The US oil rig count fell by 6 to 572 this week, according to oilfield services company Baker Hughes.
The combined count of oil and gas rigs was 771, down 4.
The tally is in a renewed slump last week after a six-week rise that was preceded by the unprecedented plunge that followed the oil crash.
Earlier on Friday, Baker Hughes said the US rig count in October was 791, down 15% year-on-year.
Ahead of the data, West Texas Intermediate crude futures in New York were down nearly 2%, at about $44.39 per barrel.