In a written statement, Treasury and Finance Minister Patrick Pruaitch defended the time taken by the PNG Government to reach a gas agreement with the ExxonMobil-led PNG LNG consortium and outlined the past and future circumstances surrounding the project.
Pruaitch said the APT, which was cancelled in 2003, will be imposed on the pioneering liquefied natural gas project and would help PNG benefit from rising commodity and energy prices.
"With many global oil companies enjoying super-profits the Government believed it would be untenable if the PNG Government, and people, were unable to share in what could potentially be windfall revenues and profits from LNG exports," he said.
While a 30% corporate tax rate applies to every company in PNG, the APT will require an additional 7.5% when PNG LNG's internal rate of return exceeds 17.5%, and another 10% when the rate exceeds 20%.
"By some estimates the Government's total tax take from this project would amount to between $US25-30 billion (K66.23-79.48 billion) over the 30-year life of the project."
Pruaitch said it was a very good outcome for PNG.
"If oil prices continue to spiral upwards in the manner they have done in the past year any windfall earnings from LNG will be equitably shared between the project owners and developers, and the PNG Government, landowners and the population at large."
As PNG LNG enters front-end engineering and design (FEED) for the next 18 months at an estimated cost of $US400 million, Pruaitch said the Government could not say they were 100% certain the project will proceed.
He said other aspects of the project during FEED will have to be bedded down, including the marketing of LNG and a detailed benefits package that met the needs of landowners and provincial governments.
Pruaitch also fought off criticism of the decision to sell wet gas as opposed to dry or lean gas.
"What we have found is that the wet gas, which includes liquefied petroleum gas, increases the value of the LNG that is exported because pricing is on the basis of calorific or energy content.
"Asian buyers in South Korea, China, India and elsewhere are willing to pay premium prices for wet gas and this has been deemed the best outcome for PNG."
However, Pruaitch said significant quantities of condensate will be stripped from the various gas fields and piped to the present Kumul oil export terminal for export to world markets.
With LPG, Pruaitch said the issue of extracting the fuel will be reviewed from time to time by ExxonMobil in its endeavour to maximise project revenues and potential profits.
On future LNG sales prospects, Pruaitch said the capital intensive nature of the project means long-term export contracts will have to be signed because buyers will need to spend billions of dollars on LNG import facilities.