Exhibit 99.1

WARBURG PINCUS PRIVATE EQUITY X O&G, L.P.

By:		Warburg Pincus X, L.P., its general partner
By:		Warburg Pincus X GP L.P., its general partner
By:		WPP GP LLC, its general partner
By:		Warburg Pincus Partners, L.P., its managing member
By:		Warburg Pincus Partners GP LLC, its general partner
By:		Warburg Pincus & Co., its managing member

By:	/s/ Robert B. Knauss
	Name:	Robert B. Knauss
	Title:	Partner

WARBURG PINCUS X PARTNERS, L.P.

By:		Warburg Pincus X, L.P., its general partner
By:		Warburg Pincus X GP L.P., its general partner
By:		WPP GP LLC, its general partner
By:		Warburg Pincus Partners, L.P., its managing member
By:		Warburg Pincus Partners GP LLC, its general partner
By:		Warburg Pincus & Co., its managing member

By:	/s/ Robert B. Knauss
	Name:	Robert B. Knauss
	Title:	Partner

WARBURG PINCUS X, L.P.

By:		Warburg Pincus X GP L.P., its general partner
By:		WPP GP LLC, its general partner
By:		Warburg Pincus Partners, L.P., its managing member
By:		Warburg Pincus Partners GP LLC, its general partner
By:		Warburg Pincus & Co., its managing member

By:	/s/ Robert B. Knauss
	Name:	Robert B. Knauss
	Title:	Partner

WARBURG PINCUS X GP L.P.

By:		WPP GP LLC, its general partner
By:		Warburg Pincus Partners, L.P., its managing member
By:		Warburg Pincus Partners GP LLC, its general partner
By:		Warburg Pincus & Co., its managing member

By:	/s/ Robert B. Knauss
	Name:	Robert B. Knauss
	Title:	Partner

WPP GP LLC

By:		Warburg Pincus Partners, L.P., its managing member
By:		Warburg Pincus Partners GP LLC, its general partner
By:		Warburg Pincus & Co., its managing member

By:	/s/ Robert B. Knauss
	Name:	Robert B. Knauss
	Title:	Partner

WARBURG PINCUS PARTNERS, L.P.

By:		Warburg Pincus Partners GP LLC, its general partner
By:		Warburg Pincus & Co., its managing member

By:	/s/ Robert B. Knauss
	Name:	Robert B. Knauss
	Title:	Partner

WARBURG PINCUS PARTNERS GP LLC

By:		Warburg Pincus & Co., its managing member

By:	/s/ Robert B. Knauss
	Name:	Robert B. Knauss
	Title:	Partner

WARBURG PINCUS & CO.

By:	/s/ Robert B. Knauss
	Name:	Robert B. Knauss
	Title:	Partner

			Date September 6, 2019

Warburg Pincus Private Equity X O&G, L.P. 4