OGJ Senior Staff Writer
HOUSTON, Sept. 20 -- The deepwater Macondo well, source of a massive oil spill in the Gulf of Mexico, has been killed, operator BP PLC said Sept. 19 in a long-awaited announcement after scientists and engineers confirmed both the casing and annulus of the well were sealed by cement.
An Apr. 20 blowout of the Macondo well resulted in an explosion and fire to Transocean Ltd.’s Deepwater Horizon semisubmersible, killing 11 people. The semi sank Apr. 22. Macondo was drilled in 5,000 ft of water on Mississippi Canyon Block 252.
An estimated 4.9 million bbl leaked from the well, of which BP estimates it captured 800,000 bbl. The well was shut in with the July 15 installation of a capping stack. Cementing operations in early August, following a “static kill” operation, plugged the well's casing with cement.
A relief well drilled by Transocean’s Development Driller III semi intercepted the Macondo annulus Sept. 15, and the DDIII crew pumped mud into the annulus Sept. 17.
Separately, National Incident Commander and retired US Coast Guard Adm. Thad Allen said the Bureau of Ocean Energy Management, Regulation, and Enforcement confirmed the well has been permanently sealed with cement plugs, and that pressure tests verified the integrity of the plugs.
BP reported $9.5 billion in spill response costs through Sept. 17, including the cost of containment efforts, relief well drilling, static kill and cementing, grants to the Gulf Coast states, claims paid, and federal costs.
Tony Hayward, BP’s group chief executive, called the announcement “a significant milestone in the response to the Deepwater Horizon tragedy and is the final step in a complex and unprecedented subsea operation.” Hayward is stepping down from his post as chief executive, effective Oct. 1.
Hayward also reaffirmed what he called “BP's commitment to complete our work and restore the damage done to the Gulf of Mexico, the Gulf Coast, and the livelihoods of the people across the region.”
The company, various government agencies, and researchers continue monitoring for oil at the surface and the subsurface levels. No volumes of oily liquid have been recovered from the gulf’s surface since July 21.
Lamar McKay, BP America chairman and president, also pledged to continue repair and restoration work in the gulf and to share knowledge gained during spill response efforts.
"BP will continue sharing what we have learned in an effort to prevent a tragedy like this from ever being repeated,” McKay said. “We also believe that the industry will gain important insights on how to be better prepared to respond to any future incidents.”
Crews now are preparing to complete the abandonment of the Macondo well, which includes removing portions of the casing and setting cement plugs. A similar plugging and abandonment of both relief wells also is planned.
Some 25,200 personnel, more than 2,600 vessels, and dozens of aircraft remain engaged in the response effort, BP said Sept. 19.
Contact Paula Dittrick at firstname.lastname@example.org.