Eneva : Reserves Certification Report - 04/30/2017

Gaffney, Cline & Associates, Inc.

5555 San Felipe St., Suite 550

Houston, TX 77056

Telephone: [phone] www.gaffney-cline.com

May 15, 2017

Parnaiba Gas Natural S.A.

Praia de Botafogo, 501, Torre Pão de Açúcar 7º andar - Botafogo - Rio de Janeiro

CEP: 22250-040

Natural Gas Reserves Audit Summary Report for Parnaiba Gas Natural S.A. Participating Interest Fields in Parnaiba Basin, Brazil as of April 30, 2017

This reserves statement has been prepared by Gaffney, Cline & Associates (GCA) and issued on May 15, 2017 at the request of Parnaiba Gas Natural S.A. (PGNSA or "the Client"). This report summarizes a previous report issued on May 11, 2017 titled "Natural Gas Reserves Audit Update Report for Parnaiba Gas Natural S.A. Participating Interest Fields in Parnaiba Basin, Brazil as of April 30, 2017".

PGNSA is operator of and 70% interest participant in several gas properties located onshore in the Parnaiba Basin, Brazil. The remaining 30% interest is held by BPMB Parnaíba S.A. Both companies are wholly owned subsidiaries of ENEVA S.A. (ENEVA). ENEVA is a Brazilian fully integrated energy company, with businesses in power generation, energy commercialization, and Oil & Gas exploration and production.

This report relates specifically and solely to the subject matter as defined in the scope of work in the Proposal for Services and subsequently agreed upon revisions and is conditional upon the assumptions described herein. The report must be considered in its entirety and must only be used for the purpose for which it was intended.

The eight PGNSA fields considered in this report are

• Gavião Real (GVR)

• Gavião Azul (GVA)

• Gavião Branco (GVB)

• Gavião Branco Sudeste (GBSE)1

• Gavião Branco Norte (GVBN)

• Gavião Caboclo (GVC)

1 Gavião Branco Sudeste field was incorporated to Gavião Branco Field area by the Regulatory Agency in 2016.

CG/AR-17-2001.00 1

Parnaiba Gas Natural S.A.

• Gavião Vermelho (GVV)

• Gavião Preto (GVP)

On the basis of technical and other information made available to GCA concerning these property units, GCA hereby provides the reserves statement in Table 1.

Table 1: Statement of Natural Gas Reserves Volumes Eight Fields, Parnaiba Basin as of April 30, 2017

Reserves Category	Gross Field Gas Volumes (100% W I) (Bm3)	Gross Gas Reserves (100% W I) (Bm3)
Proved	8.1	7.6
Developed
Undeveloped	7.5	7.7
Total Proved (1P)	15.6	15.3
2P	18.9	18.5
3P	22.0	21.6

The 2P developed would be the 1P developed. 2P = P1 + P2 and P2 is always undeveloped by definition.

Natural gas volumes have been reported in billion (109) cubic meters at standard conditions of 1 Atmosphere and 15.6 °C. Reserves volumes correspond to sales gas, after an allocation has been made for fuel and consumption at 2% of gas production.

Hydrocarbon liquid volumes to be recovered during field separation represent minor quantities and are not reported.

Gas sales volumes are based on firm and existing gas contracts.

Article 47 of the Brazilian Petroleum Law states that "…royalties are to be paid on a monthly basis, in national currency …" and, therefore, royalties (10%) are treated as cash deductions rather than a reduction to volumes.

As of April 30, 2017, all of these fields have been declared commercial.

Reserves Assessment

Gross field reserves were estimated as the gross field volumes limited by the expiry of the gas contracts at the end of 2036 net of 2% consumption and subjected to Economic Limit Test (ELT) considerations. Reserves net to PGNSA are gross reserves affected by the 70% working interest factor.

This audit examination was based on reserves estimates and other information provided by PGNSA to GCA through April 17, 2017, and included such tests, procedures and adjustments

as were considered necessary. All questions that arose during the audit process were resolved to GCA's satisfaction.

The economic tests for the April 30, 2017 reserves volumes were based on gas prices provided by PGNSA that are based on ANP reference price estimates.

Future capital costs were derived from development plans prepared by PGNSA for the fields audited. Recent historical operating expense data were used as the basis for operating cost projections. No adjustments for inflation were applied. GCA has found that PGNSA has projected sufficient capital investments and operating expenses to economically produce the projected volumes.

