Iran. 2015. Iran's oil sector is the most profitable industry of the country, its revenues account for at least 30 and some say half of its annual income. United States pressure forces all oil majors out of the country, causing the sensitive industry to go in rapid decline. Production capabilities have come down due to the use of outdated material. Officials say the industry needs $180 billion in investments, in order to regain its position as second oil producing country in the world.