Patent ID: 7654279

Claim:
A deep water gas storage system for storing a compressed gas, the system comprising: an inflexible thin walled vessel positioned under deep water and having a first end at a first water depth and a second end at a second water depth less than the first water depth, the vessel adapted to store the compressed gas such that: a pressure of the compressed gas proximate the first end is substantially equal to a hydrostatic pressure of the water at the first water depth; a pressure of the compressed gas proximate the second end is less than a hydrostatic pressure of the water at the second water depth; and a pressure of the compressed gas between the first end and the second end and at a third water depth, wherein the third water depth is between the first water depth and the second water depth, is a linear function of a density of the compressed gas and independent of a hydrostatic pressure of the water at the third water depth; wherein the compressed gas within the vessel has a compression ratio of at least 5; a compressed gas intake coupled to the vessel for admitting and discharging the compressed gas to and from the vessel; a water port in the vessel, the water port positioned at a water depth greater than that of the compressed gas intake and adapted to freely admit water to and discharge water from the vessel; a valve coupled between the compressed gas intake and the vessel, the valve operable to control compressed gas admission to and discharge from the vessel; and a tie-in to a marine riser for offloading of the compressed gas to a ship, wherein the tie-in to the marine riser comprises: a gas conduit for engaging a tie-back connector in the marine riser connected to a riser base in the sea floor; and a shut off valve disposed in the gas conduit for starting or stopping the compressed gas offloading to the ship.