Note - Occidental Petroleum Corp.


UNLESS THIS CERTIFICATE IS PRESENTED BY AN AUTHORIZED REPRESENTATIVE OF THE DEPOSITORY TRUST COMPANY, A NEW YORK CORPORATION ("DTC"), TO ISSUER OR ITS AGENT FOR REGISTRATION OF TRANSFER, EXCHANGE, OR PAYMENT, AND ANY CERTIFICATE ISSUED IS REGISTERED IN THE NAME OF CEDE & CO. OR IN SUCH OTHER NAME AS IS REQUESTED BY AN AUTHORIZED REPRESENTATIVE OF DTC (AND ANY PAYMENT IS MADE TO CEDE & CO. OR TO SUCH OTHER ENTITY AS IS REQUESTED BY AN AUTHORIZED REPRESENTATIVE OF DTC), ANY TRANSFER, PLEDGE, OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL INASMUCH AS THE REGISTERED OWNER HEREOF, CEDE & CO., HAS AN INTEREST HEREIN.

OCCIDENTAL PETROLEUM CORPORATION

1.750% SENIOR NOTE DUE 2017

NO. []-[]

PRINCIPAL AMOUNT:
U.S.$[ ]

CUSIP: []
ISIN: []
COMMON CODE: []

ORIGINAL ISSUE DATE:

August 18, 2011

MATURITY DATE:

February 15, 2017

INTEREST RATE:

1.750% per annum

INTEREST PAYMENT DATES:

February 15 and August 15, commencing February 15, 2012

REGULAR RECORD DATES:

February 1 and August 1

REDEMPTION DATE/PRICE:

See Further Provisions Set Forth Herein

OCCIDENTAL PETROLEUM CORPORATION, a corporation duly organized and existing under the laws of the State of Delaware (herein referred to as the "Company," which term includes any successor under the Indenture hereinafter referred to), for value received, hereby promises to pay to CEDE & CO., or registered assigns, the lesser of (i) the Principal Amount specified above and (ii) the Principal Amount set forth on the Schedule of Exchanges of Interests in the Global Note attached hereto on the Maturity Date specified above (unless and to the extent earlier redeemed prior to such Maturity Date) and to pay interest thereon from August 18, 2011 or from the most recent Interest Payment Date to which interest has been paid or duly provided for, semi-annually in arrears on February 15 and August 15 in each year, commencing on February 15, 2012, at the rate per annum specified above, until the principal hereof is paid or made available for payment. Interest on this Note will be computed on the basis of a 360-day year comprised of twelve 30-day months. Interest payments for this Note will include interest accrued to but excluding each Interest Payment Date. The interest so payable, and punctually paid or duly provided for, on any Interest Payment Date will, as provided in the Indenture, be paid to the Person in whose name this Note (or one or more Predecessor Securities) is registered at the close of business on the Regular Record Date, which shall be the February 1 or August 1 (whether or not a Business Day), as the case may be, immediately preceding such


Interest Payment Date. If any Interest Payment Date or Maturity with respect to this Note falls on a day that is not a Business Day, the payment due on such Interest Payment Date or Maturity will be made on the next succeeding Business Day with the same force and effect as if made on such Interest Payment Date or Maturity, and no interest shall accrue on the amount so payable for the period from and after such Interest Payment Date or Maturity, as the case may be, until such following Business Day. Except as otherwise provided in the Indenture, any Defaulted Interest will forthwith cease to be payable to the Holder on the Regular Record Date with respect to such Interest Payment Date by virtue of having been such Holder and may either (1) be paid to the Person in whose name this Note (or one or more Predecessor Securities) is registered at the close of business on a Special Record Date for the payment of such Defaulted Interest to be fixed by the Trustee (as defined below), notice of which will be given to Holders of Notes not less than 10 days prior to such Special Record Date, or (2) be paid at any time in any other lawful manner not inconsistent with the requirements of any securities exchange on which the Notes may be listed, and upon such notice as may be required by such exchange, all as more fully provided in the Indenture. Payment of the principal of and interest on this Note will be made at the Corporate Trust Office of the Trustee in the Borough of Manhattan, The City of New York, or at the office or agency of the Trustee maintained for that purpose in the Borough of Manhattan, The City of New York, or at any other office or agency designated by the Company for such purpose, in such coin or currency of the United States of America as at the time of payment is legal tender for payment of public and private debts; provided that, at the option of the Company, payment of interest due on any Interest Payment Date may be made by check mailed to the address of the Person entitled thereto as such address shall appear in the Security Register or by wire transfer of immediately available funds if appropriate wire transfer instructions have been received in writing by the Trustee not less than 15 days prior to the applicable Interest Payment Date.

Reference is hereby made to the further provisions of this Note set forth below, which further provisions shall for all purposes have the same effect as if set forth at this place.

Unless the certificate of authentication hereon has been executed by the Trustee or its duly appointed co-authenticating agent by manual signature, this Note shall not be entitled to any benefit under the Indenture or be valid or obligatory for any purpose.

[signature page follows]

2


IN WITNESS WHEREOF, OCCIDENTAL PETROLEUM CORPORATION has caused this Note to be signed by the signature or facsimile signature of its Chairman of the Board, its President, a Vice President, its Treasurer or an Assistant Treasurer and attested by its Secretary or an Assistant Secretary by his or her signature or a facsimile thereof.

Dated: August 18, 2011

OCCIDENTAL PETROLEUM CORPORATION

By:


Name: Robert J. Williams, Jr.
Title: Vice President and Treasurer

Attest:


Name: Linda S. Peterson
Title: Assistant Secretary

Signature Page to Note


TRUSTEE'S CERTIFICATE OF AUTHENTICATION

This is one of the Securities of the series designated therein referred to in the within-mentioned Indenture.

Dated: August 18, 2011

The Bank of New York Mellon Trust Company, N.A., as Trustee

By:


Authorized Signatory

Signature Page to Note


This Note is one of a duly authorized issue of securities (herein called the "Securities") of the Company, issued and to be issued pursuant to the Indenture. This Note is one of a series designated by the Company as its 1.750% Senior Notes due 2017 (the "Notes"), limited in initial aggregate principal amount to $1,250,000,000. The Indenture does not limit the aggregate principal amount of the Securities.

The Company issued this Note pursuant to an Indenture, dated as of August 18, 2011 (herein called the "Indenture" which term, for the purpose of this Note, shall include the Officers' Certificate dated August 18, 2011, delivered pursuant to Sections 201 and 301 of the Indenture), between the Company and The Bank of New York Mellon Trust Company, N.A., as trustee (herein called the "Trustee," which term includes any successor trustee under the Indenture), to which Indenture and all indentures supplemental thereto reference is hereby made for a statement of the respective rights, limitations of rights, duties and immunities thereunder of the Company, the Trustee and Holders of the Notes and of the terms upon which the Notes are, and are to be, authenticated and delivered.

The Notes are issuable as Registered Securities, without coupons, in denominations of $2,000 and any amount in excess thereof which is an integral multiple of $1,000. As provided in the Indenture and subject to certain limitations therein set forth, the Notes are exchangeable for a like aggregate principal amount of Notes of like tenor of any authorized denomination, as requested by the Holder surrendering the same, upon surrender of the Note or Notes to be exchanged at any office or agency described below where Notes may be presented for registration of transfer.

The Company may, from time to time, without notice to or the consent of the Holders of the Notes, reopen this series of Notes and issue additional Notes.

The Notes are redeemable, in whole at any time or in part from time to time, at the option of the Company at a Redemption Price equal to the greater of (i) 100% of the principal amount of the Notes to be redeemed and (ii) the sum of the present values of the remaining scheduled payments of principal and interest on the Notes to be redeemed (not including any portion of such payments of interest accrued to the Redemption Date) discounted to the Redemption Date on a semi-annual basis (assuming a 360-day year comprised of twelve 30-day months) at the Adjusted Treasury Rate (as defined herein) plus 15 basis points plus, in each case, accrued and unpaid interest on the principal amount of the Notes being redeemed to the Redemption Date; provided, however, that installments of interest whose Stated Maturity is on or prior to the relevant Redemption Date shall be payable to the Holders of the Notes, or one or more Predecessor Securities, of record at the close of business on the relevant Regular Record Dates according to their terms and the provisions of the Indenture.

"Adjusted Treasury Rate" means, with respect to any Redemption Date, the rate per annum equal to the semi-annual equivalent yield to maturity of the Comparable Treasury Issue, assuming a price for the Comparable Treasury Issue (expressed as a percentage of its principal amount) equal to the Comparable Treasury Price for such Redemption Date.

"Comparable Treasury Issue" means, with respect to any Redemption Date, the United States Treasury security selected by the Quotation Agent as having a maturity comparable to the

5


remaining term of the Notes to be redeemed that would be utilized, at the time of selection and in accordance with customary financial practice, in pricing new issues of corporate debt securities of comparable maturity to the remaining term of the Notes.

"Comparable Treasury Price" means, with respect to any Redemption Date, (i) the average of the Reference Treasury Dealer Quotations for such Redemption Date, after excluding the highest and lowest Reference Treasury Dealer Quotations, or (ii) if the Trustee obtains fewer than three Reference Treasury Dealer Quotations, the average of all such Reference Treasury Dealer Quotations, such average in any case to be determined by the Quotation Agent, or (iii) if only one Reference Treasury Dealer Quotation is received, such Reference Treasury Dealer Quotation.

"Quotation Agent" means, with respect to any Redemption Date, the Reference Treasury Dealer appointed by the Company.

"Reference Treasury Dealer" means, with respect to any Redemption Date, (i) Barclays Capital Inc., Citigroup Global Markets Inc. and J.P. Morgan Securities LLC (or their respective affiliates which are primary U.S. Government securities dealers) and their respective successors; provided, however, that if any of them shall cease to be a primary U.S. Government securities dealer in the United States of America (a "Primary Treasury Dealer"), the Company shall substitute therefor another Primary Treasury Dealer, and (ii) any other Primary Treasury Dealer or Dealers selected by the Company.

"Reference Treasury Dealer Quotations" means, with respect to each Reference Treasury Dealer and any Redemption Date, the average, as determined by the Quotation Agent, of the bid and asked prices for the Comparable Treasury Issue (expressed in each case as a percentage of its principal amount) quoted in writing to the Trustee by such Reference Treasury Dealer at 5:00 p.m. on the third Business Day in The City of New York preceding such Redemption Date.

Notice of any redemption will be mailed at least 30 days but not more than 60 days before the Redemption Date to each Holder of the Notes to be redeemed, all as more fully provided in the Indenture. Unless the Company defaults in payment of the Redemption Price (or any accrued and unpaid interest on the Notes or portions thereof to be redeemed), on and after the Redemption Date interest will cease to accrue on the Notes or portions thereof called for redemption. If less than all of the Notes are to be redeemed, the Notes (or portions thereof) to be redeemed shall be selected by the Trustee by such method as the Trustee shall deem fair and appropriate, all as more fully provided in the Indenture.

All notices of redemption shall state the Redemption Date, the Redemption Price, if fewer than all the Outstanding Notes are to be redeemed, the identification (and, in the case of partial redemption, the principal amounts) of the particular Notes to be redeemed, that on the Redemption Date the Redemption Price will become due and payable upon each Note, or portion thereof, to be redeemed, together with accrued and unpaid interest thereon, that interest on each Note, or portion thereof, called for redemption will cease to accrue on the Redemption Date and the place or places where Notes may be surrendered for redemption.

6


In the event of redemption of this Note in part only, a new Note or Notes of like tenor in aggregate principal amount equal to and in exchange for the unredeemed portion of the principal amount hereof will be issued in authorized denominations in the name of the Holder hereof upon surrender hereof.

For all purposes of this Note and the Indenture, unless the context otherwise requires, all provisions relating to the redemption by the Company of this Note shall relate, in the case that this Note is redeemed, or to be redeemed, by the Company only in part, to that portion of the principal amount of this Note that has been, or is to be, redeemed.

If an Event of Default with respect to Notes shall occur and be continuing, the principal of and accrued interest on the Notes may be declared due and payable in the manner and with the effect provided in the Indenture.

The Indenture permits, in certain circumstances therein specified, the amendment thereof without the consent of the Holders of the Securities. The Indenture also permits, with certain exceptions as therein provided, the amendment thereof and the modification of the rights and obligations under the Indenture of the Company and the rights of Holders of the Securities of each series to be affected under the Indenture at any time by the Company and the Trustee with the consent of the Holders of a majority in aggregate principal amount of the Securities at the time Outstanding of each series to be affected. The Indenture also contains provisions permitting the Holders of a majority in aggregate principal amount of the Securities of each series at the time Outstanding, on behalf of the Holders of all the Securities of such series, to waive compliance by the Company with certain provisions of the Indenture and certain past defaults under the Indenture and their consequences. Any such consent or waiver by the Holder of this Note shall be conclusive and binding upon such Holder and upon all future Holders of this Note and of any Note issued upon the registration of transfer hereof or in exchange herefor or in lieu hereof, whether or not notation of such consent or waiver is made upon this Note.

No reference herein to the Indenture and no provision of this Note, subject to the provisions for satisfaction and discharge in Article Four of the Indenture, shall alter or impair the obligation of the Company, which is absolute and unconditional, to pay the principal of and interest on this Note at the times, place and rate, and in the coin or currency, herein prescribed.

