SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES | NOTE 1 - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES NATURE OF OPERATIONS In this report, “Occidental” means Occidental Petroleum Corporation, a Delaware corporation (OPC), or OPC and one or more entities in which it owns a controlling interest (subsidiaries). Occidental conducts its operations through various subsidiaries and affiliates. On August 8, 2019, pursuant to the Agreement and Plan of Merger dated as of May 9, 2019 (the Merger Agreement), among Occidental, Baseball Merger Sub 1, Inc., a Delaware corporation and an indirect, wholly owned subsidiary of Occidental (Merger Subsidiary), and Anadarko Petroleum Corporation (Anadarko), Occidental acquired all of the outstanding shares of Anadarko through a transaction in which Merger Subsidiary merged with and into Anadarko (the Acquisition), with Anadarko continuing as the surviving entity and as an indirect, wholly owned subsidiary of Occidental. See Note 3 - The Acquisition for further information. Occidental’s principal businesses consist of three reporting segments: oil and gas, chemical and midstream and marketing. The oil and gas segment explores for, develops and produces oil and condensate, natural gas liquids (NGL) and natural gas. The chemical segment (OxyChem) mainly manufactures and markets basic chemicals and vinyls. The midstream and marketing segment purchases, markets, gathers, processes, transports and stores oil, condensate, NGL, natural gas, CO 2 and power. It also trades around its assets, including transportation and storage capacity, and invests in entities that conduct similar activities such as Western Midstream Partners, L.P. (WES). The midstream and marketing segment also includes Oxy Low Carbon Ventures (OLCV). OLCV seeks to leverage Occidental’s carbon management expertise that is derived from its enhanced oil recovery (EOR) operations to develop carbon capture, utilization and storage facilities that are expected to source anthropogenic CO 2 and promote innovative technologies that drive cost efficiencies and economically grow Occidental’s business while reducing emissions. PRINCIPLES OF CONSOLIDATION The consolidated financial statements have been prepared in conformity with United States Generally Accepted Accounting Principles (GAAP) and include the accounts of OPC, its subsidiaries, its undivided interests in oil and gas exploration and production ventures and, previously, variable interest entities (VIE) for which Occidental was the primary beneficiary. Occidental accounts for its share of oil and gas exploration and production ventures, in which it has a direct working interest, by reporting its proportionate share of assets, liabilities, revenues, costs and cash flows within the relevant lines on the balance sheets, statements of operations and statements of cash flows. The Acquisition introduced different revenue and expense streams to Occidental’s legacy operations. As a result, changes were made to the structure of certain financial statements, notes and supplementary data to provide clarity. In addition, certain prior period amounts have been reclassified to conform to the current presentation. WES INVESTMENT WES is a publicly traded limited partnership with its common units traded on the New York Stock Exchange (NYSE) under the ticker symbol “WES.” WES owns the entire non-economic general partner interest and a 98% limited partner interest in Western Midstream Operating, LP (WES Operating), a Delaware limited partnership formed by Anadarko in 2007 to acquire, own, develop and operate midstream assets. From the Acquisition date through December 31, 2019, WES was determined to be a VIE, and Occidental, through its ownership of the general partner interest in WES, had the power to direct the activities that significantly affected the economic performance of WES and the obligation to absorb losses or the right to receive benefits that could be significant to WES. As such, Occidental was considered the primary beneficiary and consolidated WES and its consolidated subsidiaries from the date of the Acquisition to December 31, 2019. All intercompany transactions were eliminated during the consolidated period. Revenues of $1.1 billion, cost of sales of $500 million and operating cash flows of $498 million from the date of the Acquisition to December 31, 2019 are attributable to WES and are included in Occidental’s consolidated financial statements. Net income from noncontrolling interest for the same period relates to the 44.6% limited partner interest of WES owned by the public. On December 31, 2019, Occidental and WES executed several agreements to allow WES to operate as an independent midstream company to support its ongoing pursuit of third-party growth opportunities. The executed agreements include amendments to the partnership agreement that significantly expand the unaffiliated limited partner unitholders’ rights. The significant amendments to the partnership agreement included: ■ Providing for a simple majority of the unaffiliated unitholders to remove and elect a new general partner; ■ Allowing for 20% of the unaffiliated unitholders to call a special meeting to vote to remove the general partner; ■ Eliminating ownership thresholds that could have prevented unaffiliated unitholders from voting; ■ Limiting Occidental’s voting percentage to 45% for certain unitholder matters until Occidental owns less than 