TEHRAN - The black chador-clad secretaries behind rows of flat computer monitors at the Petroleum Ministry building in central Tehran are all smiles. Not to mention their bosses. No wonder. According to the ministry's latest estimates in August, Iran will export at least US$60 billion in oil in 2005 - more than $10 billion more than the June estimate. And with oil hovering about $70 a barrel, it could be even more.