We are offering $   aggregate principal amount of our  % Senior Notes due 20  (the “20   notes”) and $   aggregate principal amount of our  % Senior Notes due 20   (the “20   notes,” and together with the 20   notes, the “notes”).

We will pay interest on each series of notes semi-annually in arrears on and of each year, commencing on    , 2021. 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 any series at our option at any time and from time to time at the applicable 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.

Each series of notes is a new issue of securities with no established trading market. The notes will not be listed on any securities exchange.

Investing in the notes involves risks. Please read “Risk Factors” beginning on page S-7 of this prospectus supplement, on page 7 of the accompanying prospectus and other information included or incorporated by reference into this prospectus supplement and the accompanying prospectus.

Neither the U.S. Securities and Exchange Commission (the “SEC”) 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    , 2020 in book-entry form only through the facilities of The Depository Trust Company for the accounts of its participants, which may include Clearstream Banking S.A. and Euroclear Bank S.A./N.V., against payment in New York, New York.

You should rely only on the information contained in or incorporated by reference into this prospectus supplement and the accompanying prospectus and any applicable free writing prospectuses. We have not, and the underwriters 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. This prospectus supplement, the accompanying prospectus and any applicable 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. 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 into this prospectus supplement is accurate only as of the date of such document. Our business, financial condition, results of operations and prospects may have changed since those respective dates.

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. Unless otherwise expressly stated or the context otherwise requires, the words “Occidental,” “we,” “us” and “our” as used in this prospectus supplement refer to Occidental Petroleum Corporation and its subsidiaries. However, in the “Description of the Notes” section of this prospectus supplement, references to “Occidental,” “we,” “us,” and “our” are to Occidental Petroleum Corporation only and not to any of its subsidiaries.

This prospectus supplement, the accompanying prospectus and the documents incorporated by reference herein and therein contain forward-looking statements that involve risks and uncertainties that could materially affect expected results of operations, liquidity, cash flows and business prospects. Actual results may differ from anticipated results, sometimes materially, and reported results should not be considered an indication of future performance. Factors that could cause the results to differ include, but are not limited to:

Words such as “estimate,” “project,” “predict,” “will,” “would,” “should,” “could,” “may,” “might,” “anticipate,” “plan,” “intend,” “believe,” “expect,” “aim,” “goal,” “target,” “objective,” “likely” or similar expressions that convey the prospective nature of 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 supplement or, in the case of documents incorporated by reference, as of the date of those documents. Unless legally required, we undertake no obligation to update, modify or withdraw any forward-looking statements, as a result of new information, future events or otherwise. Material risks that may affect our results of operations and financial position appear under the heading “Risk Factors” and elsewhere in this prospectus supplement, the accompanying prospectus and 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 by reference in this prospectus supplement and the accompanying prospectus.

Investing in the notes involves risks. Before you invest in the notes, 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, 2019 and in our Quarterly Reports on Form 10-Q for the quarters ended March 31, 2020, June 30, 2020 and September 30, 2020, as such risks may be updated or supplemented in this prospectus supplement, and the other information in those and the other reports that we file with the SEC that are incorporated by reference in this prospectus supplement or the accompanying prospectus for a discussion of risk factors that may affect the business.

The COVID-19 pandemic has adversely affected the global economy, disrupted global supply chains and created significant volatility in the financial markets. In addition, the pandemic has resulted in travel restrictions, business closures and the institution of quarantining and other restrictions on movement in many communities. As a result, there has been a significant reduction in demand for and prices of crude oil, natural gas and NGL. If the reduced demand for and prices of crude oil, natural gas and NGL continue for a prolonged period, our operations, financial condition, cash flows, level of expenditures and the quantity of estimated proved reserves that may be attributed to our properties may be materially and adversely affected. On April 12, 2020, certain members of OPEC+ had agreed to production cuts intended to mitigate the oil supply and demand imbalance to stabilize prices; on December 3, 2020, however, certain members agreed to modestly increase production in January 2021. Though declining U.S. production has helped mitigate the supply and demand imbalance this year, we expect that oil prices in the near term will continue to be influenced by the duration and severity of the COVID-19 pandemic and its resulting impact on oil and gas demand, the extent to which countries abide by the OPEC+ production agreement and U.S. production levels.

Our operations also may be adversely affected if significant portions of our workforce are unable to work effectively, including because of illness, quarantines, government actions, or other restrictions in connection with the pandemic. We have implemented workplace restrictions in our offices and work sites for health and safety reasons, and continue to monitor national, state and local government directives where we have operations and/or offices. Further, our business plan, including our financing and liquidity plan, includes, among other things, planned divestitures. If general economic conditions or conditions in the energy industry persist at current levels for an extended period of time, we may not be able to complete these transactions on favorable terms, in a timely manner or at all. The extent to which the COVID-19 pandemic adversely affects our business, results of operations, and financial condition will depend on future developments, which are highly uncertain and cannot be predicted, including the scope and duration of the pandemic and actions taken by governmental authorities and other third parties in response to the pandemic. The COVID-19 pandemic may also materially adversely affect our operating and financial results in a manner that is not currently known to us or that we do not currently consider to present significant risks to our operations. To the extent the COVID-19 pandemic may continue to adversely affect our business, operations, financial condition and operating results, it may also have the effect of heightening the other risks described in this “Risk Factors” section (including those described in our Annual Report on Form 10-K for the year ended December 31, 2019 and in our Quarterly Reports on Form 10-Q for the quarters ended March 31, 2020, June 30, 2020 and September 30, 2020, which are incorporated by reference in this prospectus supplement), such as those relating to our high level of indebtedness, our need to generate sufficient cash flows to service our indebtedness, and our ability to comply with the covenants contained in the agreements that govern our indebtedness.

