With its well-killing effort reported to be going "extremely well," BP now plans to start pouring concrete into the crippled well in the Gulf of Mexico.
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."
BP expects to start pumping the cement Thursday.
But Allen said BP should follow that with a second well-killing procedure which 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.
"Based on the successful completion of the static kill procedure and a positive evaluation of the test results, I have authorized BP to cement its damaged well," Allen said in a statement. "I made it clear that implementation of this procedure shall in no way delay the completion of the relief well."