UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, DC 20549

SCHEDULE 13D

Under the Securities Exchange Act of 1934

(Amendment No. 1)*

CRESTWOOD EQUITY PARTNERS LP

(Name of Issuer)

Common Units Representing Limited Partner Interests

(Title of Class of Securities)

226344208

(CUSIP Number)

M. Scott Regan

Executive Vice President, General Counsel and Secretary

Chord Energy Corporation

1001 Fannin Street, Suite 1500

Houston TX 77002

Tel: (281) 404-9500

(Name, Address and Telephone Number of Person Authorized to Receive Notices and Communications)

September 15, 2022

(Date of Event Which Requires Filing of this Statement)

If the filing person has previously filed a statement on Schedule 13G to report the acquisition that is the subject of this Schedule 13D, and is filing this schedule because of §§240.13d-1(e), 240.13d-1(f) or 240.13d-1(g), checking the following box.  ☐

The remainder of this cover page shall be filled out for a reporting person’s initial filing on this form with respect to the subject class of securities, and for any subsequent amendment containing information which would alter disclosures provided in a prior cover page.

The information required on the remainder of this cover page shall not be deemed to be “filed” for the purpose of Section 18 of the Securities Exchange Act of 1934 (“Act”) or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes).

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This Amendment No. 1 to the Statement of Beneficial Ownership on Schedule 13D (this “Amendment”) amends the Statement of Beneficial Ownership on Schedule 13D filed by the Reporting Persons on February 11, 2022 (the “Original Schedule 13D”), with respect to the common units representing limited partner interests in Crestwood Equity Partners LP (the “Crestwood Common Units). Capitalized terms used but not defined in this Amendment shall have the meanings set forth on the Original Schedule 13D. Except as amended and supplemented by this Amendment, the Original Schedule 13D remains unchanged.

As indicated below in Item 5(e), as a result of the transactions described in Item 4 below and the number of issued and outstanding Crestwood Common Units on September 9, 2022, as reported in the Issuer’s prospectus supplement, dated September 12, 2022, filed with the U.S. Securities and Exchange Commission pursuant to Rule 424(b) under the Securities Act of 1933, as amended, and after giving effect to the Repurchase (as defined below), each of the Reporting Persons ceased to be a beneficial owner of more than five percent of the Crestwood Common Units on September 15, 2022. The filing of this Amendment represents the first and final amendment to the Original Schedule 13D and constitutes an exit filing for the Reporting Persons.

This Amendment amends and restates Item 2 of the Original Schedule 13D in its entirety as follows:

(a) This Schedule 13D is being filed jointly on behalf of the following persons (collectively, the “Reporting Persons”):

(i) Chord Energy Corporation, a Delaware corporation (“Chord”) (fka Oasis Petroleum Inc.);

(ii) OMS Holdings LLC, a Delaware limited liability company (“OMS Holdings”);

(iii) Oasis Investment Holdings LLC, a Delaware limited liability company (“Oasis Investment Holdings”);

(iii) Oasis Petroleum North America LLC, a Delaware limited liability company (“OPNA”); and

(iv) Oasis Petroleum LLC, a Delaware limited liability company (“Oasis LLC”).

Each of OMS Holdings and OPNA is a wholly owned subsidiary of Oasis LLC. Oasis LLC is a wholly owned subsidiary of Chord. OMS Holdings is the managing member of and owns an 87.3% membership interest in Oasis Investment Holdings. OPNA owns the remaining 12.7% membership interest in Oasis Investment Holdings.

Each of Douglas E. Brooks, Daniel E. Brown, Susan M. Cunningham, Samantha F. Holroyd, Paul J. Korus, Kevin S. McCarthy, Lynn A. Peterson, Anne Taylor, Cynthia L. Walker and Marguerite N. Woung-Chapman is a director of Chord. The executive officers of Chord are Daniel E. Brown, Michael H. Lou, Charles J. Rimer and M. Scott Regan.

(b) The business address of the Reporting Persons and the other individuals named in this Item 2 for purposes of this filing is 1001 Fannin Street, Suite 1500, Houston, Texas 77002.

(c) The principal business of Chord is exploration and production, focusing on the acquisition and development of onshore, unconventional crude oil and natural gas resources in the United States. The principal business of OMS Holdings is to hold equity interests in Oasis Investment Holdings. The principal business of Oasis Investment Holdings is to hold and develop certain non-operated, non-reservation oil and gas assets and to hold equity interests in Chord subsidiaries. The principal business of OPNA is to conduct exploration and production activities on oil and gas properties owned by Chord. The principal business of Oasis LLC is to act as a holding company for the equity of various Chord subsidiaries.

The present principal occupation or employment of Douglas E. Brooks is as the lead independent director of Chord and as a director of California Resources Corporation. The present principal occupation or employment of Susan M. Cunningham is as a director of Chord. The present principal occupation or employment of Cynthia Walker is as a director of Chord and as a director of Sempra Energy. The present principal occupation or employment of Samantha F. Holroyd is as a director of Chord and Amerant Bancorp Inc and Principal at Golden Advisory Services

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LLC. The present principal occupation or employment of Paul J. Korus is as a director of Chord and a director of PDC Energy, Inc. The present principal occupation of Kevin S. McCarthy is as Vice Chairman at Kayne Anderson Capital Advisors, L.P and a director of Chord. The present principal occupation or employment of Lynn A. Peterson is as Executive Chairman of Chord, a director of PDC Energy, Inc. and a director of Denbury Inc. The present principal occupation or employment of Anne Taylor is as the President and sole owner of AT Strategies LLC. The present principal occupation or employment of Marguerite N. Woung-Chapman is as a director of Chord and as a director of Summit Midstream Partners LP. The present principal occupation or employment of Daniel E. Brown is as a director of Chord and as an executive of Chord and/or one or more of its affiliates. The present principal occupation of Michael Lou, Charles J. Rimer and M. Scott Regan is as an executive of Chord and/or one or more of its affiliates.