The Indenture permits the Company, by irrevocably depositing cash or U.S. Government Obligations, in amounts and maturities sufficient to pay and discharge at the Stated Maturity or Redemption Date, as the case may be, the entire indebtedness on all Outstanding Notes, with the Trustee in trust, solely for the benefit of the Holders of all Outstanding Notes, to defease the Indenture with respect to the Notes (subject to specified exceptions), and, upon such deposit and satisfaction of the other conditions set forth in the Indenture, the Company shall be deemed to have paid and discharged its entire indebtedness on the Notes.

As provided in the Indenture and subject to certain limitations therein set forth, the transfer of Notes is registrable in the Security Register, upon surrender of a Note for registration of transfer at the Corporate Trust Office of the Trustee or at the office or agency of the Trustee maintained for such purpose in the Borough of Manhattan, The City of New York, or at such other offices or agencies as the Company may designate, duly endorsed by, or accompanied by a

7


written instrument of transfer in form satisfactory to the Company and the Security Registrar duly executed by, the Holder thereof or his attorney duly authorized in writing, and thereupon one or more new Notes of like tenor, of authorized denominations and for the same aggregate principal amount, will be issued to the designated transferee or transferees.

No service charge shall be made by the Company, the Trustee or the Security Registrar for any such registration of transfer or exchange, but the Company may require payment of a sum sufficient to cover any tax or other governmental charge payable in connection therewith (other than exchanges pursuant to Sections 304, 305, 906 or 1107 of the Indenture not involving any transfer).

Prior to due presentment of this Note for registration of transfer, the Company, the Trustee and any agent of the Company or the Trustee may treat the Person in whose name this Note is registered as the owner hereof for all purposes, whether or not this Note be overdue, and neither the Company, the Trustee nor any such agent shall be affected by notice to the contrary.

This Note shall be governed by and construed in accordance with the law of the State of New York (without regard to conflicts of laws principles thereof).

Customary abbreviations may be used in the name of a Holder or an assignee, such as TEN COM (=tenants in common), TEN ENT (=tenants by the entireties), JT TEN (=joint tenants with right of survivorship and not as tenants in common), CUST (=custodian), and U/G/M/A (=Uniform Gift to Minors Act).

All undefined terms (whether or not capitalized) used in this Note which are defined in the Indenture shall have the meanings assigned to them in the Indenture.

8


ASSIGNMENT FORM

To assign this Note, fill in the form below:

(I) or (we) assign and transfer this Note to


(Insert assignee's soc. sec. or tax I.D. no.)





(Print or type assignee's name, address and zip code)

and irrevocably appoint to transfer this Note on the books of the Company. The agent may substitute another to act for him.


Date:

Your Signature:


(Sign exactly as your name(s) appear(s) on the face of this Note)

Signature Guarantee*


*NOTICE: The signature must be guaranteed by an institution that is a member of one of the following recognized signature guarantee programs: (i) The Securities Transfer Agent Medallion Program (STAMP); (ii) The New York Stock Exchange Medallion Program (MNSP); (iii) The Stock Exchange Medallion Program (SEMP); or (iv) such other guarantee program acceptable to the Trustee.

9


SCHEDULE OF EXCHANGES OF INTERESTS IN THE GLOBAL NOTE

The initial outstanding principal amount of this Global Note is $[ ]. The following exchanges of an interest in this Global Note for an interest in another Global Note or for a Definitive Note, or exchanges of an interest in another Global Note or Definitive Notes for an interest in this Global Note, have been made:

Date of Exchange

Amount of
Decrease in
Principal
Amount of this
Global Note

Amount of
Increase in
Principal
Amount of this
Global Note

Principal
Amount of this
Global Note
Following Such
Decrease (or
Increase)

Signature of
Authorized
Officer of
Trustee or
Security
Custodian

10


10595Prospectus Supplement - Occidental Petroleum Corp.

The information in this preliminary prospectus supplement and the accompanying prospectus is not complete and may be changed. This preliminary prospectus supplement and the accompanying prospectus are not an offer to sell the notes or a solicitation of an offer to buy the notes in any jurisdiction where the offer or sale is not permitted.

SUBJECT TO COMPLETION, DATED AUGUST 15, 2011

Preliminary Prospectus Supplement
(To Prospectus dated August 15, 2011)

$ % Senior Notes due 20

$ % Senior Notes due 20


We are offering $ aggregate principal amount of our % senior notes due 20 and $ aggregate principal amount of our % senior notes due 20 .

In this prospectus supplement, we refer to the % senior notes due 20 as the "20 notes" and the % senior notes due 20 as the "20 notes" and the 20 notes and the 20 notes together as the "notes". We will pay interest on the notes of each series on and of each year, beginning , 2012. The 20 notes will mature on , 20 and the 20 notes will mature on , 20 . We may redeem some or all of the notes of either series at our option at any time and from time to time at the redemption prices described under "Description of the Notes:Optional Redemption" in this prospectus supplement.

The notes will be our unsecured senior obligations and will rank equally in right of payment with all of our other unsecured senior indebtedness from time to time outstanding. The notes will be issued only in denominations of $2,000 and integral multiples of $1,000 in excess thereof. The notes will not be listed on any securities exchange.

Investing in the notes involves risks. Please read "Risk Factors" beginning on page S-1 of this prospectus supplement and in our Annual Report on Form 10-K for the year ended December 31, 2010, which is incorporated by reference into this prospectus supplement and the accompanying prospectus.

Public Offering
Price(1)

Underwriting
Discount

Proceeds,
Before Expenses,
to Us

Per 20 Note

%

%

%

Total for 20 Notes

$

$

$

Per 20 Note

%

%

%

Total for 20 Notes

$

$

$


(1)

Plus accrued interest, if any, from August , 2011.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or determined if this prospectus supplement or the accompanying prospectus is truthful or complete. Any representation to the contrary is a criminal offense.

The notes will be delivered to investors on or about August , 2011 in book-entry form only through the facilities of The Depository Trust Company for the accounts of its participants, which may include Clearstream Banking, soci t anonyme, and Euroclear Bank S.A./N.V., against payment in New York, New York.


Joint Book-Running Managers

Barclays Capital

Citigroup

J.P. Morgan


August , 2011


TABLE OF CONTENTS

Page

Prospectus Supplement

About This Prospectus Supplement


i

Risk Factors

S-1

Occidental

S-3

Use of Proceeds

S-3

Description of the Notes

S-4

Certain United States Federal Income Tax Consequences To Non-U.S. Holders

S-11

Underwriting

S-13

Legal Matters

S-15

Where You Can Find More Information

S-15

Prospectus

About This Prospectus


i

Risk Factors

1

Forward-Looking Statements

1

Where You Can Find More Information

2

Occidental

3

Use of Proceeds

4

Description of Senior Debt Securities

4

Plan of Distribution

17

Legal Matters

18

Experts

18


ABOUT THIS PROSPECTUS SUPPLEMENT

No action has been or will be taken in any jurisdiction by us or by any underwriter that would permit a public offering of the notes or the possession or distribution of this prospectus supplement, the accompanying prospectus or any related free writing prospectus in any jurisdiction where action for that purpose is required, other than the United States. Unless otherwise expressly stated or the context otherwise requires, references to "dollars," "$" and other similar references in this prospectus supplement, the accompanying prospectus and any related free writing prospectuses are to U.S. dollars.

No person is authorized to give any information or to make any representations other than those contained or incorporated by reference in this prospectus supplement, the accompanying prospectus or any free writing prospectus we may provide to you in connection with this offering and, if given or made, such information or representations must not be relied upon as having been authorized. This prospectus supplement, the accompanying prospectus and any such free writing prospectus do not constitute an offer to sell or the solicitation of an offer to buy any securities other than the securities described in this prospectus supplement or an offer to sell or the solicitation of an offer to buy those securities in any circumstances or jurisdiction in which such offer or solicitation is unlawful.

Unless otherwise expressly stated or the context otherwise requires, the words "Occidental," "we," "us" and "our" as used in this prospectus supplement refer only to Occidental Petroleum Corporation and not to any of its subsidiaries.

i


RISK FACTORS

Investing in the notes involves risks. You should carefully consider the following risk factors, in addition to the other information contained or incorporated by reference in this prospectus supplement and the accompanying prospectus. Specifically, please see "Risk Factors" included in our Annual Report on Form 10-K for the year ended December 31, 2010 and the other information in that and the other reports that we file with the Securities and Exchange Commission, or SEC, that are incorporated by reference in this prospectus supplement for a discussion of risk factors that may affect our business. Realization of any of those risks or the following risks or adverse results from any matter listed under the heading "Forward-Looking Statements" in the accompanying prospectus or in any such reports could have a material adverse effect on our business, financial condition, cash flows and results of operations, and you might lose all or part of your investment.

Risks Related to the Notes

The notes will be effectively subordinated to the indebtedness and other liabilities of our subsidiaries.

Substantially all of our operations are conducted through our subsidiaries. None of our subsidiaries is a guarantor of the notes. As a result, our right to receive assets upon the liquidation or recapitalization of any of our subsidiaries, and your consequent right to benefit from our receipt of those assets, will be subject to the claims of such subsidiary's creditors. Accordingly, the notes are effectively subordinated to all indebtedness and other liabilities, including trade payables, of our subsidiaries. Even if we were recognized as a creditor of one or more of our subsidiaries, our claims would still be effectively subordinated to any security interests in or other liens on the assets of any such subsidiary and to any indebtedness or other liabilities of any such subsidiary senior to our claims.

In addition, we derive substantially all of our revenues from our subsidiaries. As a result, our cash flow and our ability to service our debt and other obligations, including the notes, will depend on the results of operations of our subsidiaries and upon the ability of our subsidiaries to provide us with cash to pay amounts due on our obligations, including the notes. Our subsidiaries are separate and distinct legal entities and have no obligation to make payments on the notes or to make funds available to us for that purpose. In addition, dividends, loans or other distributions from our subsidiaries to us may be subject to contractual and other restrictions, are dependent upon results of operations of our subsidiaries, may be subject to tax or other laws limiting our ability to repatriate funds from foreign subsidiaries and may be subject to other business considerations.

The notes will be unsecured and therefore will be effectively subordinated to any secured indebtedness we may incur.

The notes will not be secured by any of our assets. As a result, the notes will be effectively subordinated to any secured debt we or our subsidiaries may incur in the future to the extent of the value of the assets securing such debt. In any liquidation, dissolution, bankruptcy or other similar proceeding, the holders of any of our secured debt and the secured debt of our subsidiaries may assert rights against the assets pledged to secure that debt in order to receive full payment of their debt before the assets may be used to pay other creditors, including the holders of the notes.

Our credit ratings may not reflect all risks of an investment in the notes and there is no protection in the indenture for holders of the notes in the event of a ratings downgrade.

Our credit ratings are an assessment by rating agencies of our ability to pay our debts when due but they may not reflect the potential impact of all risks related to an investment in the notes. Consequently, real or anticipated changes in our credit ratings will generally affect the market value of the notes. Credit ratings are not a recommendation to buy, sell or hold any security, and may be revised or withdrawn at any time by the issuing organization in its sole discretion. We have no

S-1


obligation to maintain the ratings and neither we nor any underwriter undertakes any obligation to advise holders of notes of any change in ratings. Each agency's rating should be evaluated independently of any other agency's rating.

The indenture does not limit the amount of indebtedness that we or our subsidiaries may incur.

The indenture does not limit our ability or that of our subsidiaries to incur additional indebtedness or contain provisions that would afford holders of the notes protection in the event of a decline in our credit quality or a take-over, recapitalization or highly leveraged or similar transaction. Accordingly, we and our subsidiaries could, in the future, enter into transactions that could increase the amount of indebtedness outstanding at that time or otherwise adversely affect your position in our consolidated capital structure or our credit ratings.

If an active trading market does not develop for the notes, you may be unable to sell your notes or to sell your notes at a price that you deem sufficient.

The notes are a new issue of securities with no established trading market, and we do not intend to list them on any securities exchange or automated quotation system. As a result, an active trading market for the notes may not develop, or if one does develop, it may not be sustained. If an active trading market fails to develop or cannot be sustained, you may not be able to resell your notes at their fair market value or at all.

S-2


OCCIDENTAL

Our principal businesses consist of three segments operated by our subsidiaries and affiliates. The oil and gas segment explores for, develops, produces and markets crude oil, including natural gas liquids (NGLs) and condensate (together with NGLs, "liquids"), as well as natural gas. The chemical segment manufactures and markets basic chemicals, vinyls and other chemicals. The midstream, marketing and other segment gathers, treats, processes, transports, stores, purchases and markets crude oil, liquids, natural gas, carbon dioxide and power. It also trades around its assets, including pipelines and storage capacity, and trades oil and gas, other commodities and commodity-related securities. Our principal executive offices are located at 10889 Wilshire Boulevard, Los Angeles, California 90024, telephone (310) 208-8800.

USE OF PROCEEDS

The net proceeds from this offering are expected to be approximately $ million, after deducting the underwriting discounts and our estimated offering expenses. We intend to use the net proceeds from the sale of the notes for general corporate purposes, which may include ordinary course working capital increases, acquisitions, retirement of debt, stock repurchases and other business opportunities.

S-3


DESCRIPTION OF THE NOTES

The 20 and the 20 notes will each constitute a separate series of senior debt securities under an indenture (the "indenture") to be entered into between us and The Bank of New York Mellon Trust Company, N.A., as trustee. We will issue the notes under an officers' certificate pursuant to such indenture setting forth the specific terms applicable to such notes. References to the "indenture" in this description mean such indenture as so supplemented by such certificate.

