BP begins slow process of testing new cap on well
NEW ORLEANS — In a potentially pivotal moment in the Gulf crisis, BP was preparing Tuesday night to begin closing valves in a slow and methodical process that could finally choke off the geyser of crude at the bottom of the sea after three gloomy months and up to 180 million gallons spilled.
A new, tighter-fitting cap was lowered over the blown-out well Monday. The next phase was to shut the openings in the 75-ton metal stack of pipes and valves gradually, one at a time, while watching pressure gauges to see if the cap would hold or any new leaks erupt.
The operation could last anywhere from six to 48 hours.
Officials stressed there were no guarantees, and they urged patience from Gulf Coast residents.
“They ought to be interested and concerned, but if they hold their breath, they’ll run out of oxygen,” said retired Coast Guard Adm. Thad Allen, the government’s point man for the Gulf of Mexico crisis.
If the new cap works, it will enable BP to stop the oil from gushing into the sea, either by holding all the oil inside the well machinery like a stopper or, if the pressure is too great, channeling some though pipes to as many as four collection ships.
BP engineers planned to shut off pipes that are already funneling some oil to two ships, to see how the cap handles the pressure of the crude coming up from the ground. Then they planned to close, one by one, three valves that let oil pass through the cap.
Experts said stopping the oil too quickly could blow the cap off or further damage the well.
Scientists will be looking for high pressure readings of 8,000 to 9,000 pounds per square inch. Anything lower than 6,000 might indicate previously unidentified leaks in the well.
“What we can’t tell is the current condition of the wellbore below the seafloor,” Allen said. “That is the purpose of the well integrity test.”
If the cap cannot handle the pressure, or if leaks are discovered, BP will have to reopen the valves and let some of the oil out. In that case, BP is ready to collect the crude by piping it to as many as four vessels on the surface.
The cap is just a stopgap measure. To end the leak for good, the well needs to be plugged at the source. BP is drilling two relief wells through the seafloor to reach the broken well, possibly by late July, and jam it permanently with heavy drilling mud and cement.
The Q4000, right, burns off oil collected from the site of the Deepwater Horizon oil spill in the Gulf of Mexico on Tuesday. A new cap is in place that could stop the underwater gusher.