BP YESTERDAY began manoeuvring a giant, purpose-built dome to the Gulf of Mexico in an untested attempt to contain oil gushing from one of its crippled wells 1.5km below the ocean surface.
It follows the successful sealing on Tuesday of one of the three leaks from the well that have been discharging crude since an explosion on the Deepwater Horizon drilling rig on April 20th.
The capping of the leak was one of the first pieces of positive news for relief teams battling the disaster, although the federal US National Oceanic and Atmospheric Administration cautioned it would not stop the overall rate of flow from the well, estimated at 5,000 barrels a day.
Coast guard officials said operations to stem the flood of oil were now potentially less complex. Action to cap the three leaks was only one aspect of a series of measures being undertaken to dam the escaping crude.
BP contractors yesterday began transporting their concrete-and-steel dome from the construction site to the location of the stricken well, 80km offshore.
The company plans to deploy the structure on the seabed today and have it operational in several days. It will be the first time such an underwater containment tank has been used at great depths.
“This has been done in shallow water. It’s never been done in deep water before,” Doug Suttles, BP’s chief operating officer, said earlier this week.
The four-storey-high dome is built to withstand the 2,500 pounds per square inch (psi) pressure on the sea floor that puts the location of the leak well beyond the range of diving teams.
If the operation is successful, it could reduce the flow of crude by about 80 per cent.
The dome is designed to capture the escaping oil and funnel it up to the Discoverer Enterprise, a drillship belonging to Transocean, which leased the rig to BP. The vessel has a capacity of 125,000 barrels of oil. With seas calmer and winds lighter following rough weather at the weekend, BP believes the dome is the best hope of containing the escaping crude.
Weighing more than 90 tonnes, the dome was being shipped by barge from Port Fourchon, Louisiana, where workers for the contractor, Wild Well Control, completed work on it on Tuesday.
A second container is also being constructed. Smaller versions of the so-called cofferdam have been successfully used in shallower waters in the Gulf.
Jason Holvey of Wild Well Control told an interviewer: “If for some reason this did not work, there are a lot of brilliant minds working for BP right now. I’m sure there are multiple efforts going on parallel to ours.”
The deep-sea deployment of the dome was among a number of untried techniques being used to attempt to contain the spread of the crude and prevent it from reaching the coastline.
In another first, BP has also been injecting dispersant chemicals directly on to the location of the leak, although environmentalists have questioned whether that might not add to the pollution threat.