Underground Storage Systems for High-Pressure Air and Gases

This paper is a discussion of the safety and cost of underground high-pressure air and gas storage systems based on recent experience with a high-pressure air system installed at Moffett Field, California. The system described used threaded and coupled oil well casings installed vertically to a depth of 1200 ft (366 m). Maximum pressure was 3000 psi (20.7 MPa) and capacity was 500,000 lb (227 kg) of air. A failure mode analysis is presented, and it is shown that underground storage offers advantages in avoiding catastrophic consequences from pressure vessel failure. Certain problems such as corrosion, fatigue, and electrolysis are discussed in terms of the economic life of such vessels. A cost analysis shows that where favorable drilling conditions exist, the cost of underground high-pressure storage is approximately one-quarter that of equivalent aboveground storage. Wider use, however, depends on a favorable reception by other experienced engineers and revisions in the ASME Boiler and Pressure Vessel Code to encompass this technique.