Underground storage of fluids

Claim 1

IN A SUBTERRANEAN CAVERN FOR STORING AT SUPERATMOSPHERIC PRESSURE A FLUID IMMISCIBLE WITH WATER AND OF LOWER SPECIFIC GRAVITY THAN WATER, SAID CAVERN HAVING A SUMP EXTENDING DOWNWARDLY FROM THE FLOOR THEREOF AND COMMUNICATING THEREWITH: A PUMP FOR TRANSFERRING FLUID FROM SAID CAVERN TO THE SURFACE, THE INTAKE FOR SAID PUMP BEING LOCATED IN SAID SUMP; A CASING SURROUNDING BUT SPACED FROM SAID PUMP, SEALED INTO SAID CAVERN, AND EXTENDING FROM SAID SUMP TO THE SURFACE, THE LOWER END OF SAID CASING BEING OPEN; A QUANTITY OF WATER MAINTAINED PERMANENTLY IN SAID SUMP; AND A WATER PIPE EXTENDING FROM THE SURFACE OF THE EARTH VERTICALLY DOWNWARDLY THROUGH A CAVERN SEAL AND OPENING AT ITS LOWER END INTO THE WATER IN SAID SUMP, THE VERTICAL LENGTH OF SAID PIPE BEING IN EXCESS OF THE LENGTH OF THE COLUMN OF WATER NECESSARY TO COUNTERBALANCE, BY HYDROSTATIC PRESSURE, THE EFFECTIVE PRESSURE OF THE STORED FLUID, AND SAID QUANTITY OF WATER BEING SUFFICIENT TO FILL SAID PIPE TO SAID COLUMN LENGTH, WHEREBY WATER SUPPLIED TO SAID PIPE, ABOVE THE TOP OF SAID COLUMN, CAN FLOW DOWN SAID PIPE INTO SAID SUMP AND THENCE UPWARDLY INTO SAID CASING TO PROVIDE A PRESSURE-COUNTERBALANCING WATER COLUMN THEREIN.