Oil workers said they began a 24-hour strike before dawn on Thursday on 39 offshore platforms to protest a paring back of overtime compensation by Brazil's state-run oil company Petroleo Brasileiro SA, or Petrobras.
A Petrobras official said there was no interruption in oil or gas production from the Campos Basin off Brazil's southeastern coast. The basin provides the bulk of Brazil's crude output.
The Sindipetro union, which represents offshore oil workers in the Campos Basin, said on its web site Thursday that the strike, which started just before 3 a.m. (2 a.m. EDT), stopped production at the P-07 and P-15 platforms.
The union said that two platforms were shut down by management. Together they typically produce 12,300 barrels per day. The other 37 platforms in the basin appear to be producing oil and gas despite the strike. Workers often maintain a skeleton staff to assure safe operation of a platform.
Workers are striking over Petrobras' decision to stop paid time off equal to 1.5 hours for each hour of overtime worked, the union said. Workers also receive time-and-a-half wages for the overtime itself.
A Petrobras spokeswoman said the company was open to talks with the union but did not say whether they were in active discussions about overtime compensation.
During similar strikes of short duration in the past, Petrobras has managed to keep producing from its platforms.
In May, the Campos Basin produced 82 percent of Brazil's total output of 1.99 million barrels of crude oil a day and 37 percent of its 74.9 million cubic meters of natural gas a day. About 90 percent of that was produced by Petrobras.