UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 13D

Item 1.

Security and Issuer.

This statement on Schedule 13D (the “Schedule 13D”) relates to the Common Units Representing Limited Partner Interests (the “Common Units”), of NGL Energy Partners LP, a Delaware corporation (the “Issuer”) whose principal executive offices are located at 6120 South Yale Avenue, Suite 805, Tulsa, Oklahoma, that would be acquired upon a conversion of the Class A 10.75% Convertible Preferred Units.

Item 2.

Identity and Background.

The Schedule 13D is being filed by the following persons (each a “Reporting Person” and, collectively, the “Reporting Persons”):

1)             Highstar NGL Prism/IV-A Interco LLC (“Highstar Prism”)

2)             Highstar NGL Main Interco LLC (“Highstar Main”)

3)             NGL CIV A, LLC (“NGL CIV”)

4)             NGL Prism/IV-A Blocker LLC (“NGL Blocker”)

5)             Highstar Capital NGL Co-Invest Manager LLC (“Highstar Co-Invest”)

6)             Highstar Capital GP IV, L.P. (“Highstar GP IV”)

7)             Highstar Capital GP IV, LLC

8)             Highstar Capital GP IV Holdings

9)             Oaktree Fund GP II, L.P.

10)      Oaktree Capital II, L.P

11)      Oaktree Holdings, Inc.

12)      Oaktree Capital Group, LLC; and

13)      Oaktree Capital Group Holdings GP, LLC

Highstar GP IV and Highstar Capital GP IV Holdings are organized under the laws of the Cayman Islands. Each of the other Reporting Persons is organized under the laws of the State of Delaware. The business address of each of the Reporting Persons is 333 South Grand Avenue, 28th Floor, Los Angeles, California 90071. The Reporting Persons are principally engaged in the business of investing in securities, including of the Issuer.

Oaktree Capital Group Holdings GP, LLC is a limited liability company managed by an executive committee, the members of which are Howard S. Marks, Bruce A. Karsh, Jay S. Wintrob, John B. Frank and Sheldon M. Stone (the “OCGH GP Members”).

During the last five years, none of the Reporting Persons or OCGH GP Members (i) has been convicted in any criminal proceeding (excluding traffic violations or similar misdemeanors) or (ii) was a party to a 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.

Item 3.

Source and Amount of Funds or Other Consideration.

On April 21, 2016, the Issuer entered into the Class A Convertible Preferred Unit and Warrant Purchase Agreement (the “Purchase Agreement”) with Highstar Prism and Highstar Main (together, the “Original Purchasers”), pursuant to which the Issuer agreed to issue and sell to the Original Purchasers in a private placement (the “Private Placement”) an aggregate principal amount of $200 million of the Issuer’s 10.75% Class A Convertible Preferred Units (the “Preferred Units”) and warrants (the “Warrants”) that may be exercised to purchase Common Units.

On June 23, 2016, the Issuer entered into an amendment to the Purchase Agreement (the “Purchase Agreement Amendment”), by and among the Issuer, the Original Purchasers and NGL CIV (together with the Original Purchasers, the “Purchasers”), pursuant to which NGL CIV was joined as a party to the Purchase Agreement and the aggregate principal amount of the Private Placement was increased from $200 million to $240 million.

In connection with the closing of the transactions contemplated by the Purchase Agreement, as amended, on June 24, 2016, the Purchasers acquired 19,942,169 Preferred Units and 4,375,112 Warrants for approximately $240 million.

Subsequently, on September 29, 2016, NGL Blocker, Highstar Main and Highstar Prism entered into a Purchase and Sale Agreement pursuant to which Highstar Main and Highstar Prism sold 2,077,309 Class A Convertible Preferred Units and 455,741 Warrants in the Issuer to NGL Blocker for an aggregate purchase price of $25,791,823.

The Purchasers and NGL Blocker obtained the funds to purchase the Preferred Units and Warrants through capital contributions from their respective members.

The foregoing description of the Purchase Agreement and the Purchase Agreement Amendment do not purport to be complete and are qualified in their entirety by reference to the full text of such agreements, which are attached as an exhibit to this Schedule 13D, and are incorporated herein by reference.

