New technology for the storage of strategic natural-gas reserves

Abstract

A structural scheme is examined for a 10.43⋅10 6 -ton strategic underwater gas-storage facility at the base of the Kurily-Kamchatka Trench (Tuskarora Trough).Today, underground storage facilities for gas (UGSF) are widely used in Russia to ensure its uninterrupted delivery to consumers. Let us point out that interruptions develop primarily during seasonal fluctuation in gas demand, especially in anomalously cold winters, during emergency situations involving gas pipelines, when the introduction of new capacities is delayed, and finally, when timely export deliveries of natural gas (NG) are impeded.In this connection, the company Gazprom is building 20 UGSF with an overall commercial-gas reserve of more than 60 billion m 3 in various regions of Russia. These include base UGSF (storage for several months), peak UGSF (storage for several days), and strategic UGSF (long-term storage). They all have a number of significant drawbacks: complexity of orifice-bracing equipment; diffusion losses of gas, which degrade the environment in the region where the UGSF are located; disruption of water-salt exchange in groundwater; and, the need to drill a large number of wells for uniform delivery of NG to the UGSF.These drawbacks have prevented the building of strategic NG reserves. Storage facilities with a high gas pressure to ensure compactness, fail-safe sealing to prevent losses and damage to the ecology of the surroundings, and with the ability to eliminate contamination of the gas and its humidification during significant flooding of the storage facility are required for this purpose. The creation of storage facilities for liquefied NG and the use of deep-water troughs, which make it possible to store gas under pressures to 100 MPa are therefore of practical interest (Russian Federation Patent No. 2263248).The container for deep-water gas storage can be fabricated from thin reinforced polyethylene film, which carries virtually no load due to pressure, since it is the same on both sides of the film during the storage of gas. On the other hand, utilization of such ultrahigh pressure permits the storage facility to contain up to 660 kg of methane per 1 m 3 ; this is of particular importance for the development of hydrogen power, when 83 kg of gaseous hydrogen can be stored in 1 m 3 under this pressure; this is 13 kg more than when liquid hydrogen is stored under normal pressure.A factor of no less importance to the operation of such a storage facility is the automated maintenance of a constant (equal to the initial) pressure in the facility as the gas is consumed; this will appreciably simplify the process of filling the facility with compressed gas and its off-loading for consumption.Let us examine the structural design for a strategic underwater gas-storage facility (SUGSF) to be created at the base of the 9717-m-deep Kurily-Kamchatka Trench (Tuskarora Trough). This trench is 2170 km long, and is, on average, 5.9 km wide with an average slope of 7°.

Storage of Compressed Natural Gases

“…A method of storing natural gas and a device for its implementation (patent RU No. 2263248) for meeting peak gas demand is known [35]. The use of the invention will make it possible to store gas compressed to 400 atm in modular thin-walled tanks.…”