SHANA - Iran has stored nearly 2 billion cubic meters of natural gas in subsurface gas storage facilities of Sarajeh and Shourijeh in the first half of the current Iranian calendar year which began on March 21.

The gas is being injected to the facilities for consumption during winter and enhancing production of the country's oilfields.

Speaking to Shana, Saeid Tavakoli, the managing director of National Iranian Transmission Company (NIGTC), said the gas is sometimes used for injection in oilfields for boosting their output and after all the recoverable oil is produced from the fields the gas will be kept there for further consumption.

Natural gas, like many other commodities, can be stored for an indefinite period of time in natural gas storage facilities for later consumption.

The most important type of gas storage is in underground reservoirs. There are three principal types � depleted gas reservoirs, aquifer reservoirs and salt cavern reservoirs. Each of these types has distinct physical and economic characteristics which govern the suitability of a particular type of storage type for a given application.

In winter, NIGTC transfers 750 mcm/d of gas in Iran and withdraws 8 mcm/d from Sarajeh during the cold snap.

The facility can store up to one billion cubic meters of gas. This is while Shourijeh facility can store up to 2.5 bcm in it. The plant received 2.5 mcm of gas in the first half of this calendar year.

Gas storage will continue until late November.