Our businesses are subject to the actions and decisions of many federal, state, local and foreign governments and political interests. As a result, we face risks of:

As an example of state governmental actions, the Colorado Oil and Gas Conservation Commission (“COGCC”) has adopted new regulations that will impose, as of January 2021, siting requirements or “setbacks” on certain oil and gas drilling locations based on the distance of a proposed well pad to occupied structures. Pursuant to the regulations, well pads cannot be located within 500 feet of an occupied structure without the consent of the property owner. As part of the permitting process, the COGCC will consider a series of siting requirements for all drilling locations located between 500 feet and 2,000 feet of an occupied structure. Alternatively, the operator may seek a waiver from each owner and tenant within the designated distance. We are currently evaluating the impact of these regulations on our business. At this time, we do not anticipate near-term changes to our development program in the DJ basin based on these regulations; we may, however, experience increased costs to comply with such requirements or delays or curtailment in permitting, impacting our exploration, development, or production activities. Such delays, curtailments, limitations, or prohibitions, if determined to be significant, could have a material adverse effect on our future cash flows and results of operations and may negatively impact our reportable quantities of proved undeveloped oil and gas reserves.

In addition, we have and may continue to experience adverse consequences, such as risk of loss or production limitations, because certain of its international operations are located in countries affected by political instability, nationalizations, corruption, armed conflict, terrorism, insurgency, civil unrest, security problems, labor unrest, OPEC production restrictions, equipment import restrictions and sanctions. Exposure to such risks may increase if a greater percentage of our future oil and gas production or revenue comes from international sources.

Our ability to satisfy our debt obligations, including the notes, will depend on our ability to generate sufficient cash flow to service our debt, which in turn depends on our future financial performance. A range of economic, competitive, business and industry factors will affect our future financial performance, and, as a result, our ability to generate cash flow from operations and to pay our debt, including our obligations under the notes. Many of these factors, such as oil and gas prices, economic and financial conditions in our industry and the global economy, the impact of legislative or regulatory actions on how we conduct our business or competition and initiatives of our competitors, are beyond our control.

We continue to review our debt management options, which could include the utilization of liability management solutions, such as debt exchanges and extension of maturities, the refinancing of debt and further accessing the capital markets. We also continue to pursue divestitures of certain assets and intend to use the proceeds from asset sales and free cash flow to repay nearer-term debt maturities (see “Summary—Recent Debt Management Transactions and Associated Maturity Profile”), but the expected timing and final proceeds from future asset sales are uncertain. If we do not generate enough cash flow from operations or through debt management options to satisfy our debt obligations, particularly in light of the inherent uncertainty associated with the duration and severity of the COVID-19 pandemic and its resulting impact on oil demand, we may have to undertake alternative financing plans, including selling additional debt or equity securities, reducing or delaying capital investments or divesting additional assets. We may not be able to refinance our debt or sell additional debt or equity securities or assets on favorable terms, if at all, and if we are forced to refinance our debt at higher interest rates, any increases in interest expense could adversely affect our cash flows and results of operations. Similarly, if we reduce or delay capital investments or sell our assets on disadvantageous terms, such reductions, delays or sales may negatively affect our ability to generate revenues or result in losses.

Our inability to generate sufficient cash flow to satisfy our debt obligations, including our obligations under the notes, or to obtain alternative financing, could materially and adversely affect our business, financial condition, results of operations and prospects, and could impede our ability to repay our indebtedness when it becomes due and also meet our other cash needs. As of September 30, 2020, after giving effect to this offering (including the application of the proceeds therefrom), we would have had approximately $      billion aggregate principal amount of outstanding indebtedness, none of which would have been secured indebtedness, including approximately $      billion of debt with maturities in 2021, 2022 and 2023 (assuming all the net proceeds of the offering are used to fund the Tender Offers). In addition, as of the date of this prospectus supplement, we had $5.0 billion of unused borrowing capacity available under our existing revolving credit facility, which matures in 2023. Our outstanding indebtedness includes the Zero Coupons, which have an aggregate principal amount of approximately $2.3 billion due at maturity in 2036 and which may be put to us in October of each year until maturity, in whole or in part, for the then-accreted value of the outstanding Zero Coupons. The Zero Coupons can next be put to us in October 2021, which, if put in whole, would require a payment of approximately $1.0 billion at such date. See “Summary—Recent Debt Management Transactions and Associated Maturity Profile.”

After the issuance of the notes, even after giving effect to the anticipated use of proceeds therefrom to fund the Tender Offers or otherwise refinance, redeem or repurchase certain of our outstanding indebtedness, we will have a significant amount of indebtedness.

Our substantial indebtedness could have negative consequences to you and us. For example, it could:

The notes will be obligations of Occidental Petroleum Corporation exclusively and not of any of our subsidiaries, and none of our subsidiaries will guarantee the notes. Consequently, the notes will be structurally subordinated to all existing and future liabilities of any of our subsidiaries (including debt obligations of our subsidiaries that remain outstanding following the Anadarko Acquisition and any future debt obligations of ours that may be guaranteed by our subsidiaries). 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 are dependent upon results of operations of our subsidiaries, may be subject to contractual and other restrictions, 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 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 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. While we do not currently have any secured debt outstanding, the terms of our outstanding indebtedness permits, and the terms of the notes will permit, us to incur a significant amount of secured debt. See “Description of the Notes.”

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 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.

