(The following is a reformatted version of a press release
issued by BP and received via electronic mail. The release was
confirmed by the sender.)
BP Completes Cofferdam Sealing Operation in Gulf of Mexico
25 October 2012
After confirming Macondo wells secure, ROVs cap and plug
containment device identified as probable source of recent
HOUSTON - BP has capped and plugged an abandoned piece of subsea
equipment known as a cofferdam that is thought to be the source
of a recently spotted surface sheen near the Mississippi Canyon
252 lease block in the Gulf of Mexico.
The cofferdam is an 86-ton, steel container that was lowered
over a leaking drill pipe during the Deepwater Horizon response
in 2010 in an attempt to capture the oil and funnel it to the
surface. It now sits on the sea floor roughly 1500 feet away
from the Macondo well.
With U.S. Coast Guard approval, BP on Tuesday deployed Remotely
Operated Vehicles (ROVs) and successfully installed a 750-lb cap
over an opening on the cofferdam known as the stovepipe and
secured it in place with clamps. ROVs also successfully inserted
plugs into four small connection ports on the top and sides of
the cofferdam. The entire operation lasted approximately 26
Initial visual inspections of the cap and plugs have observed no
oil droplets emanating from any of the openings. BP will now
monitor the sheen by satellite for several days to confirm that
the cap and plugs are secure.
Last week, a separate ROV survey confirmed once again that the
Macondo well and its two associated relief wells were not
leaking. It marked the third time since the Macondo well was
permanently sealed in September 2010 that well integrity was
confirmed by visual inspection.
The latest survey came after BP and Transocean received a Notice
of Federal Interest from the U.S. Coast Guard to determine
potential sources of the recent sheen. It focused on the wells,
wreckage and debris related to the 2010 Deepwater Horizon
BP reported the sheen on Sept. 16 to the National Response
Center. The Coast Guard has since determined it is not feasible
to recover the sheen and that the sheen does not pose a risk to
The ROV survey last week identified small, intermittent drops of
oil coming from the cofferdam’s stovepipe and one of the
connection ports, which BP concluded was the probable source of
the sheen. A mixture of oil and slushy methane hydrates was
trapped inside the cofferdam during the response.
The operation to cap and plug the cofferdam was performed in the
presence of the FOSC, as well as representatives from the
Interior Department’s Bureau of Safety and Environmental
Enforcement (BSEE) and Bureau of Ocean Energy Management (BOEM)
and representatives of the Gulf states.
Name: BP US Press Office
Phone: (281) 366-4463
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