1783results about "Anchoring arrangements" patented technology

A vortex induced vibration suppressor and method is disclosed. The apparatus includes a body that is a flexible member of a polymeric (e.g., polyurethane) construction. A plurality of helical vanes on the body extend longitudinally along and helically about the body. Each vane has one or more openings extending transversely there through. A longitudinal slot enables the body to be spread apart for placing the body upon a riser, pipe or pipeline. Tensile members that encircle the body and pass through the vane openings enable the body to be secured to the pipe, pipeline or riser.

The present invention provides drilling systems for drilling subsea wellbores. The drilling system includes a tubing that passes through a sea bottom wellhead and carries a drill bit. A drilling fluid system continuously supplies drilling fluid into the tubing, which discharges at the drill bit bottom and returns to the wellhead through an annulus between the tubing and the wellbore carrying the drill cuttings. A fluid return line extending from the wellhead equipment to the drilling vessel transports the returning fluid to the surface. In a riserless arrangement, the return fluid line is separate and spaced apart from the tubing. In a system using a riser, the return fluid line may be the riser or a separate line carried by the riser. The tubing may be coiled tubing with a drilling motor in the bottom hole assembly driving the drill bit. A suction pump coupled to the annulus is used to control the bottom hole pressure during drilling operations, making it possible to use heavier drilling muds and drill to greater depths than would be possible without the suction pump. An optional delivery system continuously injects a flowable material, whose fluid density is less than the density of the drilling fluid, into the returning fluid at one or more suitable locations the rate of such lighter material can be controlled to provide supplementary regulation of the pressure. Various pressure, temperature, flow rate and kick sensors included in the drilling system provide signals to a controller that controls the suction pump, the surface mud pump, a number of flow control devices, and the optional delivery system.

Methods and control systems are provided for a wellbore drilling system having an active differential pressure device (APD device) in fluid communication with a returning fluid. The APD Device creates a differential pressure across the device, which reduces the pressure below or downhole of the device. In embodiments, a control unit controls the APD Device to provide a selected pressure differential at a wellbore bottom, adjacent a casing shoe, in an intermediate wellbore location, or in a casing. In one arrangement, the control system is pre-set at the surface such that the APD Device provides a substantially constant pressure differential. In other arrangements, the control system measures one or more parameters (e.g., wellbore pressure, formation parameters, BHA parameters, etc.) and adjusts an operating parameter of the APD Device to provide a desired pressure differential. Devices such as an adjustable bypass can be used to control the APD Device.

A floating wind turbine platform includes a floatation frame that includes at least three columns that are coupled to each other with horizontal main beams. A wind turbine tower is mounted above a tower support column to simplify the system construction and improve the structural strength. The turbine blades are coupled to a nacelle that rotates on top of the tower. The turbine's gearbox generator and other electrical gear can be mounted either traditionally in the nacelle, or lower in the tower or in the top of the tower-supporting column. The floatation frame includes a water ballasting system that pumps water between the columns to keep the tower in a vertical alignment regardless of the wind speed. Water-entrapment plates are mounted to the bottoms of the columns to minimize the rotational movement of the floatation frame due to waves.

Methods and control systems are provided for a wellbore drilling system having an active differential pressure device (APD device) in fluid communication with a returning fluid. The APD Device creates a differential pressure across the device, which reduces the pressure below or downhole of the device. In embodiments, a control unit controls the APD Device to provide a selected pressure differential at a wellbore bottom, adjacent a casing shoe, in an intermediate wellbore location, or in a casing. In one arrangement, the control system is pre-set at the surface such that the APD Device provides a substantially constant pressure differential. In other arrangements, the control system measures one or more parameters (e.g., wellbore pressure, formation parameters, BHA parameters, etc.) and adjusts an operating parameter of the APD Device to provide a desired pressure differential. Devices such as an adjustable bypass can be used to control the APD Device.

A system for producing hydrogen from water, making use of a stream of water such as a gulf stream or tidal stream, includes a number of submerged modules, each having a turbine that can be driven by the stream of water. The turbine is coupled to a generator for generating electrical energy. Each module may have submerged decomposition means for decomposing water into hydrogen and oxygen using the electrical energy generated. The modules are provided with means to control the depth of the modules below water level, and furthermore with means for automatically orienting the front of the modules—viewed in the longitudinal direction of the turbines—to the direction of flow of the water or an angular position deviating therefrom.

