# US 10,370,186 B2 · Subsea fluid storage system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,370,186 B2 - Document ID: US10370186B2 - Status: Granted - Kind: B2 - Application number: 15/702,796 - Filed: 2017-09-13 - Published: 2018-03-15 - Granted: 2019-08-06 - Earliest claimed: 2016-09-13 - Assignees: Oceaneering International, Inc. - Applicants: Oceaneering International, Inc. - Inventors: Benjamin Primm; Christopher Leon; Earl Schultz - Web page: https://patentgrep.com/patent/US10370186B2 ## CPC - B65D 90/32: Arrangements for preventing, or minimising the effect of, excessive or insufficient pressure (valves per se F16K) - B63B 25/14: pressurised - B63G 8/001: {Underwater vessels adapted for special purposes, e.g. unmanned underwater vessels; Equipment specially adapted therefor, e.g. docking stations (self-propelled or direction controlled diving chambers with mechanical link to a base B63C11/42)} - B65D 88/60: of internal walls - B65D 88/62: the walls being deformable - B65D 88/78: for use in or under water - B63G 2008/005: {remotely controlled} - B65D 90/50: of leakage-indicating devices - B65D: CONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES - B63B: SHIPS OR OTHER WATERBORNE VESSELS; EQUIPMENT FOR SHIPPING (arrangements of vessel ventilation, heating, cooling, or air-conditioning B63J2/00; floating substructures as supports of dredgers or soil-shifting machines E02F9/06) - B63G: OFFENSIVE OR DEFENSIVE ARRANGEMENTS ON VESSELS; MINE-LAYING; MINE-SWEEPING; SUBMARINES; AIRCRAFT CARRIERS (means of attack or defence in general, e.g. turrets F41H) ## Abstract A subsea fluid storage system comprising a soft bladder disposed within a pressure balanced reservoir, a rotatable piston, and a piston rotator which rotates and twists the rotatable piston as it travels along a predetermined axis within the pressure balanced reservoir, predictably and repeatabley collapses the soft bladder when the rotating piston cooperatively travels about the piston rotator, twisting the soft bladder as the rotating piston moves along the predetermined axis, collapsing the bladder inward and thereby emptying the bladder of fluid within the bladder. The piston's rotation pulls the soft bladder away from the pressure balanced reservoir's interior, thereby preventing the bladder's binding or pinching the pressure balanced reservoir's interior. In configurations, fluid is allowed to enter the pressure balanced reservoir via a valve until a balance is achieved between an interior and an exterior of the pressure balanced reservoir. ## Claims ### Claim 1 A subsea fluid storage system suitable for use subsea, comprising: a. a pressure balanced reservoir; b. a soft bladder disposed within the pressure balanced reservoir; c. a rotatable piston disposed at least partially within the pressure balanced reservoir, the rotatable piston in communication with a top of the soft bladder, the rotatable piston configured to axially rotate and twist the soft bladder as the rotatable piston travels along a predetermined axis within the pressure balanced reservoir; and d. a piston rotator disposed within the pressure balanced reservoir, the piston rotator operatively in communication with the rotatable piston and operative to axially rotate the rotatable piston along the predetermined axis. ### Claim 2 (depends on 1) The subsea fluid storage system suitable for use subsea of claim 1, wherein the soft bladder comprises a soft, cylindrical, collapsible bladder. ### Claim 3 (depends on 1) The subsea fluid storage system suitable for use subsea of claim 1, further comprising a valve operative to allow the pressure balanced reservoir to be isolated in the event of a leak from the soft bladder. ### Claim 4 (depends on 1) The subsea fluid storage system suitable for use subsea of claim 1, wherein the volume of the soft bladder is scalable. ### Claim 5 (depends on 4) The subsea fluid storage system suitable for use subsea of claim 4, wherein the piston rotator is operative to rotate and twist the rotatable piston as the rotatable piston travels along the predetermined axis within the substantially tubular outer housing, the piston rotator comprising one of: a. a guide sleeve, the guide sleeve comprising a sleeve channel and the rotatable piston further comprising a channel post adapted to slidingly fit inside the sleeve channel; b. a housing channel disposed about an interior of the pressure balanced reservoir, the rotatable piston further comprising a channel post adapted to slidingly fit inside the housing channel; or c. a tube comprising a helical shape and a predetermined set of rollers disposed about an outer portion of the rotatable piston, the rollers configured to engage against the tube. ### Claim 6 (depends on 1) The subsea fluid storage system suitable