The following description is a summary of some of the provisions of the notes and the indenture. This summary is not complete and is qualified in its entirety by reference to the indenture. You should carefully read the summary below, the description of the general terms and provisions of our senior debt securities set forth in the accompanying prospectus under the heading "Description of Senior Debt Securities" and the indenture before investing in the notes.

This description of the notes supplements and, to the extent it is inconsistent, replaces the description of the general provisions of the senior debt securities and the indenture in the accompanying prospectus. The notes are "senior debt securities" as that term is used in the accompanying prospectus, the indenture is referred to in the accompanying prospectus as the "Senior Indenture" and the trustee is referred to in the accompanying prospectus as the "Senior Indenture Trustee." In this description, the term "Securities" refers to all senior debt securities that may be issued under the indenture and includes the notes.

Description of the Notes

The notes are unsecured and will rank equally in right of payment with all of our other senior unsecured indebtedness. The indenture does not limit the aggregate principal amount of Securities that we may issue under the indenture and we may, without the consent of holders of outstanding Securities, issue additional Securities thereunder. In addition, the indenture does not limit the amount of other unsecured debt that we or our subsidiaries may issue or incur. Such other unsecured debt may have different terms than the notes. Our previously issued and outstanding senior debt does have different terms than the notes (including different restrictive covenants and event of default provisions). The terms of the notes will only be as described in the indenture, the accompanying prospectus and this prospectus supplement. As of June 30, 2011, we had approximately $4.3 billion of senior debt securities outstanding which ranked equally in right of payment with the notes.

Substantially all of our operations are conducted through our subsidiaries. None of our subsidiaries is a guarantor of the notes. As a result, our right to receive assets upon the liquidation or recapitalization of any of our subsidiaries, and your consequent right to benefit from our receipt of those assets, will be subject to the claims of such subsidiary's creditors. Accordingly, the notes are effectively subordinated to all indebtedness and other liabilities, including trade payables, of our subsidiaries. Even if we were recognized as a creditor of one or more of our subsidiaries, our claims would still be effectively subordinated to any security interests in or other liens on the assets of any such subsidiary and to any indebtedness or other liabilities of any such subsidiary senior to our claims.

Principal, Maturity and Interest

The 20 notes will be initially limited to $ aggregate principal amount, and the 20 notes will be initially limited to $ aggregate principal amount. The 20 notes will mature on , 20 and the 20 notes will mature on , 20 . We may, from time to time, without the consent of the holders of the notes of any series, reopen the 20 notes or the 20 notes or both and issue additional notes of such series.

Interest on the 20 notes will accrue at the rate of % per year, and interest on the 20 notes will accrue at the rate of % per year. Interest on the notes will be payable semi-annually in

S-4


arrears on and , commencing on , 2012. We will make each interest payment to the holders of record of the notes at the close of business on the immediately preceding and , respectively.

If any interest payment date, maturity date or redemption date for the 20 notes or the 20 notes falls on a day that is not a business day, the payment will be made on the next business day, and no interest will accrue on that payment for the period from and after such interest payment date, maturity date or redemption date until such following business day.

Interest on the 20 notes and the 20 notes will accrue from August , 2011 and will be computed on the basis of a 360-day year comprised of twelve 30-day months.

Interest payable on any interest payment date or on the maturity date of the 20 notes or the 20 notes shall be the amount of interest accrued from, and including, the immediately preceding interest payment date in respect of which interest has been paid or duly provided for on the notes of such series (or from and including the original issue date of the notes of such series, if no interest has been paid or duly provided for on the notes of such series) to, but not including, such interest payment date or maturity date, as the case may be.

Place of Payment, Transfer and Exchange

All payments on the notes will be made, and transfers of the notes will be registrable, at the trustee's office in The City of New York, unless we designate another place for such purpose.

Optional Redemption

The 20 notes are redeemable at our option, in whole at any time or in part from time to time, and the 20 notes are redeemable at our option, in whole at any time or in part from time to time prior to , 20 , at a redemption price equal to the greater of:

100% of the principal amount of the notes of such series to be redeemed; and

the sum of the present values of the remaining scheduled payments of principal and interest on the notes of such series to be redeemed (not including any portion of such payments of interest accrued to the redemption date) discounted to the redemption date on a semi-annual basis (assuming a 360-day year comprised of twelve 30-day months) at the Adjusted Treasury Rate plus basis points, in the case of the 20 notes, and basis points, in the case of the 20 notes;

plus, in each case, accrued and unpaid interest on the principal amount of the notes of such series being redeemed to the redemption date.

On and after 20 , the 20 notes are redeemable at our option, in whole at any time or in part from time to time, at a redemption price equal to 100% of the principal amount of the 20 notes to be redeemed, plus accrued and unpaid interest on the principal amount of the 20 notes being redeemed to the redemption date.

Notwithstanding the foregoing, with respect to payments of interest on the 20 notes or the 20 notes that are due and payable on any interest payment dates falling on or prior to a redemption date for the notes of such series, we will make such payments to the record holders of such notes at the close of business on the relevant regular record dates.

We will send to each holder of the 20 notes or the 20 notes, as applicable, notice of any redemption of notes of such series at least 30 days but not more than 60 days before the applicable redemption date. Unless we default in payment of the redemption price (or accrued and unpaid interest) with respect to the notes to be redeemed, no interest will accrue on the notes or portions

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thereof so redeemed for the period on and after such redemption date. If less than all of the notes of such series are to be redeemed, the trustee will select the notes (or portions thereof) to be redeemed by such method as the trustee deems fair and appropriate.

"Adjusted Treasury Rate" means, with respect to any redemption date for the 20 notes or the 20 notes, as applicable, the rate per year equal to the semi-annual equivalent yield to maturity of the Comparable Treasury Issue, assuming a price for the Comparable Treasury Issue (expressed as a percentage of its principal amount) equal to the Comparable Treasury Price for such redemption date.

"Comparable Treasury Issue" means, with respect to any redemption date for the 20 notes or the 20 notes, as applicable, the United States Treasury security selected by the Quotation Agent as having a maturity comparable to the remaining term of the notes of such series to be redeemed that would be utilized, at the time of selection and in accordance with customary financial practice, in pricing new issues of corporate debt securities of comparable maturity to the remaining term of the notes of such series.

"Comparable Treasury Price" means, with respect to any redemption date for the 20 notes or the 20 notes, as applicable, (1) the average of the Reference Treasury Dealer Quotations for such redemption date, after excluding the highest and lowest Reference Treasury Dealer Quotations, or (2) if the trustee obtains fewer than three Reference Treasury Dealer Quotations, the average of all such Reference Treasury Dealer Quotations, such average in any case to be determined by the Quotation Agent, or (3) if only one Reference Treasury Dealer Quotation is received, such Reference Treasury Dealer Quotation.

"Quotation Agent" means, with respect to any redemption date for the 20 notes or the 20 notes, as applicable, the Reference Treasury Dealer appointed by us.

"Reference Treasury Dealer" means, with respect to any redemption date for the 20 notes or the 20 notes, as applicable, (1) Barclays Capital Inc., Citigroup Global Markets Inc. and J.P. Morgan Securities LLC (or their respective affiliates which are primary U.S. Government securities dealers) and their respective successors; provided, however, that if any of them shall cease to be a primary U.S. Government securities dealer in the United States of America (a "Primary Treasury Dealer"), we will substitute for it another Primary Treasury Dealer and (2) any other Primary Treasury Dealer or Dealers selected by us.

"Reference Treasury Dealer Quotations" means, with respect to each Reference Treasury Dealer and any redemption date for the 20 notes or the 20 notes, as applicable, the average, as determined by the Quotation Agent, of the bid and asked prices for the Comparable Treasury Issue (expressed in each case as a percentage of its principal amount) quoted in writing to the trustee by such Reference Treasury Dealer at 5:00 p.m. on the third business day in The City of New York preceding such redemption date.

Discharge

We may terminate at any time our obligations under the indenture with respect to either or both series of notes (other than certain limited obligations, such as the obligation to transfer and exchange the notes of that series) by (1)(a) delivering all of the notes of that series to the trustee to be cancelled or (b) depositing with the trustee in trust funds or non-callable United States government or government-guaranteed obligations sufficient without reinvestment to pay all remaining principal and interest on the notes of that series and (2) complying with certain other provisions of the indenture.

If we elect to discharge our obligations with respect to either or both series of notes by depositing cash or United States government or government guaranteed obligations as described above, under present law such discharge is likely to be treated for United States federal income tax purposes as a redemption of notes of that series prior to maturity in exchange for the property deposited in trust. In

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that event, each holder would generally recognize, at the time of discharge, gain or loss for United States federal income tax purposes measured by the difference between (1) the sum of (a) the amount of any cash and (b) the fair market value of any property deposited in trust deemed received by such holder (unless attributable to accrued interest) and (2) such holder's tax basis in the notes of that series deemed surrendered. After the discharge, each such holder would likely be treated as if it held an undivided interest in the cash (or investments made therewith) and the property held in trust (or investments made with interest received therefrom). Each such holder would generally be subject to tax liability in respect of interest income and original issue discount, if applicable, thereon and would recognize any gain or loss upon any disposition, including redemption, of the assets held in trust. Although tax might be owed, the holder of a discharged note would not receive cash (except for current payments of interest on that note) until the maturity or earlier redemption (or, if applicable, repurchase by us at the option of the holder) of that note. United States federal income tax treatment of this nature could affect the purchase price that a holder would receive upon the sale of the notes. You are urged to consult with your tax advisor regarding the tax consequences of the discharge of our obligations.

Book-Entry; Delivery and Form

The notes will be issued in the form of one or more global notes ("Global Notes") which will be held by the trustee as custodian for The Depository Trust Company (the "Depositary"), New York, New York, and registered in the name of Cede & Co., as nominee of the Depositary. All interests in the Global Notes will be subject to the operations and procedures of the Depositary, Euroclear Bank S.A./N.V. ("Euroclear") and Clearstream Banking, soci t anonyme ("Clearstream, Luxembourg"). The notes will be issued in fully registered form without coupons and will be issued in, and beneficial interests in the Global Notes must be held in, minimum denominations of $2,000 and integral multiples of $1,000 in excess thereof.

Notwithstanding the foregoing, if (1) the Depositary notifies us that it is unwilling or unable to continue as depositary for the notes of any series or if the Depositary ceases to be eligible to act in such capacity and a successor depositary is not appointed by us within 90 days, (2) an event or default (as defined in the indenture) with respect to the notes of any series shall have occurred and be continuing or (3) we in our sole discretion shall determine that the notes of any series will no longer be represented by Global Notes, the Global Notes of such series will be exchanged for notes of such series in definitive form of like tenor and in an equal aggregate principal amount in authorized denominations. Such definitive notes will be registered in such name or names as the Depositary instructs the trustee.

The Depositary has advised us that pursuant to procedures established by it (i) upon the issuance of the Global Notes, the Depositary or its custodian will credit, on its internal system, the principal amount of the individual beneficial interests represented by such Global Notes to the respective accounts of persons who have accounts with such Depositary and (ii) ownership of beneficial interests in the Global Notes will be shown on, and the transfer of such ownership will be effected only through, records maintained by the Depositary or its nominee (with respect to interests of participants) and the records of participants (with respect to interests of persons other than participants). Ownership of beneficial interests in the Global Notes will be limited to persons who have accounts with the Depositary ("participants") or persons who hold interests through participants. Holders may hold their interests in the Global Notes directly through the Depositary if they are participants in such system, or indirectly through organizations that are participants in such system.

So long as the Depositary, or its nominee, is the registered owner or holder of the notes, the Depositary or such nominee, as the case may be, will be considered the sole owner or holder of the notes represented by such Global Notes for all purposes under the indenture. No beneficial owner of

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an interest in the Global Notes will be able to transfer that interest except in accordance with the Depositary's procedures and those provided for under the indenture.

Payments of the principal of and premium, if any, and interest on the Global Notes will be made to the Depositary or its nominee, as the case may be, as the registered owner of the Global Notes. Neither we nor the trustee or any paying agent under the indenture will have any responsibility or liability for any aspect of the records relating to or payments made on account of beneficial ownership interests in the Global Notes or for maintaining, supervising or reviewing any records relating to such beneficial ownership interests.

The Depositary has advised us that its present practice is, upon receipt of any payment of principal of and premium, if any, and interest on the Global Notes, to credit participants' accounts immediately with payments in amounts proportionate to their respective beneficial interests in the principal amount of the Global Notes as shown on the records of the Depositary. Payments by participants to owners of beneficial interests in the Global Notes held through such participants will be governed by standing instructions and customary practice, as is now the case with securities held for the accounts of customers registered in the names of nominees for such customers. Such payments will be the responsibility of such participants. Transfers between participants in the Depositary will be effected in the ordinary way through the Depositary's same-day funds settlement system in accordance with the Depositary's rules and will be settled in same-day funds.

The Depositary has advised us as follows: the Depositary is a limited purpose trust company organized under the laws of the State of New York, a member of the Federal Reserve System, a "clearing corporation" within the meaning of the Uniform Commercial Code and a "clearing agency" registered pursuant to the provisions of Section 17A of the Securities Exchange Act of 1934. The Depositary was created to hold securities for its participants and facilitate the clearance and settlement of securities transactions between participants through electronic book-entry changes in accounts of its participants, thereby eliminating the need for physical movement of certificates. Participants include securities brokers and dealers, banks, trust companies and clearing corporations and certain other organizations. Indirect access to the Depositary system is available to others such as banks, brokers, dealers and trust companies that clear through or maintain a custodial relationship with a participant, either directly or indirectly, or indirect participants.

