Energy executives and analysts insist that in spite of the supply crunch that has kept oil above $50 a barrel for much of the year, demand and prices remain prone to ups and downs, so the industry should not rush to drill wells and expand refineries just because it is flush with cash.

"A surplus of supply is not good for the industry," Shell Oil Co. president John Hofmeister said Friday.

"Just as a surplus of demand is not good for industry. We strive for balance."

Hofmeister, speaking by phone, said "we will continue to work as an industry to increase supplies to the American people." But he said Shell executives were still debating whether it makes economic sense to expand the capacity of refineries it owns jointly with Saudi Refining Inc.