LNG exports are forecast to reach $35 billion in value next financial year, despite the major east coast gas producers' recent agreement to ensure domestic supply.
The new data from the Department of Industry, Innovation and Science also tipped at a decline in thermal coal although Australia will remain the world's second largest exporter.
While thermal coal experienced a sharp increase in prices due to the combination of higher demand and industrial action across Glencore's operations in the Hunter Valley and Queensland, spot prices are likely to fall to $US69 per tonne in 2019, the report said.
This is well below the $US84 per tonne average expected for the remainder of 2017. Exports of thermal coal will also drop 2 per cent in in 2018-19 to 198 million tonnes.
The output will be further blunted by the fall in coal prices, with expectations of total export values falling 13 per cent year-on-year, from $19.2 billion to $16.9 billion.
LNG and crude oil are forecast to buck coal's downward energy trend, with LNG expected to overtake metallurgical coal as Australia's second largest exported resource in terms of earnings.
"In the next two years, LNG export earnings are forecast to increase at an annual average rate of 26 per cent to reach $35 billion in 2018-19," the department's chief economist Mark Cully said.
This is due to increases in forecast export levels in 2018-19 rather than aggressive pricing, despite the three major east coast gas producers agreeing to supply the domestic market.
The agreement follows six months of pressure from the federal government on the Queensland LNG producers, led by Shell, Origin Energy and Santos, who have been blamed for sapping the local market of gas and driving up prices.
The Australian government forecasts a rise in coal and LNG exports to India, though nowhere near the levels of China.
"The prospects for Indian resource and energy commodity usage over the next 20 years are promising, though it won't be on the same scale that we have seen from China," Mr Cully said.
Macquarie Wealth Management analysts backed the sentiment, saying Pakistan and India had ramped up their imports driven by a shift to cleaner power generation and taking advantage of LNG prices.
LNG prices are forecast to remain steady in 2018 and 2019 at approximately $9 per gigajoule.
Oil export earnings are expected to increased 10 per cent year on year, into 2018, before seeing an aggressive 21.2 per cent spike in nominal export values in 2019, thanks to a 15.9 per cent increase in export volumes.
The mixed forecast comes as the CSIRO releases a roadmap for the development of Australia's oil and gas industry.
It painted a picture of an industry in need of change, stating that energy development locally may remain constricted as overseas markets present more attractive investment opportunities.
"To remain globally competitive, Australia's oil and gas sector cannot be complacent," the CSIRO said.
It linked the Australian oil and gas sector's high operating coast and declining exploration levels as one of the key factors that may dissuade future capital investment, as well as increasing uncertainty driven by the growth of renewables, government regulation, and changing technology.
"For example, a rapid decarbonisation of the energy sector could completely undermine the ostensible role of gas as the bridge to a zero-carbon future - a potentially large risk for the Australian gas export industry," it said.
"In the face of such uncertainty, the sector would be remiss to take a 'business as usual' approach."