Too early to make determination on China shale prospects BEIJING, Dec. 11 (UPI) -- There might not be enough geological information regarding China's shale potential and one investor said it's too early to make any assessments. The Chinese Ministry of Land Resources last week announced that 83 companies competed for 20 blocks in the country's latest shale gas auction. There were 14 state-owned and two private Chinese companies that won bids during the round, reported the official Xinhua News Agency. Chinese energy officials said Beijing isn't obligated to offer specific details about the quality of the blocks awarded during last week's auction. Xinhua said that some private and foreign companies examining China's shale potential have said that legal and geological issues made the economic advantage uncertain. Chinese shale may be located in parts of the country were infrastructure development is complex. A senior geologist at PetroChina, the country's biggest oil producer, told Xinhua on background, however, that "two or three years" worth of work in the country wasn't enough to decide future ambitions. For shale and other unconventional sources of natural gas, China aims to prove explorable reserves of around 7 trillion cubic feet by 2015.