Crude oil prices hit their highest since July 2015 Monday as Saudi Arabia's crown prince cemented his power over the weekend with an anti-corruption crackdown, while markets continued to tighten.
This came as imports of West African crude by Asian countries were expected to fall by 11 per cent in November, compared to October arising from soaring Brent prices, high freight rates and some Chinese independent refiners hitting their import quotas.
Brent crude futures traded 47 cents higher at $62.54 a barrel, after hitting a session peak of $62.90, a 28-month high.
U.S. West Texas Intermediate (WTI) crude rose 34 cents to $55.98 a barrel, having broken $56 for the first time since July 2015.
Saudi Crown Prince Mohammed bin Salman at the weekend reportedly tightened his grip with the arrest of royals, ministers and investors, including prominent billionaire Alwaleed bin Talal and the powerful head of the National Guard, Prince Miteb bin Abdullah.
Reuters quoted analysts as saying that Saudi Arabia, the world's largest oil exporter, will not change its policy of boosting crude prices.
Prince Mohammed's reforms include a plan to list parts of state-owned oil company Saudi Aramco next year, and a higher oil price is seen as beneficial for its market capitalisation.
Saudi Energy Minister Khalid al-Falih said that while there is "satisfaction" with a production-cutting deal between the Organisation of the Petroleum Exporting Countries (OPEC) and other producers led by Russia, the "job is not done yet".
OPEC is expected to extend a cut of around 1.8 million barrels per day into the whole of 2018.
Also boosting oil prices, US energy companies cut eight oil rigs last week to 729, in the biggest reduction since May 2016.
While supplies are tightening, analysts said demand remains strong.
Barclays Bank raised its forecast for the average Brent price in the fourth quarter of this year by $6 to $60 a barrel, and its full-year 2018 forecast by $3 to $55 a barrel.
Speculators have also increased to a record high their bets on gains in the price of Brent.
However, Asian loadings of West African crude are set to fall by 11 per cent in November as a result of expensive Brent prices, high freight rates and some Chinese independent refiners hitting their import quotas, industry sources said.
Reuters reported that China's loadings of West African crude were set to fall for a second month by four per cent in November at 1.235 million bpd versus October at 1.287 million bpd, despite the shorter month.
The report quoted trading sources at several Chinese refiners as saying that the decline was in part due to independent refiners having either reached or nearly reached their crude import limit for the year.
China's Ministry of Commerce reportedly increased the overall crude import quota for 2017 but cut the volume allocated to independent refiners, known as "teapot refiners", by 17 per cent.
Other factors that have continued to weigh are the wide spread between Brent and Dubai crude swaps and what was described as the backwardated structure in oil futures since September.
Backwardation is a market condition in which it is more attractive to sell oil immediately than store it, the crude also loses value as it heads to Asia.
The Brent-Dubai spread has been fluctuating around $2.50 a barrel since mid-October, close to the end-September 10-month high of $2.59 a barrel.
According to oil traders, the wide spread has made crude priced off Brent more expensive to Asian buyers, who have been increasingly looking at cheaper U.S. oil.
U.S. crude oil exports hit a fresh record high last week at 2.1 million barrels per day, according to the U.S. Energy Information Administration.