If you thought China would take a breather from its quest for natural resources when it lost out on its bid to double its stake in Rio Tinto (NYSE:RTP), you don't know determination when you see it.

You probably recall that the nation put money into Brazil's Petrobras (NYSE:PBR) not long ago. The money -- $10 billion -- will allow the Brazilian state oil company to continue chugging along toward the $175 billion it plans to spend on exploration and production during the next five years. In exchange, China will be guaranteed 200,000 barrels of Brazilian crude daily for the next decade.

China has also made energy deals with Russia and Kazakhstan, and just missed in its efforts to double its percentage holding in Rio Tinto through Aluminum Corp. of China. Now, however, it appears that both China National Petroleum Corp. and CNOOC (NYSE:CEO) may be sniffing around the Argentine YPF unit of Spain's Repsol (NYSE:REP). At this point the specifics haven't been disclosed, but Repsol has openly discussed selling a stake in YPF, and there are those who think the Chinese may be eyeing up to 75% of the Spanish company's South American assets. 

Repsol has not been the production star in recent years that, for instance, its French neighbor Total (NYSE:TOT) has become. Much of Repsol's output slide has related to declining older wells at YPF. Indeed, the South American unit saw its operating profit fall by 5.6% last year. And since YPF constitutes a sizable portion of Repsol's overall oil and gas production, the unit's first quarter slippage of nearly 5% of oil equivalent production was particularly painful.  

However, not all the news from Repsol has been negative. Indeed, the company has made several oil and gas discoveries in the Santos Basin, the deepwater play that has been so good to Petrobras, ExxonMobil (NYSE:XOM) and Hess (NYSE:HES). I have to wonder if China's interest lies in access to Repsol's Santos Basin assets, keeping in mind that Repsol has the most exploration rights of any foreign company there.

Nevertheless, if I were looking for a European-based integrated oil and gas entity into which I might drop some shekels, Repsol would not be at the top of my list. I'd much rather place my faith -- and my money -- in a star like Total.   

In the meantime, it'll be a kick to watch China continue to scour the world in its quest for natural resources with which to stock its growing economy.

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Petroleo Brasileiro and Total SA are Motley Fool Income Investor selections. CNOOC is a Motley Fool Global Gains recommendation. Try any of our Foolish newsletters today, free for 30 days.

Fool contributor David Lee Smith doesn't have financial interests in any of the companies mentioned above. He does welcome your questions or comments. The Fool has a disclosure policy that's more fun than golf.