BHP Billiton says it has no plans for further job cuts at Olympic Dam as it embarks on cost-cutting at the copper mine.

The mining giant has slashed cash costs at the South Australian site as it prepares to develop a series of underground expansions.

It comes after 550 jobs were lost at Olympic Dam in 2015, reducing the workforce to about 3000 employees and contractors.

Olympic Dam asset president Jacqui McGill says the cuts reflected the need for drastic action to improve the operation’s performance.

But she has moved to reassure workers there will be no further jobs lost at the “revitalised” mine.

“We’re done,” she told a business lunch in Adelaide.

“We’ve right-sized our organisation. We’re really just business as usual right now.”

Plans for a multibillion-dollar expansion at Olympic Dam were mothballed in 2012, which BHP blamed on lower commodity prices and higher capital costs.

Ms McGill said copper production at Olympic Dam was on track to exceed 200,000 tonnes this financial year, with a gradual increase in production expected to deliver cost efficiencies and offset ongoing weakness in the copper price.

She said the project’s unit cash costs would be about 48 per cent lower by the 2017 financial year, and a move to heap leach technology – currently in testing – could trim overall operating costs by a further 10-15 per cent.

“The results to date are an absolute credit to the team and a strong endorsement of their hard work,” Ms McGill said.

“They give us every reason to be confident that Olympic Dam can be a globally competitive and low-cost copper operation.”