Storage

Here is an interesting article concerning how the EIA reports on storage activity within the US.

  1. EIA will use five regions: East, Midwest, South Central, Mountain and Pacific
  2. changes were prompted, at least in part, by user request “A lot of our customers had been asking to see the storage data at a greater granularity”
  3. the discrepancies between the two formats are “largely a methodological issue”
  4. related to a change in how the storage numbers are rounded as well as how the non-sample estimate is calculated
  5. The new method also includes a change in rounding. Currently, storage stocks reported in each region are rounded, and then the Lower-48 total is calculated as the sum of those rounded values. This caused the sum of the three regions to always equal the Lower-48 total.
  6. However, under the new five-region format, the Lower 48 total will be calculated, and then each region and the national total will be rounded individually to the nearest Bcf. This could cause the sum of the five regions to differ from the Lower-48 total by as much as 2 Bcf in a given week. But the EIA argue this technique is a more methodologically sound approach, “as rounding is typically the very last step in an algebraic operation.”

http://ir.eia.gov/ngs/methodology.html