Although the Depositary has agreed to the foregoing procedures in order to facilitate transfers of interests in the Global Notes among participants of the Depositary, it is under no obligation to perform such procedures, and such procedures may be discontinued at any time. None of us, any of the underwriters or the trustee will have any responsibility for the performance by the Depositary or its participants or indirect participants of their respective obligations under the rules and procedures governing their operations.

Clearstream, Luxembourg and Euroclear hold interests on behalf of their participating organizations through customers' securities accounts in Clearstream, Luxembourg's and Euroclear's names on the books of their respective depositaries, which hold those interests in customers' securities accounts in the depositaries' names on the books of the Depositary. At the present time, Citibank, N.A. acts as U.S. depositary for Clearstream, Luxembourg, and JPMorgan Chase Bank, N.A. acts as U.S. depositary for Euroclear (the "U.S. Depositaries").

Clearstream, Luxembourg holds securities for its participating organizations ("Clearstream Participants") and facilitates the clearance and settlement of securities transactions between Clearstream Participants through electronic book-entry changes in accounts of Clearstream Participants, thereby eliminating the need for physical movement of certificates. Clearstream, Luxembourg provides to Clearstream Participants, among other things, services for safekeeping, administration, clearance and settlement of internationally traded securities and securities lending and borrowing.

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Clearstream, Luxembourg is registered as a bank in Luxembourg, and as such is subject to regulation by the Commission de Surveillance du Secteur Financier and the Banque Centrale du Luxembourg, which supervise and oversee the activities of Luxembourg banks. Clearstream Participants are financial institutions including investment banks, securities brokers and dealers, banks, trust companies and clearing corporations, and may include the underwriters or their affiliates. Indirect access to Clearstream, Luxembourg is available to other institutions that clear through or maintain a custodial relationship with a Clearstream Participant. Clearstream, Luxembourg has established an electronic bridge with Euroclear as the operator of the Euroclear System (the "Euroclear Operator") in Brussels to facilitate settlement of trades between Clearstream, Luxembourg and the Euroclear Operator.

Distributions with respect to the notes held beneficially through Clearstream, Luxembourg will be credited to cash accounts of Clearstream Participants in accordance with its rules and procedures, to the extent received by the U.S. Depositary for Clearstream, Luxembourg.

Euroclear holds securities and book-entry interests in securities for participating organizations ("Euroclear Participants") and facilitates the clearance and settlement of securities transactions between Euroclear Participants, and between Euroclear Participants and participants of certain other securities intermediaries through electronic book-entry changes in accounts of such participants or other securities intermediaries. Euroclear provides Euroclear Participants, among other things, with safekeeping, administration, clearance and settlement, securities lending and borrowing, and related services. Euroclear Participants are investment banks, securities brokers and dealers, banks, central banks, supranationals, custodians, investment managers, corporations, trust companies and certain other organizations, and may include the underwriters or their affiliates. Non-participants in Euroclear may hold and transfer beneficial interests in a Global Note through accounts with a participant in the Euroclear System or any other securities intermediary that holds a book-entry interest in a Global Note through one or more securities intermediaries standing between such other securities intermediary and Euroclear.

Securities clearance accounts and cash accounts with the Euroclear Operator are governed by the Terms and Conditions Governing Use of Euroclear and the related Operating Procedures of the Euroclear System, and applicable Belgian law (collectively, the "Terms and Conditions"). The Terms and Conditions govern transfers of securities and cash within Euroclear, withdrawals of securities and cash from Euroclear and receipts of payments with respect to securities in Euroclear. All securities in Euroclear are held on a fungible basis without attribution of specific certificates to specific securities clearance accounts. The Euroclear Operator acts under the Terms and Conditions only on behalf of Euroclear Participants, and has no record of or relationship with persons holding through Euroclear Participants.

Distributions on the notes held beneficially through Euroclear will be credited to the cash accounts of Euroclear Participants in accordance with the Terms and Conditions, to the extent received by the U.S. Depositary for Euroclear.

Transfers between Euroclear Participants and Clearstream Participants will be effected in the ordinary way in accordance with their respective rules and operating procedures.

Cross-market transfers between direct participants in the Depositary, on the one hand, and Euroclear Participants or Clearstream Participants, on the other hand, will be effected through the Depositary in accordance with the Depositary's rules on behalf of Euroclear or Clearstream, Luxembourg, as the case may be, by its U.S. Depositary; however, such cross-market transactions will require delivery of instructions to Euroclear or Clearstream, Luxembourg, as the case may be, by the counterparty in such system in accordance with the rules and procedures and within the established deadlines (European time) of such system. Euroclear or Clearstream, Luxembourg, as the case may be, will, if the transaction meets its settlement requirements, deliver instructions to its U.S. Depositary to

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take action to effect final settlement on its behalf by delivering or receiving interests in the Global Notes in the Depositary, and making or receiving payment in accordance with normal procedures for same-day fund settlement applicable to the Depositary. Euroclear Participants and Clearstream Participants may not deliver instructions directly to their respective U.S. Depositaries.

Due to time zone differences, the securities accounts of a Euroclear Participant or Clearstream Participant purchasing an interest in a Global Note from a direct participant in the Depositary will be credited, and any such crediting will be reported to the relevant Euroclear Participant or Clearstream Participant, during the securities settlement processing day (which must be a business day for Euroclear or Clearstream, Luxembourg) immediately following the settlement date of the Depositary. Cash received in Euroclear or Clearstream, Luxembourg as a result of sales of interests in a Global Note by or through a Euroclear Participant or Clearstream Participant to a direct participant in the Depositary will be received with value on the settlement date of the Depositary but will be available in the relevant Euroclear or Clearstream, Luxembourg cash account only as of the business day for Euroclear or Clearstream, Luxembourg following the Depositary's settlement date.

The information in this section concerning the Depositary, Euroclear and Clearstream, Luxembourg and their book-entry systems has been obtained from sources that we believe to be reliable, but we take no responsibility for the accuracy of that information.

Although Euroclear and Clearstream, Luxembourg have agreed to the foregoing procedures to facilitate transfers of interests in the Global Notes among Euroclear Participants and Clearstream Participants, they are under no obligation to perform or to continue to perform such procedures, and such procedures may be discontinued at any time. None of us, any of the underwriters or the trustee will have any responsibility for the performance by Euroclear or Clearstream, Luxembourg or their respective Participants of their respective obligations under the rules and procedures governing their operations.

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CERTAIN UNITED STATES FEDERAL INCOME TAX CONSEQUENCES
TO NON-U.S. HOLDERS

The following is a summary of certain United States federal income tax consequences of the purchase, ownership, and disposition of the notes by an initial purchaser of the notes that, for United States federal income tax purposes, is not a "United States person" as defined below (a "Non-U.S. Holder") and purchases the notes pursuant to this prospectus supplement. This summary is based upon existing United States federal income tax law, which is subject to differing interpretations or change, possibly with retroactive effect. This summary does not discuss all aspects of United States federal income taxation which may be important to particular investors in light of their individual investment circumstances, such as notes held by investors subject to special tax rules (e.g., banks, financial institutions, insurance companies, broker- dealers, partnerships and their partners, and tax-exempt organizations (including private foundations)) or to persons that will hold the notes as part of a straddle, hedge, conversion, constructive sale, or other integrated security transaction for United States federal income tax purposes, all of whom may be subject to tax rules that differ significantly from those summarized below. In addition, this summary does not discuss any (i) United States federal income tax consequences to a Non-U.S. Holder that (A) is engaged in the conduct of a United States trade or business, (B) is a nonresident alien individual and such holder is present in the United States for 183 or more days during the taxable year, or (C) is a corporation which operates through a United States branch, and (ii) state, local or non-United States tax considerations. Each prospective investor is urged to consult its tax advisor regarding the United States federal, state, local, and non-United States income and other tax considerations of the purchase, ownership, and disposition of the notes.

For the purposes of this summary, a "United States person" is, for United States federal income tax purposes, (i) a citizen or resident of the United States, (ii) a corporation (or other entity classified as a corporation for United States Federal income tax purposes) created or organized in or under the law of, the United States or any State or the District of Columbia, (iii) an estate the income of which is includible in gross income for United States federal income tax purposes regardless of its source, or (iv) a trust (A) the administration of which is subject to the primary supervision of a United States court and which has one or more United States persons who have the authority to control all substantial decisions of the trust or (B) that has otherwise validly elected to be treated as a United States person.

Interest Income

Payments of interest on the notes made to a Non-U.S. Holder will not be subject to United States federal income or withholding tax provided that (i) such holder (A) does not actually or constructively own 10% or more of the total combined voting power of all classes of our stock entitled to vote and (B) is not a controlled foreign corporation that is related to us through stock ownership for United States federal income tax purposes and (ii) the requirements of section 871(h) or 881(c) of the Internal Revenue Code of 1986, as amended (the "Code"), are satisfied as described below under the heading "Owner's Statement Requirement."

Sale or Exchange

A Non-U.S. Holder generally will not be subject to United States federal income tax on gain recognized on a sale, exchange, redemption, or other disposition of a note.

Owner's Statement Requirement

In order to avoid withholding tax on interest under section 871(h) or 881(c) of the Code, either the beneficial owner of a note or a securities clearing organization, bank or other financial institution that holds customers' securities in the ordinary course of its trade or business (a "Financial

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Institution") and that holds a note on behalf of such owner must file a statement with us or our agent to the effect that the beneficial owner is not a United States person. This requirement will be satisfied if we or our agent receives (i) a statement (an "Owner's Statement") from the beneficial owner of a note in which such owner certifies, under penalties of perjury, that such owner is not a United States person and provides such owner's name and address, and if applicable, information with respect to tax treaty benefits, on an Internal Revenue Service Form W-8BEN (or suitable substitute form) or (ii) a statement from the Financial Institution holding the note on behalf of the beneficial owner in which the Financial Institution certifies, under penalties of perjury, that it has received the Owner's Statement, together with a copy of the Owner's Statement. The beneficial owner must inform us or our agent (or, in the case of a statement described in clause (ii) of the immediately preceding sentence, the Financial Institution) within 30 days of any change in information on the Owner's Statement.

Backup Withholding and Information Reporting

In general, a Non-U.S. Holder will not be subject to backup withholding or information reporting with respect to payments of interest and proceeds from the sale or other disposition of notes, if an Owner's Statement or similar documentation is received or an exemption has otherwise been established, provided that the relevant agent does not know or have reason to know that the payee is a United States person. If a note is held by a Non-U.S. Holder through a United States or United States related broker or financial institution and, in such case, if the Non-U.S. Holder fails to provide an Owner's Statement or other appropriate evidence of non-United States status, backup withholding may apply.

Backup withholding is not an additional tax. Any amount withheld under the backup withholding rules from a payment to a Non-U.S. Holder may be refunded or credited against the Non-U.S. Holder's United States federal income tax liability if the Non-U.S. Holder provides the required information to the United States Internal Revenue Service.

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UNDERWRITING

We and the underwriters named below have entered into an underwriting agreement with respect to the notes. Subject to certain conditions, each underwriter has severally agreed to purchase the principal amount of the notes indicated in the following table.

Underwriters

Principal Amount
of 20 Notes

Principal Amount
of 20 Notes

Barclays Capital Inc.

$

$

Citigroup Global Markets Inc.

J.P. Morgan Securities LLC

Total

$

$

The underwriters are committed, subject to certain conditions, to take and, if any are taken, pay for all of the notes being offered.

Notes sold by the underwriters to the public will initially be offered at the respective initial public offering prices set forth on the cover of this prospectus supplement. Any notes sold by the underwriters to securities dealers may be sold at a discount from the initial public offering prices of up to % of the principal amount of the 20 notes and up to % of the principal amount of the 20 notes. Any such securities dealers may resell notes purchased from the underwriters to certain other brokers or dealers at a discount from the initial public offering prices of up to % of the principal amount of the 20 notes and up to % of the principal amount of the 20 notes. If all the notes of any series are not sold at the initial offering prices, the underwriters may change the offering prices to the public and the other selling terms of the notes of such series. The offering of the notes by the underwriters is subject to receipt and acceptance and subject to the underwriters' right to reject any order in whole or in part.

The following table shows the underwriting discounts that we are to pay to the underwriters in connection with this offering:

Per 20 Note

Per 20 Note

Total

Underwriting discounts

%

%

$

The notes of each series are a new issue of securities with no established trading market. We have been advised by the underwriters that the underwriters intend to make a market in each series of notes but they are not obligated to do so and may discontinue market making at any time without notice. No assurance can be given as to whether a trading market for any series of notes will develop or as to the liquidity of any trading market for any series of notes that may develop.

In connection with the offering, the underwriters may purchase and sell notes in the open market. These transactions may include short sales, stabilizing transactions and purchases to cover positions created by short sales. Short sales involve the sale by the underwriters of a greater number of notes than they are required to purchase in the offering. Stabilizing transactions consist of certain bids or purchases made for the purpose of preventing or retarding a decline in the market prices of the notes while the offering is in progress.

The underwriters also may impose a penalty bid. This occurs when a particular underwriter repays to the underwriters a portion of the underwriting discount received by it because the underwriting syndicate has repurchased notes sold by or for the account of such underwriter in stabilizing or short covering transactions.

