Operation Tidal Wave II. A US-led coalition military operation beginning late October 2015 against oil transport, refining and distribution facilities and infrastructure under the control of the Islamic State of Iraq and the Levant.
Oil was the largest source of funding for ISIL, representing about half of the group's income. Up to September 2016, ISIL controlled six "key oil fields" in Syria, as well as several oil wells in Iraq.
While oil production and refining facilities have been bombed before, ISIL had been able to quickly repair the damage. The U.S. raid in May 2015 that killed Abu Sayyaf, the "emir" of ISIL's oil production, also obtained extensive documents about the workings of ISIL's oil production and operation. This led to efforts focused on inflicting damage that requires hard-to-get parts or is difficult to repair quickly.
