CNBC has an interesting article on how natural gas supplies are calculated and reported: "One reason for differing estimates of natural gas reserves is that they can be measured in different ways. *** The Potential Gas Committee, the USGS and the EIA estimate 'technically recoverable resources,' which can be produced using current technology, regardless of the current price of gas. Those estimates change as technology changes, as has been the case in the past four years with fracking. *** A more conservative estimate is demanded by the Securities and Exchange Commission, which requires public companies to provide reserves data in their annual reports. So-called “proven reserves” are only those that can be produced profitably at current prices. Those estimates change as prices fluctuate."
