Iraq said on Monday its proven oil reserves had risen to 143 billion barrels as work by international oil companies started to yield results.   

Iraq's proven reserves had been 115 billion barrels, already the world's third largest, but the data on which that figure was based was believed to be outdated.   

The new reserve figure was reached with the help of international oil companies working at 12 fields in Iraq, Oil Minister Hussain Al-Shahristani said in a news conference.   

'The rise in reserves from West Qurna and Zubair has considerably contributed to the rise,' Shahristani said.   

Shahristani said the West Qurna field had reserves of 43.302 billion barrels, making it the second largest field in the world.

The oil ministry has been carrying out 3D seismic surveys  to update its oil reserves data. Decades have passed with very little oil exploration activity in Iraq and reserves data, largely based on outdated technology, has not been revised for years.

Oil majors are moving ahead with a series of deals to unlock reserves that could boost Iraq's production capacity to Saudi Arabia's level of 12 million barrels per day from 2.5 million bpd now.

The deals could provide Iraq with the billions of dollars it needs to rebuild after years of war, sanctions and decline.   

A rise in Iraq's proven reserves is unlikely to change the global energy scene in the short term, but will cement its position as an oil power and strengthen its hand within Opec, analysts said. - Reuters