If this were a significant amount of oil (which as others have pointed out, it’s not) development of a field takes about a decade so any real impact would still be a long way off. But more importantly if China had its own reserves this could have a great stabilizing effect on world geopolitics since one of China’s greatest fears is being cut off from oil supplies in the Middle East by a blockade of the Strait of Malacca. It’s why they have spent billions to build overland pipelines to ports on the Arabian Sea, it’s why the fortify rocks in the South China Sea. China with even a moderate reserve could perhaps feel a little more secure