An offshore floating production, storage, and off-loading vessel has a hull of generally cylindrical or polygonal configuration surrounding a central double tapered conical moon pool and contains water ballast and oil and / or liquefied gas storage compartments. The exterior side walls of the polygonal hull have flat surfaces and sharp corners to cut ice sheets, resist and break ice, and move ice pressure ridges away from the structure. An adjustable water ballast system induces heave, roll, pitch and surge motions of the vessel to dynamically position and maneuver the vessel to accomplish ice cutting, breaking and moving operations. The moon pool shape and other devices on the vessel provide added virtual mass for increasing the natural period of the roll and heave modes, reducing dynamic amplification and resonance due to waves and vessel motion, and facilitate maneuvering the vessel. A disconnectable turret buoy at the bottom of the moon pool connects risers and mooring lines.

An apparatus for releasably securing a tubular structure of a floating installation to an anchor fixedly secured to an underwater floor has a first connection element mounted at one end of the tubular structure and a second connection element configured at one end to couple with the first connection element. The second connection element includes a pair of guides secured thereto which extend horizontally therefrom. A hinge device connects the second connection element to the anchor such that the second connection element is pivotably connected to the anchor. A plurality of cables connect to both the tubular structure and the anchor, whereby the pair of guides cooperate with the cables such that when the cables are under tension, the cables urge the second connection element to pivot and align with the first connection element.

An underwater apparatus for generating electric power from ocean currents and deep water tides. A submersible platform including two or more power pods, each having a rotor with fixed-pitch blades, with drivetrains housed in pressure vessels that are connected by a transverse structure providing buoyancy, which can be a wing depressor, hydrofoil, truss, or faired tube. The platform is connected to anchors on the seafloor by forward mooring lines and a vertical mooring line that restricts the depth of the device in the water column. The platform operates using passive, rather than active, depth control. The wing depressor, along with rotor drag loads, ensures the platform seeks the desired operational current velocity. The rotors are directly coupled to a hydraulic pump that drives at least one constant-speed hydraulic-motor generator set and enables hydraulic braking. A fluidic bearing decouples non-torque rotor loads to the main shaft driving the hydraulic pumps.

An underwater chain stopper and fairlead apparatus for offshore structures, drilling platforms, ships or other vessels. The apparatus comprises a mounting member, a fairlead member and a chain stopper member. The mounting member is attached to an underwater surface of the offshore structure or vessel and includes a bracket for coupling the fairlead member. The bracket may comprise a hinge allowing the fairlead member to pivot in an approximately horizontal plane. The chain stopper member is coupled to the fairlead member through a hinge which allows the chain stopper member to pivot with respect to the fairlead member in an approximately vertical plane. The chain stopper member includes a chain stopper flapper having a horseshoe shaped opening at one end. The other end of the flapper is connected to the chain stopper member through a hinge which allows the flapper to swing between an open position and a closed position. In the open position, the chain links for the anchor chain are allowed to pass by the horseshoe shaped opening on the flapper. The horseshoe shaped opening also includes a chain link seat which stops movement of the anchor chain through the chain stopper member when the flapper is in the closed position. The chain stopper flapper moves to the closed position under the force of gravity to provide a self-locking chain stopper. A latch mechanism is provided for latching the chain stopper flapper in an open position.

Truss cable semi-submersible floater for offshore wind turbines and construction methods are provided. A floating system includes a hull, a tensioned cable system, and a tower. The hull includes vertical buoyant columns with one column at the center of the pattern, larger size column base tanks, and a truss system, all of which are coupled to each other for supporting the tower and wind turbines. The column can be made of hybrid materials, including steel and composite-concrete. The steel section and the composite-concrete section of the column can be connected by grouting. The tensioned cable system including upper, lower, and diagonal tensioned cables to connect the column, the column base, and the tower to reduce the bending moments and improve stability, strength and dynamic performance of the hull structure.

Tail fairings designed with features for fast installation and / or for suppression of vortices addition between fairings, apparatus incorporating such fairings, methods of making and using such fairings and apparatus, and methods of installing such fairings.

A mooring system including a body / arm / vessel arrangement with passive damping and / or an active force restoring system. The active force restoring system includes a sensor for generating a displacement signal representative of the displacement of the vessel from a quiescent position and an active forcing device which responds to the displacement signal to force the arm in a direction to move the vessel toward the quiescent position. The passive damping arrangement includes a device, independent of and in addition to the damping of the water on the vessel or the arm, that damps the oscillation of the vessel in response to environmental conditions which force the vessel from its quiescent position. Hydraulic cylinder arrangements are provided for active forcing and passive damping. Powered winch / cable arrangements are also provided for active force systems. Alternative devices for active and passive damping systems of torque actuators include hydraulic powered cans with internal fins, or cans with internal elastomeric elements or disk brake elements.

