Schedule II - Valuation and Qualifying Accounts

(In millions)

			Additions
	Balance at beginning of period		Charge to cost and expenses		Charge to other accounts -describe		Deductions -describe			Balance at end of period

Year ended December 31, 2011
Reserves and allowances deducted from asset accounts:
Allowance for doubtful accounts receivable	$	38	$	—	$	—	$	10	(a)	$	28
Allowance for obsolete materials and supplies	70		5		—		2		(b)	73
Valuation allowance on deferred tax assets	164		19		—		—			183

Year ended December 31, 2012
Reserves and allowances deducted from asset accounts:
Allowance for doubtful accounts receivable	$	28	$	—	$	—	$	8	(a)	$	20
Allowance for obsolete materials and supplies	73		8		—		15		(b)	66
Valuation allowance on deferred tax assets	183		28		—		1		(c)	210

Year ended December 31, 2013
Reserves and allowances deducted from asset accounts:
Allowance for doubtful accounts receivable	$	20	$	—	$	—	$	6	(a)	$	14
Allowance for obsolete materials and supplies	66		17		—		3		(b)	80
Valuation allowance on deferred tax assets	210		37		—		—			247

(a) Uncollectible accounts receivable written off, net of recoveries.

(b) Amount related to sale of rigs and related equipment.

Other schedules are omitted either because they are not required or are not applicable or because the required information is included in the financial statements or notes thereto.