China began work on its second west-to-east natural gas transmission pipeline on Friday. It will mainly carry natural gas from Turkmenistan and China's Xinjiang Uygur Autonomous Region to the Yangtze and Pearl River deltas, the country's two most developed regions.

It was the first time China had started a project to pipe natural gas from a foreign country.

Construction of the 9,102-kilometer pipeline, which consists of a main line and eight sub-lines, will cost 142.2 billion yuan (about US$20 billion).

In his congratulatory letter, President Hu Jintao said the pipeline was of "strategic significance" and would help "optimize the country's energy structure and maintain energy security."

He hoped the people involved in the construction of the pipeline would strive to make the project "first class."

With a designed gas transmission capacity of 30 billion cubic meters annually, the pipeline would traverse 12 provinces and autonomous regions before reaching Shanghai and the southern Guangdong Province.

Premier Wen Jiabao called on workers to ensure the quality of the project and make technical innovations to save land and other resources with a view to protecting the environment.

Vice Premier Zeng Peiyan said the country needed to continue integrating domestic pipeline construction with international cooperation in the oil and gas industry.

The main line extending 4,843 km would start from Khorgos in northwestern Xinjiang to Guangzhou, capital of Guangdong Province.

The western segment of the main line would go into operation by 2009. The eastern segment would start by June 2011, said Jiang Jiemin, general manager of China National Petroleum Corporation (CNPC), leader of the pipeline construction.

By the time the line goes into full operation, it will pipe gas, mainly from two contracted fields in Turkmenistan, to serve civilians, public facilities and producers who combine heat and power generation. Two domestic gas regions -- Tarim and Changqing -- would be the emergency sources.

Amid rising global oil prices and growing environmental concerns, China is looking for cheaper and cleaner energy sources. The country planned to raise the ratio of natural gas in its energy consumption by 2.5 percentage points to 5.3 percent by 2010, a figure still far below the international average of 25 percent.

The country is endeavoring to build a natural gas transmission network covering its whole territory. The first massive project to pipe natural gas from west to east was put into commercial operation in late 2004, starting from Xinjiang's Tarim Basin and going to Shanghai.

The pipeline extending 4,000 km traverses 10 province-level regions with a designed annual gas transmission capacity of 12 billion cubic meters. This can ensure a stable gas supply for 30 years.

In August, China Petroleum and Chemical Corporation (Sinopec), the country's second largest oil firm after CNPC, started construction of its project to transmit gas from the Puguang field in the southwestern Sichuan Province to Shanghai.

Copyright 2008 XINHUA NEWS AGENCY.