China launched the construction of the eastern section of the Sino-Russian natural gas pipeline within China on June 29, which is not only another milestone in Sino-Russian energy cooperation but also marks the completion of China's four major energy channels, Economic Information reports on Monday.

"The beginning of the pipeline marks that the highly anticipated mega deal of the century successfully started. It indicates Sino-Russian energy cooperation has entered a new stage and can be described as an another milestone of economic cooperation between the two countries", experts believe.

In May of last year, during the Shanghai summit of the Conference on Interaction and Confidence Building Measures in Asia (CICA), China and Russia signed a historic 30-year contract to supply natural gas to China. The deal would send 38 billion cubic meters of natural gas to China each year, starting in 2018. The gas will be sent through a new eastern pipeline linking the countries. The contract is called the "century mega deal" of the global gas market due to the huge quantity, contract longevity, and its far-reaching impact on the international energy situation. 

With the aim to protect energy security, China's four major oil and gas import channels include a sea passage and three land passages: northeastern (Sino-Russian), northwestern (Sino-Central Asia) and southwestern (Sino-Myanmar) passages. Both oil and gas will be sent through the three passages, except the Sino-Russian passage.

According to the plan, the Sino-Russian eastern gas pipeline will provide gas to the northeast, the Bohai Bay Rim and the Yangtze River Delta, which will ease the situation of gas shortage in the northeast and optimize energy structure at the Bohai Bay Rim and the Yangtze River Delta. It will also improve the air quality in these regions.