Oil and gas companies would cough up an extra $52 billion in petroleum taxes under an Australian Greens plan it admits is partly aimed at reducing production from the sector.

A costing of the plan by the independent Parliamentary Budget Office suggests the 2019-20 budget alone would be $3.3 billion better off.

The Morrison government is making changes to the Petroleum Resource Rent Tax system, which has come under fire for not raising sufficient revenue from Australia's rapid LNG expansion over the past decade.

Oil and LNG companies would face $52 billion in extra tax under Greens plan Credit:Michele Mossop

Those changes are forecast to raise an additional $6 billion by 2028-29, prompting industry concerns that planned exploration and investment may be abandoned.