Item 4.

Purpose of Transaction.

Board Representation Agreement

In connection with the closing of the transactions contemplated by the Purchase Agreement, as amended, on June 24, 2016, the Issuer, NGL Energy Holdings LLC, the Purchasers and Highstar Capital IV, L.P. (an affiliate of Highstar GP IV) entered into that certain Amended and Restated Board Representation and Observation Rights Agreement (the “Board Representation Agreement”) pursuant to which Highstar Capital IV, L.P. has the ability to appoint a director to the board of directors of the general partner of the Issuer (the “Board”). Highstar Capital IV, L.P. has appointed Jared Parker to serve as a member of the Board.

Registration Rights Agreement

Also on June 24, 2016, the Issuer and the Purchasers entered into an amendment to the Registration Rights Agreement, dated May 11, 2016, by and among the Issuer and the Original Purchasers (as amended, the “Registration Rights Agreement”). Pursuant to the Registration Rights Agreement, the Issuer has filed a registration statement to register the public resale of the Common Units issued or issuable upon conversion of the Preferred Units and exercise of the Warrants. In addition, the Registration Rights Agreement grants the Purchasers piggyback registration rights under certain circumstances. These registration rights are transferable to affiliates of the Purchasers and, in certain circumstances, to third parties.

Amended and Restated Partnership Agreement

On June 13, 2017, NGL Energy Holdings LLC, a Delaware limited liability company and the general partner of the Issuer, executed the Fourth Amended and Restated Agreement of Limited Partnership of the Issuer (the “Partnership Agreement”). Pursuant to the Partnership Agreement, at any time after May 11, 2019, the Purchasers and NGL Blocker have the right to convert any Preferred Units held by them for a number of Common Units equal to the product of the number of Preferred Units converted and the conversion ratio then in effect. If the Common Units are trading at or above $12.035 (the “initial conversion price”), the Preferred Units will be converted on a one-to-one basis. However, if the Common Units are trading below the initial conversion price, then the conversion ratio will be equal to the quotient of the initial conversion price and the greater of (i) the adjusted volume weighted average price of the Common Units for the 15 trading days immediately preceding May 11, 2019 or (ii) $5.00. Any conversion of the Preferred Units may be settled in common units, cash or a combination. The Preferred Units do not become convertible until May 13, 2019 and are currently redeemable by the Issuer for cash.

The foregoing descriptions of the Board Representation Agreement, the Registration Rights Agreement and the Partnership Agreement do not purport to be complete and are qualified in their entirety by reference to the full text of such agreements, which are attached as an exhibit to this Schedule 13D, and are incorporated herein by reference.

General

The Reporting Persons acquired the securities described in this Schedule 13D for investment purposes and they intend to review their investments in the Issuer on a continuing basis. Any actions the Reporting Persons might undertake may be made at any time and from time to time without prior notice and will be dependent upon the Reporting Persons’ review of numerous factors, including, but not limited to: an ongoing evaluation of the Issuer’s business, financial condition, operations and prospects; price levels of the Issuer’s securities; general market, industry and economic conditions; the relative attractiveness of alternative business and investment opportunities; and other future developments.

The Reporting Persons may acquire additional securities of the Issuer, or retain or sell all or a portion of the securities then held, in the open market or in privately negotiated transactions. In addition, the Reporting Persons and their designee to the Board may engage in discussions with management, the Board, and unitholders of the Issuer and other relevant parties or encourage, cause or seek to cause the Issuer or such persons to consider or explore extraordinary corporate transactions, such as: a merger, reorganization or take-private transaction that could result in the de-listing or de-registration of the Common Units; sales or acquisitions of assets or businesses; changes to the capitalization or dividend policy of the Issuer; or other material changes to the Issuer’s business or corporate structure, including changes in management or the composition of the Board.

Item 5.

Interest in Securities of the Issuer.

