The U.S. oil company said it was taking the step as a precautionary measure to study its reservoir management plans in Brazil, where it has spent over $2 billion developing the largest foreign-run oil field. If approved by Brazilian regulators, the suspension will shut down a field with the capacity to produce 80,000 barrels a day, more than 3 percent of Brazil's oil output.
Chevron's previous spill leaked 2,400 to 3,000 barrels from sea-floor cracks and resulted in an $11 billion civil lawsuit, the largest environmental damages case in Brazil's history, even though the total amount of oil was less than 0.1 percent of the BP
Chevron said there is no evidence yet that the two spills in Brazil are related or that it caused the latest leak.
The suspension of production is designed to let us analyze scientifically what caused this, Rafael Jaen Williamson, Chevron's director of corporate affairs in Brazil, said at a news conference in Rio de Janeiro. He added that he hoped the suspension would only last a matter of months and that the decision does not alter Chevron's investment plans in Brazil.
The move to suspend operations at the so-called Frade field, which is currently producing about 61,500 barrels a day, raises questions about the safety and speed with which Brazil can develop giant new offshore oil resources.
The Campos basin, where Frade is located, and the neighbouring Santos basin contain an estimated 100 billion barrels of oil, enough to provide all current U.S. needs for more than 14 years.
Brazil hopes the region, the world's most promising offshore frontier, will help it produce more than 7 million barrels a day of oil by 2020, passing the United States to be the No. 3 oil producer after Russia and Saudi Arabia.
Chevron's troubles in Brazil could force it to rethink its Latin American strategies. A shortage of trained workers, engineers and equipment have driven up costs in Brazil, and Chevron faces an $18 billion environmental verdict in Ecuador.
The request to suspend output came on the same day that Brazilian oil regulator ANP said it had notified Chevron that it would be fined an undisclosed amount for failing to prevent seepage at the site. Chevron is already facing fines of up to $121 million for the November spill and has had its drilling license suspended in Brazil.
Chevron said the decision to suspend production at Frade was supported by its partners in the field: Brazilian state oil company Petrobras
Chevron owns 52 percent of Frade and operates the field. Petrobras owns 30 percent and Frade Japan, 18 percent.
Chevron shares, which were already trading down for the second straight day before the news of the new Brazil leak, slid further. The shares fell as much as 1.1 percent to $109.47, with trading volumes reaching the highest level in three weeks.
They closed at $110.03, down 0.6 percent from Wednesday.
The ANP said the oil was seeping out of cracks in the ocean floor, not the Chevron well that was sealed following last year's leak. Williamson, the Chevron executive, said there was no evidence that the new leak was caused by drilling or production at the Frade field.
The leak was first spotted on March 4, and engineers found the source on March 13, Williamson said. Oil is leaking from an 800-meter-long crack on the sea floor, only a few millimetres wide, said Mauro Pagam, an installation engineer with Chevron.
We were not drilling or injecting water in the area of the latest leak, Williamson said. The information that we have now leads us to believe that this is not ours.
The Campos basin is known for natural leaks of oil - seepage that helped lead to the discovery of the petroleum region, responsible for 80 percent of Brazil's oil output.
There is no longer any oil on the surface and the spill did not result in a slick, only small balls of oil that have been broken up mechanically by boats, Pagam said. Only 5 litres of oil were collected during the cleanup.
The ANP said on Tuesday that Chevron could win back its drilling rights within months if it can convince Brazilian officials it understands exactly what caused the November leak.
(Additional reporting by Reese Ewing, Peter Murphy and Guillermo Parra-Bernal; Writing by Todd Benson; Editing by Alden Bentley, Jim Marshall, Gary Hill)