METHOD FOR NATURAL GAS STORAGE IN SUBSURFACE TANK CONSTRUCTED IN DEEP-FROZEN SOIL Russian patent published in 2014 - IPC B65C5/00 

FIELD: oil and gas industry.

SUBSTANCE: invention is related to methods of natural gas production and storage in the form of natural gas hydrates (NGH) in the subsurface tank cavern. The method includes preliminary filling of the cavern with salty water-ice mixture (WIM). NGH are received by pressure pumping of natural gas through a suspended casing equipped with a dispergator, its further bubbling through WIM with simultaneous injection of additional WIM to the cavern, performance of low-amplitude vibration of the mixture and extraction of water excess from the suspended casing. Thereafter pumping of gas and WIM is stopped; NGH are stored in the cavern at permanent temperature and pressure. For the purpose of NGH decomposition into water and gas pressure in the casing string is decreased by means of natural gas extraction to the consumer gas pipeline and salty water is pumped additionally to the cavern in order to deliver heat and to form WIM until the stored natural gas is extracted completely. Upon completion of gas extraction WIM is left in the cavern and stored under atmospheric pressure at temperature of frozen enclosing rocks till the tank is filled again with NGH.

EFFECT: the invention allows reduction of pressure required for natural gas storage.

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