Our corporate credit ratings were downgraded in connection with the Anadarko Acquisition and further downgraded in connection with the ongoing impact of sharp decline in oil and gas demand and prices in 2020 related to the COVID-19 pandemic and a breakdown in relations among some of the world’s largest oil producing countries, most recently as of November 19, 2020. We cannot assure you that our credit ratings will not be downgraded in the future. A downgrade in our credit ratings could negatively impact our cost of capital or our ability to effectively execute aspects of our strategy. If we were to be downgraded, it could be difficult for us to raise debt in the capital markets and the cost of any new debt could be significantly higher than our outstanding debt. In addition, as a result of any such credit ratings downgrades, we may be requested, and in some cases required, to provide collateral in the form of cash, letters of credit, surety bonds or other acceptable support as financial assurance of our performance and payment obligations under certain contractual arrangements such as pipeline transportation contracts, oil and gas purchase contracts and certain derivative instruments. To date, we have provided financial assurances through a combination of cash, letters of credit and surety bonds made available to us on a bilateral basis.

The indenture contains limited covenants, and those covenants restricting our ability and our consolidated subsidiaries’ ability to incur certain indebtedness secured by liens contain important exceptions. Further, the indenture does not restrict our ability or that of our subsidiaries to incur additional indebtedness (including guarantees of indebtedness), conduct liability management or other transactions, require us to maintain any financial ratios or contain other 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. See “Description of Senior Debt Securities” in the accompanying prospectus. Accordingly, we and our subsidiaries could, in the future, enter into transactions that could increase the amount of indebtedness outstanding at that time, including secured or guaranteed indebtedness to which the notes would be effectively subordinated, or otherwise adversely affect your position in our consolidated capital structure or our credit ratings.

Each series of notes is a new issue of securities with no established trading market, and we do not intend to list the notes 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.

We expect the net proceeds from this offering to be approximately $     million, after deducting the underwriting discounts and our estimated offering expenses.

We intend to use the net proceeds from this offering to fund the Tender Offers and to pay fees and expenses in connection therewith. See “Summary—Concurrent Tender Offers” for the maturities and interest rates of the Subject Notes. In the event that the Tender Offers are not consummated, or the net proceeds from this offering are otherwise in excess of the amount needed to fund the Tender Offers, we intend to use any remaining proceeds for [the refinancing, redemption or repayment of certain of our outstanding indebtedness, including our indebtedness with near-term maturities.

Certain of the underwriters or their affiliates may hold a portion of the Subject Notes, and may therefore receive a portion of the net proceeds of this offering. Also, certain of the underwriters or their affiliates may be agents and/or lenders under the Company’s other existing indebtedness and may receive offering proceeds to the extent proceeds are used to pay down that debt. See “Underwriting.”

In this “Description of the Notes,” references to the “Company,” “we,” “us” or “our” refer to Occidental Petroleum Corporation and not to any of its subsidiaries. Capitalized terms used in this description but not otherwise defined have the meanings assigned to them in the Indenture (as defined below).

Each of our    % Senior Notes due 20   (the “20   Notes”) and    % Senior Notes due 20   (the “20   Notes” and, together with the 20   Notes, the “Notes”) will constitute a separate series of our senior debt securities under an indenture (the “Indenture”), dated as of August 8, 2019, between the Company, as issuer, and The Bank of New York Mellon Trust Company, N.A., as trustee (the “Trustee”). The terms of the Notes will include those stated in the Indenture and those made part of the Indenture by reference to the Trust Indenture Act of 1939, as amended (the “Trust Indenture Act”). We will issue each series of Notes on , 2020 (the “Issue Date”), pursuant to an officer’s certificate, as contemplated by the Indenture, setting forth the specific terms applicable to such series of Notes. References to the “Indenture” in this description refer to the Indenture as supplemented by each applicable officer’s certificate.

The following description is a summary of certain 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, the form of which is attached as an exhibit to the registration statement of which this prospectus supplement forms a part. 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 in their entirety. See “Where You Can Find More Information.”

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 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 have been and may be issued under the Indenture and includes the Notes.

Each series of Notes will constitute a separate series of the Company’s senior debt securities under the Indenture. The Indenture will not limit the aggregate principal amount of Notes that we may issue under the Indenture and we may, without the consent of holders of outstanding Notes, issue additional Notes thereunder of any series. In addition, the Indenture does not limit the amount of other unsecured debt that we or our subsidiaries may issue or incur. Our outstanding senior debt issued under other indentures may have different terms from the Notes (including different restrictive covenants and event of default provisions) and, as a result, certain events or circumstances that may constitute an event of default with respect to that previously issued debt may not constitute an event of default under the Indenture. The Notes are unsecured and will rank equally in right of payment with all of our other senior unsecured indebtedness.

As of September 30, 2020, after giving effect to this offering (including the application of the proceeds therefrom), we would have had approximately $     billion aggregate principal amount of outstanding indebtedness, none of which would have been secured indebtedness.

In addition, as of the date of this prospectus supplement, we had $5.0 billion of unused borrowing capacity available under our existing revolving credit facility, which matures in 2023 and $382 million of capacity available under the AR Facility.

Substantially all of our operations are conducted through our subsidiaries. None of our subsidiaries will guarantee 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 will be structurally subordinated to all existing and future indebtedness and other liabilities, including trade payables, of our subsidiaries, including debt obligations of our subsidiaries that remain outstanding following the Anadarko Acquisition. Even if we were recognized as a creditor of one or more of our subsidiaries, our claims would still be effectively subordinated to any obligations secured by security interests in or other liens on the assets of any such subsidiary.

The Notes will not be entitled to any sinking fund.

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

The 20   Notes will mature on     , 20   and the 20   Notes will mature on     , 20  .

The 20   Notes will bear interest from the Issue Date at the rate of   % per annum, and the 20   Notes will bear interest from the Issue Date at the rate of    % per annum. Interest on each series of Notes will be payable semiannually on and of each year, commencing on     , 2021, in each case, to the holders of record of the Notes of the applicable series at the close of business on the immediately preceding      and     ,      respectively (whether or not a business day).

