Consolidated Statements of Cash Flows (USD $) In Millions, unless otherwise specified	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012
Operating activities:
Net income	$ 1,378	$ 1,260
Adjustments to reconcile net income to net cash provided by operating activities:
Deferred income taxes	17	(27)
Depreciation, depletion and amortization	2,205	1,779
Impairments	49	271
Pension and other postretirement benefits, net	41	(56)
Exploratory dry well costs and unproved property impairments	619	287
Net gain on disposal of assets	4	(126)
Equity method investments, net	12	(14)
Changes in:
Current receivables, changes in	(151)	(646)
Inventories, changes in	(8)	(6)
Current accounts payable and accrued liabilities, changes in	(286)	156
All other operating, net	161	(66)
Net cash provided by operating activities	4,041	2,812
Investing activities:
Acquisitions, net of cash acquired	(74)	(806)
Additions to property, plant and equipment	(3,818)	(3,509)
Disposal of assets	402	193
Investments - return of capital	45	42
All other investing, net	34	49
Net cash used in investing activities	(3,411)	(4,031)
Financing activities:
Commercial paper, net	0	1,839
Debt issuance costs	0	9
Debt repayments	(148)	(111)
Purchases of common stock	(500)	0
Dividends paid	(376)	(360)
All other financing, net	70	26
Net cash (used in) provided by financing activities	(954)	1,385
Effect of exchange rate changes on cash	(6)	12
Net decrease in cash and cash equivalents	(330)	178
Cash and cash equivalents at beginning of period	684	493
Cash and cash equivalents at end of period	$ 354	$ 671