State-owned National Iranian Oil Company (NIOC) has increased Iran’s crude oil reserves for the second time in a year, lifting the country’s estimated reserves to 155 billion barrels from 150.31 billion barrels in October.

Ahmad Qalebani, NIOC’s managing director, says Iranian production stands at “around 3.7 million barrels a day”, but put the cost of maintaining production capacity at $8bn a year. Qalebani also says there has been a “total fall of 25,000 b/d” over the past two Iranian years (running March to March), according to Platts news wire.

Analysts estimate Iran’s decline in output is between 8 to 11 per cent a year, some way above the 25,000 b/d estimated by Qalebani.

The increase in crude oil reserves is Iran’s second in less than a year. In October, Iran lifted its reserve estimate to 150.31 billion barrels from 138 billion barrels, as a response to increases in neighbouring Iraq (MEED 15:10:10).

According to an analyst note by IHS Global Insight, Iran continues to make discoveries, pinning its hopes on exploration in the Caspian Sea, although inexperience with deeper waters has delayed the completion of its first well to 2012.

“In the meantime, it is clear that the country is struggling to halt decline rates and bring big enough new oilfields onstream to start minimising its dependence on a number of old reservoirs,” says Sam Ciszuk, Middle East energy analyst at IHS.