[watchfirst9]

The main focus of the audacious attack are the aircraft carriers. Taking them out means US have a much further distance in order to launch counter-attacks. The oil tanks are not important if the aircraft carriers are sunk as it takes time to build new or repair. No ships got oil also useless. But on hindsight you are correct if cannot find the aircraft carrier they should at the quickest time destroy the oil tanks indeed as US have lot's of destroyers, cruisers etc.

Nuclear aircraft carriers came more than 10years after the war ends.
And is still the only source for planes today. 

Maybe 冥冥之中早有安排...