40% of the limited partner units for twelve consecutive months; and ■ Transferring 2% of Occidental’s limited partner interest to the general partner to provide a 2% economic interest to the general partner. In addition to the partnership agreement amendments, in December 2019, the WES management team’s employment was transferred from Occidental to WES, and WES-dedicated personnel were seconded to WES from Occidental. The seconded employees’ employment was contractually obligated to be transferred to WES during 2020 once employee benefit plans were established. As of December 31, 2020, there were no seconded employees remaining for WES. Additionally, as of December 31, 2019, Occidental employees no longer comprise a majority of the board of directors of WES’ general partner. As a result of the 2019 partnership agreement amendments and other related agreements, WES no longer met the criteria to be considered a VIE. Accordingly, Occidental evaluated WES under the voting interest model and determined, because Occidental did not control the power to appoint or remove a successor general partner, it should no longer consolidate WES. Occidental recognized, at fair value, an equity method investment of $5.1 billion based on the closing market price of WES as of December 31, 2019 and recognized a loss of approximately $1 billion that was included in asset impairments and other charges on the Statement of Operations for the year ended December 31, 2019. In the first quarter 2020, Occidental recorded a loss from an equity investment of $236 million primarily as a result of WES’ write-off of its goodwill. At the end of the third quarter 2020, Occidental recorded an other-than-temporary impairment of $2.7 billion, see Note 17 - Fair Value Measurements for a description of the inputs and assumptions utilized. In addition, Occidental recorded a loss of $46 million as a result of a non-cash transaction with WES in which Occidental exchanged approximately 27.9 million of its WES common units to retire a $260 million note payable to WES, see Note 7 - Long-Term Debt . As of December 31, 2020, Occidental’s equity method investment in WES was $1.9 billion, which exceeds Occidental’s pro-rata interest in the net assets of WES by $437 million. This basis difference is primarily associated with WES' property, plant and equipment and equity investments and is subject to amortization over their estimated average lives. Subsequent to the other-than-temporary impairment there was no equity method goodwill associated with the WES equity investment. As of December 31, 2020, Occidental has a 2% non-voting general partner interest and a 51.8% limited partner interest in WES and a 2% non-voting limited partner interest in WES Operating, a subsidiary of WES. On a combined basis, Occidental's total effective economic interest in WES and its subsidiaries is 53.5%. Occidental intends to reduce its limited partner ownership interest in WES to below 50%. INVESTMENTS IN UNCONSOLIDATED ENTITIES Occidental’s percentage interest in the underlying net assets of affiliates for which it exercises significant influence without having a controlling interest (excluding oil and gas ventures in which Occidental holds an undivided interest) are accounted for under the equity method. Occidental reviews equity-method investments for impairment whenever events or changes in circumstances indicate that an other-than-temporary decline in value may have occurred. The amount of impairment, if any, is based on quoted market prices, when available, or other valuation techniques, including discounted cash flows. See Note 16 - Investment s and R el ated - Part y Trans actions for further discussion regarding investments in unconsolidated entities. DISCONTINUED OPERATIONS In connection with the Acquisition, Occidental entered into a purchase and sale agreement with TOTAL S.A. (Total) to sell all of the assets, liabilities, businesses and operations of Anadarko's operations in Algeria, Ghana, Mozambique and South Africa. Total and Occidental completed the sale of the Mozambique assets in September 2019 for approximately $4.2 billion and the South Africa assets in January 2020 for approximately $100 million. In April 2020, subsequent to communications with Algerian government officials, Occidental determined that the sale of the Algeria operations to Total would not be consummated and the decision was made to continue to operate within Algeria. As a result, as of the second quarter of 2020, Occidental no longer classified the Algeria operations as a held for sale asset in discontinued operations and reclassified prior periods to reflect the Algeria operations as continuing operations, see Note 4 - Divestitures and Other Transactions for the impact on prior periods. In addition, in the second quarter 2020, Occidental recorded a $931 million impairment to remeasure the Algeria oil and gas properties to their fair value, which was lower than the carrying amount as if DD&A were recorded from the date of the Acquisition. The fair value of the oil and gas properties was measured based on the income approach, see Note 17 - Fair Value Measurements for a description of inputs and assumptions utilized. In May 2020, Occidental and Total mutually agreed to execute a waiver of the obligation to purchase and sell the Ghana assets, so that Occidental could begin marketing the sale of the Ghana assets to other third parties. Occidental is currently