EXHIBIT A

JOINT FILING AGREEMENT

This will confirm the agreement by and among the undersigned that the Schedule 13G filed with the Securities and Exchange Commission on or about the date hereof with respect to the beneficial ownership by the undersigned of the Class A common stock, par value $0.001 per share, of Earthstone Energy, Inc. (this “Agreement”), is being filed, and all amendments thereto will be filed, on behalf of each of the persons and entities named below that is named as a reporting person in such filing in accordance with Rule 13d-1(k) under the Securities Exchange Act of 1934, as amended. This Agreement may be executed in two or more counterparts, each of which shall be deemed an original, but all of which together shall constitute one and the same instrument.

Dated: August 22, 2022

Warburg Pincus Private Equity (E&P) XI – A, L.P.
By:	Warburg Pincus (E&P) XI, L.P., its general partner
By:	Warburg Pincus (E&P) XI LLC, its general partner
By:	Warburg Pincus Partners (E&P) XI LLC, its sole
	member
By:	Warburg Pincus Partners II (US), L.P., its managing
	member
By:	Warburg Pincus & Company US, LLC, its general
	partner
By:	/s/ Robert B. Knauss
Name:	Robert B. Knauss
Title:	Authorized Signatory
Warburg Pincus XI (E&P) Partners – A, L.P.
By:	Warburg Pincus (E&P) XI, L.P., its general partner
By:	Warburg Pincus (E&P) XI LLC, its general partner
By:	Warburg Pincus Partners (E&P) XI LLC, its sole
	member
By:	Warburg Pincus Partners II (US), L.P., its managing
	member
By:	Warburg Pincus & Company US, LLC, its general
	partner
By:	/s/ Robert B. Knauss
Name:	Robert B. Knauss
Title:	Authorized Signatory
WP IRH Holdings, L.P.
By:	Warburg Pincus (E&P) XI, L.P., its general partner
By:	Warburg Pincus (E&P) XI LLC, its general partner

By:	Warburg Pincus Partners (E&P) XI LLC, its sole
	member
By:	Warburg Pincus Partners II (US), L.P., its managing
	member
By:	Warburg Pincus & Company US, LLC, its general
	partner
By:	/s/ Robert B. Knauss
Name:	Robert B. Knauss
Title:	Authorized Signatory
Warburg Pincus XI (E&P) Partners-B IRH, LLC
By:	Warburg Pincus XI (E&P) Partners – B, L.P., its
	managing member
By:	Warburg Pincus (E&P) XI, L.P., its general partner
By:	Warburg Pincus (E&P) XI LLC, its general partner
By:	Warburg Pincus Partners (E&P) XI LLC, its sole
	member
By:	Warburg Pincus Partners II (US), L.P., its managing
	member
By:	Warburg Pincus & Company US, LLC, its general
	partner
By:	/s/ Robert B. Knauss
Name:	Robert B. Knauss
Title:	Authorized Signatory
Warburg Pincus XI (E&P) Partners – B, L.P.
By:	Warburg Pincus (E&P) XI, L.P., its general partner
By:	Warburg Pincus (E&P) XI LLC, its general partner
By:	Warburg Pincus Partners (E&P) XI LLC, its sole
	member
By:	Warburg Pincus Partners II (US), L.P., its managing
	member
By:	Warburg Pincus & Company US, LLC, its general
	partner
By:	/s/ Robert B. Knauss
Name:	Robert B. Knauss
Title:	Authorized Signatory
Warburg Pincus (E&P) XI LLC
By:	Warburg Pincus Partners (E&P) XI LLC, its sole
	member

By:	Warburg Pincus Partners II (US), L.P., its managing
	member
By:	Warburg Pincus & Company US, LLC, its general
	partner
By:	/s/ Robert B. Knauss
Name:	Robert B. Knauss
Title:	Authorized Signatory
Warburg Pincus Partners (E&P) XI LLC
By:	Warburg Pincus Partners II (US), L.P., its managing
	member
By:	Warburg Pincus & Company US, LLC, its general
	partner
By:	/s/ Robert B. Knauss
Name:	Robert B. Knauss
Title:	Authorized Signatory
WP Energy IRH Holdings, L.P.
By:	Warburg Pincus (E&P) Energy GP, L.P., its general
	partner
By:	Warburg Pincus (E&P) Energy LLC, its general
	partner
By:	Warburg Pincus Partners II (US), L.P., its managing
	member
By:	Warburg Pincus & Company US, LLC, its general
	partner
By:	/s/ Robert B. Knauss
Name:	Robert B. Knauss
Title:	Authorized Signatory
WP Energy Partners IRH Holdings, L.P.
By:	Warburg Pincus (E&P) Energy GP, L.P., its general
	partner
By:	Warburg Pincus (E&P) Energy LLC, its general
	partner
By:	Warburg Pincus Partners II (US), L.P., its managing
	member
By:	Warburg Pincus & Company US, LLC, its general
	partner
By:	/s/ Robert B. Knauss
Name:	Robert B. Knauss
Title:	Authorized Signatory

