Eneva : Material Fact - Reserve Certification (GCA - ...

MATERIAL FACT

Rio de Janeiro, January 15, 2018 - ENEVA S.A. ("Eneva" or "Company") (B3: ENEV3, GDR I: ENEVY), pursuant to article 157, paragraph 4 of Law 6404/1976 and CVM Instruction 358/2002, as amended, hereby informs its shareholders and the market in general that it has received a new reserve certification report for Parnaiba Gas Natural S.A. ("PGN") participating interest on the natural gas fields in the Parnaiba Basin, as of December 31, 2017 ("Report"). The Report was prepared by Gaffney, Cline & Associates Inc. (GCA").

According to the criteria defined in the Petroleum Resources Management System (PRMS), GCA certified PGN's natural gas reserves in the Parnaiba Basin, Brasil, as of December 31, 2017, as per Table 1:

Table 1: Statement of Natural Gas Reserves Volumes, Parnaiba Basin

(December 31, 2017)

Reserves Categorization	PGN Natural Gas Reserves (100% WI) (Bm3)
(1P)	14.2
(2P) Developed Undeveloped	18.8 15.5 3.3
(3P)	22.2

The eight PGN fields considered in the Report are: Gavião Real (GVR), Gavião Azul (GVA), Gavião Branco (GVB), Gavião Branco Sudeste (GBSE), Gavião Caboclo (GVC), Gavião Vermelho (GVV), already in production, Gavião Preto (GVP) and Gavião Branco Norte (GVBN), still in development.

Table 2 shows the evolution of certified reserves from December 31, 2016 to December 31, 2017.

Table 2: Certified Reserves Evolution in 2017

Reserves Variations	PGN Natural Gas Reserves (100% WI) (Bm3)
Certified Reserves in December 31, 2016	17.7
Change in Reserves in 2017	+2.7
Gas Production in 2017	(1.6)
Certified Reserves in December 31, 2017	18.8

The most relevant reserve variations are summarized below:

Gavião Caboclo (+ 0.9 Bm3): 6 development wells drilled, completed and tested in 2017, with better results than initially expected;

Gavião Branco e Gavião Branco Sudeste (+ 1.5 Bm3): both fields performing significantly above expectations, justifying an increase in gas volumes to fit smoother declining curves;

The Reserves Replacement Rate (RRR) in 2017 reached 170%, and the Reserves / Production ratio (R/P) is approximately 12 years.

The Report is available for download fromhere

Pedro Zinner

CEO and Investor Relations Officer

ENEVA S.A.