The 8,704 km pipeline consists of one trunk link and eight branches that will connect Horgos, located in Xinjian Uygur Autonomous Region with the Hong Kong Special Administrative Region after traversing 14 provinces, autonomous regions and municipalities.

CNPC has successfully incorporated technological breakthroughs from six of its research projects to support the construction.

Seven new products have been developed and manufactured domestically on an industrial scale. These products include large diameter, high grade steel pipe materials, spiral submerged arc welded pipes, hot bending bends and hot-drawn T-joint pipe fittings.

The new X80 steel welding wire and flux increased welding speed by up to 1.7 m per minute, which is 30 per cent higher than the speed achieved on the first West – East Gas Pipeline.

Welders on the Second West – East pipeline received guidance on more than 100 techniques developed through the project including automatic welding, semi-automatic welding, joint-connecting welding and rework welding of the X80 steel pipes. Significant progress was also made in fracture control, anti-corrosion field coating, gas storage location, integrity management technologies, and safety pre-warning technologies, which have benefited the construction and safe operation of the pipeline.

Pipeline progress

The project has been divided into eastern and western sections with Zhongwei, located in Ningxia Hui Autonomous Region, designated as the pipeline’s midpoint. The western section, running 2,461 km from Horgos to Zhongwei, commenced construction in February 2008 and the welding work on the principle parts of the trunk line is now complete.

The eastern section, running 2,477 km from Zhongwei to Guangzhou with designed pressure of 10 MPa, commenced construction in December 2008. The eastern section is expected to connect into the Turkmenistan – China Gas Pipeline, which is currently under construction, by the end of 2009 and is scheduled to be comissioned in 2011.

On November 16, the tunnelled crossing of the Changjiang River was successfully completed. The crossing was a key engineering project for the Second West – East Gas Pipeline. The crossing took place between Jiujiang City in Jiangxi Province and Wuxue City in Hubei Province, with a horizontal crossing span of 2,590 m. China Oil and Gas Pipeline Company was the engineering, procurement and construction contractor.

The next step is to lay a 48 inch diameter pipeline in the tunnel, which is expected to be completed in April 2010.

Once completed, the pipeline will transport natural gas imported from Central Asian countries, as well as gas produced domestically in the Tarim, Junggat, Tuha and Ordos basins, to the Pearl and Yangtze River delta areas and the central west part of China.

The pipeline is expected to increase the share of natural gas in China’s energy consumption by 1–2 per cent and play a significant role in boosting the country’s domestic natural gas demand, facilitate the improvement of China’s machinery manufacturing, improve the nation’s energy structure and promote economic and social development to the adjacent regions along the pipeline.