The king of Saudi Arabia wants to lower oil to 80 bucks to beat U.S. competitors mining expensive shale and deep-sea oil. In addition, they will pressure Iran and Russia to be less supportive of the kingdom’s main enemy, Assad.

This is one version.
The second version - he wants to bury shale projects at the root. First of all, U.S. projects.

There is also a third version - the King of Saudi Arabia 90 years old and he finally fucked up