It's a lot more complicated than that.
Firstly, Australia is not linked to the WTI/Crude Oil market which our media continually rant on about.
We are linked directly to the TAPIS oil market (Singapore).
Then there is a myriad of other market factors that determine the price (not OIL companies as many think).
Check out
www.aip.com.au if you want to know what contributes to it.