BP said Thursday a preliminary estimate shows between 15 and 39 barrels of oil have been recovered from the lake at its Whiting refinery. That's between 630 and 1,638 gallons.
The new figure is up from BP's initial estimate that 9-18 barrels of oil entered the lake.
The corporation said its crews have recovered "the vast majority" of oil visible along the shoreline.
The U.S. Environmental Protection Agency said EPA and U.S. Coast Guard staffers oversaw cleanup work at the spill site again Thursday, but bad weather prevented them from deploying boats into the lake.
BP reported the spill Monday.