Asset Retirement Obligations

3 Months Ended

Mar. 31, 2015

Asset Retirement Obligation Disclosure [Abstract]

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



	Three Months Ended March 31,
(millions)	2015			2014
Asset Retirement Obligations, Beginning Balance	$	751		$	586
Liabilities Incurred	10			1
Liabilities Settled	(8		)	(14		)
Revision of Estimate	24			72
Accretion Expense ⁽¹⁾	10			10
Asset Retirement Obligations, Ending Balance	$	787		$	655

⁽¹⁾Accretion expense is included in DD&A expense in the consolidated statements of operations.

For the three months ended March 31, 2015

Liabilities incurred were due to new wells and facilities and included $4 million for onshore US and $6 million for deepwater Gulf of Mexico. Liabilities settled in 2015 relate primarily to non-core US properties classified as held for sale.

Revisions in estimate for 2015 relate to changes in cost estimates for Eastern Mediterranean.

For the three months ended March 31, 2014

Liabilities settled in 2014 include $24 million for onshore US and deepwater Gulf of Mexico abandonments and $17 million related to properties classified as held for sale, offset by $27 million as a result of reclassifying remaining North Sea assets from held for sale to held and used.

Revision in estimate for 2014 included an increase of $67 million related to the non-operated MacCulloch North Sea field due to an increase in costs and a change in timing. See Note 3. Divestitures.