6.	Property, Plant and Equipment

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


	2012		2011
	(In millions)
Exploration and Production
Unproved properties	$	3,558	$	4,064
Proved properties		4,072		3,975
Wells, equipment and related facilities		35,385		29,239

		43,015		37,278
Marketing, Refining and Corporate		2,538		2,432

Total — at cost		45,553		39,710
Less: Reserves for depreciation, depletion, amortization and lease impairment		16,746		14,998

Property, plant and equipment — net	$	28,807	$	24,712

Assets Held for Sale: In September 2012, the Corporation reached an agreement to sell its assets in Azerbaijan consisting of its interests in the Azeri-Chirag-Guneshli (ACG) fields and the associated Baku-Tbilisi-Ceyhan (BTC) pipeline for approximately $1 billion before normal post-closing adjustments. This transaction is subject to various government and regulatory approvals. In October 2012, the Corporation also announced that it had reached an agreement to sell its interests in the Beryl fields in the United Kingdom North Sea. The sale was completed in January 2013 for cash proceeds of approximately $440 million, see Note 21, Subsequent Events in the notes to the Consolidated Financial Statements. At December 31, 2012, long-term assets totaling $1,092 million, primarily comprising the net property, plant and equipment balances and allocated goodwill of $100 million have been classified as held for sale and reported in Other current assets. In addition, related asset retirement obligations and deferred income taxes totaling $539 million were reported in Accrued liabilities. At December 31, 2011, long-term assets totaling $764 million, including goodwill of $62 million and liabilities totaling $556 million were reported as held for sale. Properties classified as held for sale are not depreciated but are subject to impairment testing.

Capitalized Exploratory Wells 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:


	2012			2011			2010
	(In millions)
Beginning balance at January 1	$	2,022		$	1,783		$	1,437
Additions to capitalized exploratory well costs pending the determination of proved reserves		407			512			675
Reclassifications to wells, facilities and equipment based on the determination of proved reserves		(41	)		(171	)		(87	)
Capitalized exploratory well costs charged to expense		(129	)		(90	)		(110	)
Dispositions		—			(12	)		(132	)

Ending balance at December 31	$	2,259		$	2,022		$	1,783

Number of wells at end of year		68			59			77

The preceding table excludes exploratory dry hole costs of $248 million, $348 million and $127 million in 2012, 2011 and 2010, respectively, which were incurred and subsequently expensed in the same year. In 2012, capitalized well costs reclassified based on the determination of proved reserves primarily related to projects in Indonesia, Russia and the Joint Development Area of Malaysia/Thailand.

At December 31, 2012, exploratory drilling costs capitalized in excess of one year past completion of drilling were incurred as follows (in millions):


2011	$	404
2010		357
2009		426
2008		392
2007 and prior		228

	$	1,807

The capitalized well costs in excess of one year relate to 10 projects. Approximately 36% relates to Block WA-390-P, offshore Western Australia, where development planning and commercial activities, including negotiations with potential liquefaction partners, are ongoing. Successful negotiation with a third party liquefaction partner is necessary before the Corporation can negotiate a gas sales agreement and sanction development of the project. Approximately 36% of the capitalized well costs in excess of one year relates to the Corporation’s Pony discovery on Block 468 in the deepwater Gulf of Mexico. In the third quarter of 2012, the Corporation signed an exchange agreement with partners of the adjacent Green Canyon Block 512, which contains the Knotty Head discovery. Under this agreement covering Blocks 468 and 512, Hess was appointed operator and has a 20% working interest in the blocks, now collectively referred to as Stampede. Field development planning for Stampede is progressing and the project is targeted for sanction in 2014. Approximately 14% relates to Area 54, offshore Libya, where force majeure was withdrawn in March 2012 and the Corporation is pursuing commercial options. Approximately 7% relates to offshore Ghana where the Corporation completed drilling its seventh consecutive successful exploration well in February 2013. The Corporation now plans to submit an appraisal plan to the Ghanaian government for approval on or before June 2, 2013. In parallel, the Corporation has begun pre-development studies on the block. The remainder 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.