(Bloomberg) –Iran discovered an oil field containing the equivalent of 53 billion barrels, potentially boosting its reserves as the OPEC member struggles to overcome the effects of sanctions on its energy industry.

It wasn’t immediately clear how much of the oil discovered in southern Khuzestan province is new, or how much of it can be developed commercially. Domestic media reported the discovery on Sunday, and the oil ministry said it plans to hold a news conference on Monday to announce details of the find.

Iran currently ranks fourth in reserves worldwide — behind Venezuela, Saudi Arabia and Canada — with 155.6 billion barrels, according to 2018 data from BP Plc. However, the Islamic Republic’s exports of crude have plunged since the U.S. re-imposed sanctions in 2018.

“What is important in this field is the rate of recovery, that is, how much of that we can extract and sell,” Iran’s IRIB News service cited President Hassan Rouhani as saying. “A higher recovery rate means more revenues for us.”

The deposit lies onshore at a depth of 80 meters (262 feet) and covers 2,400 square kilometers (927 square miles), semi-official Tasnim News reported. A media official at state-run National Iranian Oil Co. in Tehran gave no details when contacted by Bloomberg.