UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13D/A

Under the Securities Exchange Act of 1934
(Amendment No. 1)*

National Energy Services Reunited Corp.

(Name of Issuer)

Ordinary Shares, no par value

(Title of Class of Securities)

G6375R107

(CUSIP Number)

Mubbadrah Investments LLC

Building No. 1/21 Way No. 5001

Near Al Nadha Towers, Ghala,

Muscat, Oman

+968 24390901

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

August 30, 2019

(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 which is the subject of this Schedule 13D, and is filing this schedule because of Sections 240.13d-1(e), 240.13d-1(f) or 240.13d-1(g), check the following box. [  ]

Note: Schedules filed in paper format shall include a signed original and five copies of the schedule, including all exhibits. See Section 240.13d-7 for other parties to whom copies are to be sent.

* 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).

This Amendment No. 1 (the “Amendment”) amends and supplements the Schedule 13D filed with the Securities and Exchange Commission (the “Commission”) on September 27, 2018, by Mubbadrah Investments LLC, an Oman limited liability company (“Mubbadrah”), Wild Holding LLC, an Oman limited liability company (“Wild Holding”), Myrad Holding LLC, an Oman limited liability company (“Myrad Holding”), Yasser Al Barami (“Mr. Al Barami”), and Hilal Al Busaidi (“Mr. Al Busaidi” and, together with Mubbadrah, Wild Holding, Myrad Holding, and Mr. Al Barami, the “Reporting Persons”) (the “Original Schedule 13D”). Capitalized terms used but not otherwise defined in this Amendment have the meanings ascribed to such terms in the Original Schedule 13D. Except as expressly amended and supplemented by this Amendment, the Original Schedule 13D is not amended or supplemented in any respect, and the disclosures set forth in the Original Schedule 13D, other than as amended herein are incorporated by reference herein.

Item 3. Source and Amount of Funds or Other Consideration

On November 12, 2017, Mubbadrah, Mr. Al Barami, Mr. Al Busaidi, and Issuer entered into a purchase agreement pursuant to which Issuer agreed to purchase 61% of the outstanding equity interests of Gulf Energy S.A.O.C. (“GES”) in exchange for Issuer ordinary shares (the “GES Stock Purchase Agreement”). In accordance with the GES Stock Purchase Agreement, Mubbadrah acquired 17,242,424 Issuer ordinary shares at closing. For additional information, see Item 6 below.

On June 28, 2019, Mubbadrah transferred 140,000 ordinary shares to a third party in a private transaction.

This Amendment reports the sale by Mubbadrah in open market transactions from July 1, 2019 through September 19, 2019, of 910,000 ordinary shares of the Issuer as described on Schedule A, the sale by Mr. Al Barami in open market transactions from March 19, 2019 through September 10, 2019, of 345,700 ordinary shares of the Issuer as described on Schedule B, and the purchase by Mubbadrah in an open market transaction on September 20, 2019, of 100,000 ordinary shares for $6.92 per share.

Item 5. Interest in Securities of the Issuer

Item 6. Contracts, Arrangements, Understandings or Relationships With Respect to Securities of the Issuer.

On November 12, 2017, the Issuer, Mubbadrah, Mr. Al Barami, and Mr. Al Busaidi (the “GES Stockholders”) entered into the GES Stock Purchase Agreement by which the Issuer contracted to acquire 61% of the outstanding shares of GES in exchange for Issuer ordinary shares. For a more detailed description of the GES Stock Purchase Agreement and other related matters, please refer to the Issuer’s Current Reports on Form 8-K filed with the Securities and Exchange Commission on November 16, 2017 and June 12, 2018, which are incorporated by reference into this Schedule 13D/A.

The GES Stock Purchase Agreement provides a contractual right to Mubbadrah to nominate two members to be appointed to the Board of Directors of the Issuer.

The foregoing description of the GES Stock Purchase Agreement is not intended to be complete and is qualified in its entirety by reference to the full text of the agreement, which have been filed or are incorporated by reference into this Schedule 13D/A.

Item 7. Material to be Filed as Exhibits

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

Date: October 8, 2019

SCHEDULE A

SCHEDULE B