Every country has some strategic oil reserves. But this just reinforces with what many have long argued -- China needs a strong blue water navy.
The US for whatever reason is not running a very responsible fiscal policy and the fed has bought into the keynesian economics and is printing eye popping amount of money every day like it's just a game, China is wise to use its trillions of USD papers to buy up real physical assets abroad before the dollar gets debased any further, but this gives China a couple of problems:
1. Lots of resource rich countries in Africa or Latin america are not very stable and carries high geopolitical risk, say if China spends billions to buy up some mine and worked years to develop it, and that country in the meantime goes through a coup and the new government decides not to honour the old Chinese deal any more, then you can be sure as hell that no many countries in the world will cry out and stand up for China, in that case having a carrier battle group loaded with your advanced fighter planes and skilled marines (or merely possessing such capability) will help the new government to "remember" your investments.
2. Aside from China, there are plenty of other emerging countries which are all aspired to develop. If China, India, Brazil etc etc with multiple billions of people are all aspired to have the American life style -- big detached houses in the suburbs with 2 cars each household, massive metropolises with steel and concrete structures throughout, then there are simply not enough natural resources for all.
While on one hand every country needs to look at how to develop efficiently with aid of new technologies etc, on the other hand you do need to secure as much resources around the world for yourself as possible, China might be spending big nowadays to invest in these overseas resources, but come the days of increasingly scarce commodities, sky-rocketing prices and rising tensions, you need to have sufficient power projection to protect your investments overseas.
This is not to say China should become another America, sending carriers and meddle with other countries politics all over the world, that'll be suicidal, it just means this country has means to protect itself as its business interests expands beyond the traditional borders.
