Asset Retirement Obligations

12 Months Ended

Dec. 31, 2013

Asset Retirement Obligation Disclosure [Abstract]

Asset Retirement Obligations

Asset Retirement Obligations

Asset retirement obligations (ARO) consist primarily of estimated costs of dismantlement, removal, site reclamation and similar activities associated with our oil and gas properties. Changes in asset retirement obligations were as follows

	Year Ended December 31,
(millions)	2013			2012
Asset Retirement Obligations, Beginning Balance	$	402		$	377
Liabilities Incurred	90			43
Liabilities Settled	(41		)	(112		)
Revision of Estimate	156			102
Accretion Expense	28			22
Other	(49		)	(30		)
Asset Retirement Obligations, Ending Balance	$	586		$	402

For the year ended December 31, 2013

Liabilities incurred were due to new wells and facilities and included $68 million for deepwater Gulf of Mexico, $15 million for onshore US development, and $7 million for Eastern Mediterranean.

Liabilities settled of $41 million primarily related to deepwater Gulf of Mexico abandonment activities and non-core, onshore US assets sold.

Revisions were primarily due to changes in estimated costs for future abandonment activities and acceleration of timing and included $86 million for DJ Basin, $36 million for deepwater Gulf of Mexico, $10 million for Equatorial Guinea, and $7 million for Eastern Mediterranean. Increased US costs are due primarily to more stringent abandonment standards impacting procedures and materials.

Other includes $17 million for non-core, onshore US, and $32 million for China ARO liabilities transferred to liabilities associated with assets held for sale.

For the year ended December 31, 2012

Liabilities incurred were due to new wells and facilities and included $6 million for onshore US development, $8 million for deepwater Gulf of Mexico, and $29 million for offshore Israel.

Liabilities settled primarily included $20 million related to non-core, onshore US assets sold, $55 million related to North Sea assets sold, and $34 million related to the Leviathan-2 appraisal well, offshore Israel.

Revisions were due to changes in estimated costs for future abandonment activities and included $54 million for onshore US, $6 million for deepwater Gulf of Mexico, $26 million for offshore Israel, and $16 million for offshore China.

Other includes North Sea ARO liabilities transferred to liabilities associated with assets held for sale.

See Note 2. Additional Financial Statement Information and Note 3. Property Transactions.

Accretion expense is included in DD&Aexpense in the consolidated statements ofoperations.