If any interest payment date, maturity date or redemption date for any series of 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 each series of Notes 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 redemption date or on the maturity date of any series of 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 such series Notes (or, if no interest has been paid or duly provided for on such series of Notes, from and including the Issue Date) to, but not including, such interest payment date, redemption date or maturity date, as the case may be.

The Notes will not be listed on any securities exchange or included in any automated quotation system.

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.

Any series of Notes may be redeemed, in whole or in part, at our option, at any time or from time to time, in each case prior to the Applicable Par Call Date (as defined below) at a redemption price equal to the greater of:

On and after the Applicable Par Call Date, the Notes will be 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 Notes to be redeemed, plus accrued and unpaid interest on the principal amount of the Notes being redeemed to, but not including, the redemption date.

Notwithstanding the foregoing, with respect to interest that is due and payable on any interest payment date falling on or prior to a redemption date for such Notes, we will pay such interest to the persons who were record holders of such Notes at the close of business on the relevant regular record date.

We will send to each holder of Notes subject to redemption a notice of such redemption at least 10 days but not more than 60 days before the 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 thereof so redeemed for the period on and after such redemption date. If less than all of the Notes of a series are to be redeemed, the Notes (or portions thereof) of such series to be redeemed will be selected by such method as the Trustee deems appropriate (or, in the case of global notes, by the Depositary’s applicable policies and procedures).

We may provide in any notice of redemption that payment of the redemption price and the performance of any obligations with respect to such redemption may be performed by another person; provided, however, that we will remain obligated to pay the redemption price and perform any such obligations with respect to such redemption in the event such other person fails to do so.

“Applicable Make-Whole Spread” means, with respect to a series of Notes, the number of basis points set forth opposite such series in the table below:

“Applicable Par Call Date” means, with respect to a series of Notes, the date set forth opposite such series in the table below:

“Comparable Treasury Issue” means, with respect to any redemption date for a series of Notes, the United States Treasury security selected by the Quotation Agent 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 such series of Notes (assuming, for this purpose, that the Notes mature on the Applicable Par Call Date).

“Comparable Treasury Price” means, with respect to any redemption date for a series of Notes, (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 Quotation Agent 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 a series of Notes, the Reference Treasury Dealer appointed by us as such.

“Reference Treasury Dealer” means, with respect to any redemption date for a series of Notes, (1) each of (or their respective affiliates that 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; (2) a Primary Treasury Dealer selected by; (3) a Primary Treasury Dealer selected by; and (4) 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 a series of Notes, 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 Quotation Agent by such Reference Treasury Dealer at 5:00 p.m. (New York City time) on the third business day in The City of New York preceding such redemption date.

“Treasury Rate” means, on a redemption date, the rate per annum, as determined by the Quotation Agent, equal to:

The Treasury Rate will be calculated at 5:00 p.m. (New York City time) on the third business day preceding the redemption date by the Quotation Agent.

Each series of 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”) and registered in the name of Cede & Co., as nominee of the Depositary. 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, société 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 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 of default (as defined in the Indenture) with respect to the Notes shall have occurred and be continuing or (3) we in our sole discretion shall determine that some or all of the Notes will no longer be represented by Global Notes, the Global Notes will be exchangeable for Notes 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 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, as amended. 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 (collectively, the “U.S. Depositaries,” and each a “U.S. Depositary”), which hold those interests in customers’ securities accounts in the depositaries’ names on the books of the Depositary.

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.

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 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.

The following discussion summarizes certain U.S. federal income tax considerations that may be relevant to the acquisition, ownership and disposition of the notes.

This discussion is limited to holders who purchase the notes in this offering for cash at a price equal to the issue price of the notes (i.e., the first price at which a substantial amount of the notes is sold for cash other than to bond houses, brokers or similar persons or organizations acting in the capacity of underwriters, placement agents or wholesalers) and who hold the notes as capital assets (generally, property held for investment). This section addresses only U.S. federal income taxation and does not discuss all of the tax consequences that may be relevant to you in light of your individual circumstances, including foreign, state or local tax consequences, and tax consequences arising under the Medicare contribution tax on net investment income or the alternative minimum tax. This section does not apply to you if you are a member of a class of holders subject to special rules, such as:

If a partnership (including any entity taxed as a partnership for U.S. federal income tax purposes) holds the notes, the tax treatment of a partner in the partnership generally would depend upon the status of the partner and the activities of the partnership. If you are a partner of a partnership considering an investment in the notes, you should consult your own tax advisors regarding the tax consequences of acquiring, owning and disposing of the notes.

This summary is based on the Internal Revenue Code of 1986, as amended (the “Code”), its legislative history, existing and proposed regulations under the Code, published rulings and court decisions, all as currently in effect. These laws are subject to change, possibly on a retroactive basis. In addition, this summary does not address any tax consequences arising out of the laws of any state, local or foreign jurisdiction.

Please consult your own tax advisors concerning the consequences of the acquisition, ownership and disposition of the notes, in your particular circumstances under the Code and the laws of any other taxing jurisdiction.

This subsection describes the tax consequences to a U.S. Holder. You are a “U.S. Holder” if you are a beneficial owner of a note and you are:

If you are not a U.S. Holder, this subsection does not apply to you and you should refer to “Tax Consequences to Non-U.S. Holders” below.

