Belarusian President Alyaksandr Lukashenka announced the plan after talks with Iranian President Mahmud Ahmadinejad in Minsk.
The Jofeir field, close to Iran's border with Iraq, could produce as much as 30,000 barrels of oil per day.
In televised comments after his arrival earlier today for a two-day visit to Minsk, Ahmadinejad said there was "huge potential" for long-term cooperation between Tehran and Minsk.
For his part, Lukashenka said Belarus was "ready for cooperation in all directions."
"Many approaches by the Islamic Republic of Iran to solving international problems are consonant with our views about a just world order," he said. "I'm confident that Iran, with its rich history, culture and its strong economic potential, can become one of the most influential centers of the international community."
Lukashenka's press service said the Belarusian president told Ahmadinejad that the Minsk-Tehran relationship had reached the level of "strategic partnership."
Minsk has actively sought new sources of energy as relations with Russia have soured.
Lukashenka's autocratic and isolationist
regime had long depended on subsidized Russian energy supplies to
maintain a stable economy.
A dispute with Moscow earlier this year, however, has left Minsk facing dramatically higher gas prices.