6. 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

*	At December 31, 2013, Corporate, Interest and Other included $1,021 million of property, plant and equipment, net related to the divested Retail Marketing operations.

Assets Held for Sale: At December 31, 2014, assets totaling $1,035 million, which consisted of accounts receivable and other long-lived assets, related to the Corporation’s interest in HETCO, are reported in Other current assets in the Consolidated Balance Sheet. In addition, liabilities totaling $797 million, which consisted primarily of accounts payable, were reported in Accrued Liabilities. See Note 22, Subsequent Events.

At December 31, 2013, E&P assets totaling $1,097 million, primarily consisting of the net property, plant and equipment balances as well as allocated goodwill of $76 million, for the Corporation’s assets in Thailand and the Pangkah Field, offshore Indonesia (Hess 75%) were classified as held for sale and are reported within Other current assets in the Consolidated Balance Sheet. In addition, liabilities related to these properties totaling $286 million, primarily consisting of asset retirement obligations and deferred income taxes, are reported within Accrued liabilities. In 2014, the Corporation completed the sale of its interests in Thailand and Pangkah.

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

In 2014, reclassifications to wells, facilities and equipment based on the determination of proved reserves primarily related to the Stampede project in the Gulf of Mexico, which the co-owners sanctioned for development. Capitalized exploratory well costs charged to expense in 2014 included $169 million to write-off a previously capitalized exploration well in Green Canyon Block 469 in the Gulf of Mexico. In 2013, reclassifications to wells, facilities and equipment based on the determination of proved reserves primarily related to the Shenzi project in the Gulf of Mexico. Capitalized exploratory well costs charged to expense in 2013 included $260 million to write-off two previously capitalized exploration wells in Area 54, offshore Libya, due to civil unrest in the country. The preceding table excludes exploratory dry hole costs of $66 million, $77 million and $248 million in 2014, 2013 and 2012, respectively, which were incurred and subsequently expensed in the same year.

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

Capitalized exploratory well costs greater than one year old after completion of drilling were $1,232 million at December 31, 2014. Approximately 68% of the capitalized well costs in excess of one year relates to Block WA-390-P, offshore Western Australia, where development planning and commercial activities for the Corporation’s natural gas discoveries are ongoing. In December 2014, the Corporation executed a non-binding letter of intent with the North West Shelf (NWS), a third party joint venture with existing natural gas processing and liquefaction facilities. Successful execution of binding agreements with NWS is necessary before the Corporation can execute a gas sales agreement and sanction development of the project. Approximately 30% relates to offshore Ghana where the Corporation has drilled seven successful exploration wells. Appraisal plans for the seven wells on the block were submitted to the Ghanaian government in June 2013 for approval. Four of the plans were approved and discussions continue with the government on the three remaining appraisal plans. In the third quarter of 2014, the Corporation completed a three well appraisal program in Ghana. Well results are being evaluated and development planning is progressing. The remaining 2% of the capitalized well costs in excess of one year relates to projects where further drilling is planned or development planning and other assessment activities are ongoing to determine the economic and operating viability of the projects.