A Great Australian Bight oil industry would require decades of subsidies, experts say.

Analysis by the progressive thinktank the Australia Institute has used industry modelling to show that South Australia will receive almost no noticeable benefit from tax payments as a result of oil and gas production in the Bight.

In fact, the state would find itself paying decades of subsidies if it wants to develop the industry, according to the report.

Benefits would mostly flow to the Commonwealth, it says, pointing out that production would be minimal, paying no royalties or taxes in its exploration phase.

The report argues that the employment opportunities would be fairly slim too, with an estimated peak of 1,500 workers. Industry modelling is even less encouraging, estimating an average of 826 jobs.

The expert also highlight a range of environmental risks, partly because the Bight’s waters are unusually deep water for oil drilling.

Proponents of Bight drilling want to work a depths of approximately 1,000 to 2,500 metres, compared to WA’s offshore gas field depths of between 125 and 131 metres.

“Such deep water both increases costs for producers and increases environmental risks,” the report says.

“Specialised ultra-deepwater equipment would be required to produce oil in the Bight and one of the world’s worst oil disasters, the Deepwater Horizon oil spill in the Gulf of Mexico, occurred in water of similar depth.

“A major oil spill in the Bight could impact other industries on the coasts of South Australia, Victoria and Tasmania such as fishing, aquaculture and tourism, which are major industries for many coastal towns.”

It says a major oil spill could threaten up to 27,022 tourism, aquaculture and fisheries jobs across SA, Victoria and Tasmania.

The Norwegian company Equinor is looking to start exploratory drilling in the Bight in late 2020 – at the proposed Stromlo-1 well located 372km off the coast of SA and 476km west of Port Lincoln.

Equinor’ s draft environment plan says drilling can be done safely, but their proposals have already triggered protests in SA.

Federal resources minister Matt Canavan says encouraging offshore oil exploration is a national priority, and that it is important not to let “activists” prevent projects from proceeding.