Iraqi Oil Minister Hussain al-Shahristani said oil reserve estimates increased by 25 percent based on information from the Organization of the Petroleum Exporting Countries.
"Iraq's oil reserves which are extractable are 143.1 billion barrels," CNN International quoted the minister as saying.
The minister added that most of the reserves were locked in the Qurna oil fields in southern Iraq, which accounts for 43 billion barrels of oil reserves.
Drilling in the West Qurna-2 oil field is expected in 2011 with full-scale production slated for the end of 2012. The field should reach a peak production rate of 1.8 million barrels per day by 2017 and sustain that level for more than a decade.
West Qurna-2 holds roughly 13 billion barrels of oil. It is about 40 miles northwest of Basra near the outlets to the Persian Gulf.
Russian oil company Lukoil said it plans to dump $30 billion into developing the oil field with its partners at Statoil.
Iraq in 2009 awarded 11 deals to international oil companies in two separate bidding rounds giving Baghdad confidence to say it could one day rival Saudi Arabia in terms of oil production.