We're buying oil a lot faster than we are selling it, even after taking the Unocal deal into account. The thing to keep in mind about the Unocal deal is that it is the result of market forces. The guys who own Unocal would rather have China's dollars than the oil. Apparently, they think the dollars are worth more than the oil.
Yes, I hope they are right, too, but they are in a much better position than you or I to tell. And it's not like they don't have a choice. China is bidding against an American bidder for Unocal. They were the high bidder. Apparently, the other bidder thinks the price is too high, or they would increase their bid.
Or they could be getting out while the getting is good - nest egg and golden parachute to boot.