With the Coast Guard’s blessing, BP on Saturday removed the containment cap that for more than a month has been collecting some of the oil spewing from a collapsed Gulf rig, in preparation for installing a new sealing device that could allow the company to contain more oil or possibly stop the flow entirely.
“We are progressing on plan toward installing the sealing cap. We have removed the LMRP (lower marine riser package) cap,” BP Senior Vice President Kent Wells said in a briefing Saturday evening.
The containment cap, has been in place since June 3 and has been collecting about 15,000 to 16,000 barrels of oil a day. Removing the cap temporarily allows that oil to flow into the Gulf of Mexico alongside the thousands of gallons that BP has been unable to capture. “There’s a brief period here where we’ll have more flow,” Wells said.
But BP hopes it will recapture at least the same amount of oil starting today, when it begins siphoning oil to the Helix Producer, a ship that was connected to an elaborate system of underwater oil-collection pipes on Friday. The Helix Producer can handle up to 25,000 barrels of oil a day, although it will take about three days for the ship to hit its capacity, Wells said.
Meanwhile, another ship, the Q4000, continues to capture and burn about 8,000 barrels of oil each day, in addition to burning off natural gas.
BP has brought additional oil-skimming vessels into the area to try to scoop up the extra oil, and it is injecting dispersants at the wellhead.
The new “sealing cap” or “capping stack” that BP hopes to install in the next three to six days could allow the company to capture all of the oil coming out of its renegade well and send it up to a network of vessels, or possibly even to shut down the well entirely without pumping oil to ships.
Even if BP manages to seal the well this week, however, it will proceed with a plan to inject cement into the original well to permanently cap it. Work continues on drilling relief wells through which the cement would be injected. They are not expected to be finished until late July at the earliest, and perhaps not until mid-August.
BP had to take a number of steps to prepare for installing the capping stack, which is actually a new blowout preventer with a cap on top. The device is about 18 feet tall and weighs about 150,000 pounds.
In order to get ready to install it, BP first had to correct a lean that had developed in the equipment at the top of the blown-out well.
BP officials have said the flex joint at the top of the well’s blowout preventer tilted when the riser pipe fell over as the Deepwater Horizon rig exploded and sank in late April, killing 11 workers and unleashing the oil. But some engineers have said the well also could have developed a lean if the ground around it has been eroded by an underground oil leak, making the well less stable.
Wells said the flex joint was leaning by about 3 degrees, so BP used hydraulic jacks to straighten it and then supported the assembly with giant blocks. “We have that all perfectly aligned, so that’s done,” Wells said.
The next thing BP must do is to unscrew the flange that was beneath the original cap. The company built a special device to unscrew the six bolts that hold the flange together, and it began working on the first bolt Saturday evening.
In case the company runs into problems unscrewing the flange, it built a backup “flange-splitting tool” to pry the two halves of the flange apart.
At the request of the U.S. Department of Energy, the new capping stack that BP will install this week is equipped with sensors to measure the flow of oil from the well accurately. Current estimates suggest that the well is spewing 35,000 to 60,000 barrels of oil a day.
On Friday, BP collected about 24,790 barrels of oil, with 16,540 being captured and another 8,250 barrels being flared, or burned. BP also flared about 57.3 million cubic feet of natural gas.
Since containment operations began, the company has captured an estimated 756,000 barrels of oil.
The first relief well is at 17,810 feet, and is only about 6 or 7 feet away from the original well. Wells said BP will drill for another 60 to 70 feet. Meanwhile, it is sending out electronic signals to search for the exact position of the original well, which is only about 9 inches wide, and is positioning the drill to intercept the well at the proper angle.
The second relief well is at 15,963 feet. Wells said BP will soon stop work on it so it will not throw off the electronic signals being sent from the first relief well to the original well.