A China National Petroleum Corp gas station attendant fills up a vehicle's fuel tank in Yinchuan, the capital of Ningxia Hui autonomous region. Russia's Rosneft will supply CNPC with 360 million metric tons of crude oil for a period of 25 years, according to a deal signed between the two companies in June. [Provided to China Daily]

In addition to oil exports from Russia to China, the two countries have spent years on pricing negotiations over natural gas supplies to China.

In 2009, the two countries reached a framework agreement in which Russia would deliver about 70 billion cubic meters of natural gas to China annually for 30 years starting from 2014.

China has become the third-largest natural gas user in 2013 with a total consumption of 167.6 billion cubic meters, up 13.9 percent year-on-year, according to the institution.

Duan Zhaofang, a natural gas expert at the institute, estimated that the nation's gas use in 2014 will reach 186 billion cu m, a rise of 11 percent year-on-year.

Russia, for its part, will continue to be the largest energy exporter in the world in the next 20 years, supplying up to 4 percent of global energy demand, according to BP Energy Outlook 2035 published last week.

The outlook said Russia's energy development will grow 21 percent from 2012 to 2035 and its energy use will increase by 20 percent.