In Friday trading, New York prices hit $29.28 a barrel, a level last seen in November 2003, and following a series of new 12-year lows hit throughout the week. Brent meanwhile dropped to $29.11 - the lowest level since February 2004.
"The energy sector suffered its worst weekly set-back since June 2011 as the imminent return of Iranian barrels and milder weather in the US sent crude oil and natural gas sharply lower," said Saxo Bank analyst Ole Hansen.
"These developments combined with China growth worries also had stock markets on the run."
With major producer Iran poised to hike output after the lifting of Western-backed nuclear sanctions, some analysts have warned of further losses for crude. The implementation of a deal between the two sides, allowing the removal of sanctions, is expected by Sunday. "Commodity prices struggled again [last] week, in large part owing to further declines in Chinese equities which in turn fuelled concerns about the country's growth prospects," Capital Economics analyst Caroline Bain wrote in a note to clients on Friday.
"Weak US industrial and retail data, published [on Friday], further weighed on prices. By far the largest loser was the price of oil, which also faces the prospect of a surge in supply if Western sanctions on Iran are lifted this weekend," she added.
Crude prices have shed three-quarters of their value in 18 months and dropped under $30 this week for the first time for 12 years. Oil prices have shed about 20 per cent already this year as investors worry about the prolonged oversupply crisis and weak global economic outlook, particularly in chief energy user China, which is affecting commodity markets generally. Meanwhile, the continued plunge in prices, with some analysts now seeing a $20 price in sight, has spurred turmoil in exporters as revenues collapse.
On Friday at about 1730GMT, Brent North Sea crude for delivery in March had retreated $1.92 to stand at $29.11 a barrel compared with Thursday's close.
US benchmark West Texas Intermediate for February delivery plunged $1.67 to $29.53.
But Michael McCarthy, chief market strategist at CMC Markets in Sydney, said prices may have hit or are nearing the end of their downward spiral.
"If we're not at the lows, we're very close to the lows for oil," he told AFP. "I do expect to see a turn very soon."
By: AFP London.
Review: Emerging Market Formulations & Research Unit, Flagship Records.
For The #FacebookTeam