marketing the Ghana assets. The assets and liabilities for Ghana remain presented as held for sale at December 31, 2020. Occidental recorded an after-tax impairment of $1.4 billion in the second quarter 2020 to reflect the held for sale assets at their fair value less costs to sell based on the income approach, refer to Note 17 - Fair Value Measurement . The results of operations of Ghana continue to be presented as discontinued operations, see Note 4 - Divestitures and Other Transactions . Unless otherwise indicated, information presented in the Notes to the Consolidated Financial Statements relates only to Occidental's continuing operations. Information related to discontinued operations is included in Note 4 - Divestitures and Other Transactions and in some instances, where appropriate, is included as a separate disclosure within the individual Notes to the Consolidated Financial Statements. RISKS AND UNCERTAINTIES The process of preparing consolidated financial statements in conformity with GAAP requires Occidental’s management to make informed estimates and judgments regarding certain types of financial statement balances and disclosures. Such estimates primarily relate to unsettled transactions and events as of the date of the consolidated financial statements and judgments on expected outcomes as well as the materiality of transactions and balances. Changes in facts and circumstances or discovery of new information relating to such transactions and events may result in revised estimates and judgments and actual results may differ from estimates upon settlement. Management believes that these estimates and judgments provide a reasonable basis for the fair presentation of Occidental’s financial statements. Occidental establishes a valuation allowance against net operating losses and other deferred tax assets to the extent it believes the future benefit from these assets will not be realized in the statutory carryforward periods. Realization of deferred tax assets is dependent upon Occidental generating sufficient future taxable income and reversal of temporary differences in jurisdictions where such assets originate. The accompanying consolidated financial statements include assets of approximately $9.5 billion as of December 31, 2020 and net sales of approximately $3.4 billion for the year ended December 31, 2020, relating to Occidental’s operations in countries outside North America. Occidental operates some of its oil and gas business in countries that have experienced political instability, nationalizations, corruption, armed conflict, terrorism, insurgency, civil unrest, security problems, labor unrest, OPEC production restrictions, equipment import restrictions and sanctions, all of which increase Occidental’s risk of loss, delayed or restricted production or may result in other adverse consequences. Occidental attempts to conduct its affairs so as to mitigate its exposure to such risks and would seek compensation in the event of nationalization. Because Occidental’s major products are commodities, significant changes in the prices of oil, NGL, natural gas and chemical products may have a significant impact on Occidental’s results of operations. Also, see Property, Plant and Equipment section below. RECEIVABLES AND OTHER CURRENT ASSETS Trade receivables, net, of $2.1 billion and $4.2 billion at December 31, 2020, and 2019, respectively, represent rights to payment for which Occidental has satisfied its obligations under a contract with a customer and its right to payment is conditioned only on the passage of time. Other current assets includes amounts receivable from working interest partners in Occidental’s oil and gas operations, derivative assets and taxes receivable. INVENTORIES Materials and supplies are valued at weighted-average cost and are reviewed periodically for obsolescence. Oil, NGL and natural gas inventories are valued at the lower of cost or market. For the chemical segment, Occidental’s finished goods inventories are valued at the lower of cost or market. For most of its domestic inventories, other than materials and supplies, the chemical segment uses the last-in, first-out (LIFO) method as it better matches current costs and current revenue. For other countries, Occidental uses the first-in, first-out method (if the costs of goods are specifically identifiable) or the average-cost method (if the costs of goods are not specifically identifiable). PROPERTY, PLANT AND EQUIPMENT OIL AND GAS The carrying value of Occidental’s property, plant and equipment (PP&E) represents the cost incurred to acquire or develop the asset, including any asset retirement obligations and capitalized interest, net of accumulated DD&A and any impairment charges. For assets acquired, PP&E cost is based on fair values at the acquisition date. Asset retirement obligations and interest costs incurred in connection with qualifying capital expenditures are capitalized and amortized over the lives of the related assets. Occidental uses the successful efforts method to account for its oil and gas properties. Under this method, Occidental capitalizes costs of acquiring properties, costs of drilling successful exploration wells and development costs. The costs of exploratory wells are initially capitalized pending a determination of whether proved reserves have been found. If proved reserves have been found, the costs of exploratory wells remain capitalized. For exploratory wells