Form: 4

Statement of changes in beneficial ownership of securities

May 16, 2018

FORM 4
Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).
UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN 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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(Print or Type Responses)
1. Name and Address of Reporting Person *
ENERGY CAPITAL PARTNERS II, LLC
   2. Issuer Name and Ticker or Trading Symbol
ProPetro Holding Corp. [PUMP] 		5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
_____ Director __X__ 10% Owner
_____ Officer (give title below) _____ Other (specify below)
(Last)
(First)
(Middle)
51 JOHN F. KENNEDY PARKWAY, SUITE 200		 3. Date of Earliest Transaction (Month/Day/Year)
05/14/2018
(Street)

SHORT HILLS, NJ 07078		 4. If Amendment, Date 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
(City)
(State)
(Zip)
Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1.Title of Security
(Instr. 3)		 2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction Code
(Instr. 8)		 4. Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4 and 5)		 5. Amount of Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 3 and 4)		 6. Ownership Form: Direct (D) or Indirect (I)
(Instr. 4)		 7. Nature of Indirect Beneficial Ownership
(Instr. 4)
Code V Amount (A) or (D) Price
Common Stock 05/14/2018   S   13,800,000 D $ 19.01 6,927,928 I See footnotes (1) (2)

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
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Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security
(Instr. 3)		 2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (Month/Day/Year) 3A. Deemed Execution Date, if any (Month/Day/Year) 4. Transaction Code
(Instr. 8)		 5. Number of Derivative Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4, and 5)		 6. Date Exercisable and Expiration Date
(Month/Day/Year)		 7. Title and Amount of Underlying Securities
(Instr. 3 and 4)		 8. Price of Derivative Security
(Instr. 5)		 9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 4)		 10. Ownership Form of Derivative Security: Direct (D) or Indirect (I)
(Instr. 4)		 11. Nature of Indirect Beneficial Ownership
(Instr. 4)
Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares

Reporting Owners

Reporting Owner Name / Address Relationships
 Director  10% Owner  Officer  Other
ENERGY CAPITAL PARTNERS II, LLC
51 JOHN F. KENNEDY PARKWAY
SUITE 200
SHORT HILLS, NJ 07078		     X    
Energy Capital Partners GP II, LP
51 JOHN F. KENNEDY PARKWAY
SUITE 200
SHORT HILLS, NJ 07078		     X    
ENERGY CAPITAL PARTNERS II, LP
51 JOHN F. KENNEDY PARKWAY
SUITE 200
SHORT HILLS, NJ 07078		     X    
ENERGY CAPITAL PARTNERS II-A, LP
51 JOHN F. KENNEDY PARKWAY
SUITE 200
SHORT HILLS, NJ 07078		     X    
ENERGY CAPITAL PARTNERS II-B, LP
51 JOHN F. KENNEDY PARKWAY
SUITE 200
SHORT HILLS, NJ 07078		     X    
Energy Capital Partners II-C (Direct IP), LP
51 JOHN F. KENNEDY PARKWAY
SUITE 200
SHORT HILLS, NJ 07078		     X    
ENERGY CAPITAL PARTNERS II-D, LP
51 JOHN F. KENNEDY PARKWAY
SUITE 200
SHORT HILLS, NJ 07078		     X    
Energy Capital Partners II (Midland Co-Invest), LP
51 JOHN F. KENNEDY PARKWAY
SUITE 200
SHORT HILLS, NJ 07078		     X    
Energy Capital Partners GP II Co-Investment (Midland), LLC
51 JOHN F. KENNEDY PARKWAY
SUITE 200
SHORT HILLS, NJ 07078		     X    

