That was a 24 percent hike, which vaulted Iraq over Iran in the reserves standings and put it behind Saudi Arabia and Venezuela in terms of conventional oil reserves.
A week later, Tehran responded by boosting Iran's reserves from 138 billion barrels to 150.3 billion, a 9 percent increase, and said the figure was likely to go up again before the end of the Iranian year in March 2011.
Iran's current output, despite U.S., U.N. and European Union sanctions, is pegged at 3.7 million barrels per day while Iraq's stands at around 2.4 million bpd.
But given the ever-tightening sanctions, aimed to a large extent at Iran's troubled energy industry, Iraq stands an infinitely better chance of boosting production than Iran.
And it's production levels, rather than reserves, that count in determining the pecking order in the global oil business.