OMP Oasis Midstream Partners LP

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d)

of the Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): October 25, 2021

(Former Name or Former Address, If Changed Since Last Report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions (see General Instruction A.2. below):

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2).

Emerging Growth Company ☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

On October 26, 2021, Oasis Petroleum Inc., a Delaware corporation (the “Company”), issued a press release announcing the entry by Oasis Midstream Partners LP, a Delaware limited partnership (“OMP”), into a definitive merger agreement (the “merger agreement”) on October 25, 2021 with Crestwood Equity Partners LP, a Delaware limited partnership (“Crestwood”), containing preliminary financial results for the quarter ended September 30, 2021, and declaring a quarterly cash dividend for the quarter ended September 30, 2021 of $0.50 per share of the Company’s common stock, par value $0.01 per share, payable on November 29, 2021 to shareholders of record as of November 15, 2021. In addition, on October 26, 2021, the Company released an investor presentation regarding the transactions contemplated by the merger agreement and containing preliminary financial results for the quarter ended September 30, 2021 and updated guidance for the quarter ended December 31, 2021.

The full text of the press release and the investor presentation are included as Exhibits 99.1 and 99.2, respectively, to this Current Report on Form 8-K and are incorporated into this Item 2.02 by reference.

In accordance with General Instruction B.2 of Form 8-K, the information furnished pursuant to Item 2.02 and the press release and the investor presentation attached hereto as Exhibits 99.1 and 99.2, respectively, shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that section, nor shall such information be deemed incorporated by reference in any filing under the Securities Act of 1933, as amended, or the Exchange Act, except as shall be expressly set forth by specific reference in such a filing.

On October 26, 2021, the Company issued a press release and released an investor presentation announcing the entry by OMP into the merger agreement on October 25, 2021 with Crestwood, pursuant to which Crestwood will acquire OMP (the “merger”). Under the terms of the merger agreement, (i) 6,520,944 common units representing limited partner interests in OMP (“OMP Common Units”) issued and outstanding immediately prior to the effective time of the merger (the “effective time”) and owned by OMS Holdings LLC, a Delaware limited liability company and subsidiary of the Company (such OMP Common Units, the “Sponsor Cash Units”), will be converted into and will thereafter represent the right to receive $150,000,000 in cash in the aggregate, and each other OMP Common Unit issued and outstanding immediately prior to the effective time and owned by Oasis Petroleum or its subsidiaries (other than OMP) (together with the Sponsor Cash Units, the “Sponsor Units”) will be converted into and will thereafter represent the right to receive 0.7680 common units representing limited partner interests in Crestwood (“Crestwood Common Units”); (ii) each OMP Common Unit issued and outstanding immediately prior to the effective time (other than the Sponsor Units) will be converted into and will thereafter represent the right to receive 0.8700 Crestwood Common Units and (iii) all of the limited liability company interests of the OMP GP LLC, a Delaware limited liability company and the general partner of OMP, issued and outstanding immediately prior to the effective time will be converted into and will thereafter represent the right to receive $10,000,000 in cash.

The full text of the press release and the investor presentation are included as Exhibits 99.1 and 99.2, respectively, to this Current Report on Form 8-K and are incorporated into this Item 7.01 by reference.

In accordance with General Instruction B.2 of Form 8-K, the information furnished pursuant to Item 7.01 and the press release and the investor presentation attached hereto as Exhibits 99.1 and 99.2, respectively, shall not be deemed to be “filed” for purposes of Section 18 of the Exchange Act, or otherwise subject to the liabilities of that section, nor shall such information be deemed incorporated by reference in any filing under the Securities Act of 1933, as amended, or the Exchange Act, except as shall be expressly set forth by specific reference in such a filing.

Cautionary Statement Regarding Forward-Looking Statements

This Current Report on Form 8-K contains forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended. All statements, other than statements of historical facts, included in this Current Report on Form 8-K that address activities, events or developments that the Company expects, believes or anticipates will or may occur in the future are forward-looking statements. Without limiting the generality of the foregoing, forward-looking statements contained in this Current Report on Form 8-K specifically include the expectations of plans, strategies, objectives and