An ocean wave energy system for generating power from ocean waves includes a platform supporting an array of hollow columns whose respective lower ends are in fluidic communication with ocean waves and whose respective upper ends are in air communication with a turbine arrangement such that wave motion occurring at the lower ends is operable to cause air movement within the columns for propelling the turbine arrangement to generate power output. The system further includes one or more position-adjustable and / or angle-adjustable submerged structures near the lower ends of the columns for forming ocean waves propagating in operation towards the lower ends of the columns to couple the waves in a controllable manner into the hollow columns.

A system for harvesting, storing, and generating energy, that includes floating structure supporting machinery to extract energy from wind, waves, surface generators, or currents. At least one energy storage and power generating unit is anchored to the seafloor and adapted to tether the floating structure to the unit. The unit includes an internal chamber into which water flows through a hydroelectric turbine to generate electrical energy. A pump is provided, powered by energy from the floating structure machinery, to evacuate water from the unit and a control system directs power from the machinery to pump water out of the unit during periods of excess energy extraction by the machinery and to allow water to flow into the chamber through the hydroelectric turbine to generate electrical energy during periods of lower energy extraction by the machinery. The same internal chamber design can be utilized to store hydrocarbons in the vicinity of undersea wellheads during “shut-in” procedures when the wellhead would otherwise be secured.

One or more components of a wellbore drilling assembly utilize a modular construction to facilitate assembly, disassembly, repair and / or maintenance of a wellbore drilling assembly and / or to extend the overall operating capabilities of the drilling assembly. In one embodiment, a modular construction is used for an APD Device, a motor driving the modular APD Device, a comminution device, and an annular seal. Individual modules can be configure have different operating set points, operating parameters and characteristics (e.g., rotational speeds, flow rates, pressure differentials, etc.) and / or different responses to given environmental factors or conditions (e.g., pressure, temperature, wellbore fluid chemistry, etc.). In one embodiment, the high-pressure seals used in conjunction with the APD Device and / or motor is a hydrodynamic seal that provides a selected leak or flow rates. Optionally, the seal is modular to provide different degrees of leak rates and / or different functional characteristics.

An elongated, annular hull of a floating offshore platform includes one or more segmented, helical strakes disposed on an outer peripheral surface of the hull to reduce vortex-induced vibrations resulting from water currents. The hull may comprise a single annular hull or a plurality of parallel, adjacent hulls. Each strake includes a plurality of generally rectangular segments extending substantially radially outward from the hull. Each of the segments includes a pair of spaced-apart radial stanchions supporting a generally rectangular frame to which a corresponding panel is attached. The panels have a radial width that is about 13 percent of the effective diameter of the hull. The segments are arranged in a spaced-apart, end-to-end relationship that defines a discontinuous, but generally helical band extending around the circumference of the hull from about 35 feet (11.7 m) below the mean water line of the hull to its lowermost end.

A floating wind turbine system with a tower structure that includes at least one stability arm extending therefrom and that is anchored to the sea floor with a rotatable position retention device that facilitates deep water installations. Variable buoyancy for the wind turbine system is provided by buoyancy chambers that are integral to the tower itself as well as the stability arm. Pumps are included for adjusting the buoyancy as an aid in system transport, installation, repair and removal. The wind turbine rotor is located downwind of the tower structure to allow the wind turbine to follow the wind direction without an active yaw drive system. The support tower and stability arm structure is designed to balance tension in the tether with buoyancy, gravity and wind forces in such a way that the top of the support tower leans downwind, providing a large clearance between the support tower and the rotor blade tips. This large clearance facilitates the use of articulated rotor hubs to reduced damaging structural dynamic loads. Major components of the turbine can be assembled at the shore and transported to an offshore installation site.

A mounting system is disclosed for mounting structures and equipment such as wind-electric generators on water. The structure is attached to a carrier, which is attached to a foundation through connecting elements. Buoyancy tanks or the inherent buoyancy of the carrier or the connecting elements are used to maintain a stable position of the carrier in the water. Utilizing connecting elements that transfer pushing and pulling force undesirable movements of the carrier are suppressed while requiring only moderate forces on the foundation.

A method and apparatus for deployment of mooring systems for buoyant marine structure such as mobile offshore drilling units (MODU's) and for connecting the same to the mooring lines thereof. An anchor handling vessel carries one or more anchors each having a deployment connection and a mooring connection and individually moves each anchor over its stern roller and deploys it to the sea bottom for installation. A handling line is disconnected by ROV from the deployment connection and is moved from the deployment connection to the mooring connection so as to become the main mooring line. Syntactic buoys are then mounted on the main mooring line for elevating it above the sea bottom for recovery. When MODU stationing is desired the anchor handling vessel then recovers the surface buoy and connects to the rig mooring line using a short section of mooring chain. A J-chaser stopper device is then installed in the mooring string and is connected to the mooring line of the MODU by a short section of chain. The J-chaser lowers the mooring string, completing the mooring connection between the anchor and the MODU. A plurality of mooring strings, typically eight, are deployed in this manner to properly station the MODU. Disconnection of the MODU is accomplished essentially by the reverse of the above deployment procedure.

