Effort to place dome over oil well dealt setback, BP says

The effort to place a containment dome over a gushing wellhead was dealt a setback when a large volume of hydrates - crystals formed when gas combines with water - accumulated inside of the vessel, BP's chief operating officer said Saturday.

The dome was moved off to the side of the wellhead and is resting on the seabed while crews work to overcome the challenge, Doug Settles said.

Suttles said the gas hydrates are lighter than water, and as a result, made the dome buoyant. The crystals also blocked the top of the dome, which would prevent oil from being funneled to a drill ship.

"What we had to do was pick the dome back up, set it over to the side while we evaluate what options we have to actually try to prevent the hydrate formation or find some other method to try to capture the flow," Suttles said.

He said two options officials are looking at are heating the dome or adding ethanol to dissolve the hydrates.