Treasury regulations provide special rules for the treatment of debt instruments that provide for contingent payments. Under these regulations, a contingency is disregarded if the contingency is remote or incidental. In addition, these special rules do not apply where a debt instrument provides for alternative payment schedules applicable upon the occurrence of one or more contingencies, including an unconditional option held by the issuer or holder, and the timing and amounts of payments that comprise each payment schedule are known as of the issue date, in which case the option will be deemed to be exercised in a manner that maximizes (in the case of an option held by the holder) or minimizes (in the case of an option held by the issuer) the yield on the debt instrument. We intend to take the position that our option to redeem the notes (see “Description of the Notes—Optional Redemption”) should not cause the contingent payment debt instrument rules of the Treasury regulations to apply. This position is not binding on the Internal Revenue Service (“IRS”). A successful challenge of this position by the IRS could adversely affect the timing and amount of income inclusions with respect to the notes, and could cause any gain recognized on a sale or other taxable disposition of the notes to be treated as ordinary income rather than capital gain. The discussion below assumes that our position in this regard will be respected for tax purposes.

Under the indenture, we may discharge, at any time, our obligations in respect of the notes under certain circumstances (see “Description of Senior Debt Securities—Discharge” in the accompanying prospectus). As described further in the accompanying prospectus under “Description of Senior Debt Securities—Discharge,” such a discharge could result in a taxable exchange for U.S. federal income tax purposes of the notes that have been discharged and you may recognize gain or loss on such notes and may be required to include in income any income, gain or loss attributable thereto even though no cash was actually received. After the discharge you would likely be treated as if you held an undivided interest in the cash and the property held in trust and may be subject to tax liability with respect thereto. You should review the accompanying prospectus and you should consult your own tax advisors regarding the potential U.S. federal income tax consequences to you in the event of a discharge.

Stated interest on the notes generally will be taxable to you as ordinary income at the time that it is paid or accrued in accordance with your method of accounting for U.S. federal income tax purposes.

Upon the sale, exchange or other disposition of a note, you would recognize gain or loss equal to the difference, if any, between the amount realized on the sale, exchange or other disposition (excluding accrued but unpaid stated interest, which generally would be taxable as interest to the extent not previously included in income) and your adjusted tax basis in the note. Your adjusted tax basis in the note would be the amount you paid for the note.

Gain or loss that you recognize upon the sale, exchange or other disposition of a note would be capital gain or loss, and would be long-term capital gain or loss if your holding period for the note is more than one year at the time of the sale, exchange or other disposition. Capital gain of a non-corporate U.S. Holder generally would be taxed at preferential rates where the property is held for more than one year. The deductibility of capital losses is subject to limitations.

This subsection describes the tax consequences to a Non-U.S. Holder. You are a Non-U.S. Holder if you are a beneficial owner of a note that is not a U.S. Holder.

Subject to the discussions of backup withholding and FATCA withholding below, interest on the notes paid will be exempt from U.S. federal income tax, including withholding tax, if you meet one of the following requirements:

Subject to the discussions of backup withholding and FATCA withholding below, you generally would not be subject to U.S. federal income tax on gain realized on the sale, exchange or other disposition of your notes, unless:

If you are a corporate Non-U.S. Holder, “effectively connected” gains that you recognize may also, under certain circumstances, be subject to an additional “branch profits tax” at a 30% rate or at a lower rate if you are eligible for the benefits of an income tax treaty that provides for a lower rate.

To the extent that any portion of the amount received on a sale, exchange or other disposition of your notes is attributable to unpaid interest on such notes, this amount generally will be taxed in the same manner as described above under “—Payments of Interest.”

In general, if you are a non-corporate U.S. Holder, we and other payors may be required to report to the IRS (1) payments of principal of and premium (if any) and interest on your notes and (2) payments of the proceeds from the sale of your notes before maturity. Additionally, unless you are an exempt recipient, backup withholding would apply to any such payments if you fail to provide an accurate taxpayer identification number, or (in the case of interest payments) you are notified by the IRS that you have failed to report all interest and dividends required to be shown on your federal income tax returns.

In general, if you are a Non-U.S. Holder, you would not be subject to backup withholding and information reporting on payments of principal of and premium (if any) and interest on your notes made by us and other payors; provided that the certification requirements described above under “Tax Consequences to Non-U.S. Holders—Payments of Interest” or “Tax Consequences to Non-U.S. Holders—Sale, Exchange or other Disposition of the Notes” are satisfied or you otherwise establish an exemption. However, we and other payors would be required to report payments of interest on your notes on IRS Form 1042-S even if the payments are not otherwise subject to information reporting requirements. In addition, payments of the proceeds from the sale of your notes effected at a United States office of a broker would not be subject to backup withholding and information reporting if (i) the payor or the broker does not have actual knowledge or reason to know that you are a U.S. person and (ii) you have furnished to the broker an appropriate IRS Form W-8, an acceptable substitute form or other documentation upon which it may rely to treat the payment as made to a non-U.S. person. Payments to a Non-U.S. Holder of the proceeds from the sale of your notes effected at a foreign office of a broker would generally not be subject to information reporting or backup withholding. However, payments of proceeds received on such sales could be subject to information reporting and backup withholding in the same manner as a sale within the United States if: (i) the broker has certain connections to the United States, (ii) the proceeds or confirmation are sent to an address in the United States or (iii) the sale has certain other specified connections with the United States.

A 30% withholding tax may be imposed on certain payments to a holder or to certain foreign financial institutions, investment funds and other non-U.S. persons receiving payments on the holder’s behalf if such holder or such persons fail to comply with certain information reporting requirements (“FATCA withholding”). Such payments include U.S.-source interest on debt securities that are issued or deemed issued after June 30, 2014, including the notes. Amounts that a holder receives on the notes could be affected by this withholding if such holder is subject to the information reporting requirements and fails to comply with them or if such holder holds the notes through another person (e.g., a foreign bank or broker) that is subject to withholding because it fails to comply with these requirements (even if such holder would not otherwise have been subject to withholding). Holders should consult their own tax advisors regarding the relevant U.S. law and other official guidance on FATCA withholding.

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 set forth opposite its respective name in the following table.