A procedure and a device in connection with the use of a wind turbine offshore, including a wind turbine (2) connected via a shaft to a generator (3), which is rotationally mounted on a tower (4), and a foundation underneath in the form of a float (6) on which the tower (4) is mounted. The float is anchored so that it can move freely in the vertical plane via an anchor or a mooring in the form of mooring lines, hinges or tethers (7). As a consequence of the effect of the waves on the float, the motion of the wind turbine will act as a damping mechanism on the motion and thus extract energy from the waves. The wind turbine's resonance period can be adjusted by adjusting the platform's center of gravity and / or the tension in the anchor with which the wind turbine is attached to the sea bed.

In a method of and apparatus for offshore mooring, a clamping apparatus includes a clamping mechanism and a pulley. A mooring line connected to an anchor or a pendant line connected to a vessel to be moored extends through the clamping mechanism and around the pulley of the clamping apparatus. The distal end of the line extending through the clamping apparatus is connected to an anchor handling vessel. The anchor handling vessel is employed to apply a predetermined tension to the pendant line and the preset mooring line. A remote operated vehicle is then employed to actuate the clamping apparatus and to disengage the anchor handling vessel.

A method of controlling a tethered, underwater, water current-driven turbine, power-generating device. The device is comprised of dual turbines and dual rotor blades turned by fluid flow, each turbine including one or more generators driven by rotor blades. The device is connected by device tethers to a strut, which is moveable to control depth of the device. The strut is connected to the ocean floor by tripodal tethers: a main tether, a left side tether and a right side tether, which are strut control tethers. One or more winches are controlled to maintain operation of the device within set parameters by varying the tension on one or more of the strut control tethers.

There is provided a buoyancy system for a structure having at least one component being substantially stationary with respect to the bottom of a water covered area. The system comprises a set of buoyancy modules of engineered materials to apply an identified amount of buoyancy. The set of buoyancy modules is attached to the structure at a set of buoyancy load transfer locations. The set of buoyancy modules comprises layers of the engineered materials. The engineered materials comprise a substantially reinforced axial layer, a substantially reinforced hoop layer; and a leak prevention layer.

The present invention includes a nontwisted composite tether comprising one or more composite rods encased in a jacket and a method for manufacturing same. A portion of the rods may be bundled into one or more strands, provided however that the rods comprising the strands are not twisted into twisted strands in the assembled nontwisted tether. Such untwisted strands, if any, additionally are not twisted relative to each other. Temporary and / or permanent buoyancy may be to the tether. The present invention includes methods for preparing, transporting, and installing a composite tether on a floating platform. The tether, preferably assembled at a waterfront, is launched into the water and towed to an offshore installation site, where the tether is upended and connected via a bottom end connector on the tether to an anchor foundation in the seabed and connected a top end connector on the tether to the floating platform.

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. The buoyancy of the upper buoyancy capsule(s) is adjustably tuned to provide a buoyant force and a sufficient water plane area and moment of inertia required for stability of the floating structure, and the water mass and weight of the lower buoyancy capsule(s) or keel tank(s) is adjustably tuned to raise or lower the center of gravity of the entire mass of the floating structure with respect to its center of buoyancy according to ballast and variable or fixed loads including deck payloads to stabilize the structure. Alternatively, a keel tank may replace the lower capsule. The buoyancy of the upper buoyancy capsule(s) is adjustably tuned to provide a buoyant force and a sufficient water plane area and moment of inertia required for stability of the floating structure, and the water mass and weight of the lower buoyancy capsule(s) or keel tanks(s) is adjustably tuned to raise or lower the center of gravity of the entire mass of the floating structure with respect to its center of buoyancy according to ballast and variable or fixed loads including deck payloads, to stabilize the structure, and to compensate for different operational, environmental, survival and installation stages of the structure. The length of the upper buoyancy capsule(s) is sufficient so as to be partially submerged and allow oscillation of the trough and crest of waves within its top and bottom ends.

A floating offshore platform configuration is provided, which decouples pitch, roll, and heave motions from acting on tensioned risers and accommodates the angular displacement induced by floating offshore platform surge and / or sway excursion without inducing bending in the riser at its entrance to the floating offshore platform. The risers are guided by an inner structure that is tethered from the sea floor and centered inside an outer hull structure. Outer hull structure heave, pitch and roll motions are substantially isolated from acting on the inner structure through a connection mechanism, and each riser is allowed to individually expand or contract.