According to the U.S. Energy Information Administration , increases to natural gas inventories halfway through the 2012 injection season are the lowest they've been in more than a decade. But, just wait until November, the administration says. Here are the details.
* The U.S. is now halfway through the 2012 injection season, which is the time period between April and November when natural gas is stored underground in preparation for increased demand in the winter months.
* According to the EIA, an unseasonably warm winter led to record high inventories at the end of the winter. These inventories meant limited space for new injections.
* From April-June, the amount of working natural gas in underground storage increased 625 Bcf. This is the smallest build since 2000, when 564 Bcf was added in the same period.
* Though the net inventories increase is low, the Energy Information Administration reported. The U.S. is now at 75 percent of its underground storage capacity -- a level not generally reached until late August or early September.
* In addition to high end-of-winter inventories, the low increase in summertime inventories was also due to a large increase of natural gas use in April-June as the electric sector takes advantage of low prices. Natural gas burn increased 27 percent over the same time period in 2011.
* The EIA reported that although easing temperatures resulted in a decrease in natural gas use during the last week in July, power burn remains at historically high levels.
* According to EIA's weekly report on Aug. 1, natural gas prices have risen slightly and late July saw a decline in the natural gas rotary rig count.
* Increased dry natural gas production was up by 7 percent during the first half of 2012 and working gas inventories are expected to be at a record high by Nov. 1.
* The EIA explains that most existing gas storage in the United States occurs in depleted natural gas or oil fields. A wide availability of depleted oil and gas reservoirs makes them a convenient choice for underground storage sites.
* In some places, natural aquifers are also converted into storage reservoirs, as are salt caverns. In the past, there have been attempts to use abandoned mines for storing natural gas. No abandoned mines are currently being used as natural gas storage sites.
* The owners and operators of the country's storage sites tend to be inter- or intrastate pipeline companies, local distribution companies and independent storage service providers. Currently, there are almost 400 active storage facilities in the lower 48 states of the U.S.