for use subsea of claim 1, further comprising a plumb bob operatively connected to the rotatable piston. ### Claim 7 (depends on 6) The subsea fluid storage system suitable for use subsea of claim 6, further comprising a flexible connector disposed intermediate the plumb bob and the rotatable piston. ### Claim 8 (depends on 7) The subsea fluid storage system suitable for use subsea of claim 7, wherein the flexible connector comprises a wire. ### Claim 9 (depends on 1) The subsea fluid storage system suitable for use subsea of claim 1, wherein the pressure balanced reservoir comprises an upper cover and a lower cover. ### Claim 10 (depends on 9) The subsea fluid storage system suitable for use subsea of claim 9, wherein the upper cover and the lower cover comprise a substantially solid flange. ### Claim 11 (depends on 9) The subsea fluid storage system suitable for use subsea of claim 9, further comprising: a. a support bracket connected to the upper cover; and b. a lifting eye connected to the upper cover. ### Claim 12 (depends on 9) The subsea fluid storage system suitable for use subsea of claim 9, further comprising a support connected to the upper cover and to the lower cover. ### Claim 13 (depends on 12) The subsea fluid storage system suitable for use subsea of claim 12, further comprising a lifting eye connected to the support. ### Claim 14 (depends on 1) The subsea fluid storage system suitable for use subsea of claim 1, wherein the pressure balanced reservoir further comprises an upper cover, a lower cover, and a substantially tubular outer housing disposed intermediate the upper cover and the lower cover in which the soft bladder and the rotatable piston are disposed. ### Claim 15 A method of allowing a predictable and repeatable collapse of a soft bladder of a subsea fluid storage system suitable for use subsea and disposed subsea which comprises the soft bladder disposed within a pressure balanced reservoir, a top of the soft bladder in communication with a rotatable piston disposed at least partially within the pressure balanced reservoir, and a piston rotator operative to rotate and twist the rotatable piston and the soft bladder as the rotatable piston travels along a predetermined axis within the pressure balanced reservoir, the method comprising: a. allowing the piston rotator to cooperatively constrain travel of the rotating piston and thereby twist the soft bladder as the rotating piston moves along the predetermined axis in such a manner as to collapse the soft bladder inward, thereby emptying the soft bladder of fluid within the soft bladder, the rotation of the rotatable piston pulling the soft bladder away from an interior of the pressure balanced reservoir and thereby preventing binding or pinching of the soft bladder with respect to the interior of the pressure balanced reservoir; and b. allowing fluid to enter the pressure balanced reservoir until a balance is achieved between the interior and an exterior of the pressure balanced reservoir. ### Claim 16 (depends on 15) The method of claim 15, the system further comprising a valve, the method further comprising controlling a fluid circuit which incorporates the subsea fluid storage system by using the valve to control allowing the fluid to enter the pressure balanced reservoir until the balance is achieved between the interior and the exterior of the pressure balanced reservoir, therefore allowing the pressure balanced reservoir to be isolated if there is a bladder leak. ### Claim 17 (depends on 16) The method of claim 16, further comprising using a pressure relief device to protect against over-pressurization or under-pressurization of fluid in the pressure balanced reservoir. ### Claim 18 (depends on 15) The method of claim 15, the subsea fluid storage system further comprising a level sensor and the pressure balanced reservoir further comprising an upper cover and a lower cover, the method further comprising: a. using the level sensor to monitor a displacement of the rotatable piston relative to the upper cover or the lower cover; b. obtaining a measurement of the displacement of the rotatable piston relative to the upper or lower cover; and c. using the measurement to calculate a current volume of the soft bladder. ### Claim 19 (depends on 15) The method of claim 15, further comprising: a. disposing the subsea fluid storage system in a first orientation to allow for gravity fed fluids whereby weight placed on the top of the soft bladder forces the rotatable piston down as fluid is drawn; and b. disposing the subsea fluid storage system in second orientation to allow for buoyancy fed fluids whereby the rotatable piston provides an upward buoyant force on fluid which is less dense than fluid in an environment surrounding the subsea fluid storage system.