that find reserves that cannot be classified as proved when drilling is completed, costs continue to be capitalized as suspended exploratory drilling costs if there have been sufficient reserves found to justify completion as a producing well and sufficient progress is being made in assessing the reserves and the economic and operating viability of the project. At the end of each quarter, management reviews the status of all suspended exploratory drilling costs in light of ongoing exploration activities, in particular, whether Occidental is making sufficient progress in its ongoing exploration and appraisal efforts or, in the case of discoveries requiring government sanctioning, analyzing whether development negotiations are underway and proceeding as planned. If management determines that future appraisal drilling or development activities are unlikely to occur, associated suspended exploratory well costs are expensed. The following table summarizes the activity of capitalized exploratory well costs for continuing operations for the years ended December 31: millions 2020 2019 2018 Balance — beginning of year $ 424 $ 112 $ 108 Exploratory well costs acquired through the Acquisition — 231 — Additions to capitalized exploratory well costs pending the determination of proved reserves 122 383 220 Reclassifications to property, plant and equipment based on the determination of proved reserves (309) (230) (198) Capitalized exploratory well costs charged to expense (26) (72) (18) Balance — end of year $ 211 $ 424 $ 112 Occidental expenses annual lease rentals, the costs of injectants used in production and geological and geophysical costs as incurred. Occidental determines depreciation and depletion of oil and gas producing properties by the unit-of-production method. It amortizes leasehold costs over total proved reserves and capitalized development and successful exploration costs over proved developed reserves. Proved oil and gas reserves are those quantities of oil and gas which, by analysis of geoscience and engineering data, can be estimated with reasonable certainty to be economically producible from a given date forward, from known reservoirs and under existing economic conditions, operating methods and government regulations prior to the time at which contracts providing the right to operate expire, unless evidence indicates that renewal is reasonably certain, regardless of whether deterministic or probabilistic methods are used for the estimation. Proved reserves includes proved undeveloped reserves. Proved undeveloped reserves are supported by a management approved, detailed, field-level development plan where sufficient capital has been committed to develop those reserves. A majority of the proved undeveloped reserves are supported by a five-year, development plan while certain international proved undeveloped reserves are associated with approved long-term development plans. Occidental performs impairment tests with respect to its proved properties whenever events or circumstances indicate that the carrying value of property may not be recoverable. If there is an indication the carrying amount of the asset may not be recovered due to prolonged declines in current and forward prices, significant changes in reserve estimates, changes in management’s plans, or other significant events, management will evaluate the property for impairment. Under the successful efforts method, if the sum of the undiscounted cash flows is less than the carrying value of the proved property, the carrying value is reduced to estimated fair value and reported as an impairment charge in the period. Individual proved properties are grouped for impairment purposes at the lowest level for which there are identifiable cash flows. The fair value of impaired assets is typically determined based on the present value of expected future cash flows using discount rates believed to be consistent with those used by market participants. The impairment test incorporates a number of assumptions involving expectations of future cash flows which can change significantly over time. These assumptions include future production and timing of production, estimates of future product prices, contractual prices, estimates of risk-adjusted oil and gas reserves and estimates of future operating and development costs. See Note 17 - Fair Value Measurements and below for further discussion of asset impairments. Net capitalized costs attributable to unproved properties were $18.6 billion at December 31, 2020 and $29.5 billion at December 31, 2019. The unproved amounts are not subject to DD&A until they are classified as proved properties. Individually insignificant unproved properties are combined and amortized on a group basis based on factors such as lease terms, success rates and other factors to provide for full amortization upon lease expiration or abandonment. Significant unproved properties, primarily as a result of the Acquisition, are assessed individually for impairment and when events or circumstances indicate that the carrying value of property may not be recovered a valuation allowance is provided if an impairment is indicated. Occidental periodically reviews significant unproved properties for impairments; numerous factors are considered, including but not limited to, availability of funds for future exploration and development activities, current exploration and development plans, favorable or unfavorable