Published: May 6, 2010
BATON ROUGE, La. — With remote-controlled robots a mile underwater unable to seal the gushing well, and with the drilling of relief wells that would allow crews to plug the spouting cavity months away from completion, it is time for the big box.
The end of the oil spill, or at least the end of much of the oil leaking into the Gulf of Mexico, may soon be delivered by a 98-ton steel box standing four stories tall, with a fresh coat of white paint.
The containment dome, as engineers are calling the structure, was built over the past week by a crew of more than two dozen welders working around the clock at a shipyard in Port Fourchon, La. The dome began its journey to the site of the ruptured well on Wednesday and arrived early on Thursday; the plan is to lower it by cable to the sea floor, 5,000 feet below the surface, and sit it atop the larger of the two remaining leaks.
The dome will not shut off the gushing well, which is still spilling an estimated 210,000 gallons of oil a day; the goal is just to keep some of the oil out of the water by capturing it and then funneling it to a drill ship, called the Discoverer Enterprise, waiting on the surface.
Think of the dome as an inverted cup gathering the gushing oil, and the drill pipe as a straw carrying it to the surface. If it sounds simple, it is not. Containment domes have been used in shallow water, but never at this depth.
“This is new technology,” said Bob Fryar, BP’s senior vice president for operations in Angola, who was brought to Houston for the engineering effort. “It has never been done before.”
BP was leasing the Deepwater Horizon oil rig from the owner, Transocean, when it exploded on April 20. BP officials said they hoped the dome would be working by Monday. If successful, it will capture about 85 percent of the oil spilling into the sea, officials said.
Petty Officer Connie Terrell, a spokeswoman for the Coast Guard, said on Thursday that weather conditions looked good for work to proceed on the containment-dome plan and on several measures being taken to combat the oil spill on the surface, including skimmming, controlled burns and spreading of chemical dispersants from airplanes. She said that crews conducted five successful burns on Wednesday, and expected to do the same on Thursday.
To construct the dome, BP turned to Wild Well Control, a contractor that helps battle oil well disasters. Wild Well Control works in a crisis relief niche that rarely attracts such international attention but often provides high drama.
Despite the hopes placed on the big box, questions remain: Can it withstand the conditions nearly a mile beneath the sea? Will ice plug up the pipe? Will bad weather interrupt the work? Will the combination of gas, oil and water mix uneasily — or explosively — on the ship above? Add global scrutiny to the mix, and you have some anxious engineers.
“I’m worried,” said David Clarkson, BP’s vice president for project execution, “about every part.”
BP engineers in Houston have sketched out models to account for what they expect to happen in this novel approach, along with several contingency plans. To combat the ice, which is likely to form as gas bubbles out of the oil, engineers will inject warm water along the pipe, and methanol into the oil.
But as so many other response efforts so far have shown, engineering problems that can be solved on the ground can prove perilously stubborn 5,000 feet underwater.
“We’ll learn a lot in the first three or four days,” Mr. Clarkson said.
The oil captured in the box can be stored on the Discover Enterprise — more than five million gallons in all — and then transferred to a standby vessel to be processed, Mr. Clarkson said. It may require special treatment at a refinery before it can be used, he said.
“We know that we can get the fluid into the drill ship,” Mr. Clarkson said. “We don’t know the exact conditions that will arrive in the drill ship.”
On Wednesday, for the first time in several days, cleanup crews were able to conduct a controlled burn in two of the most concentrated areas of the oil spill. Officials also said that engineers had shut off one of the three leaks from the damaged well late Tuesday night, although that did not appear to greatly diminish the overall flow.
Rear Adm. Mary E. Landry of the Coast Guard said the spill was close to the Chandeleur Islands. “But,” she said, “the heavy concentrations are farther offshore.”
BP continued to pursue other ways to bring the well under control soon. One idea being worked on by engineers, Mr. Fryar said, is called a top kill, and involves pumping a heavy liquid into the well to counter the pressure of the oil coming from below. That could stop the flow of oil.
Mr. Fryar said a second containment dome was being built to collect oil coming from a leak in the riser, directly above the blowout preventer. But putting the dome over that leak would make it extremely difficult to work on the blowout preventer, so no decision has been made to deploy it yet.
Engineers were continuing to try to get the blowout preventer to activate fully, which would shut off the flow from the well. But after two weeks of futility, Mr. Fryar said, “the possibility of that is lessened.”
Sam Dolnick reported from Baton Rouge, and Henry Fountain from Houston.
The 98-ton, four-story container that BP hopes will take care of the main oil leak was loaded onto a barge in Port Fourchon, La., on Wednesday in preparation for its journey to the well.