It is GCA's opinion that the estimates of total remaining recoverable gas volumes, as of April 30, 2017, are, in the aggregate, reasonable and the reserves categorization is appropriate and consistent with the definitions for reserves and resources in the Petroleum Resources Management System (PRMS), which was approved by the Society of Petroleum Engineers, the World Petroleum Council, the American Association of Petroleum Geologists and the Society of Petroleum Evaluation Engineers in March 2007.

GCA concludes that the methodologies employed by PGNSA in the derivation of the reserves estimates are appropriate, and that the quality of the data relied upon and the depth and thoroughness of the reserves estimation process is adequate.

Basis of Opinion

This document reflects GCA's informed professional judgment based on accepted standards of professional investigation and, as applicable, the data and information provided by the Client, the limited scope of engagement, and the time permitted to conduct the evaluation.

In line with those accepted standards, this document does not in any way constitute or make a guarantee or prediction of results, and no warranty is implied or expressed that actual outcome will conform to the outcomes presented herein. GCA has not independently verified any information provided by, or at the direction of, the Client, and has accepted the accuracy and completeness of this data. GCA has no reason to believe that any material facts have been withheld, but does not warrant that its inquiries have revealed all of the matters that a more extensive examination might otherwise disclose.

The opinions expressed herein are subject to and fully qualified by the generally accepted uncertainties associated with the interpretation of geoscience and engineering data and do not reflect the totality of circumstances, scenarios and information that could potentially affect decisions made by the report's recipients and/or actual results. The opinions and statements contained in this report are made in good faith and in the belief that such opinions and statements are representative of prevailing physical and economic circumstances.

There are numerous uncertainties inherent in estimating reserves and resources, and in projecting future production, development expenditures, operating expenses and cash flows. Oil and gas resources assessments must be recognized as a subjective process of estimating subsurface accumulations of oil and gas that cannot be measured in an exact way. Estimates

of oil and gas resources prepared by other parties may differ, perhaps materially, from those contained within this report.

The accuracy of any resource estimate is a function of the quality of the available data and of engineering and geological interpretation. Results of drilling, testing and production that post- date the preparation of the estimates may justify revisions, some or all of which may be material. Accordingly, resource estimates are often different from the quantities of oil and gas that are ultimately recovered, and the timing and cost of those volumes that are recovered may vary from that assumed.

GCA's review and audit involved reviewing pertinent facts, interpretations and assumptions made by the Client or others in preparing estimates of reserves and resources. GCA performed procedures necessary to enable it to render an opinion on the appropriateness of the methodologies employed, adequacy and quality of the data relied on, depth and thoroughness of the reserves and resources estimation process, classification and categorization of reserves and resources appropriate to the relevant definitions used, and reasonableness of the estimates.

Definition of Reserves and Resources

Reserves are those quantities of petroleum that are anticipated to be commercially recoverable by application of development projects to known accumulations from a given date forward under defined conditions. Reserves must further satisfy four criteria, based on the development project(s) applied: discovered, recoverable, commercial and remaining (as of the evaluation date).

GCA is not aware of any potential changes in regulations applicable to these fields that could affect the ability of the Client to produce the estimated reserves.

Reserves are further categorized in accordance with the level of certainty associated with the estimates and may be sub-classified based on project maturity and/or characterized by development and production status. All categories of reserves volumes quoted herein have been derived within the context of an economic limit test (ELT) assessment (pre-tax and exclusive of accumulated depreciation amounts) prior to any Net Present Value (NPV) analysis.

GCA has not undertaken a site visit or inspection because it was not considered relevant for the purpose of this report. As such, GCA is not in a position to comment on the operations or facilities in place, their appropriateness and condition, or whether they are in compliance with the regulations pertaining to such operations. Further, GCA is not in a position to comment on any aspect of health, safety, or environment of such operation.

This report has been prepared based on GCA's understanding of the effects of petroleum legislation and other regulations that currently apply to these properties. However, GCA is not in a position to attest to property title or rights, conditions of these rights (including environmental and abandonment obligations), or any necessary licenses and consents (including planning permission, financial interest relationships, or encumbrances thereon for any part of the appraised properties).