Updated from 2:27 p.m. EST
Crude oil prices hugged a seven-week low Friday.
Based on preliminary data, the December futures contract closed 10 cents lower at $47.32 in bouncy trading, after another sharp fall Thursday.
Prices have closed lower in nine of the past 12 sessions and are down some 13% since their record high of more than $55 in late October.
Prices rose Friday as worries resurfaced about production in Nigeria, where the oil workers union has set a strike for Nov. 16.
U.S. production has been on the rebound in recent weeks after Hurricane Ivan disrupted Gulf of Mexico operations in September, a development that aggravated short-term supply worries at the time.
Prices have hit record highs on a frequent basis since May, when they broke through the long-standing previous record of about $42 a barrel touched in 1991 after Iraq had invaded Kuwait.