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

Notes sold by the underwriters to the public will initially be offered at the initial public offering price 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 price of up to the applicable percentage of the principal amount of such notes set forth below:

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 price of up to the applicable percentage of the principal amount of such notes set forth below:

If all the notes are not sold at their respective initial offering prices, the underwriters may change the offering prices to the public and the other selling terms of the notes.

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

Each series of the notes is a series of securities with no established trading market. The notes will not be listed on any securities exchange or on any automated dealer quotation system. We have been advised by certain of the underwriters that such underwriters intend to make a market in the 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 the notes will develop or as to the liquidity of any trading market for the notes that may develop. If an active trading market for the notes does not develop, the market price and liquidity of the notes may be adversely affected. If the notes are traded, they may trade at a discount from their initial offering price, depending on prevailing interest rates, the market for similar securities, our operating performance and financial condition, general economic conditions and other factors.

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.

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 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. Neither we nor any of the underwriters make any representation or prediction as to the direction or magnitude of any effect that the transactions described above may have on the price of the notes. In addition, neither we nor any of the underwriters make any representation that the representatives will engage in these transactions or that these transactions, once commenced, will not be discontinued without notice.

We estimate that our share of the total expenses of the offering, excluding the underwriting discounts, will be approximately $5.5 million.

We have agreed to indemnify the several underwriters against, or contribute to payments that the underwriters may be required to make in respect of, certain liabilities, including liabilities under the Securities Act.

Certain of the underwriters and their respective affiliates have, from time to time, performed, and may in the future perform, various financial advisory and investment banking services for us, for which they received or will receive customary fees and expenses. The underwriters are full service financial institutions engaged in various activities, which may include sales and trading, commercial and investment bank, advisory, investment management, investment research, principal investment, hedging, market making, brokerage and other financial and non-financial activities and services. For example, RBC Capital Markets, LLC, J.P. Morgan Securities LLC, Barclays Capital Inc., HSBC Securities (USA) Inc., SG Americas Securities, LLC, BofA Securities, Inc., MUFG Securities Americas Inc., SMBC Nikko Securities America, Inc. and Scotia Capital (USA) Inc. or their respective affiliates and certain other affiliates of the underwriters (i) committed to provide a 364-day senior unsecured bridge loan in connection with the Anadarko Acquisition, (ii) acted as lead arrangers, bookrunners and/or lenders with respect to our term loan agreement to, among other things, finance a portion of the Anadarko Acquisition and (iii) acted as lead arrangers, bookrunners and/or lenders with respect to our amended and restated credit agreement. In addition, (i) affiliates of RBC Capital Markets, LLC, J.P. Morgan Securities LLC, Barclays Capital Inc., HSBC Securities (USA) Inc., SG Americas Securities, LLC, SMBC Nikko Securities America, Inc. and Scotia Capital (USA) Inc. are documentation agents under our term loan agreement and (ii) affiliates of RBC Capital Markets, LLC, J.P. Morgan Securities LLC, Barclays Capital Inc., HSBC Securities (USA) Inc., SG Americas Securities, LLC, BofA Securities, Inc., MUFG Securities Americas Inc., SMBC Nikko Securities America, Inc. are documentation agents under our amended and restated Credit Agreement. Certain of the underwriters are also acting as dealer managers in connection with the Tender Offers. An affiliate of BNY

Mellon Capital Markets, LLC serves as trustee under various series of our debt securities, including the notes. Certain of the underwriters or their respective affiliates may hold a portion of the Subject Notes and may therefore receive a portion of the net proceeds of the Tender Offers. Also, certain of the underwriters or their affiliates may be agents and/or lenders under the Company’s other existing indebtedness and may receive offering proceeds to the extent proceeds are used to pay down that debt. In addition, we are required to indemnify under certain circumstances certain of the underwriters who are defendants in a putative securities class action captioned City of Sterling Heights General Employees’ Retirement System, et al. v. Occidental Petroleum Corporation, et al., No. 651994/2020 and in two additional putative class actions that were consolidated into In re Occidental Petroleum Corporation Securities Litigation, No. 651830/2020 (see “Notes to Consolidated Condensed Financial Statements—Note 10—Lawsuits, Claims, Commitments and Contingencies—Legal Matters” in our Quarterly Report on Form 10-Q for the quarter ended September 30, 2020).

In addition, in the ordinary course of their business activities, the underwriters and their affiliates may make or hold a broad array of investments and actively trade debt and equity securities (or related derivative securities) and financial instruments (including bank loans) for their own account and for the accounts of their customers. Such investments and securities activities may involve securities and/or instruments of ours or our affiliates. If any of the underwriters or their affiliates has a lending relationship with us, certain of those underwriters or their affiliates routinely hedge, certain of those underwriters or their affiliates are likely to hedge and certain other of those underwriters or their affiliates may hedge, their credit exposure to us consistent with their customary risk management policies. Typically, these underwriters and their affiliates would hedge such exposure by entering into transactions which consist of either the purchase of credit default swaps or the creation of short positions in our securities, including potentially the notes offered hereby. Any such credit default swaps or short positions could adversely affect future trading prices of the notes offered hereby. The underwriters and their affiliates may also make investment recommendations and/or publish or express independent research views in respect of such securities or financial instruments and may hold, or recommend to clients that they acquire, long and/or short positions in such securities and instruments.

We expect that delivery of the notes will be made against payment therefor on or about the settlement date specified on the cover page of this prospectus supplement, which will be the business day following the date of pricing of the notes (this settlement cycle being referred to as “T+ ”). Pursuant to Rule 15c6-1 under the Exchange Act, trades in the secondary market generally are required to settle in two business days, unless the parties to that trade expressly agree otherwise. Accordingly, purchasers who wish to trade the notes on the date of this prospectus supplement or the following business days will be required, by virtue of the fact that the notes initially will settle in T+ , to specify an alternate settlement cycle at the time of any such trade to prevent a failed settlement. Purchasers of notes should consult their own advisors.

