The EIA has said that natural gas stored in salt facilities, principally in the greater Gulf Coast gas producing region, accounts for just 10% of storage capacity in the Lower 48 states, but it does provide 28% of daily deliverability.
Salt facilities are underground caverns that operate under high storage pressure and can therefore provide much higher deliverability than other natural gas storage methods and options such as depleted fields or aquifers. Natural gas that is stored in salt facilities can also be drawn down and refilled, or even cycled, as many as 12 times a year, while gas stored in traditional depleted fields or aquifers generally cycles only once a year. As cycling is relatively difficult for these latter facilities, they typically follow a seasonal pattern of injecting gas into storage in the summer and withdrawing it for heating in the winter.
Natural gas consumption
The volume of natural gas used for power generation is increased as a component of the gas market and gas more often is called on to meet summer electricity demand for air conditioning as well as for lighting, heating and industrial uses. Generation fuelled by natural gas is also increasingly used to meet sudden, weather driven demand in any season.
The rise in salt facilities has coincided with changing consumption patterns, as salt facilities can flow gas out of storage and into pipelines headed for utility generators and industrial plants far quicker than from traditional storage. However, salt facilities are more expensive to develop and use on a per unit of capacity basis, but, their increased flexibility allows operators to more quickly adapt to changing market conditions.
Those that are holders of salt facility gas can take advantage of short term price movements by selling gas into the market quickly when price increase. Holders of gas in more traditional storage are less likely to take advantage of such movements, either because they cannot withdraw gas as quickly, or they are reluctant to reduce storage levels in August at the expense of having less gas available to them in January.
The growth in salt facility capacity has come while capacity in traditional storage facilities has declined slightly. Salt facilities in the producing region of the US have doubled their share of total available working natural gas storage capacity in the Lower 48 states since 2008. Last year, capacity in salt facilities in the producing region increased by 4.4%, resulting in an increase in total national storage capacity, which would have otherwise declined in 2014. New capacity in producing region salt facilities has accounted for approximately half of the new capacity built over the past few years.
Edited from press release by Claira Lloyd
Read the article online at: https://www.hydrocarbonengineering.com/gas-processing/27072015/salt-facility-storage/