anticipated financial and operating results of the Company, including the Company’s drilling program, production, derivative instruments, capital expenditure levels and other guidance included in this Current Report on Form 8-K, as well as the impact of the novel coronavirus 2019 (“COVID-19”) pandemic on the Company’s operations. These statements are based on certain assumptions made by the Company based on management’s experience and perception of historical trends, current conditions, anticipated future developments and other factors believed to be appropriate. Such statements are subject to a number of assumptions, risks and uncertainties, many of which are beyond the control of the Company, which may cause actual results to differ materially from those implied or expressed by the forward-looking statements. These include, but are not limited to, risks that the proposed transaction may not be consummated or the benefits contemplated therefrom may not be realized, the ability to obtain requisite regulatory and unitholder approval and the satisfaction of the other conditions to the consummation of the proposed transaction, the ability of Crestwood to successfully integrate OMP’s operations and employees and realize anticipated synergies and cost savings, the potential impact of the announcement or consummation of the proposed transaction on relationships, including with employees, suppliers, customers, competitors and credit rating agencies, changes in crude oil and natural gas prices, developments in the global economy, particularly the public health crisis related to the COVID-19 pandemic and the adverse impact thereof on demand for crude oil and natural gas, the outcome of government policies and actions, including actions taken to address the COVID-19 pandemic and to maintain the functioning of national and global economies and markets, the impact of Company actions to protect the health and safety of employees, vendors, customers, and communities, weather and environmental conditions, the timing of planned capital expenditures, availability of acquisitions, the ability to realize the anticipated benefits from the Williston Basin acquisition and Permian Basin divestitures, uncertainties in estimating proved reserves and forecasting production results, operational factors affecting the commencement or maintenance of producing wells, the condition of the capital markets generally, as well as the Company’s ability to access them, the proximity to and capacity of transportation facilities, and uncertainties regarding environmental regulations or litigation and other legal or regulatory developments affecting the Company’s business and other important factors that could cause actual results to differ materially from those projected as described in the Company’s reports filed with the U.S. Securities and Exchange Commission (the “SEC”). Additionally, the unprecedented nature of the COVID-19 pandemic and the related decline of the oil and gas exploration and production industry may make it particularly difficult to identify risks or predict the degree to which identified risks will impact the Company’s business and financial condition. Because considerable uncertainty exists with respect to the future pace and extent of a global economic recovery from the effects of the COVID-19 pandemic, the Company cannot predict whether or when crude oil production and economic activities will return to normalized levels. Any forward-looking statement speaks only as of the date on which such statement is made and the Company undertakes no obligation to correct or update any forward-looking statement, whether as a result of new information, future events or otherwise, except as required by applicable law.

No Offer or Solicitation

This communication relates to the proposed transaction between OMP and Crestwood. This communication is for informational purposes only and does not constitute an offer to sell or the solicitation of an offer to buy any securities or a solicitation of any vote or approval, in any jurisdiction, pursuant to the proposed transaction or otherwise, nor shall there be any sale, issuance, exchange or transfer of the securities referred to in this document in any jurisdiction in contravention of applicable law. No offer of securities shall be made except by means of a prospectus meeting the requirements of Section 10 of the Securities Act of 1933, as amended.

Additional Information and Where You Can Find It

In connection with the proposed transaction, Crestwood will file a registration statement on Form S-4, including a preliminary consent statement/prospectus for the unitholders of OMP with the SEC. INVESTORS AND UNITHOLDERS OF CRESTWOOD AND OMP, AS WELL AS INVESTORS AND STOCKHOLDERS OF THE COMPANY, ARE ADVISED TO CAREFULLY READ THE REGISTRATION STATEMENT AND THE PRELIMINARY CONSENT STATEMENT/PROSPECTUS (INCLUDING ALL AMENDMENTS AND SUPPLEMENTS THERETO) WHEN THEY BECOME AVAILABLE BECAUSE THEY WILL CONTAIN IMPORTANT INFORMATION ABOUT THE PROPOSED TRANSACTION, THE PARTIES TO THE PROPOSED TRANSACTION AND THE RISKS ASSOCIATED WITH THE PROPOSED TRANSACTION. The definitive consent statement/prospectus, when available, will be sent to unitholders of OMP in connection with the solicitation of consents of OMP unitholders relating to the proposed transactions. Investors and unitholders may obtain a free copy of the preliminary or definitive consent statement/prospectus (each when available) filed by Crestwood or

OMP with the SEC from the SEC’s website at www.sec.gov. Unitholders and other interested parties will also be able to obtain, without charge, a copy of the preliminary or definitive consent statement/prospectus and other relevant documents (when available) from Crestwood’s website at https://www.crestwoodlp.com/investors/ or from OMP’s website at http://oasismidstream.investorroom.com.

Participants in the Solicitation

Crestwood, OMP and their respective directors, executive officers and general partners, and the Company and its directors and executive officers, may be deemed to be participants in the solicitation of consents from the unitholders of OMP in respect of the transactions. Information about these persons is set forth in Crestwood’s Annual Report on Form 10-K for the year ended December 31, 2020, which was filed with the SEC on February 26, 2021, OMP’s Annual Report on Form 10-K for the year ended December 31, 2020, which was filed with the SEC on March 8, 2021, and the Company’s definitive proxy statement for its 2021 annual meeting filed with the SEC on April 20, 2021, respectively, and subsequent statements of changes in beneficial ownership on file for each of Crestwood, OMP and the Company with the SEC. Unitholders and investors may obtain additional information regarding the interests of such persons, which may be different than those of the respective companies’ unitholders or investors generally, by reading the preliminary or definitive consent statement/prospectus, or other relevant documents regarding the transaction (if and when available), which may be filed with the SEC.

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.