The rise in salt cavern storage of natural gas

As natural gas storage levels were at a low for most of last year and production was relatively high, minimal new natural gas storage capacity was built, according to the EIA. However, there was an exception in the form of salt facilities in the Producing region. Capacity in the East region of the US fell slightly, resulting in relatively unchanged national total capacity. The EIA has measured and does measure natural gas storage capacity in November each year, which is typically when storage withdrawals begin to exceed injections and. Between November 2013 and November 2014, the EIA found that each of its measures of storage capacity within the lower 48 states was virtually unchanged, as increases in salt facilities largely offset declines in other types of storage capacity.

Measures of capacity

The UE EIA uses two distinct measures of natural gas storage capacity. Demonstrated maximum working gas volume is the sum of peal volumes reported by the 395 active storage facilities in the lower 48, regardless of when the individual peaks occurred over the five year reporting periods ending November 2013 and 2014. This volume hardly increased from 4333 4336 billion ft3 between November 2013 and 2014.

Design capacity is the other measure and this is the sum of the working gas design capacity of the 395 active storage fields, as of November 2014, as reported on survey Form EIA-191. Design capacity is based on the physical characteristics of the reservoir, installed equipment, and operating procedures particular to the site that is often certified by federal or state regulators. Design capacity also hardly increased, from 4664 – 4665 billion ft3, between November 2013 and November 2014.

Factors of change

The EIA have commented that two primary factors affected the modest change in capacity this year compared with previous changes. Firstly low storage volumes, as for nearly all of last year, an in all regions except the Producing salt region, natural gas storage levels were below the previous five year minimum, after the extremely cold winter of 2013 – 2014 which led to large storage withdrawals. Secondly, there are no new underground storage caverns. Since November 2013, no new storage facilities commenced operation, and any increases in working gas design capacity has come from expansions of existing caverns. Capacity growth in the coming years is expected to be relatively modest and is most likely to be concentrated in salt facilities.

Edited from press release by Claira Lloyd

Read the article online at: https://www.hydrocarbonengineering.com/gas-processing/26022015/salt-cavern-natural-gas-storage/