Here is an explanation of BP’s “static kill” tactic being used to close the well from today’s Washington Post:
The "static kill" is part of a double whammy of mud and cement that would hit the runaway Macondo well high and low in quick succession. The static kill starts at the top, firing the mud and possibly cement into the blowout preventer that sits on the wellhead.
That effort, which would take a day or two, would be followed in another five to seven days by the start of the more laborious "bottom kill," in which mud and cement will be injected into Macondo through a relief well that engineers began drilling at the beginning of May.
If all goes perfectly, the one-two mud punch will literally be overkill. The static kill will terminate Macondo, and the bottom kill will be more like a confirmation test, akin to poking the body to make sure it's dead.
But optimism has been a dangerous attitude throughout the oil spill disaster, and the federal point man for the spill response, retired Coast Guard Adm. Thad Allen, has warned against complacency. "We should not be writing any obituary for this event," Allen said late last week.