BP Caps Oil Spill

After more than three months of trying, and an afternoon of careful maneuvering, it appeared Monday evening as if BP engineers had finally capped the ruptured well in the Gulf of Mexico that has created the United States' worst-ever environmental disaster.

The murky live pictures, broadcast on BP's website, appeared to show the "Top Hat 10" device hovering and then lowering completely over the well that had been gushing a mile (1,600 meters) beneath the surface.

After the valve -- designed to be a much tighter fit than its predecessor, so to eventually completely contain the oil -- is screwed into place, BP plans to perform an integrity test lasting between six and 48 hours.

Under that timeframe, the government and BP will likely decide whether the valves can stay shut -- and the well is sealed -- by Thursday at the latest.

The breakthrough came after 13 weeks, in which up to half a million barrels of crude has poured into the Gulf, and after successive weeks of "top kills," "top hats," "junk shots" and other oddly-named procedures meant to choke off the flow of oil.

BP said however that with this latest device, they finally found one that was likely to contain all of the oil for the first time since the sinking of the Deepwater Horizon rig on April 22.

The round-the-clock work on installing the new containment cap began at midday on Saturday when the old, less efficient cap was ripped off a fractured pipe a mile down on the sea floor by robotic submarines.

The new containment system is designed so that it can be disconnected and reconnected more easily in the case of a hurricane and has a built-in device that should give the first precise estimate of the overall flow.

Suttles also announced that by late Monday, a third container ship, the Helix Producer, could be attached to the oil well's blowout preventer, allowing BP to siphon an additional 20,000 to 25,000 barrels a day to the surface.

BP says the Helix Producer will raise capacity to between 60,000 and 80,000 barrels a day, enough to contain the whole leak.

The effort to attach the vessel had been delayed after engineers over the weekend encountered leaks and problems with the hydraulic system, which now have been resolved, Suttles said.

The former Coast Guard commander who is heading the government's response effort on Monday hailed the progress made over the weekend in stopping the gusher.

"This could lead to the shutting of the well," Admiral Thad Allen, told television Monday.

He added that officials are also considering sealing the well with cement, depending on the outcome of an "integrity test" -- an analysis on the amount of pressure building within the containment cap.

"This containment cap will have the ability to actually close down valves and slowly contain all the oil. Once we do that, we'll know how much pressure is in the well," Allen told CNN during a round of morning television interviews.

"It could tell us that the well is with holding the pressure and we can shut the well in or just cap it, if you will. Either way, those are two pretty good outcomes," Allen said.

Officials said work is continuing in the meantime on two relief wells to permanently seal the ruptured pipeline. That would likely occur in mid-August when the first of the two wells is due to be completed, allowing drilling fluids and cement to be injected into the well.

That operation could be ready "towards the very end of this month," Suttles said.

Meanwhile, a seven member presidential commission was starting its work Monday, meeting in New Orleans as it prepared a report to be delivered in six months' time on the cause of the oil rig disaster and how to prevent a similar occurrence in the future.

The feverish work in the Gulf -- on the containment caps, relief wells, and skimming and burning cleanup efforts -- come as officials race to take advantage of a stretch of fine weather in the midst of the Atlantic hurricane season.

Oil has washed up on beaches in all five Gulf states -- Texas, Louisiana, Mississippi, Alabama and Florida -- forcing fishing grounds to be closed and threatening scores of coastal communities with financial ruin.

BP said Monday the disastrous oil leak in the Gulf of Mexico has cost $3.5 billion, although the petroleum giant's shares rose sharply on reports it was poised to sell some of its assets.

About 46,000 personnel, more than 6,400 vessels and dozens of aircraft were engaged in the expensive response effort, BP said.