CHINA has set the route for its second west-east gas pipeline to supply energy from central Asia to its booming coastal regions.

And at more than 7,000 kilometers long, it's a massive undertaking, the project investor announced yesterday.

The pipeline will start at Huoerguosi in far northwestern Xinjiang, stretching to Shanghai in the east and Guangzhou in the south, the China National Petroleum Corp said on its Website.

CNPC, the sole investor in the project, said the pipeline will use natural gas from central Asian countries, including Turkmenistan and Kazakhstan, while domestic gas could be additional or spare supply. CNPC signed an agreement with Turkmenistan last month to buy 30 billion cubic meters of gas a year over the next 30 years.

CNPC said it expects to complete feasibility studies on the proposed pipeline by October. Construction will start next year and operation will begin in 2010. Designed annual transport capacity is 30 billion cubic meters.

Covering 13 provinces and municipalities, the pipeline has a total length exceeding 7,000 kilometers and the trunk line will be 4,859 kilometers long, CNPC said.

CNPC didn't give an estimated investment for the project. For comparison, China's first west-east gas pipeline, which came on stream in late 2004, cost about US$5 billion to build. The first pipeline is about 4,000 kilometers long, linking Xinjiang's Tarim Basin and Shanghai.

"The second west-east pipeline will connect gas resources in central Asia to Yangtze River Delta and Pearl River Delta, both China's most prosperous regions," CNPC said. "This will optimize China's energy mix, ensure gas supply, promote energy efficiency and push forward international energy cooperation."

According to state plans, natural gas, which burns cleanly, will account for 5.3 percent of China's total primary energy consumption by 2010, up from 2.8 percent in 2005.

CNPC said the new pipeline will help increase the gas-use ratio by one to two percentage points. It could replace 76.8 million tons of coal use a year, cutting emissions of sulfur dioxide by 1.66 million tons and carbon dioxide by 150 million tons.

CNPC is the state-owned parent of Hong Kong-listed PetroChina Co, Asia's top oil firm by market value.

China Petroleum and Chemical Corporation (Sinopec), China's second-largest oil firm, said it will start construction this week of a project to transmit gas from the Puguang field in southwestern Sichuan Province to Shanghai.

The Sinopec project is estimated to have a total investment of 63.2 billion yuan (US$8.3 billion). Gas supply is expected to begin by the end of 2008.