BP added another untested tool to its arsenal of spill containment options on Wednesday, a tube that engineers hope to slip into a break in a leaking pipe to intercept some of the 5,000 barrels of oil spilling into the Gulf of Mexico each day. The new option, called a riser insertion tube, was unveiled as a possible alternative to a smaller containment dome introduced earlier this week for capturing oil escaping from the ruptured Macondo well. The well, under a mile of water, has been spitting crude and natural gas since the Deepwater Horizon rig exploded and sank more than three weeks ago, killing 11 rig workers.
BP, which has amassed hundreds of engineers, scientists and operations experts at its Houston command center to work on the problem, says it is devising numerous methods to contain the spill and permanently cap the well, so that when one fails, the next can be quickly deployed. The company said it was still evaluating which approach to try next — the insertion tube or the small containment dome referred to as a top hat. Both will be ready for use late today or early Friday, said Doug Suttles, BP's chief operating officer. As hearings into the causes of the deadly Deepwater Horizon accident continued in Louisiana and Washington on Wednesday, attention in Houston remained focused on containing and stanching the well flow as quickly as possible.
At the BP command center in west Houston, Interior Secretary Ken Salazar, in his third visit to Houston in a week, and Energy Secretary Steven Chu met with government and company workers who have been working on capping and containment efforts. “The best minds in the world have been brought here,” Salazar said. “We are confident and resolute that we will solve this problem.” BP's Suttles said industrial X-rays, which use gamma rays and radiography, are being used to look inside a 450-ton stack of valves, called a blowout preventer, that sits on top of the wellhead. The device, a last line of defense against a loss of well control, failed to operate properly when the Macondo well blew.
Engineers continue to study the possibility of clipping off a pipe that once connected the mechanism to the drilling rig and swinging in a new valve system to block the oil flow. Suttles said the company was trying to determine where the oil, believed to be flowing at only a fraction of its potential capacity, is being restricted. That will help it decide whether replacing the valves is feasible. Also in the works are plans to plug up the blowout preventer with rubber cuttings and other refuse in a procedure called a junk shot. Suttles said a large manifold that will deliver the high-powered series of injections already has been installed on the seabed. The process will later involve injecting heavy drilling fluids and cement into the well bore to permanently seal it. The system should be ready by late next week, Suttles said.
Fresh off the drawing board, the riser insertion tube will attempt to insert pipe tipped with rubber flaps into the leaking pipe, to capture the oil and funnel it to the surface for collection. The flaps are designed to prevent seawater from entering the system and to keep methane hydrates from forming. The icelike hydrates, created when natural gas and water mix at certain temperatures and pressures, derailed an earlier attempt to curtail the leak with a 4-story containment box when the apparatus became plugged with slush. Suttles said the new riser insertion tube was expected to arrive at the well site Wednesday evening.
The top hat, a separate 5-foot-tall containment dome resembling a large oil drum, is now sitting on the seabed. BP said it has received permission from the Environmental Protection Agency to flush the mini-dome with methanol, a kind of antifreeze. While most of the spill still remained offshore on Wednesday, Coast Guard Rear Adm. Mary Landry said a 100- to 200-yard stretch of soft tar balls was confirmed near South Pass in Plaquemines Parish, La., and viscous oil matter had landed on Whiskey Island on the south end of the Chandeleur islands, though crews were able to clean that up.