Estimated size of oil spill doubles

(CNN) – Researchers have doubled estimates of how much oil has been spewing from a ruptured well in the Gulf of Mexico, reporting Thursday that up to 40,000 barrels (1.7 million gallons) a day may have escaped for weeks.

Well owner BP has been able to capture a varying percentage of that oil, first with a siphon inserted into the well riser and since June 3 with a cap that allowed workers to draw nearly 16,000 barrels to a ship on the surface Wednesday.

But scientists from the Flow Rate Technical Group reported Thursday that the amount of oil that has been leaking into the Gulf since late April was roughly twice the amount they previously estimated.

"The lowest estimate that we're seeing, that the scientists think is credible, is probably about 20,000 barrels," U.S. Geological Survey Director Marcia McNutt said. "And the highest that we're seeing is probably a little over 40,000, maybe a little more, depending on whether there are any systematic issues with gas."

Two weeks ago, researchers put the amount of oil escaping into the Gulf at between 12,000 and 19,000 barrels (504,000 to 798,000 gallons) per day. Read more