For many years, the three biggest oil producers have been Russia, Saudi Arabia, and the US.
Only one of those countries – Saudi Arabia – is an OPEC member, and the role of Russia and the US in setting oil prices shouldn’t be underestimated. However, without a unified report to go on, keeping a close eye on production levels outside of OPEC can be difficult.
Much of the world’s oil is produced in the Middle East, which can mean that conflict and terrorism impacts oil prices. Like in the 2000s, when the Iraq war led to a major supply deficit.
Elsewhere, weather can also have an effect. Hurricane Katrina, for example, saw oil prices rise after a major pipeline was destroyed.