UNITED STATES SECURITIES AND EXCHANGE COMMISSION

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 6-K

REPORT OF FOREIGN PRIVATE ISSUER Pursuant to Section 13a-16 or 15d-16 under the Securities Exchange Act of 1934

~~Pursuant~~For toFebruary ~~Rule~~25, ~~13a-16 or 15d-16 under the~~2013

Securities Exchange Act of 1934

For February 14, 2013

Commission File Number: 1-6702

NEXEN INC.

(Translation of registrant'’s name into English)

801- 7th Avenue S.W. Calgary, Alberta, Canada, T2P 3P7

Calgary, Alberta, Canada, T2P 3P7

(Address of principal executive offices)

Indicate by check mark whether the registrant files or will file annual reports under cover of Form 20-F or Form 40-F.

Form 20-F ~~____~~ o Form 40-F X x

Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(1): ~~____~~ o

Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(7): ~~____~~ o

DOCUMENTS FILED AS PART OF THIS FORM 6-K

See the Exhibit Index to this Form 6-K.

SIGNATURE

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

	NEXEN INC. (Registrant)
		NEXEN INC.
Date: February 14, 2013	By:	/s/ Rick C. Beingessner
		(Registrant)
		Name:	Rick C. Beingessner
Date:	February 25, 2013	By:	/s/ C. James Cummings
		Title:	Assistant Secretary
			Name: C. James Cummings
			Title: Assistant Secretary

Form 6-K Exhibit Index

Exhibit Number		Description
99.1		~~Letter~~Press ofRelease ~~Transmittal for Registered Common Shareholders of Nexen Inc. in connection with the Arrangement Agreement,~~ dated ~~July~~February 2325, ~~2012, involving Nexen Inc., CNOOC Limited and CNOOC Canada Holding Ltd.~~2013

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