UNDERGROUND LIQUID STORAGE SYSTEM AND METHOD

摘要

This invention relates to a storage system and method for storing a valuable liquid in a subterranean cavity with a displacing liquid such as brine. The valuable liquid, which normally has a density above or the same as that of the displacing liquid, is modified by dissolving therein small amounts of a light fluid such as alkanes and alkenes of up to 4 carbon atoms, hydrogen, nitrogen, carbon monoxide or combinations thereof. The amount of the light fluid dissolved in the stored liquid is sufficient to maintain the density of this phase below that of the displacing liquid so that the valuable liquid is stored over the displacing liquid. Virtually any valuable liquid desired to be stored in a subterranean cavity, which is substantially immiscible with the displacing liquid, can be so stored with the system and method of the present invention, but there will generally be no advantage in doing so unless the density of the liquid to be stored is normally greater than or the same as that of the displacing liquid at contemplated storage condition. When saturated brine is used as the displacing liquid this invention is particularly attractive for storing relatively heavy liquids such as carbon disulfide and the halogenated hydrocarbons. The density of the liquid to be stored is preferably at least 1 kg/m3 lower than that of the displacing liquid to ensure that there is a sufficient density difference to avoid phase inversion or dispersion.