Oil and gas output of Changqing oil field, hit a record-high of 51.95 million tonnes of oil equivalent in 2013, according to the oil field on Friday. It became the second oil field in China to have an annual output capacity of over 50 million tonnes of oil equivalent after Daqing, another China National Petroleum Corp. subsidiary in northeast China. Changqing has made key technological breakthroughs while developing oil reserves in the tough geological conditions of the Ordos Basin, making its oil and gas output grow from 5 million to 50 million tonnes of oil equivalent within 13 years. Changqing oil field has operations in five Chinese provinces and autonomous regions, including Gansu, Shaanxi, Ningxia, Inner Mongolia and Shanxi. It has an oil reserves of more thaan 3.4 billion tonnes and a natural gas reserve of more than 5 trillion cubic meters.