Warburg Pincus Energy (E&P) Partners-B IRH, LLC
By:	Warburg Pincus Energy (E&P) Partners-B, L.P., its
	managing member
By:	Warburg Pincus (E&P) Energy GP, L.P., its general
	partner
By:	Warburg Pincus (E&P) Energy LLC, its general
	partner
By:	Warburg Pincus Partners II (US), L.P., its managing
	member
By:	Warburg Pincus & Company US, LLC, its general
	partner
By:	/s/ Robert B. Knauss
Name:	Robert B. Knauss
Title:	Authorized Signatory
Warburg Pincus Energy (E&P) Partners-B, L.P.
By:	Warburg Pincus (E&P) Energy GP, L.P., its general
	partner
By:	Warburg Pincus (E&P) Energy LLC, its general
	partner
By:	Warburg Pincus Partners II (US), L.P., its managing
	member
By:	Warburg Pincus & Company US, LLC, its general
	partner
By:	/s/ Robert B. Knauss
Name:	Robert B. Knauss
Title:	Authorized Signatory
Warburg Pincus Energy (E&P) Partners-A, L.P.
By:	Pincus (E&P) Energy GP, L.P., its general partner
By:	Warburg Pincus (E&P) Energy LLC, its general
	partner
By:	Warburg Pincus Partners II (US), L.P., its managing
	member
By:	Warburg Pincus & Company US, LLC, its general
	partner
By:	/s/ Robert B. Knauss
Name:	Robert B. Knauss
Title:	Authorized Signatory

Warburg Pincus Energy (E&P)-A, L.P.
By:	Warburg Pincus (E&P) Energy GP, L.P., its general
	partner
By:	Warburg Pincus (E&P) Energy LLC, its general
	partner
By:	Warburg Pincus Partners II (US), L.P., its managing
	member
By:	Warburg Pincus & Company US, LLC, its general
	partner
By:	/s/ Robert B. Knauss
Name:	Robert B. Knauss
Title:	Authorized Signatory
WARBURG PINCUS (E&P) XII, L.P.
By:	Warburg Pincus (E&P) XII LLC, its general partner
By:	Warburg Pincus Partners II (US), L.P., its managing
	member
By:	Warburg Pincus & Company US, LLC, its general
	partner
By:	/s/ Robert B. Knauss
Name:	Robert B. Knauss
Title:	Authorized Signatory

WARBURG PINCUS (E&P) XII LLC
By:	Warburg Pincus Partners II (US), L.P., its managing member
By:	Warburg Pincus & Company US, LLC, its general partner
By:	/s/ Robert B. Knauss
Name: Robert B. Knauss
Title: Authorized Signatory
WARBURG PINCUS ENERGY (E&P) PARTNERS-B CHISHOLM, LLC
By:	Warburg Pincus Energy (E&P) Partners-B, L.P.,
	its managing member
By:	Warburg Pincus (E&P) Energy GP, L.P., its
	general partner
By:	Warburg Pincus (E&P) Energy LLC, its general
	partner
By:	Warburg Pincus Partners II (US), L.P., its
	managing member
By:	Warburg Pincus & Company US, LLC, its
	general partner
By:	/s/ Robert B. Knauss
Name: Robert B. Knauss
Title: Authorized Signatory
WP ENERGY CHISHOLM HOLDINGS, L.P.
By:	Warburg Pincus (E&P) Energy GP, L.P., its general partner
By:	Warburg Pincus (E&P) Energy LLC, its general partner
By:	Warburg Pincus Partners II (US), L.P., its managing member

