A gas purifying plant is seen at Sinopec's Puguang gas field in Dazhou, Sichuan province, in this handout picture taken August 29, 2009 and made available to Reuters on December 6, 2013. A $6.4 ... more 
A gas purifying plant is seen at Sinopec's Puguang gas field in Dazhou, Sichuan province, in this handout picture taken August 29, 2009 and made available to Reuters on December 6, 2013. A $6.4 billion gas project being built by Chevron in China is facing further delays due to disagreements with partner PetroChina over how to develop the technically tricky fields, three industry sources said. However, a similar sour gas development in the same geological area, the $10 billion Puguang project developed by PetroChina's domestic rival Sinopec Corp, took 32 months from start of construction to first gas in 2010. It has a designed annual capacity of 12 bcm. Picture taken August 29, 2009. REUTERS/Zheng Qiang/Sinopec/Handout via Reuters (CHINA - Tags: ENERGY BUSINESS) ATTENTION EDITORS - THIS IMAGE HAS BEEN SUPPLIED BY A THIRD PARTY. IT IS DISTRIBUTED, EXACTLY AS RECEIVED BY REUTERS, AS A SERVICE TO CLIENTS. NO SALES. NO ARCHIVES. FOR EDITORIAL USE ONLY. NOT FOR SALE FOR MARKETING OR ADVERTISING CAMPAIGNS less 
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Reuters | Photo By HANDOUT / REUTERS
Fri, Dec 6, 2013 3:17 AM EST