By Collin Eaton

Schlumberger Ltd., the world's largest oil-field services company, is cutting about 21,000 jobs as oil producers make steep spending reductions in response to a historic drop in prices amid the coronavirus pandemic.

Schlumberger recorded $3.7 billion in impairment charges in the second quarter, including about $1 billion in severance charges, it said Friday.

"This has probably been the most challenging quarter in past decades," Chief Executive Olivier Le Peuch said, noting its revenue fell sharply because of an unprecedented fall in oil-field activity in North America.

Mr. Le Peuch said oil demand is slowly returning to normal and is expected to improve as governments lift restrictions in support of increased consumption, paving the way for a modest increase in fracking activity in North America.

"Any further material Covid-19 disruption or significant setback in oil demand arising from a slower economic recovery could present downside risks to this outlook," he said.

Schlumberger reported a net loss of $3.4 billion, or $2.47 a share, compared with net income of $492 million, or 35 cents a share, in the same period last year. Revenue declined 35% year-over-year to $5.4 billion, with North American sales down 58% to about $1.2 billion.

Its earnings per share, excluding charges and credits, was 5 cents a share.

Schlumberger has corporate offices in Paris, Houston, London and The Hague.