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Inventories
9 Months Ended
Sep. 30, 2011
Disclosure Text Block [Abstract] 
Inventories

4.  Inventories

 

       The major classes of inventories, included in other current assets, are as follows:

 September 30, December 31,
millions2011 2010
Crude oil$133 $126
Natural gas 34  64
NGLs 60  61
Total$227 $251