Oil production by  Brazil's oil and gas giant Petrobras is expected to return to normal by Tuesday, despite the strike by workers from the Campos basin platforms, the company announced Monday.

     The fall in oil production reached 16 percent on Monday morning, and dropped to 7 percent in the afternoon, which corresponds to 136,000 barrels per day.

     A contingency plan has been activated to ensure the steady supply of oil during the strike, which may last another four days,  Petrobras supply director Paulo Roberto Costa said.

     According to Costa, only two of the 42 offshore platforms in the Campos basin area are still closed, and 250 workers are replacing those who joined the strike.

     The company was able to get a court order that prevented workers from occupying the platforms. Those who joined the strike had to leave the platforms, and those who did not join were given free access.

     Meanwhile, Sindipetro-NF, the union that gathers the Campos basin area workers, confirmed that emergency teams are taking over the platforms, but said workers on strike on many platforms were not being allowed to leave.

     Petrobras workers based in the Campos basin area went on strike in the early hours of Monday to push their demand that the day they leave the platform be considered a working day.

     Currently, that day is considered the first of 21 days of rest, but it is lost in the transportation between the platform and the continent.

     The Campos basin produces 80 percent of Brazil's total oil production, which now stands at 1.9 million barrels per day.