US3855809A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Underwater oil storage tank and method of submerging same
Assignee: Chevron USA Inc
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Filing: 1972-08-03
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Granted: 1974-12-24
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Expires: 1992-08-03
Abstract
Abstract A submerged tank for location on the sea bottom has upwardly opening ballast chambers. The ballast chambers have a bottom member that rests directly on the sea bottom. The storage tank is open to the entrance of water into the lower portion of the storage compartment of the tank from the surrounding waters whereby pressure within the tank and in the surrounding water is substantially equal. In a preferred embodiment the tank is of annular shape with a central ballast chamber and an outer ballast chamber surrounding the storage compartment. The tank is filled with a liquid of lower density than sea water to give it sufficient buoyancy to be floated to the desired site and is sunk at the site by displacement of low density liquid with sea water. After location of the tank on the bottom, the ballast compartments are filled with ballast to secure the tank on the sea bottom.
Inventors
- 👤 R Westling
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 19:20
CPC Classifications
B; B65; B65D; B65D88/00; B65D88/78
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
201 words
A submerged storage tank for installation on the sea bottom at offshore locations to store oil having a lower density than sea water comprising a vertical outer wall enclosing a storage compartment, a top member extending across the top of the storage compartment and connected to the outer wall to close the upper end of the storage compartment, said storage compartment being open at its lower end, a retainer wall surrounding the vertical wall and spaced therefrom to cooperate with the vertical wall in defining an upwardly opening ballast chamber between the retainer wall and the outer wall, a bottom member connected to the lower end of the vertical wall and to the retainer wall closing the lower end of the ballast chamber, said bottom member positioned and adapted to rest on the sea bottom when the tank is sunk onto the offshore site, a sea water exchange line extending from outside of the retainer wall into the storage compartment and opening into the lower part of the storage compartment, an oil inlet line opening into the upper part of the storage compartment, and an oil delivery line extending from the top of the storage compartment upwardly to the water surface.
Claim 2
Dependent Claim
201 words
A submerged storage tank for installation on the sea bottom at offshore locations to store oil having a lower density than sea water comprising a vertical outer wall enclosing a storage compartment, a top member extending across the top of the storage compartment and connected to the outer wall to close the upper end of the storage compartment, said storage compartment being open at its lower end, a retainer wall surrounding the vertical wall and spaced therefrom to cooperate with the vertical wall in defining an upwardly opening ballast chamber between the retainer wall and the outer wall, a bottom member connected to the lower end of the vertical wall and to the retainer wall closing the lower end of the ballast chamber, said bottom member positioned and adapted to rest on the sea bottom when the tank is sunk onto the offshore site, a sea water exchange line extending from outside of the retainer wall into the storage compartment and opening into the lower part of the storage compartment, an oil inlet line opening into the upper part of the storage compartment, and an oil delivery line extending from the top of the storage compartment upwardly to the water surface.
Claim 3
Dependent Claim
78 words
Apparatus as set forth in claim 1 in which the tank is of annular shape having a vertical inner wall within the outer wall, said top member extending from the inner wall to the outer wall to leave the space within the vertical inner wall opening upwardly to form a central ballast chamber, and a central bottom member connected to the lower end of the inner wall and extending across the lower end of the central ballast chamber.
Claim 4
Dependent Claim
34 words
Apparatus as set forth in claim 2 in which the inner and outer walls are cylindrical and the retainer wall surrounding the outer wall is of substantially the same height as the outer wall.
Claim 5
Dependent Claim
63 words
A submerged storage tank as set forth in claim 1 in which the vertical outer wall, the top member, the retainer wall and the bottom member are constructed of steel and a layer of concrete extends over the upper surface of the bottom member, the outer surface of the vertical outer wall and the top member to increase the rigidity of the structure.
