Comparison against Qatar is a bit meaningless. Qatar has a 10% corporate tax rate and old infrastructure which has been depreciated. Australia has brand new LNG plants still being depreciated and a higher corporate rate.
Building an LNG plant in Australia is almost twice the price as expanding the Qatar LNG for the same capacity.
Tax breaks for exploration are key to encouraging exploration, this is very short sighted impacting exploration, because if your dollars can achieve twice as much exploration wise internationally, you aren't going to explore as much in Australia.