Brent has surpassed 2015 levels and is trading around $64.75 per barrel level, while WTI is strongly holding $58 per barrel level in the worldwide market.
Worldwide benchmark Brent crude futures ended the year with a 17 percent rise, supported by ongoing supply cuts by top producers OPEC and Russian Federation as well as strong demand from China. Refiners have profited in recent months as the spread widened between US crude and Brent futures prices.
Analysts see solid global economic growth supporting high oil demand in 2018, while expectations of strong OPEC and friends' commitment to the cuts are forecast to support oil prices next year as supply will be relatively tight.
"That trend is likely to continue into 2018 and worldwide oil inventories will continue their decline", said Andrew Lipow, president of Lipow Oil Associates in Houston.
Trading was typically thin at year end, with many traders on vacation.
U.S. West Texas Intermediate (WTI) crude futures rose 1 cent to $59.65 a barrel as of 12:59 p.m. EST (1759 GMT), a day after touching $60 a barrel. Brent crude futures fell 11 cents to $66.33 a barrel. Brent broke through $67 this week for the first time since May 2015.
Oil markets have tightened after a year of production cuts led by Middle East-dominated Organization of the Petroleum Exporting Countries (OPEC) and Russian Federation.
USA output is up nearly 16 percent since mid-2016.
Libya's oil production was last put by officials at around one million bpd but exact figures are hard to obtain a country riven by factional conflict. Inventories excluding the nation's strategic reserve have declined more than 11 per cent in the previous year.
Extreme cold weather across much of North America could also boost US crude prices by causing production problems in the oilfields. China's crude inventories in November hit a seven-year low of 26.15 million tonnes, Xinhua data showed.
Armed men blew up a Libyan pipeline pumping crude oil to Es Sider port on Tuesday, reducing the North African country's output by around 90,000 barrels a day, military and oil sources said.