China reports big oil discovery: 2.2 billion barrels

PetroChina Ltd. announced it has found an offshore field that could become China's biggest new domestic-petroleum source in a decade, with reserves of 2.2 billion barrels, the official Xinhua News Agency said Wednesday. Such a field would be a "world-scale discovery". PetroChina is likely to have to do more drilling to confirm how much oil it can extract.

"They're adopting a lot of new methods, revisiting a lot of old fields using methods that were not available 10 or 15 years ago," Brock said. But much of it is of mediocre quality and in rock formations that are difficult and expensive to tap, Brock said.