Using a subsea fluid storage system 1 comprising a soft bladder (20) disposed within a pressure balanced reservoir (10), a rotatable piston (30) disposed at least partially within the pressure balanced reservoir where a top of the soft bladder is in communication with the rotatable piston, and a piston rotator (50) operative to rotate and twist the rotatable piston as the rotatable piston travels along a predetermined axis within the pressure balanced reservoir, a predictable and repeatable collapse of the soft bladder may be obtained by allowing the rotating piston (30) to cooperatively travel about the piston rotator (50) to twist the soft bladder (20) as the rotating piston moves along the predetermined axis in such a manner as to collapse the bladder inward, thereby emptying the bladder of fluid within the bladder. The rotation of the piston pulls the soft bladder away from an interior of the pressure balanced reservoir, thereby preventing binding or pinching of the bladder with respect to the interior of the pressure balanced reservoir. In configurations, fluid is allowed to enter the pressure balanced reservoir via a valve (54) until a balance is achieved between an interior and an exterior of the pressure balanced reservoir.

According to one or more embodiments disclosed herein is a method of transporting equipment between sea-surface and seafloor by providing a structure with equipment mounted thereon. The equipment may be liquid storage tanks, pumps, compressors, separators, metering systems, energy sources, communication systems, buoyancy tanks, and the like. The structure is used for disposal and installation in a subsea environment by changing the volume of buoyancy material within at least one buoyancy tank.

According to one or more embodiments disclosed herein is a method of transporting equipment between sea-surface and seafloor by providing a structure with equipment mounted thereon. The equipment may be liquid storage tanks, pumps, compressors, separators, metering systems, energy sources, communication systems, buoyancy tanks, and the like. The structure is used for disposal and installation in a subsea environment by changing the volume of buoyancy material within at least one buoyancy tank.

An oil storage, loading and offloading system includes a submerged oil storage tank with multiple vertically placed flexible containers. The system directly connects to the topsides of an offshore oil production platform above water to assist oil loading and offloading operations. During loading, oil is pumped in and stored inside flexible containers, which are expanded to displace equivalent amount of water out of the oil storage tank; during offloading, oil is pumped out from flexible containers and the reduced volume of each contracted container is then filled in by the equivalent amount of water from the surroundings There is no physical contact between water and oil. The submerged tank on-bottom weight has a limited variation during the loading and offloading operations. This disclosed system can be utilized for fixed offshore platforms, especially for shallow water marginal field developments, and for deepwater floating platforms such as SPAR and semi-submersible (SEMI) structures.

An oil storage, loading and offloading system includes a submerged oil storage tank with multiple vertically placed flexible containers. The system directly connects to the topsides of an offshore oil production platform above water to assist oil loading and offloading operations. During loading, oil is pumped in and stored inside flexible containers, which are expanded to displace equivalent amount of water out of the oil storage tank; during offloading, oil is pumped out from flexible containers and the reduced volume of each contracted container is then filled in by the equivalent amount of water from the surroundings There is no physical contact between water and oil. The submerged tank on-bottom weight has a limited variation during the loading and offloading operations. This disclosed system can be utilized for fixed offshore platforms, especially for shallow water marginal field developments, and for deepwater floating platforms such as SPAR and semi-submersible (SEMI) structures.

A system for emptying a gravity separated crude oil including a flexible bag storing the crude oil arranged within a protection structure, the protection structure including a bottom dement forming the lower section of the protection structure, the flexible bag being connected to a flange that is 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 dement 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 crude oil 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 crude oil including a flexible bag storing the crude oil arranged within a protection structure, the protection structure including a bottom dement forming the lower section of the protection structure, the flexible bag being connected to a flange that is 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 dement 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 crude oil 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.

The present disclosure provides in at least one embodiment a rotatable keel skirt assembly on a rectangular-shaped keel pontoon. The rectangular-shaped keel pontoon reduces the maximum hull width by a significant percentage compared to a circular-shaped keel pontoon while maintaining the same hull motion performance. The rotatable keel skirt assembly allows the size of the pontoon to define the width of the hull during some fabrication phases of the platform, rather than the additional width of the keel skirt assembly. Thus, the outreach of the crane and other equipment can be effectively used as if the keel skirt assembly was not present. After fabrication, the hull can be moved away from the quayside and the keel skirt assembly can be rotated into position for service. Various systems and methods are disclosed for articulating the keel skirt assembly about the hull.

An oil storage, loading and offloading system includes a submerged oil storage tank with multiple vertically placed flexible containers. The system directly connects to the topsides of an offshore oil production platform above water to assist oil loading and offloading operations. During loading, oil is pumped in and stored inside flexible containers, which are expanded to displace equivalent amount of water out of the oil storage tank; during offloading, oil is pumped out from flexible containers and the reduced volume of each contracted container is then filled in by the equivalent amount of water from the surroundings There is no physical contact between water and oil. The submerged tank on-bottom weight has a limited variation during the loading and offloading operations. This disclosed system can be utilized for fixed offshore platforms, especially for shallow water marginal field developments, and for deepwater floating platforms such as SPAR and semi-submersible (SEMI) structures.

An oil storage, loading and offloading system includes a submerged oil storage tank with multiple vertically placed flexible containers. The system directly connects to the topsides of an offshore oil production platform above water to assist oil loading and offloading operations. During loading, oil is pumped in and stored inside flexible containers, which are expanded to displace equivalent amount of water out of the oil storage tank; during offloading, oil is pumped out from flexible containers and the reduced volume of each contracted container is then filled in by the equivalent amount of water from the surroundings There is no physical contact between water and oil. The submerged tank on-bottom weight has a limited variation during the loading and offloading operations. This disclosed system can be utilized for fixed offshore platforms, especially for shallow water marginal field developments, and for deepwater floating platforms such as SPAR and semi-submersible (SEMI) structures.