Abstract: A subsea system for the storage of petroleum products or other liquids with densities lighter than water is disclosed. The system includes at least one storage tank disposed alongside a bowl-like structure. A flexible membrane sealed to a top peripheral surface of the bowl structure or a hollow bladder supported by the bowl is provided. Pipes run from the bottom of the tank to the space between the membrane and the bowl or to the interior of the bladder. Water stored in the tank is displaced to the bowl/membrane volume space or to the hollow bladder. When discharge of the petroleum products is desired, a supply/discharge valve at the top of the tank is opened and sea pressure acting on the flexible membrane forces water from the membrane/bowl space or bladder back into the bottom of the tank causing the petroleum products to be discharged via the supply/discharge pipe.
Abstract: A rotatable swivel comprising a swivel body, a ball bearing assembly, and a primary upper seal axially offset from a primary lower seal for sealing a conduit chamber is disclosed. Pressurization of the conduit chamber of the swivel in cooperation with the differential axial offset of the primary seals creates axial pre-loading of the swivel operably aiding in the sealing of the conduit chamber and maintaining the concentricity of the bearing assembly between a rotatable outer ring and a stationary inner ring and providing wear compensation for the swivel. Secondary upper and lower seals are disclosed whereby if the primary seals fail to retain pressure in the conduit chamber, the respective secondary seal maintains the initial axial loading of the failed primary seal.
Type:
Grant
Filed:
December 17, 1984
Date of Patent:
March 3, 1987
Assignee:
Sofec, Inc.
Inventors:
Charles O. Ethridge, Kristen I. Pedersen
Abstract: An offshore bulk fluid transfer system and method for its deployment in both shallow and deep water is disclosed. The system is adapted for transfer of fluids between a tanker and another location. Deep water embodiments of the invention provide for a three and four stair step method for deploying the base on the sea floor. Additionally, a method of retrieving the system from the sea floor is disclosed. The offshore bulk fluid transfer system comprises a base and buoyancy tanks attached to the base flotation for the system during its transportion to a mooring location. Buoyancy tanks are adapted for flooding to allow the system to be deployed on the sea floor.
Abstract: An offshore bulk liquid discharge system and method for its deployment are disclosed. The system is adapted for rapid deployment and facilitates rapid unloading of liquids from an ocean tanker to a shore location. The system includes a base, a mooring buoy tethered to the base and floodable buoyancy tanks which may be flooded causing the base to land on the sea floor. A product swivel mounted on the base provides fluid communication between a tanker hose and a flexible pipeline.
Abstract: A rotatable swivel adapted for assuring the passage of a scraper pig or a separator pig through a conveyance system of which and the swivel is a part is disclosed. The swivel includes a guide vane pivotally mounted in an inner ring of a swivel body to enable movement between a retracted position for assembling the inner ring with an outer ring and an operating position for insuring the passage of the pig from an inlet to an outlet communicating with a toroidally shaped conduit chamber of the rotatable swivel. A removable locking pin secures the guide vane in the operating position to assure the passage of the pig. A retracted position port and an operating position port are disposed in an outer ring of the swivel body to enable movement of the guide vane between the retracted and operating positions.
Abstract: A single point mooring apparatus for tanker loading and discharging is disclosed having a submerged base and a submerged rigid yoke connected directly to the base by a triaxial articulation joint for allowing the yoke to move while connected to a vessel in yaw, pitch and roll with respect to the submerged mooring base. The submerged yoke is connected to the vessel with weighted pendants on port and starboard sides of the bow of the vessel, providing a resilient position restoring force to the vessel as the vessel moves in response to wind, wave and currents.
Abstract: A single point mooring apparatus for tanker loading and discharging is disclosed having a fixed mooring tower and a yoke connected to the fixed tower by a triaxial articulation element for allowing the yoke to move while connected to a vessel in yaw, pitch and roll with respect to the mooring base. The yoke is shaped to straddle the bow of the moored vessel and is suspended above the water line with weighted pendants on port and starboard sides of the vessel, providing a resilient position restoring force to the vessel. Fluid transfer swivels and flexible hose connections in the cargo transfer conduits are all located above the water line.
Abstract: A single point mooring apparatus especially adapted for securing large marine tanker vessels or subsea hydrocarbon well collection and storage barges in relatively shallow water is disclosed. The floating mooring buoy structure is connected to a mooring base secured to the ocean floor by a plurality of tension leg attachment members of predetermined length. The buoyancy of the floating buoy structure is controlled to produce sufficient tension in the attachment member to provide a position restoring force to the moored marine vessel. The floating buoy structure is formed by an open frame work having a conical shape to minimize impact with ice floes on the floating buoy structure and have fully submerged buoyancy tanks to minimize the effect of wave forces and tied level variations on the position restoring force.
Abstract: An apparatus for handling hose underwater and specifically for hose connection to an underwater pipe including a saddle adapted to receive a hose, a clamp for retaining the hose in the saddle, said saddle being movable, means for pulling a hose underwater into said saddle, and means for pulling the hose, after it has been brought into alignment with the underwater pipe, into sufficiently close proximity to the end of the underwater pipe for completing the connection. The method of making an underwater hose connection including the steps of pulling a hose down in the water, orienting a saddle to a position in which its axis is parallel to the axis of the hose, pulling the hose into the saddle, clamping the hose in the saddle, orienting the saddle to position the hose in axial alignment with the pipe to which the hose is to be connected and moving the hose into sufficiently close proximity for its connection to the underwater pipe.
Abstract: A single anchor leg mooring and tanker cargo transfer system has a base with an anchor leg pipe shaft having a horizontally swiveling housing thereon to which are attached vertically pivoting cargo hose arms. The arms have widely spaced, parallel portions extending a substantial distance beyond the base portion for augmenting the torque applied to the swivels by the cargo hoses. The hose arms are stabilized and limited in their vertical pivoting by a balanced lever structure pivotally mounted on the base and carrying buoyancy tanks. Bumpers limit the vertical pivoting of the lever structure flexing of the hose arms secured thereto.
Abstract: A single anchor leg type single point mooring and cargo transfer buoy has a load-carrying central shaft pipe for anchoring on the sea bottom and having a plurality of structurally segregated transfer chambers about which rotatable housings are sealingly mounted. Cargo vessel piping connects with these rotatable housings which communicate with the sea floor piping through connections extending longitudinally through the central shaft pipe and through apertures in the central shaft pipe wall.