Construction has commenced on the southern part of the China-Russia East natural gas pipeline, according to China Oil& Gas Pipeline Network Corp, China's pipeline operator.

The 5,111-kilometer China-Russia East natural gas pipeline is the world's longest across-the-river pipeline construction project that will transport natural gas from Russia to Shanghai by 2025. The southern part of the project stretches from Hebei province to Shanghai. Upon completion, the pipeline is expected to transport 18.9 billion cubic meters of natural gas from Russia every year to the Yangtze River Delta region.

The long-distance natural gas pipeline has the largest diameter and the highest pressure among all pipelines in China. It is divided into the northern part, the middle part, and the southern part. The northern part was put into operation last year, and the middle part is expected to be completed by the end of this year.

The southern part of the pipeline is a major project for the newly formed pipeline company. It is also an important measure to promote the construction of "new infrastructure" in the energy sector, China Oil & Gas Pipeline Network Corp said.

According to the company, apart from transporting natural gas to the Yangtze River Delta region, the project will also interconnect the Yongqing county (in Hebei province)-Shanghai pipeline (under construction), the west line one, the west line two, and the Rudong (in Jiangsu province) line. All these measures are expected to improve the energy and transportation environment in the Yangtze River Delta region and enhance the emergency support capabilities of the natural gas pipeline network in the region.

Li Ziyue, an analyst with BloombergNEF, said: "The start of construction of the southern part of China-Russia East Route will further diversify natural gas sources and improve energy security in the Yangtze River Delta region. The line is expected to provide the region with 18.9 billion cu m of gas (around 30 percent of the yearly consumption of the region in 2019) when it reaches full capacity in 2025. Currently, the region is supplied by China's West-East Gas Pipelines, the Sichuan-Shanghai pipeline, and six liquefied natural gas terminals.

BNEF estimates that the delivered price of Russian gas in the Delta will likely be potentially cheaper than the long-term contracted LNG prices. This could reduce the region's appetite for contracted LNG, in favor of Russian piped supplies. However, current Asian spot LNG prices could still make LNG imports more competitive, she said.

The project involves a shield structure construction that crosses the Yangtze River. It is currently the world's across-river shield structure construction with the longest single tunneling distance, deepest buried depth, highest water pressure, and the largest diameter in the oil and gas pipeline field. The tunnel has an inner diameter of 6.8 meters, a horizontal length of 10.23 km, and a maximum water pressure of 0.73 Mpa.

The shield structure construction is a key part of the whole project. The part is an inevitable passage through which the natural gas from Russia is transported to Shanghai, also the only channel through the river for the coastal natural gas to be transported to Jiangsu.

As the project involves complex technology, difficult construction levels, and high environmental protection requirement, after organizing 10 special technical research projects, China Oil & Gas Pipeline Network Corp decided to adopt shield structure construction. Slag waste produced from tunneling and well digging will be transported to the dumping point using river transportation, in order to achieve green construction.