According to Bob Dudley, BP's new point man for the oil response, removing the cap was the right thing to do because fluid seemed to be leaking and could have been a safety hazard.
"It's a setback, and now we will go back into operation and show how this technology can work," Dudley said before the system was working again.
Clouds of black oil gushed into the Gulf again at up to 104,000 gallons per hour while the cap was off, but fortunately a specialized ship at the surface managed to suck up and incinerate 438,000 gallons.
In Florida, thick pools of oil washed up along miles of national park and Pensacola Beach shoreline Wednesday, as health advisories against swimming and fishing in the once-pristine waters were extended for 33 miles east from the Alabama line.
Only one other time during the attempts to contain the nine-week-old leak - when a submarine jarred loose a tube that been sucking oil from the broken riser - has one of the robot crews interrupted those efforts, said Coast Guard Adm. Thad Allen, the Obama administration's lead spill responder.
"I think the fact that we've had two bumps that have had some kind of a consequence associated with them in the 60-plus days response is a pretty good record," he said. "It's never going to be risk-free out there, and we need to watch it very closely."
The current worst-case estimate of what's spewing into the Gulf is about 2.5 million gallons a day. Anywhere from 67 million to 127 million gallons have spilled since the April 20 explosion on the Deepwater Horizon rig that killed 11 workers and blew out the well 5,000 feet underwater. BP PLC was leasing the rig from owner Transocean Ltd.
- Meanwhile, the Obama administration seeks to resurrect a six-month moratorium on deepwater drilling. The Justice Department filed court papers asking U.S. District Judge Martin Feldman to delay his ruling overturning the order to suspend drilling on 33 wells and stop approval of any new deepwater permits. Several companies, including Shell and Marathon Oil, said they would await the outcome of any appeals before they resume drilling.
- Interior Secretary Ken Salazar said he would issue a new order within the next few days imposing a moratorium that eliminates any doubt it is needed and appropriate.
- Britain, home of BP headquarters, said deep-sea exploration will continue in North Sea oil fields off Scotland despite safety concerns raised by the Gulf spill, the country's energy minister said Thursday.
- A federal report confirms what independent scientists have been saying for weeks about the Gulf oil spill: Undersea oil plumes extend for miles from the ruptured well. The report may help measure the effectiveness of spreading chemicals to break up the oil. Government researchers released a summary Wednesday of water sampling conducted last month near the undersea gusher. It describes a cloud of oil starting around 3,300 feet deep up to 4,600 feet deep and stretching up to 6 miles from the well. Levels of oil and gas within the cloud are significantly higher than concentrations closer to the surface.
The Associated Press contributed to this report.