Exploratory Costs (Tables)

3 Months Ended

Mar. 31, 2019

Capitalized exploratory well and project activity

Capitalized exploratory well and project activity is as follows:



	Three Months Ended March 31, 2019
	(in millions)
Beginning capitalized exploratory well costs	$	509
Additions to exploratory well costs pending the determination of proved reserves	647
Reclassification due to determination of proved reserves	(406		)
Ending capitalized exploratory well costs	$	750

Capitalized exploratory costs and the number of projects for which exploratory costs have been capitalized

Aging of capitalized exploratory costs and the number of projects for which exploratory well costs have been capitalized for a period greater than one year, based on the date drilling was completed, are as follows:



	As of March 31, 2019		As of December 31, 2018
	(in millions, except well counts)
Capitalized exploratory well costs that have been suspended:
One year or less	$	750	$	509
More than one year	—		—
	$	750	$	509
Number of wells or projects with exploratory well costs that have been suspended for a period greater than one year	—		—