Patent ID: 7901158

Claim:
An underwater oil storage method comprising the steps of: a) excavating a cellar in the ground earth and constructing a wall structure in said cellar to form a water pool; b) setting an oil tank having a predetermined shape and volume in said water pool; c) fixedly securing said oil tank within said water pool; d) supplying a predetermined amount of water in said water pool; e) filling the oil to be stored into said oil tank; and f) regulating the amount of water in said water pool responsive to the amount of storage oil stored in said oil tank where the oil to be stored has a specific gravity lower than the water filled in said water pool, and the amount of the storage oil filled into said oil tank is less than the volume of said oil tank; wherein regulating the amount of water in said water pool is achieved by an auto water control system, said auto water control system includes simultaneously filling said water pool with water and filling said oil tank with oil; whereby when filling oil the level of water in said water pool and the level of oil in said oil tank are raised synchronously using said auto water control system; wherein when pumping oil out of the oil tank for use, the auto water control system automatically pumping water out of the water pool, thereby keeping the water pressure of water in said water pool in balance with the pressure of said oil tank.