"We do believe the risks are small for any hydrocarbon release," Allen said during a teleconference in Houston.
Allen warned that with the cap and blowout preventer removed, engineers will be relying on the strength of the plug created when cement was pumped in from the top of the well.
"The goal there will be to secure the annulus as quick as we can," he said.
He says a break in the weather is expected within the next 24-36 hours, allowing engineers to proceed with the removal of the cap and then the raising of the blowout preventer.
Government investigators are waiting to take possession of the failed blowout preventer, which is a key piece of evidence in ongoing probes of the disaster.
- Meanwhile, BP said it has spent more than $5 million a week on advertising since the Gulf oil spill began - more than three times the amount it spent on ads during the same period last year.
- BP told the House Energy and Commerce Committee that it spent a total of $93 million on advertising from April to the end of July. The company says the money was intended to keep Gulf Coast residents informed on issues related to the oil spill and to ensure transparency about its actions. The increased spending was largely targeted at TV, newspapers and magazines. A small portion was directed to the Internet.
- A federal judge who overturned the Obama administration's initial six-month moratorium on deepwater oil drilling has rejected the government's bid to have the court challenge thrown out.
- Government lawyers argued that a lawsuit filed by several offshore service companies over the May 28 moratorium was moot because the Interior Department imposed a new, temporary drilling ban on July 12.
- But U.S. District Judge Martin Feldman rejected that argument Wednesday, saying the second moratorium "arguably fashions no substantial changes" from the first.
The Associated Press contributed to this report.