BP's Oil-Containment Box Hovers Just Above Seafloor
BP Plc expects tonight to sink the edges of a 40-foot-tall steel chamber into the mud 5,000 feet (1,524 meters) under the surface of the Gulf of Mexico to capture most of the oil that’s leaking from its Macondo well.
The containment system may begin funneling as much as 85 percent of the leak to an overhead drill ship as early as May 10, Doug Suttles, BP’s chief operating officer for exploration and production, said today in a press conference in Robert, Louisiana.
If it works, the rectangular structure with a pyramid- shaped dome on top will capture crude from the largest leak at the well, which began spilling oil after the Deepwater Horizon rig exploded and sank in the Gulf last month.
“They have to lower it quite precisely,” Suttles said, referring to operators of a ship-mounted crane about a mile above the leak. “The tolerances are very tight.”
To stop rest of the leaking, BP is studying the possibility of injecting pieces of rubber into the well, Suttles said.
Risk of Faster Leak
The containment box is a stopgap measure until London-based BP can complete a well started May 2 aimed at intercepting the damaged well and plugging it with cement, a job it expects may take three months. After failing to close valves to stop the flow, engineers are exploring two ways to plug the wellhead, Suttles said. Both risk accelerating the spillage rate, he said.
The U.S. Fish and Wildlife Service today stopped public access to Louisiana’s Chandeleur and Freemason islands, where BP and federal officials yesterday said oil from the spill first reached shore. The islands comprise the Breton National Wildlife Refuge, and barring the public will protect nesting birds and speed the cleanup, the service said today in a statement.
The National Oceanic and Atmospheric Administration today widened a fisheries closure in the Gulf of Mexico, calling it necessary to reassure consumers that fish and shrimp caught in the region are safe to eat.
BP was leasing the rig, which is owned by Geneva-based Transocean Ltd., when it exploded April 20 and sank two days later. NOAA has estimated the leak at 5,000 barrels of oil per day.
Burning, Skimming Used
Calm seas have enabled BP to burn as much as 9,000 barrels of oil from the surface, Suttles said.
The U.S. Coast Guard and BP have been skimming oil from the Gulf. Oil accounts for about 10 percent of the 45,000 barrels of oil and water skimming boats have recovered so far, Suttles said.
The U.S. Minerals Management Service, overseer of offshore drilling, completed inspections of all 30 deepwater drilling rigs currently in operation without identifying safety hazards, regional director Lars Herbst said at the press conference in Robert.
Inspectors checked test records of blowout preventers, an assembly of valves atop wells on the sea floor. The blowout preventer on the BP well failed to stop a mixture of oil and gas from ejecting unexpectedly and igniting the rig, Suttles has said.
BP has 20 experts studying whether a “junk shot,” an injection of rubber cuttings into the blowout preventer, might stop leaking oil not captured by the dome, Suttles said. Engineers are also considering installing a second blowout preventer atop the first, he said.
Before the box can be installed, robots must make sure the area is clear, Suttles said.
Water temperatures of about 42 degrees Fahrenheit (6 Celsius) and pressures of 2,300 pounds per square inch may cause natural gas in the oil, estimated at 3,000 cubic feet per barrel, to freeze as it rises.
BP plans to circulate warm surface water and antifreeze around the pipe to prevent clogging, Dave Clarkson, the company’s project manager for the underwater containment plan, said during a May 5 conference call.
Similar containment boxes have been used to funnel crude from leaking wells in shallow water. This is the deepest deployment of the system, according to a fact sheet provided by BP.
It may take a week to determine if the system is working, Robert Dudley, BP’s executive vice president for the Americas and Asia, said in Boston yesterday.
BP fell 13.1 pence, or 2.3 percent, to 553.9 pence at 4:35 p.m. in London. The shares have dropped 15 percent since the rig exploded.