Aug 19, 2010 10:59 AM by Melissa Canone
WASHINGTON — BP aims to permanently seal the ruptured Gulf of Mexico oil well in the second week of September, a US official said Thursday, as pressure concerns further delayed final "bottom kill" operations.
"We should be looking somewhere in the week after Labor Day," US spill chief Thad Allen told CNN television, referring to the September 6 US national holiday.
The ruptured Macondo well was capped on July 15 and earlier this month BP engineers performed a "static kill" which plugged it with heavy drilling fluid and then sealed it with cement.
However, there is an area behind the well and the outer well bore called the annulus which must still be sealed off from the reservoir miles below the surface of the Gulf of Mexico.
A relief well has been drilled and is poised to intercept the stricken well but experts are concerned that drilling into the annulus could lead to pressure problems at the top of the well.
After days of tests, Allen told CNN they had agreed the best course of action is to replace the giant blowout preventer valve with a new one.
Allen said BP would start by "flushing out the current blowout preventer.
"Then (we will) actually move to put a new blowout preventer on, and then do the 'bottom kill.' This will ensure that we can withstand any pressures that may be generated."
Allen and BP had originally pointed to mid-August as the target date for shutting down the Macondo well once and for all, although Allen had until Thursday declined to give a new timeline as that deadline passed.
Two storms in the Gulf -- one in late July and another in mid-August -- delayed by several days the drilling of the relief well.
Allen vowed to finish the job, telling MSNBC television: "We're making sure that we put a stake in the heart of this monster."
"We've been working a week and a half with BP on a way forward and I have been equivocating on the timeline for a good reason, because we needed to take concrete steps to kill this well."
The spill began after an April 20 explosion on the offshore Deepwater Horizon oil rig which killed 11 workers. The BP-leased rig sank two days later, causing a pipe to rupture and oil to gush into the Gulf of Mexico.
Some 4.1 million barrels of oil spewed into the water before BP could fully cap the ruptured well 5,000 feet (1,500 meters) below the surface and 50 miles (80 kilometers) off the coast of Louisiana.
Hundreds of miles of fragile coastal wetlands and once-pristine beaches stretching from Texas to Florida were sullied and the region's multi-billion dollar fishing and tourism industries were crippled.