HARBIN - The oil pipeline linking Russia's far east and Northeast China witnessed its one year anniversary of operation last Sunday, as operators announced an accumulated 15 million tonnes of oil had been transported into China in 2011.

"The test results of the past year showed that the crude oil had been in accordance with the standards as agreed by China and Russia," said Luo Xuefeng, director of the Mohe Office of the Heilongjiang Entry-Exit Inspection and Quarantine Bureau, which is in charge of the quality inspection of the imported oil from Russia.

The pipeline, which originates in the Russian town of Skovorodino in the far-eastern Amur region, enters China via Mohe and ends in China's northeastern city of Daqing.

Construction of the 1,000-kilometer-long pipeline project, with 72 km within Russia and 927 km in China, started in 2010, and it will transport 15 million tonnes of crude oil from Russia to China annually between 2011 to 2030, according to the agreement signed between the two countries.

The annual amount of oil shipped through the pipeline could increase, depending on the drilling capacity in Russia, Russian authorities have said.

The oil pipeline was designed to have a shipping capacity of 30 million tonnes per year, according to the agreement.

As China's first large-calibre, long-distance and cross-national oil pipeline that goes through lots of permafrost areas and virgin forests, it requires strict standards on environmental protection and tremendous efforts of technical workers due to the complicated geographical and geological conditions along the long route.

"By zero hour on Jan 1, 2012, the pipeline had been safe and sound for 365 days in operation. No accident happened," said Zhang Shibin, manager of the Jiagedaqi Oil and Gas Company under the Pipeline Branch of Petro China (PBPC), the operator of the Chinese section of the pipeline.

The decision of building the pipeline was first put forth by leaders of the two countries in 1996, and it took more than a decade for the two sides to finally put the pipeline into operation after much discussion.

Previously, China had mainly relied on railway transport to import oil from Russia, which costs were high and only provided a relatively small amount of oil per year.

The official operation of the pipeline has been hailed as a "milestone" for China and Russia in oil cooperation, as it has not only opened a stable market for Russia's oil exports but also offered a stable oil supply for China.

"Energy cooperation between China and Russia, which mainly involves oil and gas, is an important part of the bilateral economic cooperation," said Song Kui, an exprt on Russian studies from the Heilongjiang Provincial Academy of Social Sciences.

"The one year anniversary of the smooth operation of the oil pipeline indicates that bilateral energy cooperation within the framework of the China-Russia strategic partnership of cooperation has entered a long-term, stable and sustainable period," he said.