(7)	SUSPENDED EXPLORATORY WELL COSTS

We capitalize exploratory well costs until a determination is made that the well has either found proved reserves or that it is impaired. Capitalized exploratory well costs are presented in natural gas and oil properties in the accompanying consolidated balance sheets. If an exploratory well is determined to be impaired, the well costs are charged to exploration expense in the accompanying consolidated statements of operations. The following table reflects the changes in capitalized exploratory well costs for the year ended December 31, 2013, 2012 and 2011 (in thousands except for number of projects):

	2013			2012			2011
Balance at beginning of period	$	57,360		$	93,388		$	23,908
Additions to capitalized exploratory well costs pending the determination of proved reserves		39,832			153,250			86,996
Reclassifications to wells, facilities and equipment based on determination of proved reserves		(84,840	)		(184,298	)		(17,516	)
Divested wells		¾			(4,980	)		—
Capitalized exploratory well costs charged to expense		(5,388	)		—			—
Balance at end of period		6,964			57,360			93,388
Less exploratory well costs that have been capitalized for a period of one year or less		¾			(45,965	)		(83,860	)
Capitalized exploratory well costs that have been capitalized for a period greater than one year	$	6,964		$	11,395		$	9,528
Number of projects that have exploratory well costs that have been capitalized for a period greater than one year		1			5			3

As of December 31, 2013, the $7.0 million of capitalized exploratory well costs that have been capitalized for more than one year is comprised of one well which is evaluating pipeline options and is in our Marcellus Shale area. The following table provides an aging of capitalized exploratory well costs that have been suspended for more than one year as of December 31, 2013 (in thousands):

		Total				2013				2012				2011
Capitalized exploratory well costs that have been capitalized for more than one year		$	6,964			$	110			$	6,801			$	53