IRNA l Faraj Samadi: The 22nd Iran International Oil, Gas, Refining and Petrochemical Exhibition (Iran Oil Show-2017) opened in Tehran on Saturday. The exhibition slated for May 6-12, was opened in a ceremony on Saturday morning. The ceremony was attended by Iranian Parliament Speaker Ali Larijani, Oil Minister Bijan Zangeneh, some lawmakers, authorities of the oil sector, and representatives of some 4,000 local and foreign companies, from 37 countries, at the International Exhibitions venue in Tehran.