BP has agreed under pressure to show a live feed of a procedure called a “top kill” designed to choke off the oil spill in the Gulf of Mexico, a US government source said yesterday.
The company plans to try to execute the tricky procedure as early as dawn today, local time, in the latest attempt to plug the devastating oil leak.
The “top kill” involves force-feeding heavy drilling mud and cement on to the leak.
BP started showing live feed of the leak itself after pressure from the Obama administration, but politicians said they had learned that the “top kill” procedure would not be shown.
A government official, speaking anonymously, confirmed yesterday that BP had agreed to keep the public video feed, but only under pressure from the administration.
The top kill tactic is routinely used above ground but has never been tried 5,000ft underwater. Crucially, if it is not done just right, it could make the leak worse.
The stakes for BP are high, with politicians losing patience with the company over its inability to stop the oil leak that sprang more than a month ago after an offshore drilling rig exploded.
Eleven workers were killed and by the most conservative estimate, 7million gallons of crude oil have spilled into the Gulf of Mexico, fouling Louisiana’s marshes.
“We want what everybody wants – to stop the flow as quickly as possible,” said BP spokesman John Curry.
“We understand the frustration and we just want to bring this to closure.”
Engineers were doing at least 12 hours of diagnostic tests yesterday, including checking five spots on the well’s crippled five-storey blowout preventer to make sure it could withstand the heavy force of the mud. A weak spot in the device could blow under the pressure, causing a new leak.
BP has been drafting plans for the top kill for weeks but had to delay it several times as crews scrambled to assemble the equipment at the site 50 miles off the coast.
A flotilla of rigs, barges and other heavy machinery stood ready yesterday.
A top kill has worked on above-ground oil wells in Kuwait and Iraq. BP chief executive Tony Hayward pegged its chances of success in this case at 60 to 70%.
But Kent Wells, a BP senior vice president, warned that engineers were speeding through a planning process that would normally take months and said the top kill could be delayed or scuttled if pressure readings were bad.
If all goes as planned, engineers will pump fluid twice as dense as water from two barges into two 3in-wide lines that will feed it into the blowout preventer.
Crews plan to pump it in at a rate of 1,680 gallons to 2,100 gallons a minute in hopes of counteracting the upward pressure of the oil gushing to the surface. They stockpiled some 50,000 barrels of heavy mud, a manufactured substance that resembles clay.
Mr Wells said it could take anywhere from a few hours to two days to determine whether the top kill was working.
If it succeeds, BP plans to follow through by injecting a stream of cement to permanently seal up the well.
Live video of the leak has been available online for the past few days, but Democratic Rep Edward Markey said he learned yesterday that the feed would be shut off while BP attempted the top kill.
If the top kill does not work, or makes the problem worse, BP will probably turn to a containment box resting on the seabed.
The company’s back-up plans include a junk shot, which involves shooting golf balls, tyre scraps, knotted rope and other assorted objects into the well to clog it up.
BP executives say the only guaranteed permanent solution is a pair of relief wells crews have already started drilling, but that will take at least two months.