(a) — (b)

The following sets forth, as of the date of this Schedule 13D, the aggregate number of Common Units and percentage of Common Units beneficially owned by each of the Reporting Persons, as well as the number of Common Units as to which each Reporting Person has the sole power to vote or to direct the vote, shared power to vote or to direct the vote, sole power to dispose or to direct the disposition, or shared power to dispose or to direct the disposition of, as of the date hereof, based on 124,033,723 Common Units outstanding on February 4, 2019, and assumes the conversion of the Preferred Units owned by the Reporting Persons into Common Units on a one-to-one basis and the exercise of Warrants held by the Reporting Persons that are currently or will be exercisable within 60 days of the date hereof.

Reporting Person

Amount
beneficially
owned

Percent
of class

Sole
power to
vote or to
direct the
vote

Shared
power to
vote or to
direct the
vote

Sole power
to dispose
or to direct
the
disposition

Shared
power to
dispose or
to direct
the
disposition

Highstar NGL Prism/IV-A Interco LLC

5,995,491

4.6

%

0

5,995,491

0

5,995,491

Highstar NGL Main Interco LLC

4,167,787

3.3

%

0

4,167,787

0

4,167,787

NGL CIV A, LLC

8,309,237

6.3

%

0

8,309,237

0

8,309,237

NGL Prism/IV-A Blocker LLC

2,077,309

1.6

%

0

2,077,309

0

2,077,309

Highstar Capital NGL Co-Invest Manager LLC

8,309,237

3.3

%

0

8,309,237

0

8,309,237

Highstar Capital GP IV, L.P.

20,549,824

14.2

%

0

20,549,824

0

20,549,824

Highstar Capital GP IV, LLC

20,549,824

14.2

%

0

20,549,824

0

20,549,824

Highstar Capital GP IV Holdings

20,549,824

14.2

%

0

20,549,824

0

20,549,824

Oaktree Fund GP II, L.P.

20,549,824

14.2

%

0

20,549,824

0

20,549,824

Oaktree Capital II, L.P.

20,549,824

14.2

%

0

20,549,824

0

20,549,824

Oaktree Holdings, Inc.

20,549,824

14.2

%

0

20,549,824

0

20,549,824

Oaktree Capital Group, LLC

20,549,824

14.2

%

0

20,549,824

0

20,549,824

Oaktree Capital Group Holdings GP, LLC

20,549,824

14.2

%

0

20,549,824

0

20,549,824

Highstar Prism, Highstar Main, NGL CIV and NGL Blocker are the record holders of 5,637,025, 3,918,598, 8,309,237 and 2,077,309 Preferred Units, respectively. In addition, Highstar Prism and Highstar Main are the record holders of 358,466 and 249,189 Warrants, respectively, that are currently exercisable or will become exercisable within 60 days of the date of this Schedule 13D.

Highstar Co-Invest is the managing member of NGL CIV and as a result may be deemed to share beneficial ownership of the securities held of record by NGL CIV.

Highstar GP IV is one of two members of Highstar Prism and is the non-member manager of the other member. In addition, Highstar GP IV is the non-member manager of Highstar Main and is the managing member of NGL Blocker and Highstar Co-Invest. As a result, Highstar GP IV may deemed to share beneficial ownership of the securities held of record by each of the Purchasers.

Oaktree Capital Group Holdings GP, LLC is the duly elected manager of Oaktree Capital Group, LLC, which is the sole shareholder of Oaktree Holdings, Inc., which is the general partner of Oaktree Capital II, L.P., which is the general partner of Oaktree Fund GP II, L.P., which is the sole shareholder of Highstar Capital GP IV Holdings, which is the sole member of Highstar Capital GP IV, LLC, which is the general partner of Highstar GP IV. Oaktree Capital Group Holdings GP, LLC is a limited liability company managed by the OCGH GP Members. As a result, each of the foregoing entities and individuals may be deemed to share beneficial ownership of the securities beneficially owned by Highstar GP IV. Each such entity or person disclaims any such beneficial ownership of such securities.

(c)           During the past 60 days none of the Reporting Persons or the OCGH GP Members has effected any transactions in the Common Units.

(d)                                 None.

(e)                                  Not applicable.

Item 6.

