By Laura Goldberg, Houston Chronicle Knight Ridder/Tribune Business News
Feb. 19--Shares in El Paso fell more than 17 percent Wednesday after the company said it had significantly reduced its proven natural gas and oil reserve estimates.
Proven reserves, a key number used in the industry for predicting the potential of oil and gas production, gained attention after last month's announcement by Royal Dutch/Shell Group that it was cutting its proven reserve base by 20 percent.
Others, including Houston-based El Paso, followed Shell with downwa