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			Three months ended
(in thousands)	March 31, 2014			March 31, 2013
Capitalized exploratory well costs at beginning of period	$	57,600		$	79,791
Additions pending determination of proved reserves	164,842			95,861
Reclassifications due to determination of proved reserves	(112,474		)	(69,477		)
Capitalized exploratory well costs at end of period	$	109,968		$	106,175

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



	Three months ended		Three months ended
(in thousands)	March 31, 2014		March 31, 2013
Exploratory wells in progress	$	62,280	$	21,676
Capitalized exploratory well costs capitalized for a period of one year or less	46,460		83,301
Capitalized exploratory well costs for a period greater than one year	1,228		1,198
Total capitalized exploratory well costs	$	109,968	$	106,175