Signatures

 Energy Capital Partners II, LLC By: /s/ Christopher M. Leininger, Managing Director and Deputy General Counsel   05/16/2018
**Signature of Reporting Person Date
 Energy Capital Partners GP II, LP By: Energy Capital Partners II, LLC, its general partner By: /s/ Christopher M. Leininger, Managing Director and Deputy General Counsel   05/16/2018
**Signature of Reporting Person Date
 Energy Capital Partners II, LP By: Energy Capital Partners GP II, LP, its general partner By: Energy Capital Partners II, LLC, its general partner By: /s/ Christopher M. Leininger, Managing Director and Deputy General Counsel   05/16/2018
**Signature of Reporting Person Date
 Energy Capital Partners II-A, LP By: Energy Capital Partners GP II, LP, its general partner By: Energy Capital Partners II, LLC, its general partner By: /s/ Christopher M. Leininger, Managing Director and Deputy General Counsel   05/16/2018
**Signature of Reporting Person Date
 Energy Capital Partners II-B, LP By: Energy Capital Partners GP II, LP, its general partner By: Energy Capital Partners II, LLC, its general partner By: /s/ Christopher M. Leininger, Managing Director and Deputy General Counsel   05/16/2018
**Signature of Reporting Person Date
 Energy Capital Partners II-C (Direct IP), LP By: Energy Capital Partners GP II, LP, its general partner By: Energy Capital Partners II, LLC, its general partner By: /s/ Christopher M. Leininger, Managing Director and Deputy General Counsel   05/16/2018
**Signature of Reporting Person Date
 Energy Capital Partners II-D, LP By: Energy Capital Partners GP II, LP, its general partner By: Energy Capital Partners II, LLC, its general partner By: /s/ Christopher M. Leininger, Managing Director and Deputy General Counsel   05/16/2018
**Signature of Reporting Person Date
 Energy Capital Partners II (Midland Co-Invest), LP By: Energy Capital Partners GP II Co-Investment (Midland), LLC, its GP By: Energy Capital Partners II, LLC, its sole member By: /s/ Christopher M. Leininger, Managing Director and Deputy General Counsel   05/16/2018
**Signature of Reporting Person Date
 Energy Capital Partners GP II Co-Investment (Midland), LLC By: Energy Capital Partners II, LLC, its sole member By: /s/ Christopher M. Leininger, Managing Director and Deputy General Counsel   05/16/2018
**Signature of Reporting Person Date

Explanation of Responses:

* If the form is filed by more than one reporting person, see Instruction 4(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).
(1) Following the transaction reported herein, includes (i) 103,753 shares held by Energy Capital Partners II, LP ("ECP II"), (ii) 3,379,615 shares held by Energy Capital Partners II-A, LP ("ECP II-A"), (iii) 707,671 shares held by Energy Capital Partners II-B, LP ("ECP II-B"), (iv) 1,243,091 shares held by Energy Capital Partners II-C (Direct IP), LP ("ECP II-C"), (v) 832,938 shares held by Energy Capital Partners II-D, LP ("ECP II-D"), and (vi) 660,860 shares held by Energy Capital Partners II (Midland Co-Invest), LP ("ECP Co-Invest"). Each of ECP II, ECP II-A, ECP II-B, ECP II-C and ECP II-D is managed by its general partner, Energy Capital Partners GP II, LP. Energy Capital Partners GP II, LP is managed by its general partner, Energy Capital Partners II, LLC ("Energy Capital Partners"). ECP Co-Invest is managed by its general partner, Energy Capital Partners GP II Co-Investment (Midland), LLC, which is managed by its sole member, Energy Capital Partners.
(2) As a result, each of Energy Capital Partners GP II, LP and Energy Capital Partners may be deemed to share beneficial ownership of the shares held by ECP II, ECP II-A, ECP II-B, ECP II-C and ECP II-D, and each of Energy Capital Partners GP II Co-Investment (Midland), LLC and Energy Capital Partners may be deemed to share beneficial ownership of the shares held by ECP Co-Invest. Douglas W. Kimmelman, Peter Labbat, Thomas K. Lane, Tyler Reeder and Andrew D. Singer are the managing members of, and Rahman D'Argenio and Schuyler E. Coppedge are partners of, Energy Capital Partners and share the power to direct the voting and disposition of the shares beneficially owned by Energy Capital Partners. Each such individual disclaims beneficial ownership of such shares except to the extent of their pecuniary interest therein.

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