Washed It!

A top BP official said Sunday that the full seal on top of the company’s well in the Gulf of Mexico could remain in place for a few weeks until the well is permanently plugged by a relief well deep underground — meaning there is a chance, if all goes well, that the last of the oil has flowed into the gulf.

The well was fully sealed Thursday using a massive, custom-built cap, which stopped the oil flow for the first time in 85 days. But government and other experts worried about the consequences of the seal: If the well’s underground pipes were cracked, they said, the seal could force more oil out of the cracks and up to the ocean’s surface, creating multiple new leaks.

In an attempt to see if the well was cracked, BP and federal officials began a 48-hour pressure test inside the well Thursday. On Saturday, Thad Allen, the national leak response leader, announced the test would be extended for another day so experts could continue to study the results.