Note 8—Suspended Wells

The following table reflects the net changes in suspended exploratory well costs during 2011, 2010 and 2009:


	Millions of Dollars
	2011			2010			2009
Beginning balance at January 1	$	1,013			908			660
Additions pending the determination of proved reserves		96			216			342
Reclassifications to proved properties		(72	)		(106	)		(39	)
Sales of suspended well investment		—			(4	)		(21	)
Charged to dry hole expense		—			(1	)		(34	)

Ending balance at December 31	$	1,037			1,013			908

The following table provides an aging of suspended well balances at December 31, 2011, 2010 and 2009:


	Millions of Dollars
	2011		2010		2009
Exploratory well costs capitalized for a period of one year or less	$	115		220		319
Exploratory well costs capitalized for a period greater than one year		922		793		589

Ending balance	$	1,037		1,013		908

Number of projects that have exploratory well costs that have been capitalized for a period greater than one year		40		40		34

The following table provides a further aging of those exploratory well costs that have been capitalized for more than one year since the completion of drilling as of December 31, 2011:


	Millions of Dollars
			Suspended Since
Project	Total		2008-2010		2005-2007		2001-2004
Aktote—Kazakhstan⁽²⁾	$	19		—		—		19
Alpine Satellite—Alaska⁽²⁾		21		—		—		21
Browse Basin—Australia⁽¹⁾		216		216		—		—
Caldita/Barossa—Australia⁽¹⁾		77		—		77		—
Fiord West—Alaska⁽²⁾		16		16		—		—
Harrison—U.K.⁽²⁾		15		—		15		—
Kairan—Kazakhstan⁽²⁾		27		—		14		13
Kalamkas—Kazakhstan⁽¹⁾		14		5		5		4
Kashagan—Kazakhstan⁽¹⁾		44		19		15		10
Malikai—Malaysia⁽²⁾		52		—		40		12
NPR-A—Alaska⁽²⁾		17		17		—		—
Petai—Malaysia⁽²⁾		30		19		11		—
Point Thomson—Alaska⁽²⁾		37		37		—		—
Rak More—Kazakhstan⁽¹⁾		22		22		—		—
Saleski—Canada⁽¹⁾		14		14		—		—
Shenandoah—Lower 48⁽¹⁾		43		43		—		—
Sunrise 3—Australia⁽²⁾		13		13		—		—
Surmont III and beyond—Canada⁽¹⁾		26		6		18		2
Su tu Nau—Vietnam⁽²⁾		18		9		9		—
Thornbury—Canada⁽¹⁾		19		19		—		—
Tiber—Lower 48⁽¹⁾		40		40		—		—
Titan—Norway⁽²⁾		11		11		—		—
Ubah—Malaysia⁽²⁾		34		34		—		—
Uge—Nigeria⁽¹⁾		29		15		14		—
Sixteen projects of $10 million or less each⁽¹⁾⁽²⁾		68		34		32		2

Total of 40 projects	$	922		589		250		83

(1) Additional appraisal wells planned.

(2) Appraisal drilling complete; costs being incurred to assess development.