BP Begins Cementing of Oil Well

Retired Coast Guard Adm.

Thad Allen has approved the cementing, but he stresses that BP must still go ahead with a second, ongoing well-plugging effort that involves injecting mud and cement down a relief well, which is expected to be completed by mid-August. "I made it clear that implementation of this procedure shall in no way delay the completion of the relief well," Allen said.

The U.S. official overseeing the response to the spill, retired Adm. Thad Allen, has given BP a green light to pour cement on top of the 2,300 barrels of heavy drilling mud already sent down the well. The mud drove oil back into the reservoir in an operation known as a "static kill."

But Allen said BP should follow that with a second well-killing procedure that has been in the works as sort of an insurance policy -- pouring additional mud and cement through a relief well that's expected to be ready in mid-August.