Crippled by a series of mysterious explosions, the world's largest offshore oil rig sunk into the Atlantic Ocean on Tuesday, the state-owned oil company Petrobras announced.
The accident has sparked fears of a massive oil spill, despite assurances from Petrobras that the slick would not wash up on the beach.
The 210-meter-high (690-foot-high) rig, which had been in operation less than a year, took more than 1.5 million liters (330,000 gallons) of oil with it as it headed 1,368 meters (4,514 feet) down to the ocean floor.
"Because of the depth, the tanks and pipes that contain oil will certainly break under pressure, and part of the oil will be released into the water," Segen Stefen, an expert in such structures, said at a news conference.
Petrobras said in a statement that there was "no danger" that an oil slick from the rig would reach the coastline, 150 kilometers (90 miles) away.
On Thursday, three unexplained explosions in one of the piles that supported the P-36 rig on the seabed caused two confirmed deaths, with eight more people missing.
Dutch environmental experts, US consultants and workers from Petrobras battled to refloat the rig, pumping nitrogen into its flooded floaters and expelling 4,100 tones of water.
They managed to reduce the massive platform's list from 30 degrees to 24 degrees, but after heavy weather overnight, the huge steel structure suddenly started keeling over at 10:25 (1325 GMT.) Within less than 10 minutes the rig -- as big as a 40-story building -- had disappeared under the waters, heading to the ocean floor.
"The damage must have been enormous, because platforms of this size can stay afloat even in critical conditions," said Stefen, head of the postgraduate engineering program at the Federal University of Rio de Janeiro.
Greenpeace and other environmentalist groups have demanded that Petrobras take all necessary measures to prevent an ecological disaster.
A flotilla of 26 vessels and a semi-submersible platform had already been deployed to form a barrier around the stricken oil rig ahead of its sinking.
Twenty divers engaged in efforts to find the eight people missing since the platform explosions called off the search following the sinking, Petrobras said.
The company has been plagued by a series of recent spills and accidents, which have tarnished its reputation. Petrobras shares fell sharply following the news that the P-36 oil rig had sunk.
Before noon, Petrobras preferred shares were 2.72 percent lower at 49.70 reals and the common shares were down 2.56 percent at 53.10 on Brazil's Bovespa leading share index.
The 33,000-tone platform, the world's biggest, sat atop the Roncador oil field in the Campos basin, which contains an estimated two billion barrels of crude. The field accounts for 60 percent of Brazilian crude oil production.
The Italian-built rig, installed at a cost of more than $400 million, produced 84,000 barrels of crude oil and 1.3 million cubic meters (4.6 million cubic feet) of natural gas per day.
About 175 people worked on the platform located some 270 kilometers (170 miles) northeast of Rio de Janeiro.
Virtually all of them had been evacuated after the explosion, and emergency teams trying to keep the platform afloat in recent days were ordered to head to safety 40 minutes before the rig sank, witnesses reported.
Globonews TV showed oil workers watching in tears from a neighboring platform as they watched the P-36 disappear.
Petrobras President Henri Philippe Reichstul said he felt "sad, frustrated and above all in mourning," for the workers who lost their lives on the rig.
Speaking at a news conference, he said the loss of the platform should not affect plans to increase crude output above last year's figure of 1.3 million barrels a day, which accounted for 75 percent of the country's needs.
He said production loss should be compensated when another platform, P-40 goes into operation, probably later this year.—AFP.
©--Agence France Presse 2001.
© 2001 Mena Report (www.menareport.com)