By David Winning

SYDNEY--Woodside Petroleum Ltd. forecast an impairment charge of US$3.92 billion against the value of its oil and gas assets, as it grapples with a more subdued outlook for energy prices amid the coronavirus pandemic.

Woodside said a US$2.76 billion charge would be taken against oil and gas properties from Australia to Senegal. The largest hit, at nearly US$1 billion after tax, relates to the Wheatstone liquefied-natural-gas project offshore Australia and reflects the company's reduced assumptions for oil prices.

A further US$1.16 billion impairment charge will be taken against four exploration and evaluation assets, including the Sunrise natural-gas project offshore East Timor and the Kitimat LNG project in Canada.

"Although these are difficult and uncertain times, the medium-term outlook for Woodside's growth prospects and for our core product, natural gas, is positive," said Chief Executive Peter Coleman.

Woodside said it expects its first-half results in August to include an onerous-contract provision of US$447 million for the Corpus Christi LNG sale-and-purchase agreement.

Write to David Winning at david.winning@wsj.com