Claim 6
Dependent Claim
126 words
In a method of installing a submerged oil storage tank at an offshore location, said tank having upwardly opening ballast compartments outside of the storage compartment, the lower end of the storage compartment being open, the improvement comprising floating the tank on water, filling the storage compartment with oil to provide a buoyancy adequate to float the tank, floating the tank to the desired offshore site, displacing a portion of the oil from the tank with sea water to give the tank a slight negative buoyancy to sink the tank onto the sea bottom, and filling the ballast chambers with ballast material after the tank is on bottom and in an amount adequate to hold the tank on bottom when the tank is filled with oil.
Claim 7
Dependent Claim
126 words
In a method of installing a submerged oil storage tank at an offshore location, said tank having upwardly opening ballast compartments outside of the storage compartment, the lower end of the storage compartment being open, the improvement comprising floating the tank on water, filling the storage compartment with oil to provide a buoyancy adequate to float the tank, floating the tank to the desired offshore site, displacing a portion of the oil from the tank with sea water to give the tank a slight negative buoyancy to sink the tank onto the sea bottom, and filling the ballast chambers with ballast material after the tank is on bottom and in an amount adequate to hold the tank on bottom when the tank is filled with oil.
Claim 8
Dependent Claim
144 words
In a method of installing a submerged oil storage tank at an offshore location, said tank having upwardly opening ballast compartments outside of the storage compartment, the lower end of the storage compartment being open, the improvement comprising floating the tank on water, filling the storage compartment with oil to provide a buoyancy adequate to float the tank, floating the tank to the desired offshore site, attaching cables at intervals around the periphery of the storage tank and running the cables to barges surrounding the storage tank, displacing oil from the tank with sea water until the tank has a slight negative buoyancy, sinking the tank onto the sea bottom while guiding the tank with the cables to maintain it in a horizontal position, filling the ballast chambers with ballast material after the tank is on bottom, and disconnecting the cables from the tank.
Claim 9
Dependent Claim
144 words
In a method of installing a submerged oil storage tank at an offshore location, said tank having upwardly opening ballast compartments outside of the storage compartment, the lower end of the storage compartment being open, the improvement comprising floating the tank on water, filling the storage compartment with oil to provide a buoyancy adequate to float the tank, floating the tank to the desired offshore site, attaching cables at intervals around the periphery of the storage tank and running the cables to barges surrounding the storage tank, displacing oil from the tank with sea water until the tank has a slight negative buoyancy, sinking the tank onto the sea bottom while guiding the tank with the cables to maintain it in a horizontal position, filling the ballast chambers with ballast material after the tank is on bottom, and disconnecting the cables from the tank.
Claim 10
Dependent Claim
144 words
In a method of installing a submerged oil storage tank at an offshore locatioN, said tank having upwardly opening ballast compartments outside of the storage compartment, the lower end of the storage compartment being open, the improvement comprising floating the tank on water, filling the storage compartment with oil to provide a buoyancy adequate to float the tank, floating the tank to the desired offshore site, sinking a plurality of anchors onto the sea bottom surrounding the desired site of the tank, running cables from the tank through sheaves on the anchors and to barges surrounding the tank, displacing oil from the tank with sea water until the tank has a slight positive buoyancy, taking up on the cables to pull the storage tank downwardly onto the sea bottom, and filling the ballast chamber with ballast material to anchor the storage tank on bottom.
Claim 11
Dependent Claim
144 words
In a method of installing a submerged oil storage tank at an offshore locatioN, said tank having upwardly opening ballast compartments outside of the storage compartment, the lower end of the storage compartment being open, the improvement comprising floating the tank on water, filling the storage compartment with oil to provide a buoyancy adequate to float the tank, floating the tank to the desired offshore site, sinking a plurality of anchors onto the sea bottom surrounding the desired site of the tank, running cables from the tank through sheaves on the anchors and to barges surrounding the tank, displacing oil from the tank with sea water until the tank has a slight positive buoyancy, taking up on the cables to pull the storage tank downwardly onto the sea bottom, and filling the ballast chamber with ballast material to anchor the storage tank on bottom.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-12-23 | 1978-06-24 | 1978-12-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-12-23 | 1982-06-24 | 1982-12-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-12-23 | 1986-06-24 | 1986-12-24 | $7700.00 | Window Closed / Lapsed |