These activities by the underwriters, as well as other purchases by the underwriters for their own accounts, may stabilize, maintain or otherwise affect the market prices of the notes. As a result, the prices of the notes may be higher than the prices that otherwise might exist in the open market. If

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these activities are commenced, they may be discontinued by the underwriters at any time without notice. These transactions may be effected in the over-the-counter market or otherwise.

We estimate that our share of the total expenses of the offering, excluding underwriting discounts and commissions, will be approximately $ .

We have agreed to indemnify the several underwriters against certain liabilities, including liabilities under the Securities Act of 1933.

In the ordinary course of their respective businesses, the underwriters and their respective affiliates have engaged, and may in the future engage, in commercial banking and investment banking transactions with us and our affiliates, for which they have received and in the future may receive compensation.

European Economic Area

In relation to each Member State of the European Economic Area which has implemented the Prospectus Directive (each, a Relevant Member State), each underwriter has represented and agreed that with effect from and including the date on which the Prospectus Directive is implemented in that Relevant Member State (the Relevant Implementation Date) it has not made and will not make an offer of notes to the public in that Relevant Member State other than:

a.

to any legal entity which is a qualified investor as defined in the Prospectus Directive;

b.

to fewer than 100 or, if the Relevant Member State has implemented the relevant provision of the 2010 PD Amending Directive, 150, natural or legal persons (other than qualified investors as defined in the Prospectus Directive), as permitted under the Prospectus Directive, subject to obtaining the prior consent of the representatives of the underwriters for any such offer; or

c.

in any other circumstances fully within Article 3(2) of the Prospectus Directive,

provided that no such offer of notes shall requires us or any underwriter to publish a prospectus pursuant to Article 3 of the Prospectus Directive or supplement a prospectus pursuant to Article 16 of the Prospectus Directive.

For the purposes of this provision, the expression an "offer of notes to the public" in relation to any notes in any Relevant Member State means the communication in any form and by any means of sufficient information on the terms of the offer and the notes to be offered so as to enable an investor to decide to purchase or subscribe the notes, as the same may be varied in that Member State by any measure implementing the Prospectus Directive in that Member State and the expression "Prospectus Directive" means Directive 2003/71/EC (and amendments thereto, including the 2010 PD Amending Directive, to the extent implemented in the Relevant Member State), and includes any relevant implementing measure in each Relevant Member State and the expression "2010 PD Amending Directive" means Directive 2010/73/EU.

United Kingdom

Each underwriter has represented and agreed that:

a.

it has only communicated or caused to be communicated and will only communicate or cause to be communicated an invitation or inducement to engage in investment activity (within the meaning of Section 21 of the Financial Services and Markets Act 2000, as amended ("FSMA")) received by it in connection with the issue or sale of the notes in circumstances in which Section 21(1) of the FSMA would not apply to us; and

b.

it has complied and will comply with all applicable provisions of the FSMA with respect to anything done by it in relation to the notes in, from or otherwise involving the United Kingdom.

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LEGAL MATTERS

Certain legal matters in connection with the offering of the notes will be passed upon for us by Kendrick F. Royer, our Assistant General Counsel. Certain matters relating to federal income tax considerations will be passed upon for us by Skadden, Arps, Slate, Meagher & Flom LLP, Los Angeles, California. Sidley Austin LLP, San Francisco, California, will act as counsel to the underwriters.

WHERE YOU CAN FIND MORE INFORMATION

We file annual, quarterly and current reports, proxy statements and other information with the Securities and Exchange Commission, or SEC. You may read and copy any document we file at the SEC's Public Reference Room at 100 F Street, N.E., Room 1580, Washington, D.C. 20549. Please call the SEC at 1-800-SEC-0330 for further information on the Public Reference Room. The SEC also maintains a website at www.sec.gov that contains reports, proxy statements and other information regarding issuers that file electronically with the SEC, including us. These reports, proxy statements and other information can also be read through the Investor Relations section of our website at www.oxy.com. Information on our website does not constitute part of, and is not incorporated by reference in, this prospectus supplement or the accompanying prospectus and should not be relied upon in connection with making any investment decision with respect to the notes.

The SEC allows us to "incorporate by reference" the information that we file with the SEC. This permits us to disclose important information to you by referencing these filed documents. Any information referenced this way is considered part of this prospectus supplement, and any information filed with the SEC subsequent to the date of this prospectus supplement will automatically be deemed to update and supersede this information. We incorporate by reference the following documents (except for "furnished" information described below) which have been filed with the SEC:

Annual Report on Form 10-K for the year ended December 31, 2010;

Quarterly Reports on Form 10-Q for the quarters ended March 31, 2011 and June 30, 2011; and

Current Reports on Form 8-K filed on January 20, 2011, January 26, 2011, April 28, 2011, May 6, 2011, May 10, 2011, July 18, 2011 and July 26, 2011.

We also incorporate by reference all documents we may subsequently file with the SEC pursuant to Sections 13(a), 13(c), 14 or 15(d) of the Securities Exchange Act of 1934 after the date of this prospectus supplement until the termination of the offering.

Information furnished under Items 2.02 or 7.01 (or corresponding information furnished under Item 9.01 or included as an exhibit) in any past or future Current Report on Form 8-K (including the Current Reports on Form 8-K listed above) that we file with the SEC, unless otherwise expressly specified in such report, is not incorporated by reference in this prospectus supplement.

We will provide without charge upon written or oral request, a copy of any or all of the documents which are incorporated by reference into this prospectus supplement. Requests should be directed to:

Occidental Petroleum Corporation
10889 Wilshire Boulevard
Los Angeles, California 90024
Attn: Robert J. Williams
Telephone: (310) 208-8800

You should rely only on the information contained or incorporated by reference in this prospectus supplement and the accompanying prospectus and any applicable free writing prospectuses. We have not authorized any person to provide you with different information. If anyone provides you with different or inconsistent information, you should not rely on it. We are not making an offer to sell

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these securities in any jurisdiction where the offer or sale is not permitted. The information contained in this prospectus supplement and the accompanying prospectus is accurate only as of the respective dates on the front covers of this prospectus supplement and the accompanying prospectus, the information contained in any related free writing prospectus will be accurate only as of the date of that document, and the information contained in any document incorporated by reference in this prospectus supplement is accurate only as the date of such document. Our business, financial condition, results of operations and prospects may have changed since those respective dates.

Except as provided above, no other information, including information on our internet site, is incorporated by reference in this prospectus supplement, the accompanying prospectus or any free writing prospectus.

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Prospectus

OCCIDENTAL PETROLEUM CORPORATION

Senior Debt Securities


We may offer, issue and sell senior debt securities from time to time.

We may offer and sell these senior debt securities to or through one or more underwriters, dealers and agents, or directly to purchasers, on a continuous or delayed basis.

This prospectus describes some of the general terms that may apply to these senior debt securities. The specific terms of any senior debt securities to be offered will be described in a supplement to this prospectus. The prospectus supplement may also add, update or change information contained in this prospectus. You should read this prospectus and the applicable prospectus supplement carefully before you make your investment decision.

Investing in our senior debt securities involves risks. See "Risk Factors" in our most recent annual report on Form 10-K, which is incorporated herein by reference, in any of our subsequently filed quarterly and current reports that are incorporated herein by reference and in any applicable prospectus supplement.


This prospectus may not be used to sell senior debt securities unless accompanied by a prospectus supplement.


Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or determined if this prospectus or the accompanying prospectus supplement is truthful or complete. Any representation to the contrary is a criminal offense.


The date of this prospectus is August 15, 2011.


TABLE OF CONTENTS

Page

About This Prospectus

i

Risk Factors


1

Forward-Looking Statements


1

Where You Can Find More Information


2

Occidental


3

Use of Proceeds


4

Description of Senior Debt Securities


4

Plan of Distribution


17

Legal Matters


18

Experts


18

ABOUT THIS PROSPECTUS

Unless otherwise stated or the context otherwise requires, the terms "Occidental," "we," "us" and "our" refer to Occidental Petroleum Corporation and not any of its subsidiaries.

This prospectus is part of a registration statement we filed with the Securities and Exchange Commission (the "SEC") using a "shelf" registration process. Under this shelf registration process, we may from time to time sell the senior debt securities described in this prospectus in one or more offerings.

This prospectus describes some of the general terms that may apply to these senior debt securities. The specific terms of any senior debt securities to be offered will be described in a supplement to this prospectus. The prospectus supplement may also add, update or change information contained in this prospectus. You should read carefully this prospectus and the applicable prospectus supplement together with any additional information described under the heading "Where You Can Find More Information" before you make your investment decision.


RISK FACTORS

Investing in our senior debt securities involves risks. You should carefully consider the risk factors incorporated by reference in this prospectus and included in any accompanying prospectus supplement. Specifically, please see "Risk Factors" included in our Annual Report on Form 10-K for the year ended December 31, 2010 and the other information in that and the other reports that we file with the SEC that are incorporated by reference in this prospectus for a discussion of risk factors that may affect our business. Realization of any of those risks or the risks disclosed in any accompanying prospectus supplement or adverse results from any matter listed under the heading "Forward-Looking Statements" in this prospectus, in any accompanying prospectus supplement or in any such reports could have a material adverse effect on our business, financial condition, cash flows and results of operations, and you might lose all or part of your investment.

FORWARD-LOOKING STATEMENTS

This prospectus, any accompanying prospectus supplement and the documents incorporated by reference herein and therein contain forward-looking statements and involve risks and uncertainties that could materially affect expected results of operations, liquidity, cash flows and business prospects. Factors that could cause results to differ materially include, but are not limited to:

global commodity pricing fluctuations;

international political conditions;

general domestic political conditions, including permitting;

supply and demand considerations for our products;

not successfully completing, or any material delay of, any development of new fields, expansion projects, capital expenditures, efficiency-improvement projects, acquisitions or dispositions;

failure to achieve expected production from existing and future oil and gas development projects or acquisitions

exploration risks such as drilling unsuccessful wells;

any general economic recession or slowdown domestically or internationally;

higher-than-expected costs;

liability for remedial actions under existing or future environmental regulations and litigation;

liability resulting from pending or future litigation;

potential disruption or interruption of our production or manufacturing facilities due to accidents, chemical releases, labor unrest, weather, natural disasters, political events or insurgent activity;

changes in law or regulations; and

changes in tax law or regulations.

Words such as "estimate," "project," "predict," "will," "would," "should," "could," "may," "might," "anticipate," "aim," "goal," "target," "objective," "plan," "intend," "believe," "expect" or similar expressions that convey the uncertainty of future events or outcomes generally indicate forward-looking statements. You should not place undue reliance on these forward-looking statements, which speak only as of the date of this prospectus or, in the case of documents incorporated by reference, as of the date of those documents. Unless legally required, we do not undertake any obligation to update any forward-looking statements, as a result of new information, future events or otherwise. Certain risks

1


that may affect our results of operations and financial position appear under the heading "Risk Factors" and elsewhere in our most recent annual report on Form 10-K, which is incorporated herein by reference, as well as in any of our subsequently filed quarterly or current reports that are incorporated herein by reference and any applicable prospectus supplement.

WHERE YOU CAN FIND MORE INFORMATION

We file annual, quarterly and current reports, proxy statements and other information with the SEC. You may read and copy any document we file at the SEC's Public Reference Room at 100 F Street, N.E., Room 1580, Washington, D.C. 20549. Please call the SEC at 1-800-SEC-0330 for further information on the Public Reference Room. The SEC also maintains a website at www.sec.gov that contains reports, proxy statements and other information regarding issuers that file electronically with the SEC, including us. These reports, proxy statements and other information can also be read through the Investor Relations section of our website at www.oxy.com. Information on our website does not constitute part of, and is not incorporated by reference in, this prospectus and should not be relied upon in connection with making any investment decision with respect to our securities.

The SEC allows us to "incorporate by reference" the information that we file with the SEC. This permits us to disclose important information to you by referencing these filed documents. Any information referenced this way is considered part of this prospectus, and any information filed with the SEC subsequent to the date of this prospectus, or contained in any accompanying prospectus supplement or related free-writing prospectus, will automatically be deemed to update and supersede this information. We incorporate by reference the following documents (except for "furnished" information described below) which have been filed with the SEC:

Annual Report on Form 10-K for the year ended December 31, 2010;

Quarterly Reports on Form 10-Q for the quarters ended March 31, 2011 and June 30, 2011; and

Current Reports on Form 8-K filed on January 20, 2011, January 26, 2011, April 28, 2011, May 6, 2011, May 10, 2011, July 18, 2011 and July 26, 2011.

We also incorporate by reference all documents we may subsequently file with the SEC pursuant to Sections 13(a), 13(c), 14 or 15(d) of the Securities Exchange Act of 1934 after the initial filing date of the registration statement of which this prospectus is a part and prior to the termination of the offering.

Information furnished under Items 2.02 or 7.01 (or corresponding information furnished under Item 9.01 or included as an exhibit) in any past or future Current Report on Form 8-K (including the Current Reports on Form 8-K listed above) that we file with the SEC, unless otherwise expressly specified in such report, is not incorporated by reference in this prospectus.

