HOUSTON, Oct. 25
10/25/2012
By Paula Dittrick
OGJ Senior Staff Writer
BP PLC has capped and plugged an abandoned piece of subsea equipment known as a cofferdam that was believed to be the source of a recent surface oil sheen observed near Mississippi Canyon 252 Block in the Gulf of Mexico off Louisiana.
The cofferdam is an 86-ton, steel container that was lowered over a leaking drill pipe during oil spill response efforts in 2010 following the blowout of the deepwater Macondo well. In 2010, that particular containment dome was unsuccessful, and the equipment was moved and left 500 m from the wellhead.
With US Coast Guard approval, BP deployed remotely operated vehicles on Oct. 23 to install a 750-lb cap over the stovepipe on the cofferdam and secured the cap in place with clamps. ROVs also inserted plugs into four small connection ports on the top and sides of the cofferdam. The operation lasted 26 hr.
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