(d) None of the Reporting Persons or, to the best knowledge of the Reporting Persons, any of the other individuals named in this Item 2, has been convicted in a criminal proceeding (excluding traffic violations or similar misdemeanors) during the last five years.

(e) None of the Reporting Persons or, to the best knowledge of the Reporting Persons, any of the other individuals named in this Item 2, has been party to any civil proceeding of a judicial or administrative body of competent jurisdiction and as a result of such proceeding was or is subject to a judgment, decree, or final order enjoining future violations of, or prohibiting or mandating activities subject to, federal or state securities laws, or finding any violation with respect to such laws during the last five years.

(f) Chord, OMS Holdings, Oasis Investment Holdings, OPNA and Oasis LLC are organized under the laws of the State of Delaware. Each other individual named in this Item 2 is a United States citizen.

This Amendment amends and supplements Item 4 of the Original Schedule 13D by adding the following:

Crestwood Secondary Offering

On September 12, 2022, OMS Holdings and Oasis Investment Holdings, entered into that certain Underwriting Agreement (the “Underwriting Agreement”) with the Issuer and Citigroup Global Markets Inc., acting as the sole underwriter (the “Underwriter”), pursuant to which OMS Holdings and Oasis Investment Holdings have agreed to sell to the Underwriter, and the Underwriter has agreed to purchase from OMS Holdings and Oasis Investment Holdings, an aggregate 11,400,000 Crestwood Common Units at a price of $26.7097 per Crestwood Common Unit, subject to and upon the terms and conditions set forth therein (the “Offering”). The Offering closed on September 15, 2022. OMS Holdings and Oasis Investment Holdings completed the sale of 2,184,000 and 9,216,000 Crestwood Common Units, respectively, in the Offering pursuant to the Issuer’s effective shelf registration statement on Form S-3 (Registration No. 333-262722), a base prospectus dated February 14, 2022, included as part of the registration statement, and a prospectus supplement, dated September 12, 2022, filed with the U.S. Securities and Exchange Commission pursuant to Rule 424(b) under the Securities Act of 1933, as amended (the “Securities Act”).

The Underwriting Agreement includes customary representations, warranties and covenants by OMS Holdings, Oasis Investment Holdings and the Issuer and customary obligations of the parties and termination provisions. Additionally, under the terms of the Underwriting Agreement, OMS Holdings, Oasis Investment Holdings and the Issuer have agreed to indemnify the Underwriter against certain liabilities, including liabilities under the Securities Act, or to contribute to payments the Underwriter may be required to make in respect of these liabilities.

Crestwood Repurchase

On September 12, 2022, in connection with the Offering, OMS Holdings entered into that certain Common Unit Repurchase Agreement (the “Repurchase Agreement”) with the Issuer, pursuant to which the Issuer has agreed to repurchase 4,600,000 Crestwood Common Units held by OMS Holdings, conditioned on the closing of the Offering (the “Repurchase”). The price per unit of $26.90 was equal to the price at which the Crestwood Common Units were sold to the public in the Offering, and the aggregate purchase price paid by the Issuer was approximately $123.7 million. The Repurchase closed on September 15, 2022 and the Issuer subsequently retired the repurchased Crestwood Common Units.

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The foregoing summaries of the Underwriting Agreement and Repurchase Agreement do not purport to be complete and are subject to, and are qualified in their entirety by, the full text of the Underwriting Agreement and Repurchase Agreement, which are filed as Exhibits D and E, respectively, hereto and incorporated herein by reference.

This Amendment amends and restates Item 5 of the Original Schedule 13D in its entirety as follows:

To the best knowledge of the Reporting Persons, none of the individuals named in Item 2 beneficially own any Crestwood Common Units except as described herein.

This Amendment amends and restates Item 6 of the Original Schedule 13D in its entirety as follows:

The information provided or incorporated by reference in each of Items 3 and 4 regarding the Mergers, the Merger Agreement, the Registration Rights Agreement, the Director Nomination Agreement, the Offering, the Underwriting Agreement, the Repurchase and the Repurchase Agreement is hereby incorporated by reference herein.

This Amendment amends and restates Item 7 of the Original Schedule 13D in its entirety as set forth below:

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SIGNATURES

After reasonable inquiry and to the best of my knowledge and belief, each of the undersigned certifies that the information set forth in this Schedule 13D is true, complete and correct.

Date: September 19, 2022

[Signature Page to Schedule 13D]

Exhibit F

JOINT FILING AGREEMENT

In accordance with Rule 13d-1(k)(1) under the Securities Exchange Act of 1934, as amended, the persons named below agree to the joint filing on behalf of each of them of a statement on Schedule 13D (including amendments thereto) with respect to the common units representing limited partner interests of Crestwood Equity Partners LP and further agree that this Joint Filing Agreement be included as an Exhibit to such joint filing. In evidence thereof, the undersigned, being duly authorized, have executed this Joint Filing Agreement this 19th day of September, 2022.