Beach announced to the ASX on Friday morning that plummeting oil prices had led to impairment adjustments of $609 million to Beach’s oil and gas assets.

This mean, the company registered a net loss after tax of $600 million, and a small underlying net profit of $9 million, down 88 per cent.

The half-year results were directly impacted by a 49 per cent reduction in the average oil and liquids price compared to the previous corresponding period, with sales revenue down 36 per cent to $272 million.

Acting chief executive officer Neil Gibbins said Beach’s operational performance over the past six months was “pleasing and strong”.

“Our half-year production was 4.5 MMboe with oil production from the Western Flank’s ex PEL 91 permit increased by 10 per cent due to well connections and an investment in infrastructure,” Gibbins said.

“We also delivered a successful exploration program in the Windorah Trough with a five-well exploration program completed and five new field discoveries made.

“During the first half of FY16 we brought four wells online and we anticipate fracture stimulation and flow testing during the second half of the financial year,” he said.

Gibbins said Beach’s growth strategy had made significant progress to date with all formal approvals required for the proposal to merge Beach and Drillsearch granted.

“From 1 March 2016 the integration of Beach and Drillsearch will commence and over time the merger will start to deliver a range of synergies and benefits.

“Some of the benefits will include full ownership of the Western Flank oil permits ex PEL 91 and PEL 106, an increased gas and gas liquids footprint in the Cooper Basin, expansion of Beach’s Nappamerri Trough unconventional acreage and data and an increase in Cooper Basin footprint of around 19,000 square kilometres.

“The combined entity will become Australia’s largest onshore oil producer by a significant margin,” he said.