The nuclear talks that have been ongoing for more than twelve years between Iran and the P5 1 are in their final stage. Parties have until 30 June to finalise an accord which could lead to the lifting of sanctions on Iran's oil and gas industry. Iran has huge potential. It has the third largest volume of remaining reserves in the world and could become a key source of global oil supply after 2020. However Iran s oil and gas industry is in need of significant external investment.