in mooring the tanker. In one system, the structure that is fixed to the sea floor is a largely cylindrical tower (12) with a mooring yoke (20) rotatably mounted on its upper end. A floating structure (14) such as a barge that weathervanes, has a bow end pivotally connected to a distal end of the yoke, so the barge is held close to the tower but can drift around the tower with changing winds, waves and currents. The tanker is moored to the barge so the barge and tanker form a combination that weathervanes as a combination.

Abstract: A method and a suitable arrangement for installation of a deck structure at an offshore location, where the deck structure is put on a vessel at a location inshore, then transported on the vessel to the offshore location and positioned relative to legs (13) of a jacket or gravity base type support structure standing on the sea bottom, or the legs or columns of a floating substructure, the deck structure having deck legs (5) corresponding to support legs (13) on the support structure, the deck legs (5) each being provided with a jack type of mechanism with an associated piston (1) which is extended into contact with and supported by the top part (3) of the corresponding support leg (13) at the beginning of a procedure for transferring the weight of the deck structure from the vessel to the support legs (13).

Abstract: A system for offloading LNG (liquified natural gas) from a tanker (26) in shallow waters, for regasing, or heating the offloaded LNG to produce gaseous hydrocarbons, or gas, for pressurizing the gas, and for flowing the gas to an onshore station (56), includes a structure that is fixed to the sea floor and projects above the sea surface and aids in mooring the tanker. In one system, the structure that is fixed to the sea floor is a largely cylindrical tower (12) with a mooring yoke (20) rotatably mounted on its upper end. A floating structure (14) such as a barge that weathervanes, has a bow end pivotally connected to a distal end of the yoke, so the barge is held close to the tower but can drift around the tower with changing winds, waves and currents. The tanker is moored to the barge so the barge and tanker form a combination that weathervanes as a combination.

Abstract: The method for re-deploying an offshore jacket using a plinth involves the steps of locating an offshore jacket; constructing a plinth with a plinth legs, a skirt pile sleeve, a mud mat, a space frame, guide cones, and a trestle per plinth leg; placing the plinth at the second site; driving one skirt pile into each skirt pile sleeve; disconnecting the jacket legs from the seabed at the first site; lifting the offshore jacket above the seabed; moving the offshore jacket from the first site to the second site; and lowering the offshore jacket such that each jacket leg stabs into each guide cone on the plinth until each jacket leg mud mat contacts each trestle; and inserting pin piles through each jacket leg and plinth leg and grouting the pin piles to effect a permanent structural connection between plinth and jacket.

Abstract: Platform for drilling after or production of hydrocarbons at sea, consisting of a semi-submersible platform body which supports drilling and/or production equipment on its upper surface. The platform body is designed as a vertical mainly flat bottomed cylinder which is provided with at least one peripheral circular cut-out in the lower section of the cylinder since the centre of buoyancy for the submerged section of the platform is positioned lower than the centre of gravity of the platform.

Abstract: An extendable draft offshore oil and gas drilling and production platform (“EDP”) includes a buoyant deck having a central opening, an adjustably buoyant pontoon, and a single, adjustably buoyant column. The column is mounted upright on the pontoon, and is vertically movable through the central opening of the deck. The deck is supported on an upper end of the column above a body of water for offshore operations. The pontoon, and optionally, the column, have compartments with a buoyancy that is adjustable by pumps or sea water ballast and pressurized air. In one embodiment, the compartments can comprise a plurality of tubes. In another embodiment, a lower end of the column may comprise an open truss structure. The platform combines the advantages of a SPAR platform with those of a deep draft extendable draft platform.

Abstract: A floating offshore fluid storage caisson platform has a large diameter vertically oriented buoyant column or caisson, or multiple caissons, defining a storage chamber, and a telescopic keel tank disposed at the bottom end thereof, and may have deck on top of the caisson to support storage, drilling and production structures, equipment, and quarters. The structure can be transported horizontally either dry on a transporting vessel or towed with its keel tank in a fully retracted position. At the field of operation, the structure initially floats horizontally.

