BP Plc, Transocean Ltd. and the U.S. Coast Guard confronted the possibility of a major oil spill in the Gulf of Mexico as hope faded for workers missing since an offshore drilling rig exploded on April 20 and sank yesterday.
U.S. Coast Guard Rear Admiral Mary Landry told reporters yesterday afternoon in New Orleans that the search for survivors from Transocean’s Deepwater Horizon rig would continue for about another 12 hours. Ships hired by BP began skimming a sheen of oil from the surface after the vessel sank late yesterday.
If the 11 missing workers died, it would be the deadliest U.S. offshore rig explosion since 1968, when 11 died and 20 were injured at a platform owned by Gulf Oil Corp., according to data from the Minerals Management Service. As aircraft searched yesterday, remote-operated vehicles were probing underwater to find if the well is still leaking oil.
“This certainly has the potential to be a major spill,” David Rainey, BP’s vice president for Gulf of Mexico production, said at the press conference. BP has a rig capable of drilling down to plug the well if it is found to be leaking and if the underwater vehicles can’t shut it off by closing valves on the sea floor, he said.
Rainey and Adrian Rose, Transocean’s vice president for quality, healthy, safety and the environment, didn’t say how long it may take to stop the well.
President Barack Obama was briefed on the accident yesterday afternoon, the White House said in a statement.
A “rainbow sheen” of crude oil extends five miles (8 kilometers) from the site of the sinking and is 1 mile wide, Landry said. The sheen is comprised of oil left on the surface after the rig sank, although BP and the Coast Guard are prepared should a continued leak from the well appear, she said.
BP will have 1 million feet (304 kilometers) of floating boom used to contain oil slicks at the site, Rainey said. The company also has four aircraft available to apply chemical oil dispersant and federal permission to use it, he said.
Dispersants break an oil slick into small droplets that sink, keeping it away from birds, sea turtles and beaches. The National Oceanic and Atmospheric Administration will forecast the path of any slick, and shallow-water oil spill vessels are standing by should oil threaten to wash ashore, Rainey said.
BP has 100,000 gallons of dispersants on hand, enough to fill 11 tanker trucks, with more available, according to the Coast Guard.
Dispersants may be less effective if waves whip the oil together with water, or emulsify it, said Chris Piehler, water quality assessment division administrator at the Louisiana Department of Environmental Quality.
Piehler’s department has not yet been involved with the slick from Deep Horizon, as it remains in federal waters, but he said he believed the oil was emulsified.
The equipment needed to contain oil spills in the high seas can be unwieldy, Piehler said.
Floating mechanisms and containment booms must be much heavier and larger to function in high seas, he said. “It’s harder to get a large number of them out to distances that far out,” he said.
In some cases, deepwater oil spills can be burned, he said, but in this case, work going on around the rig itself may make that impossible. BP did not mention the possibility of burning the oil at yesterday’s press conference.
The oil sheen is now 42 miles offshore, Landry said. It could move toward the southeastern U.S. coastline, according to meteorologists at accuweather.com. The nearest landfall from where the rig was located is East Bay on the Louisiana coast, about 87 miles (140 kilometers) southeast of New Orleans.
“As of midday Thursday, the Gulf of Mexico current is taking oil from the sunken rig away from land, but meteorologists expect the current to change course as a storm from the Rockies begins to move toward the Mississippi Valley,” the State College, Pennsylvania-based forecasting firm said in a report to clients today.
The rig itself has settled under the surface, according to the Coast Guard. Two undersea pipelines, one a mile away from the rig, were shut as precaution against damage should the sunken rig drift into them, Landry said.