(Adds that Petrobras says platform still shut late Thursday)
By Marta Nogueira and Jeb Blount
RIO DE JANEIRO, Jan 21 (Reuters) - Petrobras stopped output from its P-31 oil and natural gas production ship in the Albacora Field northeast of Rio de Janeiro for the second time in eight days on Tuesday as a result of gas and oil leaks, union officials told Reuters on Thursday.
It remained closed late Thursday, two days after it was shut down for safety reasons, Petrobras said in a statement.
Albacora produced an average of 18,378 barrels of oil and 300,460 cubic meters (10.6 million cubic feet) of natural gas a day in November, according to Brazil's petroleum regulator ANP.
Petroleo Brasileiro SA, as the state-controlled oil company is known, said it shut P-31, a floating oil production, storage and offloading ship or an FPSO on Tuesday, after a mixture of oil and water leaked in the FPSO's pump room.
Petrobras added that nobody was hurt and said there was no damage to the environment.
The union representing workers on the ship, known as Sindipetro Norte Fluminense, said the incident was similar to an emergency shutdown of the same platform on Jan. 11 after a gas leak in the same area forced the crew to assemble at emergency posts for a potential evacuation of the ship.
The union also said the sensors that led to Petrobras' decision to shut the P-31 on Tuesday were the same that detected the gas on Jan. 11 and initiated the automatic shutdown.
The fumes may have come from oil or gas accumulating in an area of the ship near slop tanks whose heat may have caused oily waste water from the pump room to vaporize, releasing flammable gases, the union said.
An explosion in the same area of another FPSO, the City of Sao Mateus in the Camarupim gas and oil field, in February killed nine and injured 10.
The Panamanian-flagged P-31, which began producing in 1998, was converted from an oil tanker built in 1974. It is one of the oldest FPSOs in Petrobras. (Editing by Matthew Lewis and Alan Crosby)