Abstract: A semi-submersible, multicolumn, deep draft, floating offshore oil and gas drilling and production platform comprises a floating hull having an adjustably buoyant base, a plurality of columns vertically upstanding from the base, and an equipment deck that is supported atop the columns when the platform is operationally deployed. Each of the columns comprises a cellular structure that includes a plurality of elongated tubes having a variety of cross-sectional shapes extending from the base to the top of the column. Each of the tubes defines one or more closed compartments. At least one of the compartments has a buoyancy that is fixed, and at least another one of the compartments has a buoyancy that is adjustable. The buoyancy of the compartments and the base can be controllably adjusted with pressurized air to provide a safer and less costly method for deploying the platform for offshore operations.

Abstract: An offshore lifting construction is able to control buoyancy for the lifting of jackets for offshore platforms. The lifting construction is designed such that it can be ballasted for raising and lowering and such that it can take several positions. The lifting construction is designed as an arm equipped with a joint for attachment to a vessel. The arm includes two substantially parallel longitudinal elements with intermediate supporting elements. One of the ends of the arm includes at least two tubular branches substantially perpendicular to the longitudinal direction of the substantially parallel longitudinal elements. At least one of the elements of the arm includes at least one ballastable tank. The arm is equipped with device for attachment to the jacket that is to be lifted. A method for rising jackets or jacket legs for offshore platforms is also described.

Abstract: The invention is a method for drilling a well and for well intervention using a multipurpose system on a pivoting, slidable cantilever on a platform to drill a well and to perform well intervention operations, wherein the method involves pulling a completion tubing out of the well; forming completion tubing segments pulled from the well; setting back the segments into a storage area; running the coiled tubulars into the well; removing used completion equipment from the well; preparing the well for new completion equipment with the coiled tubulars; pulling segments of new completion tubing from the storage area and breaking segments of new completion tubing into individual joints and removing the individual joints from the cantilever; running into the well with coiled tubulars and installing the new completion equipment; building segments from individual joints and setting the segments in the storage area; and running segments and new completion equipment into the well.

Abstract: Jacket frame floating structures comprise one or more elongate vertical support columns formed of an open cross-braced jacket formwork of tubular members interconnected together and at least one cylindrical buoyancy capsule disposed in the open framework near an upper end and at least one cylindrical second buoyancy capsule near a lower end in vertically spaced relation. The buoyancy capsule(s) may be a single, or a plurality of upper and lower capsules bundled in circumferentially spaced relation with a central opening therethrough. Alternatively, a keel tank may replace the lower capsule.

Abstract: A mudmat foundation for supporting an item of subsea equipment on the sea floor comprises a mudmat on which the item of subsea equipment may be supported and a plurality of legs which are pivotably connected to and depend downwardly from the mudmat. The legs are free to pivot outwardly relative to the mudmat upon insertion of the legs into the sea floor to thereby increase the load bearing capacity of the mudmat.

Abstract: A device for lifting a seagoing construction such as a drilling rig, which device comprises one or more floater bodies, one or more beam-like lifting members supported movably on a floater body and running parallel or practically parallel to each other, wherein the or each lifting member is supported on at least two support points of the floater body, at least one of which is adjustable in height direction, and the end part of the lifting member lying outside the floater body has a pressure point which is in contact with the construction for lifting, this such that the seagoing construction can be easily connected to the end of the lifting member without this construction suffering damage as a result of the sea swell.

Abstract: A bottom-supported jack-up rig has a hollow ring mat with a central opening for accommodating a lower portion of a hull nested therein when the rig is in transit. The ring mat has a predetermined surface footprint sufficient to provide stability to the rig when embedded in the sea bottom. The mat buoyancy helps support the hull and the legs in a floating position when the rig is in transit, while allowing lowering of the mat to the sea bottom without assistance of a ballasting/de-ballasting means.

Abstract: The present invention concerns an offshore lifting construction with means for controllable buoyancy for the lifting of jackets (13) for offshore platforms. The lifting construction is designed such that it can be ballasted for raising and lowering and such that it can take several positions. The lifting construction is designed as an arm (1) equipped with a joint (10) for attachment to a vessel (2). The arm (1) comprises two substantially parallel longitudinal elements (5) with intermediate supporting elements (6). One of the ends of the arm comprises at least two tubular branches (8) substantially perpendicular to the longitudinal direction of the substantially parallel longitudinal elements (5). At least one of the elements of the arm (1) comprises at least one ballastable tank. The arm (1) is equipped with means (9) for attachment to the jacket (13) that is to be lifted. A method for rising jackets (13) or jacket legs for offshore platforms is also described.

