EIA's March 9, 2017 account reported a 7-billion-cubic-foot net increase in Lower 48 natural gas storage for the week ending February 24. After that change, stored working gas totaled 2,363 billion cubic feet. The first number is a weekly flow; the second is the inventory level after additions and withdrawals were combined. [30272][29712]
The stock was about 300 billion cubic feet above the average for the same week in 2012–2016. That comparison is separate from the claim that this was the first February weekly injection in the collected data series. Neither statement measures gas production, the physical capacity of storage facilities or underground geological reserves. [30272][29712]
A January 27 EIA article explains the measurement. Weekly working-gas figures are estimates based on a sample of Lower 48 storage operators, so they are subject to sampling error. Beginning with data for the week ending January 20, the report supplied additional statistical information. EIA said the underlying storage estimation method had not changed. [30272][29712]
The January article illustrated a different observation: a 119-billion-cubic-foot withdrawal for January 20, with a standard error of 2.9 billion and a 95 percent interval from 113 to 125 billion. Those uncertainty figures belong to January, not February's injection. Reading the articles together supplies a method for interpreting the later estimate, not a license to attach an earlier week's numerical error bounds to it. [30272][29712]
Source documents
- Warm weather leads to first recorded natural gas storage injection in Februaryhttps://www.eia.gov/todayinenergy/detail.php?id=30272
- EIA’s weekly natural gas storage data now include measures of sampling variabilityhttps://www.eia.gov/todayinenergy/detail.php?id=29712