BP works to swap out oil well cap in undersea maneuver
Sunday, July 11, 2010
BP took one step back Saturday in order to take two steps forward in its struggle to tame the gushing Macondo oil well at the bottom of the Gulf of Mexico, removing a cap that was catching some of the oil in the hopes of replacing it with one that would capture most or all of the leaking crude.
The effort was broadcast live via Web video cameras attached to remotely operated vehicles at the sea floor, revealing movements as frenetic as the final minutes of a close soccer match and as slow-motion as a space walk. Ungainly robotic arms and claws lassoed tools, wrestled the first of six giant bolts off a piece of broken pipe and nudged devices into position while a brightly illuminated brownish geyser of oil and gas surged upward.
The stakes are high for BP, the Obama administration and the Gulf of Mexico. For a day or two, the damaged wellhead will gush anew -- with the estimated 15,000 barrels of oil a day that had been captured by the old cap now flowing freely. But if all goes well, said BP senior vice president Kent Wells, additional ships and a sturdier cap with a tighter seal will be in place in four to seven days. The new system would capture most or even all of the oil leaking from the damaged BP well. Ships would also be able to disconnect from the new system faster in the event of a hurricane and reconnect faster afterward.
"We're on plan," Wells said in a conference call Saturday evening.
The old cap was removed at 12:30 p.m. local time Saturday, uncorking the steel pipe on top of the blowout preventer on the sea floor, one mile below the surface. Although the amount of oil flowing into the Gulf of Mexico abruptly increased, a new ship on the scene, the Helix Producer I, is being hooked up to lines that should enable it to capture 25,000 barrels a day of oil -- more than offsetting the capacity lost by the removal of the old cap.
The Helix owners said the ship was connected overnight Friday to a free-standing riser pipe and should be ready to start sucking up oil and gas by Sunday afternoon. It will separate the oil and transfer it to a tanker called the Loch Rannoch. With the extra collection capacity, BP would no longer need to burn oil channeled to the surface.
Eyes on the weather
BP and its contractors are racing against the next storm, which could throw plans off course. For the next week to 10 days, though, the weather and seas are expected to be calm and the company got the go-ahead from the national incident commander, retired Coast Guard Adm. Thad W. Allen, to push ahead changing the cap without waiting for the Helix Producer to be hooked up.
The operation is not expected to affect another system that is collecting about 10,000 barrels a day.
The suspense is heightened by BP's poor track record; several earlier efforts to slow or stop the leak have failed.
The new "total sealing cap" -- nearly 160,000 pounds and more than 30 feet tall -- would be installed in two pieces over the next four to seven days; on Saturday it was still on one of the boats on the surface. The cap has many of the same components as the blowout preventer that failed to close the well after the accident. Three rams would allow the company to seal the well from the top if it chose to do so. BP and its contractors have been working on the cap since the days after the accident and designed it to be smaller than a standard blowout preventer, keeping its weight down to better withstand the storm season.
The new cap can also endure high pressure from the well, enabling BP to test the conditions inside the hole by pushing back against the oil and gas surging from below -- estimated at 35,000 to 60,000 barrels a day.
The live video feeds from the mile-deep construction site showed a dance of machines that was choreographed from surface ships. Robot arms with different types of metal claws slowly grabbed rope leashes attached to tools and equipment in a basket on the ocean floor and carried them over to the collection of valves and equipment atop the wellhead. At times bright sea creatures with tentacles floated in front of the camera.