Once that intersection occurs sometime after Labor Day, BP is expected to use mud and cement to plug the blown-out well for good from the bottom.
The April 20 rig explosion killed 11 workers and led to an estimated 206 million gallons of oil spewing from BP’s well.
As the cap was slowly removed at 4:25 p.m. Central Daylight Time, there was no sign of anything spewing into the water. Undersea video feeds showed the cap suspended in the water. BP planned to place the cap nearby on the seafloor.
With the cap gone, the old blowout preventer can be removed and a new one put in place before engineers try to seal the well underground.
Once the blowout preventer is removed, a lot will be riding on the stability of a plug that was created when mud and cement were pumped into the well from the top.
But Rice University engineering professor George Hirasaki said there is still uncertainty about whether the cement settled everywhere it needed to in order to keep oil and gas from finding its way up.
“Just because it didn’t flow when they tested it doesn’t mean the cement displaced all of the oil and gas,’’ Hirasaki said.
That’s why many people have felt that finishing a relief well and pumping mud and cement in through the bottom would be the ultimate solution to the crisis, said Hirasaki.
The government still plans on ordering BP PLC, the majority owner of the well, to do the so-called bottom kill operation. But it believes the wisest course is to install a new blowout preventer first to deal with any pressure that is caused when the relief well intersects the blown-out well.