The notes are not intended to be offered, sold or otherwise made available to and should not be offered, sold or otherwise made available to any retail investor in the European Economic Area (“EEA”) or the United Kingdom. For these purposes, a retail investor means a person who is one (or more) of: (i) a retail client as defined in point (11) of Article 4(1) of Directive 2014/65/EU (as amended, “MiFID II”); or (ii) a customer within the meaning of Directive (EU) 2016/97/EU (as amended), where that customer would not qualify as a professional client as defined in point (10) of Article 4(1) of MiFID II; or (iii) not a qualified investor as defined in Regulation (EU) 2017/1129 (the “Prospectus Regulation”). Consequently no key information document required by Regulation (EU) No 1286/2014 (as amended, the “PRIIPs Regulation”) for offering or selling the notes or otherwise making them available to retail investors in the EEA or the United Kingdom has been prepared and therefore offering or selling the notes or otherwise making them available to any retail investor in the EEA or the United Kingdom may be unlawful under the PRIIPs Regulation. This prospectus supplement and the accompanying short form base shelf prospectus have been prepared on the basis that any offer of notes in any Member State of the EEA or the United Kingdom will be made pursuant to an exemption under the Prospectus Regulation from the requirement to publish a prospectus for offers of notes. This prospectus supplement and the accompanying short form base shelf prospectus are not a prospectus for the purposes of the

Prospectus Regulation. References to Regulations or Directives include, in relation to the UK, those Regulations or Directives as they form part of UK domestic law by virtue of the European Union (Withdrawal) Act 2018 or have been implemented in UK domestic law, as appropriate.

Further, in the United Kingdom, this prospectus supplement is for distribution only to, and is directed only at, persons who (i) have professional experience in matters relating to investments falling within Article 19(5) of the Financial Services and Markets Act 2000 (Financial Promotion) Order 2005 (as amended, the “Financial Promotion Order”), (ii) are persons falling within Article 49(2)(a) to (d) (“high net worth companies, unincorporated associations, etc.”) of the Financial Promotion Order or (iii) are persons to whom an invitation or inducement to engage in investment activity (within the meaning of Section 21 of the Financial Services and Markets Act 2000) in connection with the issue or sale of the notes may otherwise lawfully be communicated or caused to be communicated (all such persons together being referred to as “relevant persons”). This prospectus supplement is directed only at relevant persons and must not be acted on or relied on by persons who are not relevant persons. Each underwriter has represented and agreed that:

Any investment or investment activity to which this prospectus supplement relates is available only to relevant persons and will be engaged in only with relevant persons. Recipients of this prospectus supplement are not permitted to transmit it to any other person. The notes are not being offered to the public in the United Kingdom.

This prospectus supplement and the accompanying prospectus may not be circulated or distributed in the People’s Republic of China (“PRC”) and the notes may not be offered or sold, and will not be offered or sold, directly or indirectly, to any resident of the PRC or to persons for re-offering or resale, directly or indirectly, to any resident of the PRC except pursuant to applicable laws, rules and regulations of the PRC. For the purpose of this paragraph only, the PRC does not include Taiwan and the special administrative regions of Hong Kong and Macau.

The notes may not be offered or sold by means of any document other than (i) in circumstances which do not constitute an offer to the public within the meaning of the Companies Ordinance (Cap. 32, Laws of Hong Kong), or (ii) to “professional investors” within the meaning of the Securities and Futures Ordinance (Cap. 571, Laws of Hong Kong) and any rules made thereunder, or (iii) in other circumstances which do not result in the document being a “prospectus” within the meaning of the Companies Ordinance (Cap. 32, Laws of Hong Kong), and no advertisement, invitation or document relating to the notes may be issued or may be in the possession of any person for the purpose of issue (in each case whether in Hong Kong or elsewhere), which is directed at, or the contents of which are likely to be accessed or read by, the public in Hong Kong (except if permitted to do so under the laws of Hong Kong) other than with respect to notes which are or are intended to be disposed of only to persons outside Hong Kong or only to “professional investors” within the meaning of the Securities and Futures Ordinance (Cap. 571, Laws of Hong Kong) and any rules made thereunder.

The notes have not been and will not be registered under the Securities and Exchange Law of Japan (the “Securities and Exchange Law”) and no underwriter may offer or sell any notes, directly or indirectly, in Japan or to, or for the benefit of, any resident of Japan (which term as used herein means any person resident in Japan, including any corporation or other entity organized under the laws of Japan), or to others for re-offering or resale, directly or indirectly, in Japan or to a resident of Japan, except pursuant to an exemption from the registration requirements of, and otherwise in compliance with, the Securities and Exchange Law and any other applicable laws, regulations and ministerial guidelines of Japan.

This prospectus has not been registered as a prospectus with the Monetary Authority of Singapore. Accordingly, this prospectus and any other document or material in connection with the offer or sale, or invitation for subscription or purchase, of the notes may not be circulated or distributed, nor may the notes be offered or sold, or be made the subject of an invitation for subscription or purchase, whether directly or indirectly, to persons in Singapore other than (i) to an institutional investor under Section 274 of the Securities and Futures Act, Chapter 289 of Singapore (the “SFA”), (ii) to a relevant person, or any person pursuant to Section 275(IA), and in accordance with the conditions, specified in Section 275 of the SFA or (iii) otherwise pursuant to, and in accordance with the conditions of, any other applicable provision of the SFA.

