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ASSET RETIREMENT OBLIGATION (Tables)
 12 Months Ended
Dec. 31, 2012
Asset Retirement Obligation

The following table describes changes to the Company’s asset retirement obligation (ARO) liability for the years ended December 31, 2012 and 2011:

 

     2012     2011  
     (In millions)  

Asset retirement obligation at beginning of year

    $ 3,887     $ 2,872  

Liabilities incurred

      592       419  

Liabilities acquired

      72       592  

Liabilities settled

      (550 )      (549 ) 

Accretion expense

      232       154  

Revisions in estimated liabilities

      345       399  
  

 

 

    

 

 

  

Asset retirement obligation at end of year

      4,578       3,887  

Less current portion

      (478 )      (447 ) 
  

 

 

    

 

 

  

Asset retirement obligation, long-term

    $ 4,100     $ 3,440