BP, the company that operated the rig at the time of an April 20 explosion that began the spill, said workers using unmanned submersibles removed the cap that had been limiting the flow of oil. The next step is to install another cap, one that could cut off the flow of oil completely.
Tens of millions of barrels of oil have fouled the gulf since the Deepwater Horizon rig sank in April. Emergency crews have been trying various methods to shut off the flow, including drilling of relief wells, which are expected to reach the leaking well "the first half of August," BP said in a news release.
BP officials said it would be later this week before they have the new cap in place and can report on progress in stopping the leak. Other containment systems remained in place. The company said it captured more than 15,000 barrels of oil Saturday.
Surface efforts continue to skim oil and carry out controlled burns.
However, oil has reached beaches across the U.S. Gulf Coast. The National Oceanic and Atmospheric Administration said a patch of floating oil threatened shorelines near the Texas-Louisiana border with other patches likely to affect Mississippi and Alabama. Also, gulf currents led NOAA to extend an area of possible additional landfalls into Florida.