1973 Volume 52 Issue 2 Pages 80-88
Although some oil and gas fields had been known in China since long ago, it had not been expected that China would become a major oil producing country because it consists mostly of metamorphic rocks and continental sediment formations in geology. After the revolution, over fifty oil and gas fields have been discovered in 16 continental sedimental basins. Major oil fields are Karamai and Lengho in Northwest and Tachin and Shenri in North and Central East. After discevery of Tachin oil field, production of crude oil climbed rapidly up to 25 million tons in 1971.
Oil reserves in the land is estimated at one to three billion tons. In addition to this, vast oil resources are expected in Gulf of Pohai and East Chima Sea.