"We have done new drilling in Jofeir and have discovered a new oilfield with an in-place reserve of 750 million barrels," the oil ministry's news website SHANA quoted Nozari as saying.
Nozari said with the new discovery Jofeir's output would reach 33,000 barrels per day, from the 25,000 barrels previously reported.
OPEC member Iran has in the past put its oil reserves at 138 billion barrels.
Iran, the world's fourth largest crude oil exporter, said in September it had signed a $450 million contract with Belarus for Minsk to extract 40,000 barrels of oil per day from its Jofeir oilfield.
(Writing by Zahra Hosseinian; editing by David Stamp)
