The Petroleum Resources Rent Tax is the profit-based mechanism for oil and gas producers in Australian waters to pay for the resources they extract.
It is frequently criticised for being unable to generate sufficient revenue.
Shell's accountants predict the Dutch giant will never pay Australia for gas consumed at the Gorgon and Prelude LNG projects that it can sell for up to about $4 billion a year.
Much of the $52 billion cost to decommission Australia's offshore oil and gas infrastructure will fall on the Federal Government via the tax system and work has started to boost industry collaboration and find cost savings.
The Inpex-led Ichthys LNG project will export $195 billion of LNG, LPG and condensate over 30 years but it will not pay Australia anything for the gas it extracts.
The credibility of estimates from US giant Chevron of the tax it will pay for its LNG production has been undermined by questions from the Senate committee on corporate tax avoidance.
Australia's Petroleum Resources Rent Tax has incredibly generous annual uplifts in allowable deductions that will likely see little or no payments from its offshore LNG projects.
