OPEC stated in the past (from memory think it was 2013) they would no longer alter production levels in attempt to stabilise price of oil between roughly $70 and $100, every time OPEC has altered production over last 10 years or so it's had less effect on price of oil due to other producers not within OPEC increasing their production to fill the gap and also due to differences and disagreements on production levels within OPEC itself.
OPEC today isn't the monopolistic power it use to be in the 1970s 1980s
