October 11, 2023

I’m pleased to share that earlier this morning we jointly announced with Pioneer Natural Resources an agreement for their company to merge with ExxonMobil.

As many of you know, Pioneer is one of the leading companies in the Permian, well known for innovative, hard-working employees who I’m certain will bring real value to our company, not just in our unconventional business but across ExxonMobil. Pioneer’s tier-one acreage is largely contiguous in the Midland Basin and will essentially double our presence in the Permian.

As we considered this merger it was clear Pioneer’s 850,000 net acres and decades of experience in reliable unconventional operations would, when combined with our own industry-leading expertise and technology, allow us to accomplish much more together than we could separately. This will lead to substantial capital efficiencies, including reduced surface infrastructure and a greater ability to drill longer lateral wells.

In addition to more efficient operations, we’re also pleased that we’ll be able to accelerate Pioneer’s net-zero pledge from 2050 to 2035 for its Permian operations. Pioneer has also done impressive work in water management – including managing wastewater for the cities of Midland and Odessa, in addition to their own operations. In our view, our combined efforts and expertise in environmental issues will improve both our operations over time.

We’re proud of our work in the Permian. Our proprietary drilling and completions technology and expertise allow us to recover far more than competitors and do it more efficiently and with much lower environmental impact. Having Pioneer’s acreage means we can apply these skills and technology to even more high-quality acreage, allowing us to produce at a cost-of-supply under $35 a barrel.

The transaction will require the approval of Pioneer’s shareholders and will be subject to customary regulatory reviews and approvals in the months ahead. We hope to finalize the transaction in the first half of 2024. And, as we have done in the past, when the time is right, we’ll stand up a robust integration team to bring the Pioneer team onboard.

We’ve described our company as a “picky acquirer,” meaning we would only invest in truly advantaged assets to which we could bring enough incremental value that the case for an acquisition would be obvious. Today’s announcement fully reflects that view, and I’m excited about the opportunities for our combined companies. Pioneer is one of the best companies in our industry, and I look forward to welcoming their employees into our ranks in the not-too-distant future.

For additional details, please see the full news release.

Darren

Important Information about the Transaction and Where to Find It

In connection with the proposed transaction between Exxon Mobil Corporation (“ExxonMobil”) and Pioneer Natural Resources Company (“Pioneer”), ExxonMobil and Pioneer will file relevant materials with the Securities and Exchange Commission (the “SEC”), including a registration statement on Form S-4 filed by ExxonMobil that will include a proxy statement of Pioneer that also constitutes a prospectus of ExxonMobil. A definitive proxy statement/prospectus will be mailed to stockholders of Pioneer. This communication is not a substitute for the registration statement, proxy statement or prospectus or any other document that ExxonMobil or Pioneer (as applicable) may file with the SEC in connection with the proposed transaction. BEFORE MAKING ANY VOTING OR INVESTMENT DECISION, INVESTORS AND SECURITY HOLDERS OF EXXONMOBIL AND PIONEER ARE URGED TO READ THE REGISTRATION STATEMENT, THE PROXY STATEMENT/PROSPECTUS AND ANY OTHER RELEVANT DOCUMENTS THAT ARE FILED OR WILL BE FILED WITH THE SEC, AS WELL AS ANY AMENDMENTS OR SUPPLEMENTS TO THESE DOCUMENTS, CAREFULLY AND IN THEIR ENTIRETY WHEN THEY BECOME AVAILABLE BECAUSE THEY CONTAIN OR WILL CONTAIN IMPORTANT INFORMATION ABOUT THE PROPOSED TRANSACTION AND RELATED MATTERS. Investors and security holders may obtain free copies of the registration statement and the proxy statement/prospectus (when they become available), as well as other filings containing important information about ExxonMobil or Pioneer, without charge at the SEC’s Internet website (http://www.sec.gov). Copies of the documents filed with the SEC by ExxonMobil will be available free of charge on

ExxonMobil’s internet website at www.exxonmobil.com under the tab “investors” and then under the tab “SEC Filings” or by contacting ExxonMobil’s Investor Relations Department at investor.relations@exxonmobil.com. Copies of the documents filed with the SEC by Pioneer will be available free of charge on Pioneer’s internet website at https://investors.pxd.com/investors/financials/sec-filings/. The information included on, or accessible through, ExxonMobil’s or Pioneer’s website is not incorporated by reference into this communication.

Participants in the Solicitation

ExxonMobil, Pioneer, their respective directors and certain of their respective executive officers may be deemed to be participants in the solicitation of proxies in respect of the proposed transaction. Information about the directors and executive officers of Pioneer is set forth in its proxy statement for its 2023 annual meeting of stockholders, which was filed with the SEC on April 13, 2023, in its Form 10-K for the year ended December 31, 2022, which was filed with the SEC on February 23, 2023, in its Form 8-K filed on May 30, 2023, in its Form 8-K filed on April 26, 2023 and in its Form 8-K filed on February 13, 2023. Information about the directors and executive officers of ExxonMobil is set forth in its proxy statement for its 2023 annual meeting of stockholders, which was filed with the SEC on April 13, 2023, in its Form 10-K for the year ended December 31, 2022, which was filed with the SEC on February 22, 2023, in its Form 8-K filed on June 6, 2023 and in its Form 8-K filed on February 24, 2023. Additional information regarding the participants in the proxy solicitations and a description of their direct or indirect interests, by security holdings or otherwise, will be contained in the proxy statement/prospectus and other relevant materials filed with the SEC when they become available.