Abstract: A floating plant for liquefying natural gas having a barge provided with a liquefaction plant, member for receiving natural gas and with member for storing and discharging liquefied natural gas. The liquefaction plant involves a heat exchange in which heat is removed when liquefying natural gas is transferred to water. The barge is further provided with a receptacle; an open-ended water intake conduit having an inlet; a connecting conduit extending from the outlet of the water intake conduit to the receptacle; a pump for transporting water from the receptacle to the heat exchanger and a water discharge system for discharging water removed from the heat exchanger. The connecting conduit has the shape of an inverted “U” of which the top is located above the receptacle.

Abstract: A semi-submersible, multicolumn, deep draft, floating offshore oil and gas drilling and production platform comprises a floating hull having an adjustably buoyant base, a plurality of columns vertically upstanding from the base, and an equipment deck that is supported atop the columns when the platform is operationally deployed. Each of the columns comprises a cellular structure that includes a plurality of elongated tubes having a variety of cross-sectional shapes extending from the base to the top of the column. Each of the tubes defines one or more closed compartments. At least one of the compartments has a buoyancy that is fixed, and at least another one of the compartments has a buoyancy that is adjustable. The buoyancy of the compartments and the base can be controllably adjusted with pressurized air to provide a safer and less costly method for deploying the platform for offshore operations.

Abstract: An offshore hydrocarbon production system includes a vessel (12) with a turret (16), and a fluid swivel (50) on the turret that is connected to risers (41-43) that extend to the sea floor (26), wherein a drilling/workover rig (60) on the vessel can lower tubing (65) toward the sea floor without danger that the tubing will wrap about the risers when the hull weathervanes. The rig is mounted on the turret. Pipes (54) that extend from the rotatable part of the fluid swivel to fittings (55) on the hull (14), are supported on a gantry (80) that is fixed to the hull and having a gantry middle portion (106) that extends over the turret. The gantry middle portion extends higher than the top (88) of the rig.

Abstract: A method and a suitable arrangement for installation of a deck structure at an offshore location, where the deck structure is put on a vessel at a location inshore, then transported on the vessel to the offshore location and positioned relative to legs (13) of a jacket or gravity base type support structure standing on the sea bottom, or the legs or columns of a floating substructure, the deck structure having deck legs (5) corresponding to support legs (13) on the support structure, the deck legs (5) each being provided with a jack type of mechanism with an associated piston (1) which is extended into contact with and supported by the top part (3) of the corresponding support leg (13) at the beginning of a procedure for transferring the weight of the deck structure from the vessel to the support legs (13).

Abstract: A vessel, preferably a chip, for transport and mounting of structures has a hull and at least four vertically elevated support legs and displacement apparatus for elevating the support legs so as to stabilize the ship for lifting heavy loads from the ship for mounting for example to a preinstalled base on the seabed.

Abstract: A method and system for attaching a TLP to its tendons using pull-down lines to rapidly submerge the hull to installation draft while compensating for inherent hull instability during submergence and to provide motion arrest and aid in station keeping. The system includes tensioning devices mounted on the TLP, usually one for each tendon. Each tensioning device is equipped with a pull-down line which is connected to the corresponding tendon. The TLP hull is submerged to lock-off draft by applying tensions to the pull-down lines connected to the top of the tensions, or by a combination of applying tensions to the pull-down lines and ballasting the hull. As the tensioners take in pull-down line, the hull submerges, i.e. the draft increases.

Abstract: The disclosed catenary anchor leg mooring system includes a cylindrical hull portion which reduces the tendency of the cylindrical hull to roll and pitch in response to the action of winds and waves. This motion reduction comes from changing the diameter and draft of the cylindrical hull.