Contracts, Arrangements, Understandings or Relationships with Respect to Securities of the Issuer.

Item 3 above summarizes certain provisions of the Purchase Agreement and the Purchase Agreement Amendment and Item 4 above summarizes certain provisions of the Board Representation Agreement, the Registration Rights Agreement and the Partnership Agreement. A copy of each of these agreements is attached as an exhibit to this Schedule 13D, and each is incorporated herein by reference.

Except as set forth herein, none of the Reporting Persons or the OCGH GP Members has any contracts, arrangements, understandings or relationships (legal or otherwise) with any person with respect to any securities of the Issuer, including but not limited to any contracts, arrangements, understandings or relationships concerning the transfer or voting of such

securities, finder’s fees, joint ventures, loan or option arrangements, puts or calls, guarantees of profits, division of profits or losses, or the giving or withholding of proxies.

Item 7.

Materials to be Filed as Exhibits

Exhibit
Number

Description

1

Joint Filing Agreement.

2

Class A Convertible Preferred Unit and Warrant Purchase Agreement, dated as of April 21, 2016, by and among NGL Energy Partners LP, Highstar NGL Prism/IV-A Interco LLC and Highstar NGL Main Interco LLC, including the form of Board Representation and Observation Rights Agreement attached as Exhibit B thereto (incorporated by reference to Exhibit 10.1 to the Issuer’s Current Report on Form 8-K filed on April 27, 2016)

3

Amendment to Class A Convertible Preferred Unit and Warrant Purchase Agreement, dated as of June 23, 2016, by and among NGL Energy Partners LP and Highstar NGL Prism/IV-A Interco LLC, Highstar NGL Main Interco LLC and NGL CIV A, LLC (incorporated by reference to Exhibit 10.1 to the Issuer’s Current Report on Form 8-K filed on June 28, 2016).

4

Registration Rights Agreement, dated May 11, 2016, by and among NGL Energy Partners LP and Highstar NGL Prism/IV-A Interco LLC and Highstar NGL Main Interco LLC (incorporated by reference to Exhibit 4.1 to the Issuer’s Current Report on Form 8-K filed on June 28, 2016).

5

Amendment to Registration Rights Agreement, dated June 24, 2016, by and among NGL Energy Partners LP and Highstar NGL Prism/IV-A Interco LLC, Highstar NGL Main Interco LLC and NGL CIV A, LLC (incorporated by reference to Exhibit 4.2 to the Issuer’s Current Report on Form 8-K filed on June 28, 2016).

6

Fourth Amended and Restated Agreement of Limited Partnership of NGL Energy Partners LP, dated as of June 13, 2017 (incorporated by reference to Exhibit 3.1 to the Issuer’s Current Report on Form 8-K filed on June 13, 2017).

Date:   March 22, 2019

Highstar NGL Prism/IV-A Interco LLC

By:

Highstar Capital GP IV, L.P.

Its:

Managing Member

By:

Highstar Capital GP IV, LLC

Its:

General Partner

By:

/s/ Henry E. Orren

Name:

Henry E. Orren

Title:

Vice President

Highstar NGL Main Interco LLC

By:

Highstar Capital GP IV, L.P.

Its:

Manager

By:

Highstar Capital GP IV, LLC

Its:

General Partner

By:

/s/ Henry E. Orren

Name:

Henry E. Orren

Title:

Vice President

NGL CIV A, LLC

By:

Highstar Capital NGL Co-Invest Manager LLC, its managing member

By:

Highstar Capital GP IV, L.P., its managing member

By:

Highstar Capital GP IV, LLC, its general partner

By:

/s/ Henry E. Orren

Name:

Henry E. Orren

Title:

Vice President

NGL Prism/IV-A Blocker LLC

By:

Highstar Capital GP IV, L.P., its managing member

By:

Highstar Capital GP IV, LLC, its general partner

By:

/s/ Henry E. Orren

Name:

Henry E. Orren

Title:

Vice President

Highstar Capital NGL Co-Invest Manager LLC

By:

Highstar Capital GP IV, L.P., its managing member

By:

Highstar Capital GP IV, LLC, its general partner

By:

/s/ Henry E. Orren

Name:

Henry E. Orren

Title:

Vice President

Highstar Capital GP IV, L.P.

