Oil companies need to make profits - the shareholders drive that one.
If an oil company can sell the oil for $42 a barrel, then why should they be forced to sell for less? Its a business.
The market price is driven by demand. OPEC simply cuts supply and bingo, demand raises, price goes up.
If you were selling your car and found you could sell your car for 10% more to someone from interstate, would you then sell it at the lesser price? no, you get the most you can
oil companies are no different - profit driven. sucks, but that is life.
If you want to know who to blame, Paul Keating introduced parody pricing of fuel in the 80's? before this time, the cost australian oil producers could ask for their oil was limited by government regulation, but its just too late now.