Abstract: Platform for drilling after or production of hydrocarbons at sea, consisting of a semi-submersible platform body (2) which supports drilling and/or production equipment on its upper surface. The platform body (2) is designed as a vertical mainly flat bottomed cylinder which is provided with at least one peripheral circular cut-out (5, 30, 35, 36) in the lower section of the cylinder since the centre of buoyancy for the submerged section of the platform (1) is positioned lower than the centre of gravity of the platform.

Abstract: An apparatus for use in offshore oil or gas production in which a plurality of vertical stabilizing columns are supported on a submerged horizontal water entrapment plate is provided to support minimum offshore oil and gas production facilities above a subsea wellhead, or subsea processing facilities, or a submarine pipeline, and whose main function is to provide power or chemicals or to perform other operations such as compression, injection, or separation of water, oil and gas. The apparatus is maintained in the desired location by a plurality of mooring lines anchored to the sea-bed. The respective size and shape of the columns and water entrapment plate are designed to provide sufficient buoyancy to carry the weight of all equipment on the minimum floating platform and mooring lines, umbilical and risers attached to it, and to minimize the platform motion during normal operations.

Abstract: An apparatus and method for ballasting and de-ballasting a vessel having a hull with a plurality of watertight ballast compartments wherein each ballast compartment has an individual pump caisson extending vertically to the top of the hull, but the ballast/de-ballast system contains no valves within the hull. An external caisson is used to provide a source of seawater. Several submersible pumps are available for rigging into and out of the internal and external caissons and provide the ballast and de-ballast operations via an installed manifold system at the top of the columns. Venting of the ballast tanks may be accomplished through a connection to atmosphere near the top of the pump caissons.

Abstract: A floating drilling rig configured for performing drilling operations while floating on a body of water is modified to become a converted vessel configured for performing drilling operations while resting on bottom by attaching a support barge component adapted to add rest-on-bottom functionality. The support barge component has a ballast system that alone or by supplementing the ballast system of the floating drilling vessel enables the floating drilling vessel to be ballasted to rest on bottom. The ballast system of the support barge component is adapted to be opened to the water to fill and drain as the water level raises and lowers, and thereby maintain a constant soil pressure. The support barge component may also have a suction breaker system to break suction formed between the support barge and bottom.

Abstract: The invention relates to a vessel having an elongated shape, and being moored to the sea bed in a substantially fixed orientation. The vessel comprises at least along its longitudinal sides, near keel level, two transverse skirts having such a width that the natural roll period of the vessel is above a predetermined period, the natural roll period of the vessel without the skirts being below said predetermined period.

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 device for lifting a seagoing construction such as a drilling rig, which device comprises one or more floater bodies, one or more beam-like lifting members supported movably on a floater body and running parallel or practically parallel to each other, wherein the or each lifting member is supported on at least two support points of the floater body, at least one of which is adjustable in height direction, and the end part of the lifting member lying outside the floater body has a pressure point which is in contact with the construction for lifting, this such that the seagoing construction can be easily connected to the end of the lifting member without this construction suffering damage as a result of the sea swell.

Abstract: A marine platform (and method of installation) provides a plurality of buoys, a platform having a peripheral portion that includes a plurality of attachment positions, one attachment position for each buoy, and an articulating connection that connects each buoy to the platform at a respective attachment position, the connection allowing for sea state induced buoy motions while minimizing effect on the platform. A method of installation places the platform (including oil and gas drilling and/or production facility next to the buoys. Ballasting moves the platform and buoys relative to one another until connections are perfected between each buoy and the platform.

Abstract: A conduit structure (44) connects subsea oil wells to a floating structure (12) such as a vessel, in shallow water, the conduit structure providing a low cost and reliable fluid connection during drift of the vessel. The conduit structure includes a seafloor riser support (50) with a lower end (52) fixed to the seafloor and an upper end (54) lying a plurality of meters above the seafloor. A flexible pipe or hose (46) extends in a double catenary curve from the top of the seafloor riser support, at a downward incline away from the seafloor riser support and then at an upward incline to the floating structure. A rigid pipe (70) can extend along a plurality of meters of the height of the riser support to minimize the required length of flexible hose and facilitate installation.

