The following table sets forth capitalized exploratory well costs and includes additions pending determination of proved reserves, reclassifications to proved reserves and costs charged to expense:



	Three months ended September 30,						Nine months ended September 30,
(in thousands)	2014			2013			2014			2013
Capitalized exploratory well costs at beginning of period	$	166,458		$	72,172		$	57,600		$	79,791
Additions pending determination of proved reserves	258,724			99,428			623,913			319,008
Reclassifications due to determination of proved reserves	(258,123		)	(112,821		)	(513,263		)	(340,020		)
Exploratory well costs charged to expense	(1,217		)	—			(2,408		)	—
Capitalized exploratory well costs at end of period	$	165,842		$	58,779		$	165,842		$	58,779

The following table sets forth capitalized exploratory wells costs and includes amounts capitalized for a period greater than one year:



(in thousands)	September 30, 2014		December 31, 2013
Exploratory wells in progress	$	29,059	$	14,794
Capitalized exploratory well costs capitalized for a period of one year or less	136,783		42,481
Capitalized exploratory well costs for a period greater than one year	—		1,206
Total capitalized exploratory well costs	$	165,842	$	58,481