MIAMI — BP vessels that evacuated ahead of Tropical Storm Bonnie returned Saturday to the Deepwater Horizon well site in the Gulf of Mexico to resume permanently capping the damaged well after a three-day halt.
"It's very good news," said retired Coast Guard Adm. Thad Allen, who's leading the government's spill response.
Although Bonnie had weakened into a depression, the storm still forced the evacuation of 10 to 15 ships and disassembly of a portion of the relief tunnel. That means a 7- to 9-day delay in completing the ultimate fix.
On the bright side, Jane Lubchenco, the administrator of the National Oceanic and Atmospheric Administration, said the storm's wave action of up to 8 feet in the northern Gulf will churn the oil, spreading what's left of the surface oil slicks and breaking tar balls up into smaller parts that will biodegrade more quickly.
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The storm was too weak to churn up any oil deep under the sea, Lubchenco said.
However, the tropical depression, with sustained winds of about 30 mph, could drive some oil into marshes and bayous and onto beaches. Its counter-clockwise rotation also could move some oil away from the coastlines.
"The bottom line: It's better than it might have been," Lubchenco said of Bonnie, which packed far less punch than originally forecast.
No oil leaked from the Deepwater Horizon well during the storm, Allen said.
The mechanical cap that's been preventing oil from leaking into the Gulf for the past eight days remained in place. With Bonnie bearing down Friday, BP decided to leave two vessels with skeleton staffs at the site. They monitored the cap using video imaging and at least one underwater robot at all times. Seismic readings were stopped during the storm, Allen said.
Now the goal is to seal the damaged well permanently before another storm forms during this hurricane season, which meteorologists predict will be busier than normal.
"We're going to play a cat-and-mouse game for the remainder of the hurricane season," Allen said.
Another weather disturbance is already in the Caribbean, but Lubchenco said it has little chance of developing into a tropical storm in the next 48 hours, and only a 10 percent chance of intensifying much in the next five days.
On Monday, BP should be able to resume drilling the relief well, the second part of the two-phase process to seal the well permanently.
Workers are simultaneously drilling a relief tunnel to reach two miles under the sea and pump in more cement and mud from the top of well, which could kill it right away. It could take as much as a week before crews begin pumping in the mud and cement, Allen said.
Workers on the Development Drill 3 rig spent Thursday and Friday disassembling parts of the relief tunnel by pulling nearly a mile of steel pipe in 40- to 50-foot sections up and onto the deck, a safety measure ahead of the storm.
Now they return to the site and reverse the process, which is a big reason for delay.
Some support vessels took safe harbor up the Mississippi river and may take longer to return to the site of the blowout.
Clark is a Miami Herald reporter.
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