Acquisitions and divestitures.

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Business Acquisition Percentage Of Voting Interests Acquired Retained.

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Net production of natural gas per day.

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Net production of oil and natural gas liquids per day.

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Period of pipeline agreement.

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Period of provision of renewals.

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Preferential purchase right.

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The total cost of the acquired entity including the cash paid to shareholders of acquired entities, fair value of debt and equity securities issued to shareholders of acquired entities, the fair value of the liabilities assumed, and direct costs of the acquisition.

+ References

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-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

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Percentage of voting equity interests acquired in the business combination.

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The amount of acquisition cost of a business combination allocated to liabilities assumed.

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This element represents the acquisition-date fair value of the total consideration transferred which consists of the sum of the acquisition-date fair values of the assets transferred by the acquirer, the liabilities incurred by the acquirer to former owners of the acquiree, and the equity interests issued by the acquirer.

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Cost incurred, including capitalized costs and costs charged to expense, in acquisition of oil and gas properties.

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Amount of sales or other form of revenues attributable to the disposal group, including a component of the entity (discontinued operation), during the reporting period.

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Net quantities of an enterprise's interests in proved developed reserves of either crude oil (including condensate and natural gas liquids), natural gas, synthetic oil and gas, or other nonrenewable natural resource that is intended to be upgraded into synthetic oil and gas as of the beginning and the end of the year. "Net" quantities of reserves include those relating to the enterprise's operating and nonoperating interests in properties. Quantities of reserves relating to royalty interests owned are included in "net" quantities if the necessary information is available to the enterprise. "Net" quantities does not include reserves relating to interests of others in properties owned by the enterprise. The unit of measure for reserve quantities is defined as "barrels" for oil and synthetic oil reserves or "cubic feet" or "cubic meters" for natural gas and synthetic gas reserves.

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Acquisitions and Divestitures (Details Textuals) (USD $)	9 Months Ended														9 Months Ended							9 Months Ended
	Sep. 30, 2011	Mar. 31, 2011	Aug. 10, 2010	Jul. 31, 2010	Nov. 30, 2010 Mariner Energy Inc [Member]	Jun. 30, 2010 Gulf of Mexico, Devon [Member]	Dec. 31, 2010 Kitimat LNG [Member] Apache Canada [Member]	Dec. 31, 2010 Kitimat LNG [Member] EOG Canada [Member]	Mar. 31, 2011 Kitimat LNG [Member] Encana [Member]	Feb. 28, 2011 Pacific Trails Pipeline [Member] Apache Canada [Member]	Dec. 31, 2010 Pacific Trails Pipeline [Member] Apache Canada [Member]	Feb. 28, 2011 Pacific Trails Pipeline [Member] EOG Canada [Member]	Dec. 31, 2010 Pacific Trails Pipeline [Member] EOG Canada [Member]	Aug. 10, 2010 BP's Oil And Gas Operations [Member]	Sep. 30, 2011 PNG [Member]	Mar. 31, 2011 PTP and Kitimat LNG [Member] Apache Canada [Member]	Feb. 28, 2011 PTP and Kitimat LNG [Member] Apache Canada [Member]	Mar. 31, 2011 PTP and Kitimat LNG [Member] EOG Canada [Member]	Jul. 31, 2010 Bp Acquisitions [Member]	Oct. 08, 2010 Western Canada Sedimentary Basin [Member]	Nov. 04, 2010 Western Desert, Egypt [Member]	Sep. 30, 2011 Exxon Mobil United Kingdom North Sea Asset [Member] bpd bbl	Sep. 21, 2011 Exxon Mobil United Kingdom North Sea Asset [Member] cf	Dec. 31, 2010 Exxon Mobil United Kingdom North Sea Asset [Member] bbl
Acquisitions and Divestitures (Textuals) [Abstract]
Acquisitions of oil and gas property	$ 493,000,000
Sale of oil and gas property	202,000,000
Percentage of acquisition							51.00%	49.00%	30.00%	51.00%	25.50%	49.00%	24.50%			40.00%		30.00%
Total consideration transferred					2,700,000,000												50,000,000
Percentage of retained interest in acquisition		40.00%
Period of provision of renewals															5 years
Period of pipeline agreement															7 years
Purchase price of acquisition				6,400,000,000		1,050,000,000								3,100,000,000					7,000,000,000	3,250,000,000	650,000,000		1,750,000,000
Preferential purchase right			658,000,000
Liabilities assumed					$ 1,700,000,000
Net production of natural gas																							58,000,000
Net production of oil and natural gas liquids																						19,000
Proved reserve of oil																								68,000,000