Abstract: A method of constrcuting a precast, modular marine structure for offshore use, including but not limited to drilling, oil and gas production, and oil storage in a variety of water depths. The marine structure includes an equalized pressure system and concrete modular components cast with at least one cell and a central longitudinal passageway. The equalized pressure system fluidly connects the cell(s) to the adjacent body of water by at least one substantially vertical segmented water column to equalize the hydrostatic pressure differential experienced at a wall of the marine structure. A truss section may be attached to the concrete portion of the marine structure to form a truss spar. A mooring and tether system may be included to maintain the marine structure's station and attitude.

Abstract: A floating platform for use in a body of water comprises an uppermost buoyant and ballastable hull partially submerged in the water without contacting the floor of the body of water and usually without being moored to the floor of the body of water. The bottom of the uppermost hull is attached to the top of a lower buoyant and ballastable hull after the lower hull has been completely submerged in the water and anchored to the floor of the body of water with flexible moorings.

Abstract: In one embodiment of the present invention an offshore construction system is provided. The offshore construction system comprises a work module support vessel having a ballast-down mode, in which a deck of the work module support vessel is submerged, and a ballast-up mode, in which the deck is above water. The system further comprises a pontoon supported work module carried on the deck of the support vessel. The system further comprises a draw connected between the work module and the work module support vessel having a draw-over mode, in which the work module is drawn over the deck, and a remove mode, in which the work module is removed from the deck.

Abstract: A heave suppressed, floating offshore drilling and production platform comprises vertical columns, lateral trusses connecting adjacent columns, a deep-submerged horizontal plate supported from the bottom of the columns by vertical truss legs, and a topside deck supported by the columns. The lateral trusses connect adjacent columns near their lower end to enchance the structural intergrity of the platform. During the launch of the platform and towing in relatively shallow water, the truss legs are stowed in shafts within each column, and the plate is carried just below the lower ends of the columns. After the platform has been floated to the deep water drilling and production site, the truss legs are lowered from the column shafts to lower the plate to a deep draft for reducing the effect of wave forces and to provide heave and vertical motion resistance to the platform.

Abstract: A jack-up platform comprising a deck structure, a column with a base structure and a jack-up system for moving the column and the deck structure relative to each other. The base structure comprises a base and at least three base supporting parts, while the deck structure, starting from at least three spaced coupling places, can be connected by a tensioning apparatus with at least three mutually spaced connecting places on or near the base supporting parts. Before the installation the platform, floating with pulled-up column, is brought to the desired location where the base supporting parts are brought into contact with the floor and the deck structure is raised out of contact with the water. After providing the tensioning apparatus and bringing the deck structure to working height, the tensioning apparatus is tensioned, for instance by slightly further raising the deck structure which is then secured relative to the column.

Abstract: A portable flotation platform is disclosed for use in supporting a load of equipment or hunting dogs above the level of a shallow body of water. The platform includes a deck constructed to be of an overall density less than that of water and sized so as to support the load above the level of the water. An anchor extends down to the bottom of the water and up to the deck to hold the deck on station in the water. The deck is provided with a carrying attachment to facilitate the user carrying the deck to the point of deployment on the water.

Abstract: A launchable rigid jacket of an offshore platform has a structure including an exterior framing and a plurality of cross-sectional frame sections. The exterior framing has four outside legs, which are spaced apart to define four corners of a trapezoidal cross section. The jacket also includes two launch runners mounted on adjacent parallel outside legs. The cross-sectional frame sections are horizontally positioned at periodic intervals along the height of the jacket and each has a plurality of members, which interconnect the four outside legs and are part of the exterior framing. The exterior framing in total defines an integral launch box for the jacket. A plurality of perpendicularly oriented conductors pass through each cross-sectional frame from the base to the top of the jacket and conductor guides connected to the respective frame sections slidably engage the conductors to laterally support them.

Abstract: Hydrocarbon mooring and transfer system includes a tower resting on the seabed, a vessel containing hydrocarbons, anchoring elements having at least four spaced-apart anchoring members connected via a respective anchor line to the vessel. A hydrocarbon transfer duct extends between a coupling position, located between the bow and stern of the vessel and the tower. The system includes at least six anchoring members, at least four of which are connected to the vessel, the vessel being attachable to at least two different groups consisting of four anchoring members in at least two orientations.

