Spill Could Last 2 to 4 Years

BP CEO Tony Hayward says the reservoir that feeds the gushing well in the Gulf of Mexico probably still holds about 2 billion gallons of oil.

Appearing before a House subcommittee, Hayward estimated that the reservoir tapped by the out-of-control well holds at least 50 million barrels of oil. At 42 gallons per barrel, that's 2.1 billion gallons.

According to government estimates of daily flow figures, anywhere from 73.5 million to 126 million gallons gushed from the breached wellhead — whether into the water or captured.

That means the reservoir likely holds 94 to 97 percent of its oil. At the current flow rate, it would take from two to nearly four years for all the oil to leak from the field if it can't be stopped.