A high-performance seafloor flexible oil storage system, solving the existing problems of high storage cost and difficult maintenance of crude oil in offshore oilfields, comprises, sequentially connected, an oil-water separator, a pressure pump, and an input riser extending downward below the sealevel; and a pipeline and multiple flexible oil storage tanks having the same structure with each communicated therewith through a control valve are arranged below the sealevel. One end of the pipeline is communicated with the input riser through a blocking valve and an input valve, and the other end further sequentially connected with an outlet booster pump, an output valve, and an output riser extending upwards above the sealevel and connected to a tanker through a cooler and an output pump. The flexible oil storage tank has a concrete counterweight connected thereunder for fixing it to a seabed. The system has simple structure, convenient maintenance and good practicability.

A towed vessel suitable for containing and transporting various liquids is disclosed. The vessel further comprises various features useful in the transportation, navigation, and storage of the towable vessel, both when in use for transporting fluids and when transported in an emptied state. Such features include navigational and positioning devices and methods, power supply devices and methods, and means for filling, inflating, emptying, and deflating a non-rigid, towed vessel. Aspects of embodiments of the present invention further include features useful for purifying or preserving the purity of the fluid to be transported.

A new Abstract is submitted herewith following page 9 of this paper.

A new Abstract is submitted herewith following page 9 of this paper.

An underwater energy storage system includes a tank for storing a compressed gas that is adapted to be stored underwater. The tank includes at least one water opening through which water from surrounding environment can flow into and out of the tank, and at least one gas opening through which the compressed gas is received. The underwater energy storage system further includes at least one duct communicating between the at least one opening for gas flow and a source of compressed gas and a compartment constructed over a roof of the tank, wherein said compartment is adapted for receiving weights at a sinking site of the tank.

An underwater energy storage system includes a tank for storing a compressed gas that is adapted to be stored underwater. The tank includes at least one water opening through which water from surrounding environment can flow into and out of the tank, and at least one gas opening through which the compressed gas is received. The underwater energy storage system further includes at least one duct communicating between the at least one opening for gas flow and a source of compressed gas and a compartment constructed over a roof of the tank, wherein said compartment is adapted for receiving weights at a sinking site of the tank.

A system for emptying a gravity separated fluid including a flexible bag storing the fluid arranged within a protection structure, the protection structure including a bottom element forming the lower section of the protection structure, the flexible bag being connected to the protection structure, and includes at least one fluid conduit providing fluid communication between the flexible bag and outside the protection structure. A first outlet pipe is arranged inside the flexible bag near the bottom element and is connected to and in fluid communication with the at least one fluid conduit. A perforated tube surrounding the outlet pipe provides an annulus fluid passage, water is supplied to the structure volume, and the fluid is emptied through the at least one fluid conduit, through the perforations in the perforated tube, through the annulus fluid passage to the first outlet pipe.

A system for emptying a gravity separated fluid including a flexible bag storing the fluid arranged within a protection structure, the protection structure including a bottom element forming the lower section of the protection structure, the flexible bag being connected to the protection structure, and includes at least one fluid conduit providing fluid communication between the flexible bag and outside the protection structure. A first outlet pipe is arranged inside the flexible bag near the bottom element and is connected to and in fluid communication with the at least one fluid conduit. A perforated tube surrounding the outlet pipe provides an annulus fluid passage, water is supplied to the structure volume, and the fluid is emptied through the at least one fluid conduit, through the perforations in the perforated tube, through the annulus fluid passage to the first outlet pipe.

A subsea storage unit includes a pressure hull having a cargo hold configured for storing cargo. The pressure hull has a movable hatch, providing access to the cargo hold; and a base configured for supporting the storage unit on a seabed. The unit also includes a suspension, whereby the storage unit can be lifted and lowered in a body of water, and a ballast. A seabed facility can be configured for receiving and accommodating at least one subsea storage unit.

A subsea storage unit includes a pressure hull having a cargo hold configured for storing cargo. The pressure hull has a movable hatch, providing access to the cargo hold; and a base configured for supporting the storage unit on a seabed. The unit also includes a suspension, whereby the storage unit can be lifted and lowered in a body of water, and a ballast. A seabed facility can be configured for receiving and accommodating at least one subsea storage unit.