Iran has discovered shale oil reserves of two billion barrels of light crude in its western Lorestan province, a senior official at the state-run National Iranian Oil Company (NIOC) was quoted as saying on Saturday.

“Based on studies, it is estimated that the shale oil reserves in Ghali Koh in Lorestan amount to two billion barrels of oil in place,” Bahman Soleimani, NIOC’s deputy director for exploration, told the semi-official news agency Tasnim.

He added that exploration of shale gas reserves is also in progress in the area, highlighting that the projected is likely to be completed in October.

Iran had previously announced new shale oil discoveries in the provinces of Kerman and Semnan.

Iran is believed to have around 160 billion barrels of proven conventional oil reserves, the fourth largest in the world, said the Tasnim report.

According to an assessment of world shale oil and shale gas resources released by the US Energy Information Administration (EIA) in September 2015, 46 countries around the world possess deposits of shale oil and shale gas. The assessment put the unproved technically recoverable deposits of shale oil at 418.9 billion barrels and those of shale gas at 7,576.6 trillion cu ft in these countries.