US oil settles down 3.39%, or $1.29, at $36.81 a barrel

WTI, Brent trade flips as oil prices fall
How low can oil go in 2016?
Strategies for volatility

Crude prices fell over 3 percent on Monday with Brent back near 11-year lows and trading lower to U.S. crude, pressured by weak Japanese consumption of oil and renewed worries about oversupply.

U.S. gasoline also fell about 3 percent while heating oil slid 1 percent as the selloff extended to refined products on the New York petroleum futures complex.

Crude futures slumped in Asian trading as Japanese data showed a 46-year low in oil sales in the world's fourth largest crude buyer. They slid more in the New York session, as some traders reckoned the two-day pre-Christmas rebound, where crude rose about $2 a barrel, had been overdone.

"Volume isn't great, which is typical for this time of year, and most guys are either flat on their books and positioning themselves for a weaker first quarter in 2016," said Tariq Zahir, an oil bear at Tyche Capital Advisors in Long Island, New York.

Brent was down $1.28 at $36.61 a barrel by 2:30 p.m. EST. It had hit a 2004 low of $35.98 on Tuesday.

U.S. crude's West Texas Intermediate (WTI) futures settled at $36.81, down $1.29, or 3.39 percent. Oil bears are looking to beat WTI's previous low of $32.40 in December 2008.

Energy Futures

"A bearish trading stance is still being advised as we still view an ultimate price decline in nearby WTI and Brent futures to the $32.50 area," said Jim Ritterbusch at Chicago-based oil markets consultancy Ritterbusch & Associates.

Figures from the Organization of the Petroleum Exporting Countries imply an oil glut of more than 2 million barrels per day, equal to more than 2 percent of world demand.

Crude futures have plunged nearly 70 percent from highs above $100 a barrel in June 2014 after OPEC, led by top exporter Saudi Arabia, dropped its longstanding policy of cutting output to support prices in favor of defending market share.

While the collapse has partly achieved OPEC's goals by curbing growth of competing supplies, it has put finances in producing nations under more strain, even in the relatively wealthy Gulf states.

Saudi Arabia on Monday announced plans to shrink a record state budget deficit with spending cuts and a drive to raise revenues from sources other than oil.

The 2016 budget, released by the finance ministry on Monday, marked the biggest shake-up to economic policy in the world's top crude exporter for over a decade, and includes politically sensitive reforms from which authorities previously shied away.

The government ran a deficit of 367 billion riyals ($97.9 billion) in 2015, or 15 percent of gross domestic product, officials said. The 2016 budget plan aims to cut that to 326 billion riyals, reducing pressure on Riyadh to pay its bills by liquidating assets held abroad.

Iranian oil minister Bijan Namdar Zanganeh said Iran would cut prices in order to support crude exports as the country seeks to return to the oil market next year, state news reported.

Iran has said it plans to export 500,000 barrels per day as soon as possible. That outcome is contingent upon years-old sanctions being lifted as planned.

How cheap oil raises political risks in Saudi Arabia

Severe weather in parts of the U.S. South and Midwest has disrupted regional shipments of some refined products and oil, including a trickle of crude trucked into the storage hub of Cushing, Oklahoma.

Sources said several truck racks, which serve as distribution centers to move refined products such as gasoline and diesel to market, reported outages following a weekend of tornadoes and flooding that killed 43 people, leveled buildings and snarled transportation.

In Cushing, truck deliveries slowed due to dangerous road conditions, according to a source familiar with operations in the area. Although the majority of oil is piped into Cushing, truck deliveries can total between roughly 25,000 to 50,000 barrels per day, according to sources.

—CNBC's Tom DiChristopher contributed to this report.

2015’s top-performing assets around the world