exploration activity on the property or the adjacent property, geologists’ evaluation of the property, the current and projected political and regulatory climate, contractual conditions and the remaining lease term for the properties. If an impairment is indicated, Occidental will first determine whether a comparable transaction for similar properties or implied acreage valuation derived from domestic onshore market participants is available and will adjust the carrying amount of the unproved property to its fair value using the market approach. In situations where the market approach is not observable and unproved reserves are available, undiscounted future net cash flows used in the impairment analysis are determined based on managements’ risk adjusted estimates of unproved reserves, future commodity prices and future costs to produce the reserves. If undiscounted future net cash flows are less than the carrying value of the property, the future net cash flows are discounted and compared to the carrying value for determining the amount of the impairment loss to record. Occidental utilizes the same assumptions and methodology discussed above for cash flows associated with proved properties. CHEMICAL Occidental’s chemical assets are depreciated using either the unit-of-production or the straight-line method, based upon the estimated useful lives of the facilities. The estimated useful lives of Occidental’s chemical assets, which range from three years to 50 years, are also used for impairment tests. The estimated useful lives for the chemical facilities are based on the assumption that Occidental will provide an appropriate level of annual expenditures to ensure productive capacity is sustained. Such expenditures consist of ongoing routine repairs and maintenance, as well as planned major maintenance activities (PMMA). Ongoing routine repairs and maintenance expenditures are expensed as incurred. PMMA costs are capitalized and amortized over the period until the next planned overhaul. Additionally, Occidental incurs capital expenditures that extend the remaining useful lives of existing assets, increase their capacity or operating efficiency beyond the original specification or add value through modification for a different use. These capital expenditures are not considered in the initial determination of the useful lives of these assets at the time they are placed into service. The resulting revision, if any, of the asset’s estimated useful life is measured and accounted for prospectively. Without these continued expenditures, the useful lives of these assets could decrease significantly. Other factors that could change the estimated useful lives of Occidental’s chemical assets include sustained higher or lower product prices, which are affected by domestic and international competition, demand, feedstock costs, energy prices, environmental regulations and technological changes. Occidental performs impairment tests on its chemical assets whenever events or changes in circumstances lead to a reduction in the estimated useful lives or estimated future cash flows that would indicate that the carrying amount may not be recoverable, or when management’s plans change with respect to those assets. Any impairment loss would be calculated as the excess of the asset’s net book value over its estimated fair value. MIDSTREAM AND MARKETING Occidental’s midstream and marketing PP&E is depreciated over the estimated useful lives of the assets, using either the unit-of-production or straight-line method. Occidental performs impairment tests on its midstream and marketing assets whenever events or changes in circumstances lead to a reduction in the estimated useful lives or estimated future cash flows that would indicate that the carrying amount may not be recoverable, or when management’s plans change with respect to those assets. Any impairment loss would be calculated as the excess of the asset’s net book value over its estimated fair value. GOODWILL As of December 31, 2019, Occidental had $1.2 billion of goodwill related to its ownership in WES, which was included in long-term receivables and other assets, net. Significant declines in the market value of WES’ publicly traded units resulted in management’s determination that, more likely than not, the fair value of the reporting unit was significantly less than its carrying value and the entire $1.2 billion in goodwill was fully impaired in the first quarter of 2020. The market value of WES’ publicly traded units is considered a Level 1 input. IMPAIRMENTS AND OTHER CHARGES During 2020, Occidental’s oil and gas segment recognized pre-tax impairment and related charges of $7.0 billion relating to proved and unproved properties. An additional pre-tax impairment of $2.2 billion related to Ghana is included in discontinued operations. During 2019, Occidental’s oil and gas segment recognized pre-tax impairment and related charges of $285 million related to domestic undeveloped leases that were set to expire in the near-term, where Occidental had no plans to pursue exploration activities, and $39 million related to Occidental’s mutually agreed early termination of its Qatar Idd El Shargi South Dome (ISSD) contract. In 2018, Occidental recognized pre-tax impairment and related charges of $416 million related to Qatar Idd El Shargi North Dome (ISND) and ISSD proved properties and inventory. Also in 2018, the midstream and marketing segment