Engineers on Thursday removed a temporary cap that stopped oil from gushing into the Gulf of Mexico from BP’s blown-out well in mid-July. No more oil was expected to leak into the sea, but crews were standing by with collection vessels just in case.
The cap was removed as a prelude to raising the massive piece of equipment underneath that failed to prevent the worst offshore oil spill in US history.
The government wants to replace the failed blowout preventer first to deal with any pressure that is caused when a relief well BP has been drilling intersects the blown-out well.
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 780 million liters of oil spewing from BP’s well.
BP was leasing the rig from owner Transocean.
As the cap was slowly removed in late afternoon, hours after a pipe latched to the top of it, there was no sight of anything spewing into the water. Undersea video feeds showed the cap suspended in the water. BP planned to place the cap on the seafloor nearby.
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 for good deep 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 down into the well from the top. Essentially, the pressure exerted downward served to counter the pressure coming up.
However, 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.
BP said the cost of dealing with its oil spill in the Gulf of Mexico had risen to US$8 billion as the oil giant prepared to release the findings of an internal probe into the causes of the disaster.
BP published figures yesterday which showed that since it capped the well on July 15, it had spent around US$90 million a day, in line with the spend rate while the well was gushing over 60,000 barrels per day into the sea.
Analysts had expected that BP’s costs would fall off sharply after the well was sealed for good by drilling a relief well into the base of the blown out well and pumping it full of concrete.
However, a successful effort to install a temporary cap on the well delayed work on the relief well, which BP said on Friday was now likely to be completed in the middle of this month.
After this, the armada of rigs and ships, some of which cost US$1 million a day to operate, working at the drill site will no longer be needed.
“Until it’s killed for good, you can’t move the kit away,” one BP source said.
However, BP also indicated that there had been no major uptick in the amount of money being handed out to those affected by the spill, under the new independent compensation system, established in a deal with the White House.
On average, since Aug. 23, the Gulf Coast Claims Facility, a US$20 billion fund headed by former government pay Czar Ken Feinberg, paid out around US$3.5 million per day, broadly in line with the amount paid before BP handed over responsibility for administering claims.