Oil output at Rosneft's Vankor deposit, a driver of Russia's recent oil production growth, may start declining next year, a top company official said, underlining the challenges of production in far-flung regions.

Russia, one of the world's top oil producers, is tapping oil at a pace of 10.65 million barrels per day, a post-Soviet record-high, thanks to a ramp-up at Vankor and other new fields.

"(Vankor's) oil production will stay at the plateau of 22 million tonnes this year, while next year it may decline slightly," said Alexander Cherepanov, the chief engineer of Vankorneft, a Rosneft subsidiary which is developing the field.

Vankor, launched by state-run Rosneft in August 2009, is Russia's northernmost onshore oil production project. It is part of Russia's push to tap new, challenging regions, such as Arctic offshore and East Siberia as oil deposits in West Siberia, the heartland of Russian oil production, are gradually depleted.

Oil from the field, located partly on the Taimyr peninsula beyond the Polar circle, is delivered to China by pipelines.

Rosneft's production, which account for 40 percent of Russia's total oil output, declined in 2014 to 205 million tonnes from 207 million in 2013.

Production at Vankor, which has initial recoverable reserves of 476 million tonnes of oil and gas condensate, has been complicated by harsh climate, with winter temperatures falling as low as minus 60 Celsius (minus 76 Fahrenheit). The nearest town, Igarka, is 142 kilometres (88 miles) away.

Total reserves at the Vankor cluster, including Vankor and nearby fields, are estimated at 876 million tonnes.

Rosneft had originally envisaged Vankor to reach peak output of 25 million tonnes a year (500,000 barrels per day) in 2013. It will now do so in 2019 - and only with the help of three other nearby fields acquired with the $55 billion takeover of TNK-BP two years ago.

The fields, Suzun, Tagul and Lodochnoye, will be launched within the next few years with Suzun seen starting production by the end of next year. Rosneft is building a pipeline with a capacity of 4.5 million tonnes a year from Suzun to Vankor.