incurred approximately $100 million of charges primarily for lower of cost or market adjustments on its crude inventory and line fill. It is reasonably possible that prolonged declines in commodity prices, reduced capital spending in response to lower prices or increases in operating costs could result in additional impairments. FAIR VALUE MEASUREMENTS Occidental has categorized its assets and liabilities that are measured at fair value in a three-level fair value hierarchy, based on the inputs to the valuation techniques: Level 1 – using quoted prices in active markets for the assets or liabilities; Level 2 – using observable inputs other than quoted prices for the assets or liabilities; and Level 3 – using unobservable inputs. Transfers between levels, if any, are reported at the end of each reporting period. FAIR VALUES - RECURRING Occidental primarily applies the market approach for recurring fair value measurements, maximizes its use of observable inputs and minimizes its use of unobservable inputs. Occidental utilizes the mid-point between bid and ask prices for valuing the majority of its assets and liabilities measured and reported at fair value. In addition to using market data, Occidental makes assumptions in valuing its assets and liabilities, including assumptions about the risks inherent in the inputs to the valuation technique. For assets and liabilities carried at fair value, Occidental measures fair value using the following methods: ■ Occidental values exchange-cleared commodity derivatives using closing prices provided by the exchange as of the balance sheet date. These derivatives are classified as Level 1. ■ OTC bilateral financial commodity contracts, foreign exchange contracts, interest rate swaps, warrants, options and physical commodity forward purchase and sale contracts are generally classified as Level 2 and are generally valued using quotations provided by brokers or industry-standard models that consider various inputs, including quoted forward prices for commodities, time value, volatility factors, credit risk and current market and contractual prices for the underlying instruments, as well as other relevant economic measures. Substantially all of these inputs are observable in the marketplace throughout the full term of the instrument, and can be derived from observable data or are supported by observable prices at which transactions are executed in the marketplace. ■ Occidental values commodity derivatives based on a market approach that considers various assumptions, including quoted forward commodity prices and market yield curves. The assumptions used include inputs that are generally unobservable in the marketplace or are observable but have been adjusted based upon various assumptions and the fair value is designated as Level 3 within the valuation hierarchy. ■ Occidental values debt using market-observable information for debt instruments that are traded on secondary markets. For debt instruments that are not traded, the fair value is determined by interpolating the value based on debt with similar terms and credit risk. NON-FINANCIAL ASSETS Occidental uses market-observable prices for assets when comparable transactions can be identified that are similar to the asset being valued. When Occidental is required to measure fair value and there is not a market-observable price for the asset or for a similar asset then the cost or income approach is used depending on the quality of information available to support management’s assumptions. The cost approach is based on management’s best estimate of the current asset replacement cost. The income approach is based on management’s best assumptions regarding expectations of future net cash flows. The expected cash flows are discounted using a commensurate risk-adjusted discount rate. Such evaluations involve significant judgment, and the results are based on expected future events or conditions such as sales prices, estimates of future oil and gas production or throughput, development and operating costs and the timing thereof, economic and regulatory climates and other factors, most of which are often outside of management’s control. However, assumptions used reflect a market participant’s view of long-term prices, costs and other factors and are consistent with assumptions used in Occidental’s business plans and investment decisions. ACCRUED LIABILITIES - CURRENT Accrued liabilities - current included accrued payroll, commissions and related expenses of $461 million and $1.2 billion at December 31, 2020, and 2019, respectively. Dividends payable, also included in accrued liabilities - current, were $189 million and $884 million at December 31, 2020, and 2019, respectively. Derivative financial instruments, also included in accrued liabilities - current, were $1.1 billion and $641 million at December 31, 2020, and 2019, respectively. ENVIRONMENTAL LIABILITIES AND EXPENDITURES Environmental expenditures that relate to current operations are expensed or capitalized as appropriate. Occidental records environmental liabilities and related charges and expenses for estimated remediation costs that relate to existing conditions from past operations when environmental remediation efforts are probable and the costs can be reasonably estimated. In determining the environmental remediation liability and the range of reasonably possible additional losses, Occidental refers to currently available informati |