SEC Form 3

FORM 3

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person* Diamondback Energy, Inc. (Last) (First) (Middle) 500 WEST TEXAS AVENUE, SUITE 1200 (Street) MIDLAND TX 79701 (City) (State) (Zip)	2. Date of Event Requiring Statement (Month/Day/Year) 05/22/2019	3. Issuer Name and Ticker or Trading Symbol RATTLER MIDSTREAM LP [ RTLR ]
		4. Relationship of Reporting Person(s) to Issuer (Check all applicable) X Director 10% Owner Officer (give title below) Other (specify below)	5. If Amendment, Date of Original Filed (Month/Day/Year)
			6. Individual or Joint/Group Filing (Check Applicable Line) Form filed by One Reporting Person X Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Beneficially Owned
1. Title of Security (Instr. 4)	2. Amount of Securities Beneficially Owned (Instr. 4)	3. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	4. Nature of Indirect Beneficial Ownership (Instr. 5)

Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 4)	2. Date Exercisable and Expiration Date (Month/Day/Year)		3. Title and Amount of Securities Underlying Derivative Security (Instr. 4)		4. Conversion or Exercise Price of Derivative Security	5. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	6. Nature of Indirect Beneficial Ownership (Instr. 5)
	Date Exercisable	Expiration Date	Title	Amount or Number of Shares

1. Name and Address of Reporting Person* Diamondback Energy, Inc. (Last) (First) (Middle) 500 WEST TEXAS AVENUE, SUITE 1200 (Street) MIDLAND TX 79701 (City) (State) (Zip)

1. Name and Address of Reporting Person* Energen Resources Corp (Last) (First) (Middle) 500 WEST TEXAS AVENUE, SUITE 1200 (Street) MIDLAND TX 79701 (City) (State) (Zip)

Explanation of Responses:

Remarks:

This Form 3 is being filed jointly by Diamondback Energy, Inc. and Energen Resources Corporation (together, the "Reporting Persons") in connection with the effectiveness of the Registration Statement on Form S-1, as amended (File No. 333-226645), filed by Rattler Midstream LP (the "Issuer"). Diamondback Energy, Inc. is the sole shareholder of Energen Resources Corporation, which is the sole member of Rattler Midstream LLC (the "General Partner"), which owns the non-economic general partner interest in the Issuer. On the basis of the relationship between the Reporting Persons (whether directly or through their affiliates) and certain directors of the General Partner, the general partner of the Issuer, the Reporting Persons may be deemed to be directors of the Issuer.

No securities are beneficially owned.

	/s/ Teresa L. Dick, as Executive Vice President, Chief Accounting Officer and Assistant Secretary of Diamondback Energy, Inc.	05/22/2019
	/s/ Teresa L. Dick, as Executive Vice President, Chief Accounting Officer and Assistant Secretary of Energen Resources Corporation	05/22/2019
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 5 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
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