© D.L. Crumbley
There are almost as many oil/gas reserve definitions as there are countries.
During the first week of January 2004, Royal Dutch/Shell Group slashed its estimates of oil reserves by 20% or about 3.9 billion barrels of oil.
Stock fell 9%.
Shell, Exxon/Mobil, and Chevron/Texaco make the estimates themselves.
Source: Susan Warren and P.A. Mckay, “Methods for Citing Oil Reserves Prove Unrefined,” Wall Street Journal, January 14, 2004, p. C-4