Changqing oilfield, China's largest oil and gas field, has produced over 600 billion cubic meters of natural gas, hitting a record high, China National Petroleum Corporation (CNPC) announced Tuesday. The cumulative production is equivalent to China's total natural gas consumption in two years. It can replace 720 million tons of standard coal and reduce carbon emissions by 1.657 billion tons. Located in northwest China's Erdos Basin, Changqing has played an important role in safeguarding the country's energy security, supplying gas to more than 50 cities in north and northwest China. (full story)