CNOOC, China's offshore oil producer offers big money for Unocal, as reported here. Many are atwitter with concern over the Chinese buying "our oil supply" - I, on the other hand, like it. I would rather the Chinese buy into the US market than almost anything. It shows they are, despite their Communist tradition, playing in the fields of capitalism and are truly members of the "core."
And if Chevron outbids them, then goodie for the Unocal shareholders.
By the way, Citgo is owned by the Venezuela's Petróleos de Venezuela (PDVSA) (think Chavez) - and China already has owned some interests in US refineries - Sinochem owned part of Pacific Refining Company in Hecules, CA (closed down 1994) (source). And don't forget British Petroleum (BP) owning Amoco and Total ( a French corporation) owning oil reserves in the US.