The final price may be around $400 per 1,000 cubic meters, Sun Yongxiang, a researcher with the Development and Research Institute of the State Council, China's cabinet, said. He said China and Russia should cooperate more in energy, beyond natural gas trading.

CNPC said that in 2014, Russia will continue to increase the oil supplied through both China's eastern and western routes. How much the supply will grow is to be negotiated.

China discovers huge oil, gas deposits

China imports more natural gas in 2013

In June 2013, the two sides reached agreement to raise the oil supply this year from 2013's 15 million metric tons. Supply on China's eastern route will grow by 15 million tons annually, and on the western route through Kazakhstan, 7 million tons more crude will be added each year.

Liu Qian, an assistant researcher with China University of Petroleum in Beijing, said it's possible that Sino-Russian oil trade could be settled in Chinese yuan in the future.

On one hand, Russia has long sought to get rid of the US dollar's dominance over its oil trade. That intensified after Western sanctions were imposed on Russia amid the tensions over Ukraine.

On the other hand, the yuan's internationalization and China's growing influence in global energy pricing is a strategic goal of the Chinese leadership, Liu said.

The China (Shanghai) Pilot Free Trade Zone is building an oil futures trading center, which may facilitate the yuan's rise as a currency for oil settlements.

The yuan has been used as settlement currency in Sino-Russian trade and has changed hands in Russia's foreign exchange houses.

Bloomberg News reported on Wednesday that Gazprom will not bring partners from neighboring countries into drilling projects and it is focused on supplying gas to Chinese companies.