UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 13G

Under the Securities Exchange Act of 1934

(Amendment No. 2)*

(Name of issuer)

(Title of class of securities)

(CUSIP number)

(Date of event which requires filing of this statement)

Check the appropriate box to designate the rule pursuant to which this Schedule is filed:

¨ Rule 13d-1(b)

x Rule 13d-1(c)

¨ Rule 13d-1(d)

The information required in the remainder of this cover page shall not be deemed to be “filed” for the purpose of Section 18 of the Securities Exchange Act of 1934 (“Act”) or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes).

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Item 1(a) Name of Issuer

Penn West Petroleum Ltd.

Item 1(b) Address of Issuer’s Principal Executive Offices

c/o Penn West Petroleum Ltd.

200, 207 – 9^th Avenue S.W.

Calgary, Alberta T2P 1K3

Canada

Item 2(a) Name of Persons Filing

China Investment Corporation

Land Breeze II S.À.R.L.

Item 2(b) Address of Principal Business Office or, if none, Residence

The address of China Investment Corporation is as follows:

New Poly Plaza

No. 1 Chaoyangmen Beidajie

Dongcheng District

Beijing 100010

People’s Republic of China

The address of Land Breeze II S.À.R.L. is as follows:

18, avenue Marie-Therese, L-2132 Luxembourg

Item 2(c) Citizenship

China Investment Corporation is established under the Company Law of the People’s Republic of China.

Land Breeze II S.À.R.L. is a société à responsibilité limitée incorporated and existing under the laws of Luxembourg.

Item 2(d) Title of Class of Securities

Common Stock

Item 2(e) CUSIP Number

707887105

Item 3 If this statement in filed pursuant to §§240.13d-1(b), or 13d-2(b) or (c), check whether the person filing is a:

Not applicable

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Item 4 Ownership

The number of shares of Common Stock beneficially owned by China Investment Corporation and Land Breeze II S.À.R.L. is as follows:

China Investment Corporation is a wholly state-owned company incorporated under the Company Law of the People’s Republic of China. Land Breeze II S.À.R.L is a wholly-owned subsidiary of China Investment Corporation. All information above regarding China Investment Corporation reflects the inclusion of 23,524,209 shares of Common Stock held by Land Breeze II S.À.R.L, a wholly-owned subsidiary of China Investment Corporation, and 180,225 shares of Common Stock held by another wholly owned subsidiary of China Investment Corporation, all as of December 31, 2011.

Item 5 Ownership of Five Percent or Less of a Class

Not applicable.

Item 6 Ownership of More than Five Percent on Behalf of Another Person

Not applicable.

Item 7 Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on by the Parent Holding Company

Not applicable.

Item 8 Identification and Classification of Members of the Group

Not applicable.

Item 9 Notice of Dissolution of Group

Not applicable.

Item 10 Certifications

By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect.

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SIGNATURE

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct as of February 9, 2012.

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Exhibit Index

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