Exhibit 99.1

Occidental Petroleum Announces 1st Quarter 2018 Results

·                 Total company production of 609,000 BOE per day, exceeding guidance driven by Permian Resources and International

·                 Sustained basin-leading well results in Greater Sand Dunes with 16 wells reporting average 30-day production rates of 3,100 BOE per day

·                 Achieved record quarterly earnings in Chemical and another quarter of improved earnings in Midstream

·                 Continued progress toward Breakeven Plan with the addition of 18,000 BOE per day in Permian Resources

·                 Intend to resume share repurchase program in 2018

HOUSTON — May 8, 2018 — Occidental Petroleum Corporation (NYSE:OXY) today announced reported and core income for the first quarter of 2018 of $708 million, or $0.92 per diluted share. Reported income for the fourth quarter of 2017 was $497 million, or $0.65 per diluted share, and core income was $313 million, or $0.41 per diluted share.

“All three business segments achieved outstanding performance in the first quarter,” said President and Chief Executive Officer Vicki Hollub. “Occidental’s value-based development approach and use of innovative technologies are driving strong results across the company, making us more efficient and competitive. We are on track to complete our Breakeven Plan in the third quarter and are well positioned for continued strong performance and growth. Therefore, we now intend to resume our long-standing share buyback program.”

QUARTERLY RESULTS
Oil and Gas

Total average daily production volumes were 609,000 barrels of oil equivalent (BOE) for the first quarter of 2018, compared to 621,000 BOE in the fourth quarter of 2017. Permian Resources average daily production volumes improved from the prior quarter by 18,000 BOE or 11 percent to 177,000 BOE in the first quarter of 2018, due to better-than-expected well results, especially in the Greater Sand Dunes, where Occidental continues to produce sustained basin-leading well results with 16 wells reporting 30-day production rates averaging 3,100 BOE per day. Compared to the first quarter of 2017, Permian Resources production increased by 37 percent.

International average daily volumes were lower in the first quarter of 2018 by 29,000 BOE, compared to the fourth quarter of 2017, due to planned maintenance related to Al Hosn Gas and Dolphin operations, as well as the impact of higher prices on production sharing contracts.

Page 1 of 3

Oil and gas pre-tax income for the first quarter of 2018 was $750 million, compared to $44 million for the prior quarter. The fourth quarter of 2017 reflected impairment charges net of gains on sales of $337 million. The $369 million improvement in first quarter income, excluding the impact of the impairment charges net of gains on sales, reflected significantly higher oil prices and lower depreciation, depletion and amortization rates, partially offset by lower volumes in the Middle East due to planned maintenance.

For the first quarter of 2018, average WTI and Brent marker prices were $62.87 per barrel and $67.18 per barrel, respectively. Average worldwide realized crude oil prices were $61.04 per barrel for the first quarter of 2018, an increase of 14 percent compared with the fourth quarter of 2017. Average worldwide realized natural gas liquids and domestic realized natural gas prices were $25.35 per barrel and $2.06 per MCF, respectively, in the first quarter of 2018, which were about flat to the fourth quarter of 2017.

Chemical

Chemical pre-tax income for the first quarter of 2018 was $298 million, compared to pre-tax income of $222 million in the fourth quarter of 2017. The fourth quarter included a gain on a sale of $5 million. The increase in earnings resulted primarily from higher realized prices across most product lines, lower ethylene costs and improved margins throughout the quarter. The first quarter also benefited from the December 2017 start-up of the Geismar, Louisiana, plant expansion to produce 4CPe, a new raw material used in making next-generation refrigerants.

Midstream and Marketing

Midstream pre-tax income for the first quarter of 2018 was $179 million, compared to $9 million for the fourth quarter of 2017. Income for first quarter of 2018 included a $43 million pre-tax gain on sale of interests in a gas plant, and the fourth quarter of 2017 income included non-cash charges of $120 million on idled facilities. Excluding these amounts, the increase in first quarter income reflected lower operating expenses for the gas plants and improved operational efficiencies at the Seminole San Andres CO2 plant acquired in 2017.

About Occidental Petroleum

Occidental Petroleum Corporation is an international oil and gas exploration and production company with operations in the United States, Middle East and Latin America. Headquartered in Houston, Occidental is one of the largest U.S. oil and gas companies, based on equity market capitalization. Occidental’s midstream and marketing segment gathers, processes, transports, stores, purchases and markets hydrocarbons and other commodities. The company’s wholly owned subsidiary OxyChem manufactures and markets basic chemicals and vinyls. Occidental posts or provides links to important information on its website at www.oxy.com.

Page 2 of 3

Forward-Looking Statements

Portions of this press release contain forward-looking statements and 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 results to differ include, but are not limited to: global commodity pricing fluctuations; supply and demand considerations for Occidental’s products; higher-than-expected costs; the regulatory approval environment; not successfully completing, or any material delay of, field developments, expansion projects, capital expenditures, efficiency projects, acquisitions or dispositions; uncertainties about the estimated quantities of oil and natural gas reserves; lower-than-expected production from development projects or acquisitions; exploration risks; general economic slowdowns domestically or internationally; political conditions and events; liability under environmental regulations including remedial actions; litigation; disruption or interruption of production or manufacturing or facility damage due to accidents, chemical releases, labor unrest, weather, natural disasters, cyber-attacks or insurgent activity; failure of risk management; changes in law or regulations; reorganization or restructuring of Occidental’s operations; or changes in tax rates. 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 release. Unless legally required, Occidental does not undertake any obligation to update any forward-looking statements, as a result of new information, future events or otherwise. Material risks that may affect Occidental’s results of operations and financial position appear in Part I, Item 1A “Risk Factors” of Occidental’s Annual Report on Form 10-K for the year ended December 31, 2017 (the 2017 Form 10-K).

-0-

Contacts:

Media:
Melissa E. Schoeb
713-366-5615
melissa_schoeb@oxy.com

or

Investors:
Richard A. Jackson
713-215-7235
richard_jackson@oxy.com

On the web: www.oxy.com

Page 3 of 3

Occidental Petroleum Corporation

Quarter 1 2018 Earnings Release Schedules Index

SCHEDULE 1

Occidental Petroleum Corporation

Summary Highlights

SIGNIFICANT TRANSACTIONS AND EVENTS AFFECTING EARNINGS

Occidental’s results of operations often include the effects of significant transactions and events affecting earnings that vary widely and unpredictably in nature, timing and amount. These events may recur, even across successive reporting periods. Therefore, management uses a measure called “core results,” which excludes those items. This non-GAAP measure is not meant to disassociate those items from management’s performance, but rather is meant to provide useful information to investors interested in comparing Occidental’s earnings performance between periods. Reported earnings are considered representative of management’s performance over the long term. Core results are not considered to be an alternative to operating income reported in accordance with generally accepted accounting principles.

SCHEDULE 2

Occidental Petroleum Corporation

Segment Results Before Tax Allocations

(Amounts in millions, except per share and effective tax rate amounts)