ISIL transferred oil in different ways out of its territory. Oil could be trucked to Turkey, refined there and be used in Turkey or transported to tankers at the ports of Ceyhan or Dortyol. Oil could also be sold to middlemen in northern Iraq who then would mix it with legitimate oil that enter through one of many feeders the Kirkuk-Ceyhan pipeline. At the end of the pipeline it would have been difficult to determine if some ISIS oil was present in the mix that was supposed to come from Kurdish fields.