Abstract: A floating plant for liquefying natural gas comprising a barge (2) provided with a liquefaction plant (3), means for receiving natural gas and with means for storing and discharging liquefied natural gas, which liquefaction plant (3) includes a heat exchange (12) in which heat removed when liquefying natural gas is transferred to water, which barge (2) is further provided with a receptacle (20), an open-ended water intake conduit (25) having an inlet (28), a connecting conduit (35) extending from the outlet (30) of the water intake conduit (25) to the receptacle (20), a pump (40) for transporting water from the receptacle (20) to the heat exchanger (12) and a water discharge system (45) for discharging water removed from the heat exchanger (12), wherein the connecting conduit (35) has the shape of an inverted “U” of which the top (47) is located above the receptacle (20).

Abstract: A bracing structure is provided in the form of an elongated bracing member having first and second ends, the first end having a pile sleeve for engaging the bottom, the second end having a doubler plate or the like for engaging a caisson above the water line. A pulley may be provided on the caisson above the water line, in the vicinity of where the doubler plate is to be mounted on the caisson. A cable having first and second ends is provided, the first end affixed to the bracing member in the vicinity of the doubler plate, the second end engaging the tugger or winch. In use, the tugger draws the cable so as to urge the doubler plate to the caisson above the water line in the vicinity of the installation area.

Abstract: A support structure for supporting a lift crane, and in particular to a lift crane jack-up structures, including rigs, platforms, barges, boats or the like, wherein the lift crane is positioned about a leg of the jack-up structure atop the jack-house. The preferred embodiment of the present invention contemplates a system for elevating a lift crane above the deck and about the leg of the jack-up structure, without relying upon the leg for structural support. A structurally reinforced jack-house having jacking units interfacing with the leg is provided at the deck of the vessel the jack-house configured to engage and support a crane tube column upon the roof of the jack house, which crane tube column in turn has situated thereupon the lift crane.

Abstract: A conduit structure (44) connects subsea oil wells to a floating structure (12) such as a vessel, in shallow water, the conduit structure providing a low cost and reliable fluid connection during drift of the vessel. The conduit structure includes a seafloor riser support (50) with a lower end (52) fixed to the seafloor and an upper end (54) lying a plurality of meters above the seafloor. A flexible pipe or hose (46) extends in a double catenary curve from the top of the seafloor riser support, at a downward incline away from the seafloor riser support and then at an upward incline to the floating structure. A rigid pipe (70) can extend along a plurality of meters of the height of the riser support to minimize the required length of flexible hose and facilitate installation.

Abstract: An anchoring arrangement is provided for anchoring a dock leg to a bottom of a body of water. A base plate has a lumber or timber receiver on its top surface and has three or more anchor legs that are attached to the base plate and that extend downwardly. At least one of the anchor legs preferably has a fluke pivotally attached to it so that when the anchor leg is pushed downwardly into a bottom of a body of water the fluke pivots into contact with the anchor leg. A subsequent attempt to pull the anchor leg upward causes the fluke to pivot into an extended position in which it provides additional resistance to the upward motion of the anchoring leg. Most small docks have legs made of conventional lumber or timbers large enough to provide a buoyant force adequate to support thsi metal anchoring apparatus.

Abstract: A method of removing a deck from an offshore structure (11) including a deck (13) supported on a jacket (12), includes the following steps: a) positioning a floating vessel (10) around the jacket with respective parts of the vessel on opposite sides of the jacket (12) and trusses (3, 4) extending between the opposite parts of the vessel, b) engaging parts of the trusses (3, 4) with legs (15) of the jacket, c) securing the trusses (3, 4) to the jacket (12), d) relieving the load carried by portions of the legs (15) of the jacket (12), e) cutting through the portions of the legs (15) of the jacket to divide the jacket into a lower part and an upper part carrying the deck, the trusses (3, 4) being secured to the upper part of the jacket (12), f) transferring the weight of the upper part of the jacket (12) and of the deck (13) via the trusses (3, 4) to the floating vessel (10), and g) removing the floating vessel (10), with the trusses (3, 4), the upper part of the jacket (12) and the deck (13) supported thereon,