By Mauro Orru

Total SE said Wednesday that it booked exceptional asset impairments of $8.1 billion in the second quarter of 2020 amid revised price assumptions for the coming years and a review of oil assets.

The French oil-and-gas company said the impairments included $7 billion on Canadian oil-sands assets, harming its gearing ratio by 1.3%.

The company anticipates Brent prices at $35/b in 2020, $40/b in 2021, $50/b in 2022, and $60/b in 2023, with gas prices adjusted accordingly.

The short-term price revision brought an impairment charge of $2.6 billion, with the remaining $5.5 billion due to the review of "stranded" oil assets, "with reserves beyond 20 years and high production costs, whose overall reserves may therefore not be produced by 2050," the company said in a statement.

Total said only its Canadian oil-sands projects Fort Hills and Surmont fall under this category.

Write to Mauro Orru at mauro.orru@wsj.com; @MauroOrru94