We will provide without charge upon written or oral request, a copy of any or all of the documents which are incorporated by reference into this prospectus. Requests should be directed to:

Occidental Petroleum Corporation
10889 Wilshire Boulevard
Los Angeles, California 90024
Attn: Robert J. Williams
Telephone: (310) 208-8800

You should rely only on the information contained or incorporated by reference in this prospectus and any accompanying prospectus supplements and any applicable free writing prospectuses. We have not authorized any other person to provide you with different information. If anyone provides you with different or inconsistent information, you should not rely on it. We are not making an offer to sell these securities in any jurisdiction where the offer or sale is not permitted. The information contained

2


in this prospectus is accurate only as of the date on the front cover of this prospectus, the information contained in any accompanying prospectus supplement or related free writing prospectus will be accurate only as of the date of that document, and the information contained in any document incorporated by reference in this prospectus is accurate only as the date of such document. Our business, financial condition, results of operations and prospects may have changed since that date.

Except as provided above, no other information, including information on our internet site, is incorporated by reference in this prospectus.

OCCIDENTAL

Our principal businesses consist of three segments operated by our subsidiaries and affiliates. The oil and gas segment explores for, develops, produces and markets crude oil, including natural gas liquids (NGLs) and condensate (together with NGLs, "liquids"), as well as natural gas. The chemical segment manufactures and markets basic chemicals, vinyls and other chemicals. The midstream, marketing and other segment gathers, treats, processes, transports, stores, purchases and markets crude oil, liquids, natural gas, carbon dioxide and power. It also trades around its assets, including pipelines and storage capacity, and trades oil and gas, other commodities and commodity-related securities. Our principal executive offices are located at 10889 Wilshire Boulevard, Los Angeles, California 90024; telephone (310) 208-8800.

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USE OF PROCEEDS

Unless we inform you otherwise in a prospectus supplement, the net proceeds we receive from the sale of senior debt securities, if any, offered under this prospectus may be used for general corporate purposes, including working capital, acquisitions, retirement of debt, stock repurchases and other business opportunities.

DESCRIPTION OF SENIOR DEBT SECURITIES

General

We may issue one or more series of senior debt securities pursuant to this prospectus. We may issue the senior debt securities under an indenture (the "Senior Indenture") to be entered into between us and The Bank of New York Mellon Trust Company, N.A., as trustee ("Senior Indenture Trustee"). The form of Senior Indenture is included as an exhibit to the registration statement of which this prospectus is a part.

Below is a description of certain general terms of the senior debt securities. The description is not complete and is subject to and qualified in its entirety by reference to the Senior Indenture. The particular terms of a series of senior debt securities will be described in a prospectus supplement and, if applicable, a pricing supplement. Capitalized terms used but not defined in this summary have the meanings specified in the Senior Indenture.

The senior debt securities will rank equally with all of our unsecured and unsubordinated debt. The Senior Indenture is subject to the Trust Indenture Act of 1939, as amended (the "Trust Indenture Act"). The Senior Indenture does not limit the amount of senior debt securities which we may issue, nor does it limit us or our subsidiaries from issuing any other unsecured debt. Such other unsecured debt may have different terms than the senior debt securities. Our previously issued and outstanding senior debt does have different terms than the senior debt securities (including different restrictive covenants and event of default provisions). The terms of the senior debt securities issued under this prospectus will only be as described in the Senior Indenture, this prospectus and any prospectus supplement.

Each prospectus supplement, together with a pricing supplement, if applicable, will describe the terms relating to a series of senior debt securities, which may include:

the title;

any limit on the amount that may be issued (unless expressly provided in the applicable prospectus supplement or pricing supplement, a series of our senior debt securities may be re-opened from time to time for the issuance of additional senior debt securities of that series subject to any terms and conditions set forth in or established pursuant to the Senior Indenture);

whether or not that series of senior debt securities will be issued as registered securities, bearer securities or both;

the price at which that series of senior debt securities will be issued, which may be at a discount;

whether or not that series of senior debt securities will be issued in global form and, if applicable, who the depositary will be;

the maturity date(s) or the method of determining the maturity date(s);

the person to whom any interest will be payable on any registered security, if other than the person in whose name that security is registered at the close of business on the regular record date;

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the interest rate(s), if any, (which may be fixed or variable) or the method for determining the rate(s) and the date(s) interest will begin to accrue, the date(s) interest will be payable and the regular record date(s) for interest payment date(s);

the place(s) where payments shall be payable, registered securities may be surrendered for registration of transfer, securities may be surrendered for exchange, and notices and demands to or upon us may be served;

the period(s) within which, and the price(s) at which, that series of senior debt securities may, pursuant to any optional or mandatory redemption provisions, be redeemed, in whole or in part, and other related terms and conditions;

any mandatory or optional sinking fund provisions or any provisions for remarketing that series of senior debt securities and other related terms and provisions;

the denominations in which that series of senior debt securities will be issued, if other than denominations of $1,000 in the case of registered securities and any integral multiple thereof, and in the case of bearer securities, if other than denominations of $5,000 and $100,000;

the currency or currencies, including composite currencies or currency units, in which that series of senior debt securities may be denominated or in which payment of the principal of and interest, if any, on that series of senior debt securities shall be payable, if other than the currency of the United States of America, and, if so, whether that series of senior debt securities may be satisfied and discharged other than as provided in Article Four of the Senior Indenture;

if the amounts of payments of principal of and interest on, if any, that series of senior debt securities are to be determined by reference to an index, formula or other method, or based on a coin or currency other than that in which that series of senior debt securities are stated to be payable, the manner in which such amounts shall be determined and the calculation agent, if any, with respect thereto;

if other than the principal amount thereof, the portion of the principal amount of that series of senior debt securities that will be payable upon declaration of acceleration of the maturity thereof pursuant to an event of default;

whether we will pay additional amounts on any of the senior debt securities and coupons, if any, of the series to any non-United States holder in respect of any tax, assessment or governmental charge withheld or deducted, and under what circumstances and with what procedures we will pay such additional amounts;

if other than as defined in the Senior Indenture, the meaning of "Business Day" when used with respect to that series of senior debt securities;

if that series of senior debt securities may be issued or delivered (whether upon original issuance or upon exchange of a temporary security of such series or otherwise), or any installment of principal or interest is payable, only upon receipt of certain certificates or other documents or satisfaction of other conditions in addition to those specified in the Senior Indenture, the forms and terms of those certificates, documents or conditions;

any addition to, or modification or deletion of, any event of default, covenant or other term or provision specified in the Senior Indenture with respect to that series of senior debt securities; and

any other terms, which other terms may, subject, in the case of an existing outstanding series of senior debt securities, to the provisions of the Senior Indenture described below under ":Modification of Senior Indenture; Waiver," amend, supplement or replace any of the terms of the Senior Indenture insofar as it concerns the senior debt securities of that series.

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Each prospectus supplement or pricing supplement, as applicable, may describe certain United States federal income tax considerations applicable to the purchase, holding and disposition of the senior debt securities that the prospectus supplement or pricing supplement covers, as applicable.

Limitation on Liens

We will not, nor will we permit any Consolidated Subsidiary (as defined below) to, incur, create, assume, guarantee or otherwise become liable with respect to any Secured Debt (as defined below), unless the senior debt securities are secured equally and ratably with (or prior to) such Secured Debt. This covenant will not apply to:

(1) Liens (as defined below) existing on the date of the Senior Indenture;

(2) Liens existing on property of, or on any shares of Capital Stock or Indebtedness (each as defined below) of, any Business Entity at the time such Business Entity becomes a Consolidated Subsidiary or at the time such Business Entity is merged into or consolidated with us or any Consolidated Subsidiary or at the time of sale, lease or other disposition of the properties of such Business Entity (or a division of such Business Entity) to us or a Consolidated Subsidiary as an entirety or substantially as an entirety;

(3) Liens in favor of us or a Consolidated Subsidiary;

(4) Liens in favor of governmental bodies to secure progress, advance or other payments pursuant to any contract or provision of any statute;

(5) Liens existing on property, shares of Capital Stock or Indebtedness at the time of acquisition thereof (including acquisition through merger or consolidation) or Liens to (i) secure the payment of all or any part of the purchase price thereof or the cost of construction, installation, expansion, renovation, improvement or development on or of such property or (ii) secure any Indebtedness incurred prior to, at the time of, or within two years after the later of the acquisition, the completion of such construction, installation, expansion, renovation, improvement or development or the commencement of full operation of such property or within two years after the acquisition of such shares or Indebtedness for the purpose of financing all or any part of the purchase price or cost thereof;

(6) Liens on any specific oil or gas property to secure Indebtedness incurred by us or any Consolidated Subsidiary to provide funds for all or any portion of the cost of exploration, production, gathering, processing, marketing, drilling or development of such property;

(7) Liens on any Principal Domestic Property securing Indebtedness incurred under industrial development, pollution control or other revenue bonds issued or guaranteed by the United States of America or any State thereof or any department, agency, instrumentality or political subdivision of either;

(8) Liens on any Principal Domestic Property securing Indebtedness arising in connection with the sale of accounts receivable resulting from the sale of oil or gas at the wellhead; and

(9) certain extensions, renewals or refundings of any Liens referred to in the foregoing clauses (1) through (8).

Notwithstanding the foregoing, we and one or more Consolidated Subsidiaries may incur, create, assume, guarantee or otherwise become liable with respect to any Secured Debt that would otherwise be subject to the foregoing restrictions if, after giving effect thereto, the aggregate amount of all Secured Debt, together with the Discounted Rental Value (as defined below) in respect of sale and leaseback transactions involving Principal Domestic Properties (excluding sale and leaseback transactions exempted from the restrictions discussed below under the caption ":Limitations on Sale

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and Leaseback Transactions" pursuant to clause (1) or (2) of the second paragraph under such caption), would not exceed 15% of Consolidated Net Tangible Assets (as defined below).

Limitations on Sale and Leaseback Transactions

We will not, nor will we permit any Consolidated Subsidiary to, sell or transfer any Principal Domestic Property (as defined below), with us or any Consolidated Subsidiary taking back a lease of such Principal Domestic Property, unless:

(1) such Principal Domestic Property is sold within 360 days after the later of the date of acquisition, completion of construction or commencement of full operations of such Principal Domestic Property;

(2) we or such Consolidated Subsidiary could subject such Principal Domestic Property to a Lien securing Indebtedness pursuant to the provisions described above under ":Limitation on Liens" in an amount equal to the Discounted Rental Value with respect to the lease entered into in connection with such sale and leaseback transaction without equally and ratably securing the senior debt securities; or

(3) we or such Consolidated Subsidiary, within 360 days after such sale, applies or causes to be applied to the retirement of our or its Funded Debt (as defined below) an amount not less than the greater of (a) the net proceeds of the sale of the Principal Domestic Property leased pursuant to such sale and leaseback transaction or (b) the fair value (as determined in any manner approved by our Board of Directors) of the Principal Domestic Property so leased (provided, however, that the amount applied to the retirement of Funded Debt shall be reduced by the principal amount of Funded Debt of us or such Consolidated Subsidiary voluntarily retired by us or such Consolidated Subsidiary within 360 days after such sale).

This restriction will not apply to any sale and leaseback transaction (1) between us and a Consolidated Subsidiary or between Consolidated Subsidiaries or (2) involving the sale or transfer of any Principal Domestic Property with a lease for a period, including renewals, of not more than 36 months.

Certain Definitions

"Business Entity" means a corporation, association, business trust, partnership, limited liability company or other business entity.

"Capital Stock" means (a) in the case of a corporation, common stock, preferred stock and any other capital stock, (b) in the case of a partnership, partnership interests (whether general or limited), (c) in the case of a limited liability company, limited liability company interests, and (d) in the case of any other Business Entity, any other interest or participation that confers on a Person the right to receive a share of the profits and losses of, or distribution of assets of, such Business Entity, but excluding from all of the foregoing any debt securities convertible into Capital Stock, whether or not such debt securities include any right of participation with Capital Stock.

"Consolidated Net Tangible Assets" means the total of the Net Tangible Assets of us and our Consolidated Subsidiaries, included in our and our Consolidated Subsidiaries' financial statements prepared on a consolidated basis in accordance with United States generally accepted accounting principles, after eliminating all intercompany items.

"Consolidated Subsidiary" means any Subsidiary included in our and our Subsidiaries' financial statements prepared on a consolidated basis in accordance with United States generally accepted accounting principles.

"Current Liabilities" means all Indebtedness that may properly be classified as current liabilities in accordance with United States generally accepted accounting principles.

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"Discounted Rental Value" means, as to any particular lease under which any Person is at the time liable and at any date as of which the amount thereof is to be determined, the total net amount of rent (after deducting the amount of rent to be received by such Person under noncancelable subleases) required to be paid by such Person under such lease during the remaining noncancelable term thereof (including any such period for which such lease has been extended or may, at the option of the lessor, be extended), discounted from the respective due dates thereof to such date at a rate per annum of 113/4%. The net amount of rent required to be paid under any such lease for any such period shall be the aggregate amount of the rent payable by the lessee with respect to such period, after excluding amounts required to be paid on account of maintenance and repairs, insurance, taxes, water rates and similar charges. In the case of any lease which is terminable by the lessee upon the payment of a penalty, such net amount shall also include the amount of such penalty, but no rent shall be considered as required to be paid under such lease subsequent to the first date upon which it may be so terminated. If and to the extent the amount of any rent during any future period is not definitely determinable under the lease in question, the amount of such rent shall be estimated in such reasonable manner as our Board of Directors may in good faith determine.

"Funded Debt" means all Indebtedness maturing one year or more from the date of the creation thereof, all Indebtedness directly or indirectly renewable or extendible, at the option of the debtor, by its terms or by the terms of any instrument or agreement relating thereto, to a date one year or more from the date of the creation thereof, and all Indebtedness under a revolving credit or similar agreement obligating the lender or lenders to extend credit over a period of one year or more, even though such Indebtedness may also conform to the definition of Short-Term Borrowing.