By:	Warburg Pincus & Company US, LLC, its general partner
By:	/s/ Robert B. Knauss
Name: Robert B. Knauss
Title: Authorized Signatory
WP ENERGY PARTNERS CHISHOLM HOLDINGS, L.P.
By:	Warburg Pincus (E&P) Energy GP, L.P., its general partner
By:	Warburg Pincus (E&P) Energy LLC, its general partner
By:	Warburg Pincus Partners II (US), L.P., its managing member
By:	Warburg Pincus & Company US, LLC, its general partner
By:	/s/ Robert B. Knauss
Name: Robert B. Knauss
Title: Authorized Signatory
WARBURG PINCUS PRIVATE EQUITY (E&P) XII (A), L.P.
By:	Warburg Pincus (E&P) XII, L.P., its general partner
By:	Warburg Pincus (E&P) XII LLC, its general partner
By:	Warburg Pincus Partners II (US), L.P., its managing member
By:	Warburg Pincus & Company US, LLC, its general partner
By:	/s/ Robert B. Knauss
Name: Robert B. Knauss
Title: Authorized Signatory
WP XII CHISHOLM HOLDINGS, L.P.
By:	Warburg Pincus (E&P) XII, L.P., its general partner
By:	Warburg Pincus (E&P) XII LLC, its general partner
By:	Warburg Pincus Partners II (US), L.P., its managing member
By:	Warburg Pincus & Company US, LLC, its general partner
By:	/s/ Robert B. Knauss
Name: Robert B. Knauss
Title: Authorized Signatory
WARBURG PINCUS XII (E&P) PARTNERS-2 CHISHOLM, LLC
By:	Warburg Pincus XII (E&P) Partners-2, L.P., its managing member
By:	Warburg Pincus (E&P) XII, L.P., its general partner
By:	Warburg Pincus (E&P) XII LLC, its general partner
By:	Warburg Pincus Partners II (US), L.P., its managing member
By:	Warburg Pincus & Company US, LLC, its general partner
By:	/s/ Robert B. Knauss
Name: Robert B. Knauss
Title: Authorized Signatory
WARBURG PINCUS PRIVATE EQUITY (E&P) XII-D (A), L.P.
By:	Warburg Pincus (E&P) XII, L.P., its general partner
By:	Warburg Pincus (E&P) XII LLC, its general partner
By:	Warburg Pincus Partners II (US), L.P., its managing member
By:	Warburg Pincus & Company US, LLC, its general partner
By:	/s/ Robert B. Knauss
Name: Robert B. Knauss
Title: Authorized Signatory

WARBURG PINCUS PRIVATE EQUITY (E&P) XII-E (A), L.P.
By:	Warburg Pincus (E&P) XII, L.P., its general partner
By:	Warburg Pincus (E&P) XII LLC, its general partner
By:	Warburg Pincus Partners II (US), L.P., its managing member
By:	Warburg Pincus & Company US, LLC, its general partner
By:	/s/ Robert B. Knauss
Name: Robert B. Knauss
Title: Authorized Signatory
WP XII (E&P) PARTNERS (A), L.P.
By:	Warburg Pincus (E&P) XII, L.P., its general partner
By:	Warburg Pincus (E&P) XII LLC, its general partner
By:	Warburg Pincus Partners II (US), L.P., its managing member
By:	Warburg Pincus & Company US, LLC, its general partner
By:	/s/ Robert B. Knauss
Name: Robert B. Knauss
Title: Authorized Signatory
WARBURG PINCUS XII (E&P) PARTNERS-1, L.P.
By:	Warburg Pincus (E&P) XII, L.P., its general partner
By:	Warburg Pincus (E&P) XII LLC, its general partner
By:	Warburg Pincus Partners II (US), L.P., its managing member
By:	Warburg Pincus & Company US, LLC, its general partner
By:	/s/ Robert B. Knauss
Name: Robert B. Knauss
Title: Authorized Signatory
WARBURG PINCUS XII (E&P) PARTNERS-2, L.P.
By:	Warburg Pincus (E&P) XII, L.P., its general partner
By:	Warburg Pincus (E&P) XII LLC, its general partner
By:	Warburg Pincus Partners II (US), L.P., its managing member
By:	Warburg Pincus & Company US, LLC, its general partner
By:	/s/ Robert B. Knauss
Name: Robert B. Knauss
Title: Authorized Signatory
WARBURG PINCUS (E&P) ENERGY GP, L.P.
By:	Warburg Pincus (E&P) Energy LLC, its general partner
By:	Warburg Pincus Partners II (US), L.P., its managing member
By:	Warburg Pincus & Company US, LLC, its general partner
By:	/s/ Robert B. Knauss
Name: Robert B. Knauss
Title:	Authorized Signatory

WARBURG PINCUS (E&P) ENERGY LLC
By:	Warburg Pincus Partners II (US), L.P., its managing member
By:	Warburg Pincus & Company US, LLC, its general partner
By:	/s/ Robert B. Knauss
Name:	Robert B. Knauss
Title:	Authorized Signatory
WARBURG PINCUS PARTNERS II (US), L.P.
By:	Warburg Pincus & Company US, LLC, its general partner
By:	/s/ Robert B. Knauss
Name:	Robert B. Knauss
Title:	Authorized Signatory
WARBURG PINCUS & COMPANY US, LLC
By:	/s/ Robert B. Knauss
Name:	Robert B. Knauss
Title:	Authorized Signatory
WARBURG PINCUS LLC
By:	/s/ Robert B. Knauss
Name:	Robert B. Knauss
Title:	Managing Director