By:

Highstar Capital GP IV, LLC, its general partner

By:

/s/ Henry E. Orren

Name:

Henry E. Orren

Title:

Vice President

Highstar Capital GP IV, LLC

By:

/s/ Henry E. Orren

Name:

Henry E. Orren

Title:

Vice President

Highstar Capital GP IV Holdings

By:

Oaktree Capital Management, L.P.

Its:

Director

By:

/s/ Henry E. Orren

Name:

Henry E. Orren

Title:

Vice President

Oaktree Fund GP II, L.P.

By:

/s/ Henry E. Orren

Name:

Henry E. Orren

Title:

Vice President

Oaktree Capital II, L.P.

By: Oaktree Holdings, Inc., its general partner

By:

/s/ Henry E. Orren

Name:

Henry E. Orren

Title:

Vice President

Oaktree Holdings, Inc.

By:

/s/ Henry E. Orren

Name:

Henry E. Orren

Title:

Vice President

Oaktree Capital Group, LLC

By:

/s/ Henry E. Orren

Name:

Henry E. Orren

Title:

Vice President

Oaktree Capital Group Holdings GP, LLC

By:

/s/ Henry E. Orren

Name:

Henry E. Orren

Title:

Vice President

Highstar NGL Prism/IV-A Interco LLC

By:

Highstar Capital GP IV, L.P.

Its:

Managing Member

By:

Highstar Capital GP IV, LLC

Its:

General Partner

By:

/s/ Henry E. Orren

Name:

Henry E. Orren

Title:

Vice President

Highstar NGL Main Interco LLC

By:

Highstar Capital GP IV, L.P.

Its:

Manager

By:

Highstar Capital GP IV, LLC

Its:

General Partner

By:

/s/ Henry E. Orren

Name:

Henry E. Orren

Title:

Vice President

NGL CIV A, LLC

By:

Highstar Capital NGL Co-Invest Manager LLC, its managing member

By:

Highstar Capital GP IV, L.P., its managing member

By:

Highstar Capital GP IV, LLC, its general partner

By:

/s/ Henry E. Orren

Name:

Henry E. Orren

Title:

Vice President

NGL Prism/IV-A Blocker LLC

By:

Highstar Capital GP IV, L.P., its managing member

By:

Highstar Capital GP IV, LLC, its general partner

By:

/s/ Henry E. Orren

Name:

Henry E. Orren

Title:

Vice President

Highstar Capital NGL Co-Invest Manager LLC

By:

Highstar Capital GP IV, L.P., its managing member

By:

Highstar Capital GP IV, LLC, its general partner

By:

/s/ Henry E. Orren

Name:

Henry E. Orren

Title:

Vice President

Highstar Capital GP IV, L.P.

By:

Highstar Capital GP IV, LLC, its general partner

By:

/s/ Henry E. Orren

Name:

Henry E. Orren

Title:

Vice President

Highstar Capital GP IV, LLC

By:

/s/ Henry E. Orren

Name:

Henry E. Orren

Title:

Vice President

Highstar Capital GP IV Holdings

By:

Oaktree Capital Management, L.P.

Its:

Director

By:

/s/ Henry E. Orren

Name:

Henry E. Orren

Title:

Vice President

Oaktree Fund GP II, L.P.

By:

/s/ Henry E. Orren

Name:

Henry E. Orren

Title:

Vice President

Oaktree Capital II, L.P.

By: Oaktree Holdings, Inc., its general partner

By:

/s/ Henry E. Orren

Name:

Henry E. Orren

Title:

Vice President

Oaktree Holdings, Inc.

By:

/s/ Henry E. Orren

Name:

Henry E. Orren

Title:

Vice President

Oaktree Capital Group, LLC

By:

/s/ Henry E. Orren

Name:

Henry E. Orren

Title:

Vice President

Oaktree Capital Group Holdings GP, LLC

By:

/s/ Henry E. Orren

Name:

Henry E. Orren

Title:

Vice President