"Indebtedness," as applied to a Person, means, as of the date on which Indebtedness is to be determined (a) all items (except items of Capital Stock or of surplus or of deferred credits or noncontrolling interest in Subsidiaries) which, in accordance with United States generally accepted accounting principles in effect from time to time, would be included in determining total liabilities, as shown on the liability side of a balance sheet of such Person; (b) all indebtedness secured by any mortgage on any property or asset owned or held by such Person subject thereto, whether or not the indebtedness secured thereby has been assumed; and (c) all indebtedness of others which such Person has directly or indirectly guaranteed, endorsed (otherwise than for collection or deposit in the ordinary course of business), discounted with recourse, agreed (contingently or otherwise) to purchase or repurchase or otherwise acquire, or in respect of which such Person has otherwise become directly or indirectly liable. For the purpose of computing Indebtedness of any Person, there shall be excluded any particular Indebtedness which meets one or more of the following categories:

(i) Indebtedness with respect to which sufficient cash or cash equivalents or securities have been deposited in trust to provide for the full payment, redemption or satisfaction of the principal of, premium, if any, and interest to accrue on, such Indebtedness to the stated maturity thereof or to the date of prepayment thereof, as the case may be, and, as a result of such deposit, such particular Indebtedness, in accordance with United States generally accepted accounting principles, is no longer required to be reported on a balance sheet of such Person as a liability, and such cash or cash equivalents or securities are not required to be reported as an asset;

(ii) Indebtedness which is not classified as Indebtedness under clause (a) of this definition and which arises from any commitment of such Person relating to pipeline operations to pay for property or services substantially without regard to the non-delivery of such property or the non-furnishing of such services; or

(iii) Indebtedness which is not classified as Indebtedness under clause (a) of this definition and which is payable solely out of certain property or assets of such Person, or is secured by a mortgage on certain property or assets owned or held by such Person, in either case without any further recourse to or liability of such Person, to the extent such Indebtedness exceeds (x) if such

8


Person records such property or assets on its books, the value for such property or assets recorded on such books or (y) if such Person does not record such property or assets on its books, (1) if such Indebtedness is a general obligation of the entity which does record such property or assets on its books, the net investment in or advances to such entity as recorded on the books of such Person or (2) if such Indebtedness is payable solely out of certain property or assets of such entity, the lesser of the value for such property or assets recorded on the books of such entity or the net investment in or advances to such entity as recorded on the books of such Person, in each case determined in accordance with United States generally accepted accounting principles.

"Lien" means and includes any mortgage, pledge, lien, security interest, conditional sale or other title retention agreement or other similar encumbrance to secure Indebtedness for borrowed money, but excluding (i) any security interest which a lessor may be deemed to have under a lease and (ii) any lien which may be deemed to exist under a Production Payment or under any subordination arrangement.

"Net Tangible Assets" of any specified Person means the total of all assets properly appearing on a balance sheet of such Person prepared in accordance with United States generally accepted accounting principles, after deducting from such total, without duplication of deductions, (a) all Current Liabilities of such Person; (b) that portion of the book amount of all such assets which would be treated as intangibles under United States generally accepted accounting principles, including, without limitation, all such items as goodwill, trademarks, trade names, brands, copyrights, patents, licenses and rights with respect to the foregoing and unamortized debt discount and expense; and (c) the amount, if any, at which any Capital Stock of such Person appears on the asset side of such balance sheet.

"Original Issue Discount Security" means any senior debt security which provides for an amount less than the principal amount thereof to be due and payable upon a declaration of acceleration of the Maturity thereof pursuant to the Senior Indenture.

"Person" means any individual, corporation, partnership, limited liability company, joint venture, association, joint-stock company, trust, unincorporated organization or government or any agency or political subdivision thereof.

"Principal Domestic Property" means any (1) developed oil or gas producing property or (2) processing or manufacturing plant, in each case which we or any Consolidated Subsidiary own or lease as of the date of the Senior Indenture or thereafter and which is located in the continental United States (provided, however, that any such property or plant declared by our Board of Directors by Board Resolution not to be of material importance to our and our Consolidated Subsidiaries' business, taken as a whole, will be excluded from the foregoing definition).

"Production Payment" means any economic interest in oil, gas or mineral reserves which (1) entitles the holder thereof to a specified share of future production from such reserves, free of the costs and expenses of such production, and (2) terminates when a specified quantity of such share of future production from such reserves has been delivered or a specified sum has been realized from the sale of such share of future production from such reserves.

"Redemption Date" when used with respect to any senior debt security to be redeemed, means the date fixed for such redemption by or pursuant to the Senior Indenture.

"Secured Debt" means any Indebtedness of us or any Consolidated Subsidiary for borrowed money, secured by a Lien on any Principal Domestic Property or on any shares of Capital Stock or on any Indebtedness of any Consolidated Subsidiary which owns any Principal Domestic Property.

"Short-Term Borrowing" means all Indebtedness in respect of borrowed money maturing on demand or within one year from the date of the creation thereof and not directly or indirectly renewable or extendible, at the option of the debtor, by its terms or by the terms of any instrument or

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agreement relating thereto, to a date one year or more from the date of the creation thereof; provided that Indebtedness in respect of borrowed money arising under a revolving credit or similar agreement which obligates the lender or lenders to extend credit over a period of one year or more will constitute Funded Debt and not Short-Term Borrowing, even though it matures on demand or within one year from the date as of which such Short-Term Borrowing is to be determined.

"Subsidiary" means a Business Entity more than 50% of the outstanding Voting Stock of which is owned, directly or indirectly, by us or by one or more of our other Subsidiaries, or by us and one or more of our other Subsidiaries.

"Voting Stock" means, with respect to any Business Entity, any class or series of Capital Stock of such Business Entity the holders of which are ordinarily, in the absence of contingencies, entitled to vote for the election of, or to appoint or to approve the appointment of, the directors, trustees or managing members of, or other persons holding similar positions with, such Business Entity.

Consolidation, Merger or Sale

The Senior Indenture generally permits us to consolidate with, merge into or convey, transfer or lease our properties and assets substantially as an entirety, to any Business Entity, so long as, immediately after giving effect to such transaction, no event of default under the Senior Indenture or event which, after notice or lapse of time or both, would become an event of default shall have occurred and be continuing. However, any successor or acquiror of such assets must assume all of our obligations under the Senior Indenture and the senior debt securities and be organized and existing under the laws of the United States of America, any state thereof or the District of Columbia.

Events of Default Under the Senior Indenture

The following are events of default under the Senior Indenture with respect to each series of senior debt securities:

failure to pay any installment of interest upon any senior debt security of such series when it becomes due and payable, and continuance of such failure to pay for a period of 30 days; or

failure to pay the principal of any senior debt security of such series when due;

failure to perform or breach of any other covenant or warranty contained in the senior debt securities or the Senior Indenture (other than a covenant or warranty specifically benefiting only another series of senior debt securities), and the continuance of such failure for a period of 90 days after we receive notice from the Senior Indenture Trustee or holders of at least 25% in principal amount of the outstanding senior debt securities of that series;

certain events of bankruptcy, insolvency or reorganization relating to us; and

any other event of default specified in the prospectus supplement or pricing supplement, if any, relating to that series of senior debt securities.

If an event of default with respect to senior debt securities of any series occurs and is continuing, the Senior Indenture Trustee or the holders of at least 25% in principal amount of the outstanding senior debt securities of that series, by notice in writing to us (and to the Senior Indenture Trustee if notice is given by such holders), may declare the principal of (or if such senior debt securities are Original Issue Discount Securities, the portion of the principal amount specified in the applicable prospectus supplement or pricing supplement, if any), and accrued interest, if any, on the senior debt securities of such series to be due and payable immediately. At any time after such a declaration of acceleration has been made and before a judgment or decree for payment of the money due has been obtained holders of a majority in principal amount of the outstanding senior debt securities of that

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series, by written notice to us and the Senior Indenture Trustee, may rescind and annul such declaration and its consequences if:

we have paid or deposited with the Senior Indenture Trustee a sum sufficient to pay all overdue installments of interest on the senior debt securities of that series, the principal of any senior debt securities of that series which have become due otherwise than by such declaration of acceleration and interest thereon, to the extent payment of such interest is lawful, interest on overdue installments of interest, all sums paid or advanced by the Senior Indenture Trustee, the reasonable compensation, expenses, disbursements and advances of the Senior Indenture Trustee, its agents and counsel and any other amount due to the Senior Indenture Trustee under the Senior Indenture, and

all events of default with respect to outstanding senior debt securities of that series, other than the non-payment of the principal of and interest on such senior debt securities which became due solely by such declaration of acceleration, have been cured or waived in accordance with the terms of the Senior Indenture.

The holders of a majority in principal amount of the outstanding senior debt securities of any series may waive any past default with respect to that series and its consequences, except defaults regarding:

payment of principal or interest; or

covenants that cannot be modified or amended without the consent of the holder of each outstanding senior debt security of such series affected (as described under ":Modification of Senior Indenture; Waiver" below).

Any waiver shall cure such default and the corresponding event of default.

Subject to the terms of the Senior Indenture, the Senior Indenture Trustee will be under no obligation to exercise any of its rights or powers under the Senior Indenture at the request or direction of any of the holders of the applicable series of senior debt securities, unless the holders have offered the Senior Indenture Trustee reasonable security or indemnity against costs, expenses and liabilities to be incurred in compliance with such request. The holders of a majority in principal amount of the outstanding senior debt securities of any series will have the right to direct the time, method and place of conducting any proceeding for any remedy available to the Senior Indenture Trustee, or exercising any trust or power conferred on the Senior Indenture Trustee, with respect to the senior debt securities of that series, provided that:

the direction given to the Senior Indenture Trustee is not in conflict with any law or the Senior Indenture;

the Senior Indenture Trustee may take any other action deemed proper by it which is not inconsistent with that direction; and

the Senior Indenture Trustee has not determined that the action would be unjustly prejudicial to the holders not involved in the proceeding.

A holder of the senior debt securities of any series will have the right to institute a proceeding under the Senior Indenture or to appoint a receiver or trustee, or to seek other remedies only if:

the holder has given written notice to the Senior Indenture Trustee of a continuing event of default with respect to that series;

the holders of at least 25% in principal amount of the outstanding senior debt securities of that series have made written request, and have offered reasonable indemnity, to, the Senior Indenture Trustee to institute the proceedings as trustee; and

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the Senior Indenture Trustee does not institute the proceeding, and does not receive from the holders of a majority in principal amount of the outstanding senior debt securities of that series other conflicting directions, within 60 days after the notice, request and offer of indemnity.

The Senior Indenture provides that no holder or group of holders of senior debt securities will have any right to affect, disturb or prejudice the rights of other holders, obtain or seek priority or preference over another holder or enforce its rights under the Senior Indenture except as provided in the Senior Indenture for the equal and ratable benefit of all holders.

These limitations on instituting proceedings do not apply to a suit instituted by a holder of senior debt securities to enforce the payment of the principal of or interest on the senior debt securities.

We will periodically file statements with the Senior Indenture Trustee regarding our compliance with the conditions and covenants in the Senior Indenture.

Modification of Senior Indenture; Waiver

We and the Senior Indenture Trustee may amend or supplement the Senior Indenture without the consent of any holders to, among other things:

evidence the succession of another Business Entity to us and the assumption by such successor of our covenants in the Senior Indenture and the senior debt securities;

add to our covenants, agreements and obligations for the benefit of the holders of all senior debt securities or any series thereof, or to surrender any right or power the Senior Indenture confers upon us;

add to or change any of the provisions of the Senior Indenture to provide that bearer securities may be registrable as to principal, to change or eliminate any restrictions (including restrictions relating to payment in the United States) on the payment of principal of or any premium or interest, if any, on bearer securities, to permit bearer securities to be issued in exchange for registered securities, to permit bearer securities to be issued in exchange for bearer securities of other authorized denominations or to permit the issuance of senior debt securities in uncertificated form;

establish the form and terms of the senior debt securities of any series and (unless prohibited by the terms of the senior debt securities of any series pursuant to the Senior Indenture) to provide for the re-opening of a series of senior debt securities and for the issuance of additional senior debt securities of such series;

evidence and provide for the acceptance of appointment under the Senior Indenture of a successor Senior Indenture Trustee with respect to the senior debt securities of one or more series;

cure any ambiguity, to correct or supplement any provision in the Senior Indenture which may be inconsistent with any other provision in the Senior Indenture or make other provisions with respect to matters or questions arising under the Senior Indenture;

add, change or eliminate any provisions of the Senior Indenture (which addition, change or elimination may apply to one or more series of senior debt securities), provided that the addition, change or elimination neither (a) applies to any senior debt security of any series created prior to the execution of the supplemental indenture that is entitled to the benefit of the provision nor (b) modifies the rights of holders of those senior debt securities with respect to those modified provisions;

add to or change or eliminate any provision of the Senior Indenture as shall be necessary to comply with any amendments to the Trust Indenture Act or to otherwise maintain qualification

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of the Senior Indenture under the Trust Indenture Act or to comply with the rules of any applicable depositary;

secure the senior debt securities; or

change anything else that does not adversely affect the interests of any holder of senior debt securities.

