Property, Plant and Equipment (Tables)

12 Months Ended

Dec. 31, 2014

Property Plant And Equipment [Abstract]

Components of Property, Plant and Equipment

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

	2014		2013
	(In millions)
Exploration and Production
Unproved properties	$	1,468	$	2,460
Proved properties		4,211		4,121
Wells, equipment and related facilities		40,649		37,274
		46,328		43,855
Corporate, Interest and Other		194		2,095
Total — at cost		46,522		45,950
Less: Reserves for depreciation, depletion, amortization and lease impairment		19,005		17,179
Property, plant and equipment — net*	$	27,517	$	28,771

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:

	2014			2013			2012
	(In millions)
Beginning balance at January 1	$	2,045		$	2,259		$	2,022
Additions to capitalized exploratory well costs pending the determination of proved reserves		292			237			407
Reclassifications to wells, facilities and equipment based on the determination of proved reserves		(629	)		(106	)		(41	)
Capitalized exploratory well costs charged to expense		(235	)		(267	)		(129	)
Dispositions and other		(57	)		(78	)		—
Ending balance at December 31	$	1,416		$	2,045		$	2,259
Number of wells at end of year		37			50			68

Exploratory Drilling Costs Capitalized

At December 31, 2014, exploratory drilling costs capitalized in excess of one year past the indicated year of completion of drilling were as follows (in millions):

2013	$	74
2012		373
2011		338
2010		211
2009 and prior		236
	$	1,232