An employee walks past oil tanks at a Sinopec refinery in Wuhan, Hubei province, in this April 25, 2012 file picture. China's biggest state-owned oil firms, sitting on ageing fields, are scrambling to... more 
An employee walks past oil tanks at a Sinopec refinery in Wuhan, Hubei province, in this April 25, 2012 file picture. China's biggest state-owned oil firms, sitting on ageing fields, are scrambling to ramp up crude oil and natural gas production to meet surging domestic demand through a slew of investments that also risk pushing up their costs. PetroChina, Sinopec Corp and CNOOC Ltd produced more oil and gas in the first nine months of this year. That was partly in response to the government's recent hike of domestic natural gas prices and moves to link pump prices more closely with international crude costs. Asia's largest refiner Sinopec Corp on October 29, 2013 posted a 20 percent rise in third-quarter net profit, beating forecasts, boosted by higher refining margins after China allowed domestic fuel prices to move more closely in line with global crude prices. REUTERS/Stringer/Files (CHINA - Tags: ENERGY BUSINESS) CHINA OUT. NO COMMERCIAL OR EDITORIAL SALES IN CHINA less 
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Reuters | Photo By DARLEY SHEN / REUTERS
Tue, Oct 29, 2013 2:27 PM EDT