In addition, under the Senior Indenture, the rights of holders of a series of senior debt securities may be changed by us and the Senior Indenture Trustee with the written consent of the holders of at least a majority in principal amount of the outstanding senior debt securities of each series that is affected. However, no change may be made without the consent of the holder of each outstanding senior debt security affected if such change would, among other things:

change the stated maturity of principal of, or any installment of principal or interest on, any such senior debt security;

reduce the principal amount of, or the rate of interest on, or any premium payable on, any such senior debt security;

reduce the principal of any such Original Issue Discount Security that would be due and payable upon declaration of acceleration;

change the place where, or currency in which, any principal of or interest on any such senior debt security is payable;

impair the right to institute suit for the enforcement of any payment of any such senior debt security on or after the stated maturity thereof (or, in the case of redemption, on or after the Redemption Date or, in the case of any senior debt security which is subject to repurchase or redemption by us at the option of the holders, on or after the date fixed for such repurchase or redemption);

reduce the percentage in principal amount of outstanding senior debt securities of any series, the holders of which are required to consent to any such change, or the consent of whose holders is required for any waiver (of compliance with certain provisions of the Senior Indenture or certain defaults thereunder and their consequences) with respect to the senior debt securities of such series provided for in the Senior Indenture; and

modify any of the foregoing requirements or the provisions regarding waivers of any covenant or past default other than to increase the percentage of holders required for consent or waiver or add consent requirements for modification or waiver of other provisions.

Form, Exchange and Transfer

The senior debt securities of each series may be issued as registered securities, as bearer securities (with or without coupons) or both. Unless otherwise specified in the applicable prospectus supplement or the pricing supplement, if any, registered securities will be issued in denominations of $1,000 and any integral multiple thereof and bearer securities will be issued in denominations of $5,000 and $100,000. Subject to the terms of the Senior Indenture and the limitations applicable to global securities described in the applicable prospectus supplement or the pricing supplement, if any, registered securities will be exchangeable for other registered securities of the same series, in any authorized denomination and of like tenor and aggregate principal amount.

Subject to the terms of the Senior Indenture and the limitations applicable to global senior debt securities set forth in the applicable prospectus supplement or pricing supplement, if any, senior debt securities issued as registered securities may be presented for exchange or for registration of transfer (duly endorsed or with the form of transfer duly executed) at the office of the registrar or at the office

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of any transfer agent we designate for that purpose. Unless otherwise provided in the senior debt securities to be transferred or exchanged, no service charge will be made for any registration of transfer or exchange, but we may require payment of any taxes or other governmental charges. We have appointed the Senior Indenture Trustee as registrar. Any transfer agent (in addition to the registrar) initially designated by us for any senior debt securities will be named in the applicable prospectus supplement or pricing supplement. We may at any time designate additional transfer agents or rescind the designation of any transfer agent or approve a change in the office through which any transfer agent acts, except that we will be required to maintain a transfer agent in each place of payment for the senior debt securities of each series.

If the senior debt securities of any series are to be redeemed, we will not be required to:

issue, register the transfer of, or exchange any senior debt securities of, that series during a period beginning at the opening of business 15 days before any selection of senior debt securities for redemption and ending, in the case of registered securities, on the day of mailing of the relevant notice of redemption and, in the case of bearer securities, the first publication date of the notice, or if the senior debt securities of that series are also issuable as registered securities and there is no publication, on the day of mailing of the notice;

in the case of registered securities, register the transfer of or exchange any senior debt securities so selected for redemption, in whole or in part, except the unredeemed portion of any registered security being redeemed in part; or

in the case of bearer securities, exchange any senior debt securities so selected for redemption, except to exchange a bearer security for a registered security that is immediately surrendered for redemption.

Global Senior Debt Securities

The senior debt securities of each series may be issued in whole or in part in global form. A senior debt security in global form will be deposited with, or on behalf of, a depositary, which will be named in an applicable prospectus supplement or pricing supplement, if any. A global senior debt security may be issued in either registered or bearer form and in either temporary or definitive form. A global senior debt security may not be transferred, except as a whole, among the depositary for that senior debt security and its nominees and their respective successors. If any senior debt securities of a series are issuable as global senior debt securities, the applicable prospectus supplement or pricing supplement, if any, will describe any circumstances when beneficial owners of interests in that global senior debt security may exchange their interests for definitive senior debt securities of like series and tenor and principal amount in any authorized form and denomination.

Discharge

Unless otherwise indicated in an applicable prospectus supplement or pricing supplement, if any, we may terminate at any time our obligations under the Senior Indenture with respect to any series of senior debt securities (other than certain limited obligations, such as the obligation to transfer and exchange senior debt securities of that series) by (1)(a) delivering all of the outstanding senior debt securities of that series to the Senior Indenture Trustee to be cancelled or (b) depositing with the Senior Indenture Trustee in trust funds or non-callable United States government or government-guaranteed obligations sufficient without reinvestment to pay all remaining principal and interest on the series of senior debt securities and (2) complying with certain other provisions of the Senior Indenture.

If we elect to discharge our obligations by depositing cash or United States government or government guaranteed obligations as described above, under present law such discharge is likely to be treated for United States federal income tax purposes as a redemption of the senior debt securities of

14


that series prior to maturity in exchange for the property deposited in trust. In that event, each holder would generally recognize, at the time of discharge, gain or loss for United States federal income tax purposes measured by the difference between (1) the sum of (a) the amount of any cash and (b) the fair market value of any property deposited in trust deemed received by such holder (unless attributable to accrued interest) and (2) such holder's tax basis in the senior debt securities deemed surrendered. After the discharge, each such holder would likely be treated as if it held an undivided interest in the cash (or investments made therewith) and the property held in trust (or investments made with interest received therefrom). Each such holder would generally be subject to tax liability in respect of interest income and original issue discount, if applicable, thereon and would recognize any gain or loss upon any disposition, including redemption, of the assets held in trust. Although tax might be owed, the holder of a discharged senior debt security would not receive cash (except for current payments of interest on that senior debt security) until the maturity or earlier redemption (or, if applicable, repurchase by us at the option of the holder) of that senior debt security. United States federal income tax treatment of this nature could affect the purchase price that a holder would receive upon the sale of the senior debt securities. You are urged to consult with your tax advisor regarding the tax consequences of the discharge of our obligations.

Information Concerning the Senior Indenture Trustee

The Senior Indenture Trustee, other than during the occurrence and continuance of an event of default under the Senior Indenture, undertakes to perform only those duties as are specifically set forth in the Senior Indenture and, upon an event of default under the Senior Indenture, must use the same degree of care as a prudent person would exercise or use in the conduct of his or her own affairs. Subject to this provision, the Senior Indenture Trustee is under no obligation to exercise any of the rights or powers given it by the Senior Indenture at the request or direction of any holder of senior debt securities unless the Senior Indenture Trustee is offered reasonable security or indemnity by that holder against the costs, expenses and liabilities that it might incur. The Senior Indenture Trustee is not required to spend or risk its own money or otherwise become financially liable while performing its duties unless it reasonably believes that it will be repaid or receive adequate indemnity.

The Bank of New York Mellon is a participating lender under our revolving credit agreement and provides commercial banking services to us and our affiliates. The Bank of New York Mellon Trust Company, N.A. is the Senior Indenture Trustee. However, if The Bank of New York Mellon Trust Company, N.A. acquires any conflicting interest when an event of default is pending, it must (with certain exceptions) eliminate the conflict or resign.

Payment and Payment Agents

The person in whose name a senior debt security is registered will be treated as the owner of such security for the purpose of receiving payment of principal and, unless otherwise indicated in an applicable prospectus supplement or pricing supplement, if any, interest on such senior debt security and for all other purposes.

Unless otherwise indicated in the applicable prospectus supplement or pricing supplement, if any, payment of interest on any senior debt securities (other than bearer securities) on any interest payment date will be made to the person in whose name those senior debt securities (or one or more predecessor securities) are registered at the close of business on the regular record date for the interest. Unless otherwise indicated in the applicable prospectus supplement or pricing supplement, if any, principal and interest on the senior debt securities of a particular series will be payable at the office of the paying agents that we designate, except that payments of interest (other than interest on bearer securities) may, at our option, be made by wire transfer or check mailed to the address of the person entitled thereto. Unless otherwise indicated in an applicable prospectus supplement or pricing

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supplement, if any, any payment of an installment of interest on any bearer security will be made only if the coupon relating to the interest installment is surrendered.

We will be required to maintain a paying agent in each place of payment for the senior debt securities of a particular series. Unless otherwise indicated in the applicable prospectus supplement or pricing supplement, if any, the corporate trust office of the Senior Indenture Trustee in The City of New York will be designated as the paying agent for payments with respect to senior debt securities (other than bearer securities).

All moneys that we pay to a paying agent or the Senior Indenture Trustee for the payment of the principal or interest, if any, on any senior debt securities which remain unclaimed at the end of two years after that principal or interest has become due and payable will be repaid to us, and the holder of the security thereafter may look only to us for payment thereof.

Unless otherwise indicated in an applicable prospectus supplement or pricing supplement, if any, interest shall be computed, for fixed rate securities, on the basis of a 360-day year comprised of twelve 30-day months, and, for variable rate securities, on the basis of the actual number of days in the interest period divided by 360.

Governing Law

The Senior Indenture and senior debt securities will be governed by and construed in accordance with the law of the State of New York (without regard to conflicts of laws principles thereof).

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PLAN OF DISTRIBUTION

We may sell the senior debt securities being offered hereby in one or more of the following ways from time to time:

to underwriters or dealers for resale to the public or to institutional investors;

directly to institutional investors;

directly to agents;

directly to a limited number of purchasers or to a single purchaser;

through agents to the public or to institutional investors;

if indicated in the prospectus supplement, pursuant to delayed delivery contracts or by remarketing firms; or

through a combination of any of the previous methods of sale.

The prospectus supplements and pricing supplements, if any, will set forth the terms of the offering of each series of senior debt securities, including the name or names of any underwriter, dealers or agents, the purchase price of the senior debt securities and the proceeds to us from such sale, any underwriting discounts or agency fees and other items constituting underwriters' or agents' compensation, any initial public offering price, any discounts or concessions allowed or reallowed or paid to dealers and any securities exchanges on which the senior debt securities may be listed.

If underwriters or dealers are used in the sale, the senior debt securities will be acquired by the underwriters or dealers for their own account and may be resold from time to time in one or more transactions, including privately negotiated transactions, at a fixed public offering price or prices, which may be changed, in "at the market offerings," at prices related to prevailing market prices or at negotiated prices or varying prices determined at the time of sale.

Unless otherwise set forth in a prospectus supplement or a pricing supplement, if any, the obligations of the underwriters to purchase any series of senior debt securities will be subject to certain conditions precedent and the underwriters will be obligated to purchase all of the series of senior debt securities, if any are purchased.

If a dealer is utilized in the sale of senior debt securities, we will sell the senior debt securities to the dealer, as principal. The dealer may then resell the senior debt securities to the public at varying prices to be determined by the dealer at the time of resale. The names of the dealers and the terms of the transaction will be set forth in the prospectus supplement relating to that transaction.

Senior debt securities may also be offered and sold, if so indicated in the prospectus supplement or a pricing supplement, if any, in connection with a remarketing upon their purchase, in accordance with a redemption or repayment pursuant to their terms, or otherwise, by one or more firms ("remarketing firms") acting as principals for their own accounts or as agents for us. Any remarketing firm will be identified and the terms of its agreement, if any, with us and its compensation will be described in the prospectus supplement or a pricing supplement, if any.

Underwriters, agents, dealers and remarketing firms may be entitled under agreements entered into with us to indemnification by us against certain civil liabilities, including liabilities under the Securities Act, or to contribution with respect to payments which the underwriters or agents may be required to make in respect thereof, and to reimbursement by us for certain expenses. Underwriters, agents, dealers and remarketing firms may be customers of, engage in transactions with, or perform services for us and our affiliates in the ordinary course of business.

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Each series of senior debt securities will be a new issue of senior debt securities and will have no established trading market. Unless otherwise specified in the applicable prospectus supplement or pricing supplement, the senior debt securities will not be listed on a national securities exchange. Any underwriters to whom we sell senior debt securities for public offering and sale may make a market in those senior debt securities, but such underwriters will not be obligated to do so and may discontinue any market making at any time without notice.

LEGAL MATTERS

Unless otherwise specified in a prospectus supplement accompanying this prospectus a senior attorney in our legal department will provide opinions regarding the authorization and validity of the senior debt securities. Any underwriters will be advised about legal matters by their own counsel, which will be named in the prospectus supplement.

EXPERTS

The consolidated financial statements and financial statement schedule of Occidental Petroleum Corporation and its subsidiaries as of December 31, 2010 and 2009, and for each of the years in the three-year period ended December 31, 2010, and management's assessment of the effectiveness of internal control over financial reporting as of December 31, 2010 have been incorporated by reference herein and in the registration statement in reliance upon the reports of KPMG LLP, independent registered public accounting firm, incorporated by reference herein, and upon the authority of said firm as experts in accounting and auditing.

Ryder Scott Company, L.P., independent petroleum engineering consultants, reviewed Occidental's oil and gas estimation process, which review information is included in Occidental's Annual Report on Form 10-K for the year ended December 31, 2010, which is incorporated by reference in this prospectus. Ryder Scott's review information is incorporated by reference herein in reliance upon the authority of said firm in such matters.

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Occidental Petroleum Corporation

$ % Senior Notes due 20

$ % Senior Notes due 20


PRELIMINARY PROSPECTUS SUPPLEMENT


Joint Book-Running Managers

Barclays Capital

Citigroup

J.P. Morgan

August , 2011