Asset Retirement Obligations

12 Months Ended

Dec. 31, 2016

Asset Retirement Obligation Disclosure [Abstract]

11. Asset Retirement Obligations

The following table describes changes to our asset retirement obligations:

	2016			2015
	(In millions)
Balance at January 1	$	2,383		$	2,723
Liabilities incurred		42			57
Liabilities settled or disposed of		(196	)		(360	)
Accretion expense		117			126
Revisions of estimated liabilities		(230	)		92
Foreign currency translation		12			(255	)
Balance at December 31		2,128			2,383
Less: Current Obligations		216			225
Long-term Obligations at end of period	$	1,912		$	2,158

The liabilities settled or disposed of related primarily to abandonment activities conducted at the Valhall field offshore Norway in 2016 and 2015, the Gulf of Mexico in 2016, and the U.K. North Sea in 2015. The revisions in 2016 primarily relate to the South Arne Field, offshore Denmark, as a result of a 20-year extension to the license that extends expiry to 2047. Other revisions in 2016 and 2015 reflect changes in the expected scope of operations and updates to service and equipment costs. The fair value of sinking fund deposits that are legally restricted for purposes of settling asset retirement obligations, which are included in non-current Other assets in the Consolidated Balance Sheet, was $102 million at December 31, 2016 and $79 million at December 31, 2015.