World’s largest natural gas field. The Iranian South Pars field is the northern extension of Qatar’s giant North Field. It covers an area of 500 square miles and is located 3,000m below the seabed at a water depth of 65m. The Iranian side accounts for 10% of the world’s and 60% of Iran’s total gas reserves. Iran’s portion of the field contains an estimated 436 trillion cubic feet. The field is planned to be developed in around 30 phases, each of which will require an initial investment of around $1bn. Total investment will range between $30-50 billion.