In a remote corner of southwestern Sichuan Province, in an area of lush, terraced hillsides, oil exploration teams have been scaling cliffs to lay seismic charges and struggling to move heavy equipment along winding mountain roads.

That is where China hopes to find vast stores of natural gas trapped in shale rock. The U.S. Energy Information Administration has estimated that China's technically recoverable shale gas resources could be 50 percent bigger than those in the United States, where shale has transformed the energy sector.

That has sparked hopes that unlocking those resources could help meet China's relentlessly growing energy demand and ease its reliance on heavily polluting coal-fired power plants.