[DantesPeak]

Simmons mentioned in article.

$this->bbcode_second_pass_quote('', 'D')HAHRAN, Saudi Arabia - In a room nearly as big as a football field, engineers at Saudi Aramco monitor the flow of 12 percent of the world's daily oil production.

Facing a curved display wall 10 feet high and 220 feet long, they manage production and pipeline flows while also directing giant tankers to export terminals in the Persian Gulf or the Red Sea. Ten million barrels of oil are tracked on these screens each day.

For the secretive kingdom, this is among the most secret of all sanctuaries: it is Saudi Arabia's oil spigot.

But the doors to this control room at the headquarters of Saudi Aramco, in the eastern town of Dhahran, were recently flung open to a 10-member American delegation headed by Samuel W. Bodman, the energy secretary.

Mr. Bodman and his top-level team spent three days in Saudi Arabia, meeting with King Abdullah, visiting oil fields in the desert, touring Aramco's facilities and getting a direct peek inside the world's largest oil producer.

Mr. Bodman was seeking firsthand evidence of Saudi Arabia's expansion plans at a time when, analysts say, the kingdom's position in the global oil markets is slowly shifting. As the sharp rise in oil demand whittles away its spare capacity, Saudi Arabia is shunning its traditional role of the swing producer who stands by with excess oil to pour into tight markets; rather, it now aims to produce supplies just in time to ship when consumption dictates.

More recently, some critics, led by Matthew R. Simmons, a Houston-based investment banker, have accused Aramco of overstating oil reserves and minimizing production problems. While Mr. Simmons still represents a minority opinion, Aramco does not readily share information to disprove it.

Saudi oil officials and executives at Aramco declined to make themselves available for interviews.