Where the notes are subscribed or purchased under Section 275 by a relevant person which is: (a) a corporation (which is not an accredited investor) the sole business of which is to hold investments and the entire share capital of which is owned by one or more individuals, each of whom is an accredited investor or (b) a trust (where the trustee is not an accredited investor) whose sole purpose is to hold investments and each beneficiary is an accredited investor, shares, debentures and units of shares and debentures of that corporation or the beneficiaries’ rights and interest in that trust shall not be transferable for 6 months after that corporation or that trust has acquired the notes under Section 275 except: (1) to an institutional investor under Section 274 of the SFA or to a relevant person, or any person pursuant to Section 275(IA), and in accordance with the conditions, specified in Section 275 of the SFA; (2) where no consideration is given for the transfer; or (3) by operation of law.

Solely for the purposes of its obligations pursuant to sections 309B(1)(a) and 309B(1)(c) of the SFA, the Company has determined, and hereby notifies all relevant persons (as defined in Section 309A of the SFA) that the Notes are “prescribed capital markets products” (as defined in the Securities and Futures (Capital Markets Products) Regulations 2018) and Excluded Investment Products (as defined in MAS Notice SFA 04-N12: Notice on the Sale of Investment Products and MAS Notice FAA-N16: Notice on Recommendations on Investment Products).

We have not and will not register with the Swiss Financial Market Supervisory Authority (“FINMA”) as a foreign collective investment scheme pursuant to Article 119 of the Federal Act on Collective Investment Scheme of 23 June 2006, as amended (“CISA”), and accordingly the notes being offered pursuant to this prospectus supplement and the accompanying prospectus have not and will not be approved, and may not be licensable, with FINMA. Therefore, the notes have not been authorized for distribution by FINMA as a foreign collective investment scheme pursuant to Article 119 CISA and the notes offered hereby may not be offered to the public (as this term is defined in Article 3 CISA) in or from Switzerland. The notes may solely be offered to “qualified investors,” as this term is defined in Article 10 CISA, and in the circumstances set out in Article 3 of the Ordinance on Collective Investment Scheme of 22 November 2006, as amended (“CISO”), such that there is no public offer. Investors, however, do not benefit from protection under CISA or CISO or supervision by FINMA. This prospectus supplement, the accompanying prospectus and any other materials relating to the notes are strictly personal and confidential to each offeree and do not constitute an offer to any other person. This prospectus supplement and the accompanying prospectus may only be used by those qualified investors to whom it has been handed out in connection with the offer described herein and may neither directly or indirectly be distributed or made available to any person or entity other than its recipients. It may not be used in connection with any other offer and shall in particular not be copied and/or distributed to the public in Switzerland or from Switzerland. This prospectus supplement and the accompanying prospectus do not constitute an issue prospectus as that term is understood pursuant to Article 652a and/or 1156 of the Swiss Federal Code of Obligations.

Cravath, Swaine & Moore LLP will pass upon the validity of the notes offered hereby. The validity of the notes will be passed upon for the underwriters by Weil, Gotshal & Manges LLP.

The consolidated financial statements of Occidental Petroleum Corporation and subsidiaries as of December 31, 2019 and 2018, and for each of the years in the three-year period ended December 31, 2019 and management’s assessment of the effectiveness of internal control over financial reporting as of December 31, 2019 have been incorporated by reference herein in reliance upon the reports of KPMG LLP, an independent registered public accounting firm, incorporated by reference herein, and upon the authority of said firm as experts in accounting and auditing. The audit report covering the December 31, 2019 financial statements refers to a change in the method of accounting for leases in 2019 due to the adoption of Accounting Standards Codification Topic 842, Leases.

The consolidated financial statements of Anadarko Petroleum Corporation and subsidiaries as of December 31, 2018 and 2017, and for each of the years in the three-year period ended December 31, 2018, have been incorporated by reference herein in reliance upon the report of KPMG LLP, an independent registered public accounting firm, incorporated by reference herein, and upon the authority of said firm as experts in accounting and auditing. The audit report covering the December 31, 2018 consolidated financial statements refers to a change in the method of accounting for revenue recognition in 2018.

Certain information with respect to the oil and gas reserves associated with Occidental’s oil and gas properties is confirmed in the process review letter of Ryder Scott Company, L.P., independent petroleum engineering consultants, and has been incorporated by reference herein, upon the authority of said firm as experts with respect to the matters covered by such process review letter and in giving such process review letter.

Certain information with respect to the oil and gas reserves associated with Anadarko’s oil and gas properties is confirmed in the procedures and methods review letter of Miller and Lents, Ltd., an independent petroleum consulting firm, and has been incorporated by reference herein, upon the authority of said firm as experts with respect to the matters covered by such procedures and methods review letter and in giving such procedures and methods review letter.

We are subject to the information reporting requirements of the Securities Exchange Act of 1934, as amended (the “Exchange Act”). In accordance with the Exchange Act, we file annual, quarterly and current reports, proxy statements and other information with the SEC. Our SEC file number is 001-09210. The SEC maintains a website that contains reports, proxy statements and other information about issuers, like us, that file electronically with the SEC. The address of that site is at www.sec.gov. Such reports, proxy statements and other information filed by us 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 such information filed with the SEC subsequent to the date of this prospectus supplement will automatically be deemed to update and supersede this information. This prospectus supplement incorporates by reference the documents listed below that we have previously filed with the SEC. They contain important information about us and our financial condition.

We also incorporate by reference all documents we may subsequently file with the SEC pursuant to Section 13(a), 13(c), 14 or 15(d) of the Exchange Act from the date of this prospectus supplement until the termination of the offering to which this prospectus supplement relates. Information furnished under Items 2.02 or 7.01 (and corresponding information furnished under Item 9.01 or included as an exhibit) in any past or future Current Report on Form 8-K 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: