Property, Plant and Equipment (Tables)

12 Months Ended

Dec. 31, 2016

Property Plant And Equipment [Abstract]

Components of Property, Plant and Equipment

Property, plant and equipment at December 31 were as follows:

	2016		2015
	(In millions)
Exploration and Production
Unproved properties	$	710	$	958
Proved properties		4,258		4,202
Wells, equipment and related facilities		38,821		38,738
		43,789		43,898
Bakken Midstream		3,018		2,757
Corporate and Other		100		171
Total — at cost		46,907		46,826
Less: Reserves for depreciation, depletion, amortization and lease impairment		23,312		20,474
Property, Plant and Equipment — Net	$	23,595	$	26,352

Net Changes in Capitalized Exploratory Well Costs

Capitalized Exploratory Well Costs:  The following table discloses the amount of capitalized exploratory well costs pending determination of proved reserves at December 31, and the changes therein during the respective years:

	2016			2015			2014
	(In millions)
Balance at January 1	$	1,415		$	1,416		$	2,045
Additions to capitalized exploratory well costs pending the determination of proved reserves		79			424			292
Reclassifications to wells, facilities and equipment based on the determination of proved reserves		—			(72	)		(629	)
Capitalized exploratory well costs charged to expense		(897	)		(356	)		(235	)
Dispositions and other		—			3			(57	)
Balance at December 31	$	597		$	1,415		$	1,416
Number of Wells at December 31		17			35			37

Exploratory Drilling Costs Capitalized in Excess of One Year After Completion of Drilling

Exploratory well costs capitalized for greater than one year following completion of drilling were $511 million at December 31, 2016, separated by year of completion as follows (in millions):

2015	$	238
2014		80
2013		48
2012		145
	$	511