As investors wonder how pitched the battle for Unocal will become, one thing is clear: the company's assets would be a strong addition to the portfolio of either Chevron or China National Offshore Oil Corporation (CNOOC).

Many of Unocal's prime assets are in Chevron's core areas of operation: Unocal has a leading position in Asian gas, a strong standing in the Gulf of Mexico, and good assets in the Caspian. Key among those, however, are its Asian assets.