With that leak sealed, the plan is to inject heavyweight "kill mud" into the lower part of the blowout preventer, followed by cement that will effectively entomb the well.

WSJ: Spill Fight Shows Progress

For instance, as I talked about yesterday, in a normal process, there are choke and kill lines that are supposed to -- that in some cases will force mud, as they did under the top kill, into the blowout preventer.

WHITEHOUSE: Press Briefing

This is what this data is supposed to monitor, but the well flow evidence would appear to have been ignored, because at this point the BP rig supervisors should have gone to a well kill operation and started to pump heavy mud back into the well bore to restore the primary control mechanism.

WSJ: The Oil Disaster Is About Human, Not System, Failure

We did the top kill -- we were able to force mud down the wellbore to the point where we actually suppressed all the oil.

WHITEHOUSE: Daily Press Briefing

The solutions for -- the solution with the top kill, first in stabilizing the well with heavy drilling mud, ultimately would lead to the cement capping of that well.

WHITEHOUSE: Press Briefing

From that point, it will take another few days to permanently seal the well with mud and cement from below in what's called a "bottom kill" procedure.

CNN: STORY HIGHLIGHTS