No Offer or Solicitation

This communication is for informational purposes and is not intended to, and shall not, constitute an offer to sell or the solicitation of an offer to buy any securities or a solicitation of any vote or approval, nor shall there be any offer, solicitation or sale of securities in any jurisdiction in which such offer, solicitation or sale would be unlawful prior to registration or qualification under the securities laws of any such jurisdiction. No offering of securities shall be made except by means of a prospectus meeting the requirements of Section 10 of the U.S. Securities Act of 1933, as amended.

Forward-Looking Statements

This communication contains “forward-looking statements” within the meaning of the federal securities laws, including Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended. In this context, forward-looking statements often address future business and financial events, conditions, expectations, plans or ambitions, and often contain words such as “expect,” “anticipate,” “intend,” “plan,” “believe,” “seek,” “see,” “will,” “would,” “target,” similar expressions, and variations or negatives of these words, but not all forward-looking statements include such words. Forward-looking statements by their nature address matters that are, to different degrees, uncertain, such as statements about the

that impact demand, prices and differentials, including reservoir performance; changes in technical or operating conditions, including unforeseen technical difficulties; those risks described in Item 1A of ExxonMobil’s Annual Report on Form 10-K, filed with the SEC on February 22, 2023, and subsequent reports on Forms 10 Q and 8-K, as well as under the heading “Factors Affecting Future Results” on the Investors page of ExxonMobil’s website at www.exxonmobil.com (information included on or accessible through ExxonMobil’s website is not incorporated by reference into this communication); those risks described in Item 1A of Pioneer’s Annual Report on Form 10-K, filed with the SEC on February 23, 2023, and subsequent reports on Forms 10-Q and 8-K; and those risks that will be described in the registration statement on Form S-4 and accompanying prospectus available from the sources indicated above. References to resources or other quantities of oil or natural gas may include amounts that ExxonMobil or Pioneer believe will ultimately be produced, but that are not yet classified as “proved reserves” under SEC definitions.

These risks, as well as other risks associated with the proposed transaction, will be more fully discussed in the proxy statement/prospectus that will be included in the registration statement on Form S-4 that will be filed with the SEC in connection with the proposed transaction. While the list of factors presented here is, and the list of factors to be presented in the registration statement on Form S-4 will be, considered representative, no such list should be considered to be a complete statement of all potential risks and uncertainties. Unlisted factors may present significant additional obstacles to the realization of forward-looking statements. We caution you not to place undue reliance on any of these forward-looking statements as they are not guarantees of future performance or outcomes and that actual performance and outcomes, including, without limitation, our actual results of operations, financial condition and liquidity, and the development of new markets or market segments in which we operate, may differ materially from those made in or suggested by the forward-looking statements contained in this communication. Neither ExxonMobil nor Pioneer assumes any obligation to publicly provide revisions or updates to any forward-looking statements, whether as a result of new information, future developments or otherwise, should circumstances change, except as otherwise required by securities and other applicable laws. Neither future distribution of this communication nor the continued availability of this communication in archive form on ExxonMobil’s or Pioneer’s website should be deemed to constitute an update or re-affirmation of these statements as of any future date.

Actions needed to advance ExxonMobil’s 2030 and 2035 greenhouse gas emission-reductions plans are incorporated into its medium-term business plans, which are updated annually. The reference case for planning beyond 2030 is based on the Company’s Energy Outlook research and publication. The Outlook is reflective of the existing global policy environment, the Energy Outlook does not attempt to project the degree of required future policy and technology advancement and deployment for the world, or ExxonMobil, to meet net zero by 2050. As future policies and technology

advancements emerge, they will be incorporated into the Outlook, and the Company’s business plans will be updated accordingly. Actual future results, including the achievement of net zero in Upstream Permian Basin unconventional operated assets by 2030/2035 and plans to lower methane emissions from operated assets, to increase water recycling in our combined Permian operations, and to feed hydrogen, ammonia, and carbon capture projects could vary depending on the ability to execute operational objectives on a timely and successful basis; policy support for emission-reduction products and technologies; changes in laws, regulations and international treaties regarding lower emission technologies and projects; government incentives; unforeseen technical or operational difficulties; the outcome of research efforts and future technology developments, including the ability to scale projects, technologies, and markets on a commercially competitive basis; changes in supply and demand and other market factors affecting future prices of oil, gas, and petrochemical products; the actions of competitors; and other factors discussed in this release and in the additional Forward Looking Statement disclaimer included above.

All references to production rates, project capacity, resource size, and acreage are on a gross basis, unless otherwise noted.