An audacious plan

The root of the problem appears to be a towering stack of heavy equipment 5,000 feet below the surface of the gulf known as a blowout preventer. It is a steel-framed stack of valves, rams, housings, tanks and hydraulic tubing that is designed to seal the well quickly in the event of a burst of pressure. It did not work when the Deepwater Horizon oil rig exploded.

Mr. Fryar and Charlie Holt, BP’s drilling operations manager for the gulf, described an audacious plan to confront the blowout preventer problem. In this approach, they would seal the well by cutting the riser at the wellhead, sliding a huge piece of equipment called the riser package out of the way and bolting a second blowout preventer atop the first one

The risk in attempting such a maneuver — which would be performed, as all the undersea work has been, by robotic submersibles tethered to support ships 5,000 feet above — is that the pressure of the oil rising from the well could be overwhelming, and the well could gush oil at a far higher rate. Mr. Fryar said a pressure gauge would be installed soon to determine if it was safe to attempt the operation.