Oil prices steadied late last week but were still headed for a second year of steep declines after a race to pump by Middle East crude producers and US shale oil drillers created an unprecedented global glut that may take through 2016 to clear.
The global oil benchmarks - Brent and US crude's West Texas Intermediate (WTI) - saw futures on track to finish 2015 down more than 30pc after another year that showed the helplessness of Saudi Arabia and others in the once-powerful Organization of the Petroleum Exporting Countries (Opec) to support oil prices.
The US shale industry, meanwhile, surprised the world again with its ability to survive rock-bottom crude prices, churning out more supply than had been anticipated, even as the sell-off in oil slashed by two-thirds the number of drilling rigs in the country from a year ago.
The United States also took a historic move in repealing a 40-year ban on US crude exports to countries outside Canada, acknowledging the industry's growth.
"You do have to tip your hat to the US shale industry and its ongoing ability to drive down costs and hang in there, albeit by its fingernails," said John Kilduff, a partner at Again Capital, an energy hedge fund in New York.
Brent crude was up 30c at $36.76 a barrel towards the end of trading, rebounding from a near 11-year low of $36.10 earlier in the session.
For the month, it was down 17pc and for the year it fell 36pc. In 2014, Brent lost 48pc.
WTI rose 13c to $36.73 a barrel. It slid 12pc in December and 31pc for the year, after a 46pc loss in 2014.
The immediate outlook for oil prices remains bleak. Goldman Sachs has said prices as low as $20 per barrel might be necessary to push enough production out of business and allow a rebalancing of the market.
"We have brimming oil inventories in Europe," Bjarne Schieldrop, chief commodity analyst at SEB in Oslo, said. "And our predictions are that oil inventories in Asia are going to get closer to saturation in the first quarter."
Morgan Stanley said in its outlook for next year that "headwinds are growing for 2016 oil." The bank cited ongoing increases in available global supplies, despite some cuts by US shale drillers. "The hope for a rebalancing in 2016 continues to suffer serious setbacks," the bank said.
Brent prices briefly hit a 2004 bottom below $36 this year, effectively wiping out the gains from a decade-long commodity super-cycle sparked by China's unprecedented energy demand boom.
The downturn has caused pain across the energy supply chain - including shippers, private oil drillers and oil-dependent countries from Venezuela and Russia to the Middle East.
Analysts estimate that global crude production exceeds demand by anywhere between 0.5 million and two million barrels every day.
This means that even the most aggressive estimates of expected US production cuts of 500,000 barrels per day for 2016 would be unlikely to fully rebalance the market.
Oil began falling in mid-2014 as surging output from Opec, Russia and US shale producers outpaced demand. The downturn accelerated at the end of 2014 after a Saudi-led Opec decision to keep production high to defend global market share, rather than cut output to support prices.
Opec failed to agree on any production targets at its December 4 meeting in Vienna, cementing its decision to protect market share, as the organisation braces for the return of Iranian exports to the market after the lifting of Western sanctions.
Russia and Opec show no signs of reining in production, leading traders to establish record high active short positions in the market that would profit from further crude price falls.