Like that'll work

Henry Fountain has an article in The New York Times about the 'junk shot' solution to the Gulf leak:

Can golf balls save the gulf? That question hangs in the air here at a BP crisis center, as hundreds of engineers and scientists work to cap the undersea well that for more than three weeks has spewed oil into the Gulf of Mexico.
Officials with BP and other companies involved in the effort, who discussed the plans in detail at some of the operations rooms, said the best of several options included a “junk shot”, which could be tried within the week. The method involves pumping odds and ends like plastic cubes, knotted rope, even golf balls, into the blowout preventer, the safety device atop the well.
As Rube Goldberg as it sounds, the basic techniques are straightforward and have been used successfully on out-of-control wells around the world. “The problem here is they all have to be executed 5,000 feet under the water,” said Pat Campbell, a well-control expert who is working with BP on the project.
The enormous depth, with its low temperatures and high pressure, greatly complicates planning and execution and could cause the approach to fail, just as earlier stopgap efforts like a large containment dome did not work. One potential problem, the officials said, is the presence of several right-angle turns in the plumbing of the blowout preventer where the objects could become stuck.
The goal of the junk shot is to force-feed the preventer, the device that failed when the disaster unfolded on 20 April, until it becomes so plugged that the oil stops flowing or slows to a relative trickle. That would be followed by a “top kill”, the pumping of heavy mud into the well to overcome the pressure of the rising oil, followed in turn by cement that would permanently seal it. The officials expressed optimism the methods would succeed; if they did not, they said, there was little risk of making the situation worse until a relief well was finished several months from now.
“Where you want to end up is, you want to have killed the well,” said Kent Wells, a BP senior vice president who is overseeing much of the planning. Mr. Wells bridled at the term “junk shot”, which he said betrayed the seriousness of the effort. “We don’t pump junk,” he said. The technical term, he noted, is “bridging agent”, because the materials are meant to bridge gaps inside the blowout preventer where the oil is flowing.
As with all the other efforts to stop or contain the leak, the underwater work would be done by robotic submersibles. They are operated by pilots aboard surface ships above the well, but the work is coordinated in a darkened room in the Houston center, one wall of which is taken up by live video from the craft.
On Friday, seven submersibles were on duty, and the video feed from an eighth was a blank green screen, indicating it was out of service. Technicians and engineers were seated at worktables arranged in a square; one of them, facing the video screens directly, served as a kind of mission controller, speaking to the operators in the Gulf.
The room was one of many used for the crisis operation, on the third floor of a BP office building west of downtown. The space is normally used for managing the shutdown of drill rigs when a hurricane approaches. But the operation soon became so big that it spilled over into an adjacent training center. People work in shifts around the clock on various tasks: the containment team, the “well kill” team, and the robot team. Because there is no proper cafeteria, lines for hot food form at mealtimes in the halls around small pantries.
“This is the biggest response effort that we could ever relate to,” Mr. Wells said.
Mr. Campbell, executive vice president of Superior Energy Services, who used junk shots in the Kuwaiti oil fields after the 1991 Persian Gulf war, among other places, said the technique was far easier on land. Workers could try one material— short pieces of lamp wire were a personal favorite, he said, because they contain both strong copper and flexible plastic— and if that did not plug the gaps, quickly try something else that was bigger and harder. “If you were on land, you’d hear a big thwap and it just means it sheared and went through,” he said.
But in the abyss no one can hear junk shear, and everything must be planned in advance. Materials had been chosen and tested over the past several weeks, and two 20-foot sections of pipe filled with them are now on the seabed. When various plumbing jobs are finished on and around the blowout preventer, the material will be ready to be injected, although Mr. Wells said they may decide to pump just mud first and see if that works.
“There are two things at work here,” Mr. Campbell said. “One is the science, and the other is based on our historical experience with what’s worked.”
The junk shot technique is so common that it was suggested “a matter of hours after we first assembled” in the wake of the explosion aboard the Deepwater Horizon drilling rig, said Mark Mazzella, a BP well-control expert. But the logistics of designing, testing, assembling, installing, and adapting the needed equipment are such that it has taken weeks to be on the verge of trying it, he said. Choreographing the work of so many submersibles is a challenge, because they are tethered to large ships on the surface.
“You’ve got a big traffic jam above that well,” Mr. Mazzella said. “You’ve got to have vessels in here to install all of that. It’s just not like when you park them in a parking lot.” So one of the rooms in the crisis center is used for “simultaneous operations,” coordinating the surface movements of all the ships.
Since the disaster began, engineers and technicians had been trying to activate hydraulic rams on the blowout preventer that, in normal operation, are used to cope with pressure surges in a well by sealing it temporarily. It is unclear why this preventer did not work when the blowout occurred on 20 April.
Mr. Wells said diagnostic work on the device, including gamma-ray inspection, strongly suggested that many of the rams were closed, but that an upper one, called a blind shear ram, was letting oil through. “For whatever reason, it’s not holding,” he said. The material for the junk shot would be introduced below this ram and the force of the oil stream would drive the material into the gaps.
Mr. Mazzella said if the first two pipes full of material did not work, submersibles would retrieve them and they would try again. “If we have to pull this and reload it,” he said, “we’re going to have a cannon loaded up for the next one.”