BP Plc engineers desperately explored options on Sunday to control oil gushing from a ruptured well deep under the Gulf of Mexico after a setback with a huge undersea containment dome fueled fears of a prolonged and growing environmental disaster.
The spill is spreading west, further from Florida's beaches but toward the important shipping channels and rich seafood areas of the central Louisiana coast, where fishing, shrimping and oyster harvesting bans were extended.
BP is exploring several new options to control the spill after its 98-ton containment chamber, which took about two weeks to build, struck a snag on Saturday.
A buildup of crystallized gas in the dome forced engineers to delay efforts to place the huge containment device over the rupture and funnel leaking oil to a waiting drillship.
"We're gathering some data to help us with two things. One is another way to do containment, the second is other ways to actually stop the flow," BP chief operating officer Doug Suttles told Reuters in Venice, Louisiana.
BP was also exploring ways to work around the containment dome's problem with gas hydrates, or slushy methane gas that would block the oil from being siphoned.
"One is a smaller dome; we call it the 'top hat.' The second is to find a way to tap into the riser, the piece of pipe the oil is flowing through, and taking it directly to the pipe up to a ship on the surface," Suttles said.
Conducting operations a mile (1.6 km) below the ocean's surface complicated BP's efforts. Engineers worked with remote-controlled vehicles in the blackness of "inner space."
At least 5,000 barrels (210,000 gallons/795,000 litres) of oil a day have been gushing unchecked into the Gulf since the Deepwater Horizon rig exploded on April 20, rupturing the well and killing 11 crew members. The leak threatens to become the worst-ever U.S. oil spill.
On Dauphin Island, Alabama, a barrier island and beach resort, sunbathers found tar balls along a short stretch of beach on Saturday, and experts were testing the tar to determine if it came from the Gulf spill.
The spill threatens economic and ecological disaster on Gulf Coast tourist beaches, wildlife refuges and fishing
grounds. It has forced President Barack Obama to rethink plans to open more waters to drilling.
The disaster could slow the exploration and development of offshore oil projects worldwide, Nobuo Tanaka, executive
director of the International Energy Agency warned on Sunday.