80 percent of Exxon Mobil income came from outside the U. S.
Worldwide tax expenses in 2009 were US$ 81 billion. The tax goes to the place where the income is generated.
This is the case for all multi-national companies.

According to a later item in Forbes, on form 10K, Exxon Mobil paid US$7.7 billion in taxes in the US other than income in 2009.
Alan Jeffers of Exxon Mobil told Forbes that they paid substantial taxes to the U. S. Treasury in 2009, but that they were not required to disclose that information.