Here's the scoop: BP's attempt to stop the oil spill using the "Top Kill" method has failed.
How do I know?
Well, as the New York Times notes:
BP officials, who along with government officials created the impression early in the day that the strategy was working, disclosed later that they had stopped pumping the night before when engineers saw that too much of the drilling fluid was escaping along with the oil.
Indeed, BP stopped pumping "mud" for more than 16 hours (the material gushing out of the leaking riser didn't stop during that time).
Basically, BP has failed in trying to drive enough "mud" down the well to provide enough weight to tamp down the oil gushing out. It didn't work.
Indeed, BP's "re-starting" Top Kill really means that Top Kill Version 1.0 was tried and failed, and now BP will try Top Kill Version 2.0 - adding "junk" to the mix.
Unless BP can get very lucky and plug the holes with miscellaneous junk, Top Kill 2.0 won't be any more effective than Operation Sombrero.
As the Guardian explains:
Doug Suttles, BP's chief operating officer, insisted that the operation was going to plan, but admitted: "What we do know is that we have not yet stopped the flow."
He said BP engineers would soon use additional materials to try to plug the well, suggesting heavy mud deployed so far would not work on its own.
And the Guardian's oil spill blog (a great resource which I just discovered) notes:
6pm CDT: Doug Suttles makes an appearance on CNN ....
Asked by CNN what had happened, Suttles said: "Too much of the mud is exiting the riser as opposed to going down the well bore." This could be fixed in several ways, including the infamous "junk shot", using a more viscous mud type, or finally restarting pumping at very high rates.
7.30pm CDT: The Washington Post has more details on BP's stop-start top kill process, and mentions that BP is considering a "junk shot" tonight:
Doug Suttles, BP's chief operating officer, said that on Wednesday the company had blasted high-pressure mud into the leaking well two times, trying to force the oil down in a procedure compared to using one firehose against another.
After doing it twice, Suttles said, the company stopped about midnight Wednesday, and spent Thursday assessing the plumes still shooting out of broken machinery. He said that company officials believed the two efforts had probably made some progress.
"I think some people believe it has. Some people believe it's less obvious it has," Suttles said. "What we do believe we've done is successfully pumped some mud, some of this drilling mud, into this wellbore."
But, Suttles said, oil was still coming out, despite these efforts: "What we do know is that we have not yet stopped the flow."
He said the company would try the procedure again Thursday evening and might add chunkier debris such as rubber balls to the mix in hopes of clogging the leaking pipe. That procedure is known as a "junk shot."