Before you think I'm crazy, hear me out 
Admitting it's a controlled market (which one isn't)
Do the old Ben Franklin T (plus on one side minus on the other)
Minus
1. USA just discovered the "Saudi Arabia" of oil (shale)
(Nat Gas fell to $2 from recent dicoveries)
Other finds - i.e. deep water off S. America, etc.
2. Alternatives: Solar, Wind, Nat. Gas, etc.
3. New CAFE standards
4. Alt. Fuel vehicles
5. Global warming
Plus
1. Whole world is driving more vehicles, flying more planes, etc.
2. As price declines exploration will decrease
3. Controlled market - but supply can only be cut so much before vol.
decreases cut into OPEC earnings.
Admittedly this is a simple analysis. But, if supply increases as demand decreases, price declines. (I know, I know, econ 101)
What's long term ? Good queston.
It won't happen overnight (obviously) but we used to use horse and buggies too.
JMHOs

Admitting it's a controlled market (which one isn't)
Do the old Ben Franklin T (plus on one side minus on the other)
Minus
1. USA just discovered the "Saudi Arabia" of oil (shale)
(Nat Gas fell to $2 from recent dicoveries)
Other finds - i.e. deep water off S. America, etc.
2. Alternatives: Solar, Wind, Nat. Gas, etc.
3. New CAFE standards
4. Alt. Fuel vehicles
5. Global warming
Plus
1. Whole world is driving more vehicles, flying more planes, etc.
2. As price declines exploration will decrease
3. Controlled market - but supply can only be cut so much before vol.
decreases cut into OPEC earnings.
Admittedly this is a simple analysis. But, if supply increases as demand decreases, price declines. (I know, I know, econ 101)
What's long term ? Good queston.
It won't happen overnight (obviously) but we used to use horse and buggies too.
JMHOs