An oil company announced Thursday that it had found a conglomerate oil field with an estimated one-billion-ton reserve in the Junggar Basin in northwest China's Xinjiang Uygur Autonomous Region. The oil field in the Mahu Area, with a proven reserve of 520 million tons, may store up to 1.2 billion tons, according to the PetroChina Xinjiang branch. Tang Yong, a geologist with PetroChina, a leading oil producer in the country, said the area had the natural conditions for another one-billion-ton reserve.