Iraq's Sunni Islamist insurgency has further crippled the nation's dream to match the oil power of Saudi Arabia, making oil fields in the safer south even more vital — but even that region has not been completely free from attacks.

Baghdad is struggling to contain the Islamic State militancy, which seized some oil facilities when it swept through the northwest in June, emboldening the Kurds in their autonomous northern region to capture the giant Kirkuk oil fields.

There has been little impact on southern oil output, which is around 3.15 million barrels per day.