Exhibit 99.1



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Gaffney, Cline & Associates, Inc.

5555 San Felipe St., Suite 550

Houston, TX 77056

Telephone: +1 713
850 9955

www.gaffney-cline.com

March 9, 2017

Mr. Javier Sanagua

Auditor de Reservas

YPF S.A.

Macacha Guemes 515

C1106BKK Buenos Aires

Argentina

javier.sanagua@ypf.com

Dear Mr. Javier Sanagua,

Proved
Hydrocarbon Reserves Statement

for YPF S.A. for Certain Argentine Properties

as of December 31, 2016

This Proved
reserves statement has been prepared by Gaffney, Cline & Associates (GCA) and issued on March 9, 2017 at the request of YPF S.A. (YPF), operator of certain assets in Argentina. YPFs participating interest in each asset are shown
in Appendix V.

GCA has conducted an independent audit examination as of December 31, 2016, of the hydrocarbon liquid and natural gas proved reserves
of 47 units. On the basis of technical and other information made available to GCA concerning these property units, GCA hereby provides the reserves statement in the following table:

Statement of Remaining Hydrocarbon Volumes

YPF S.A. Certain Properties in Argentina

as of December 31, 2016



|                        |               |                           |      |          |                  |  |               |  |  |          |      |  |  |  |      | 
|----------------------- | ------------- | ------------------------- | ---- | -------- | ---------------- |  | ------------- |  |  | -------- | ---- |  |  |  | ---- | 
|Reserves                |               | Gross (100%)Field Volumes |      |          | YPF Net Reserves | 
|                        | Liquids(MMm3) |                           |      | Gas(Bm3) |                  |  | Liquids(MMm3) |  |  | Gas(Bm3) |     
|Proved                  |               |                           |      |          |                  |  |               |  |  |          |      |  |  |  |      | 
|Developed Producing     |               |                           | 27.9 |          |                  |  | 34.5          |  |  |          | 26.1 |  |  |  | 20.5 | 
|Developed Non Producing |               |                           | 0.2  |          |                  |  | 0.0           |  |  |          | 0.2  |  |  |  | 0.0  | 
|Undeveloped             |               |                           | 12.7 |          |                  |  | 11.3          |  |  |          | 12.6 |  |  |  | 7.0  | 
|                        |               |                           |      |          |                  |  |               |  |  |          |      |  |  |  |      | 
|Total Proved            |               |                           | 40.9 |          |                  |  | 45.9          |  |  |          | 38.9 |  |  |  | 27.5 | 
|                        |               |                           |      |          |                  |  |               |  |  |          |      |  |  |  |      | 



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Notes:



| | 1. | Gross Field (100%) Volumes represents 100 working interest.
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| | 2. | YPF Net Reserves represent YPFs working interest volumes and therefore include volumes related to royalties payable to the relevant Argentine provinces, which according to domestic treatment in Argentina and
reporting in YPFs 20-F filings with the SEC, are treated as financial obligations.
| | -- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------



| | 3. | Hydrocarbon liquid volumes represent crude oil, condensate, gasoline and NGL estimated to be recovered during field separation and plant processing and are reported in millions of stock tank cubic meters (MMm3).
| | -- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------



| | 4. | Natural gas volumes represent expected gas sales plus produced gas used for consumption and are reported in billion (109) standard cubic meters (Bm3) at standard condition of 15 degrees Celsius and 1 atmosphere. The total YPF Net Proved reserves gas volume estimate of 27.5 Bm3 includes 7.9 Bm3 used for fuel.
| | -- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------



| | 5. | Totals may not exactly equal the sum of the individual entries because of rounding.
| | -- | -----------------------------------------------------------------------------------

This report relates
specifically and solely to the subject matter as defined in the scope of work in the Proposal for Services 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. This report is intended for inclusion in YPFs filings (20-F, F-3) with the United States Securities and Exchange Commission.

Gas reserves sales volumes are based on firm and existing gas contracts, or on the reasonable expectation of a contract or on the reasonable expectation that
any such existing gas sales contracts will be renewed on similar terms in the future.

Appendices II and III provide the Gross Field (100%) and YPF Net
Reserves for each basin.

YPF has advised GCA that the YPF reserves estimated in this report constitute approximately 37.5% percent of YPFs Proved
reserves and that the Proved Undeveloped Reserves estimated in this report constitute approximately 41.4% percent of all YPFs Proved Undeveloped Reserves as of December 31, 2016. These proportions are on a barrel oil equivalent (BOE)
basis. GCA is not in a position to verify these statements because it was not requested to review YPFs other oil and gas assets. Our study was completed on January 31, 2017.

Reserves Assessment

GCAs audit of the YPF reserves
estimates was based on decline curve analysis to extrapolate the production of existing wells or elaborate type curves to estimate future production from the locations proposed by YPF. Geological information, material balance, fluid laboratory tests
and other pertinent information was used to assess the reserves estimates and the classification/categorization of the proposed development plan.

This
audit examination was based on reserves estimates and other information provided by YPF to GCA from September to December 2016 and included such tests, procedures and adjustments as were considered necessary under the circumstances to prepare the
report. All questions that arose during the course of the audit process were resolved to our satisfaction.

The economic tests for the December 31,
2016 Proved Reserve volumes were based on realized crude oil, condensate, NGL and average gas sales prices as shown in the Appendix IV, as advised by YPF. YPF is subject to extensive regulations relating to the oil and gas industry in Argentina
which include specific natural gas market regulations.



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Information on net proved reserves as of December 31, 2016 was calculated in accordance with the SEC rules and
Financial Accounting Standards Board (FASB) Accounting Standards Codification (ASC) 932, as amended. Accordingly oil prices used to determine volumes and reserves were calculated each month, for crude oils of different
quality produced by the Company. Consequently, for calculation of volumes and reserves as of December 31, 2016 the Company considered the realized for crude oil in the domestic market (which are higher than those that had prevailed in the
international market) taking into account the unweighted average price for each month within the twelve-month period ended December 31, 2016. There are no benchmark crude oil prices in Argentina that relate to YPFs oil production from
which first-day-of-month prices could be obtained. Additionally, since there are no benchmark market natural gas prices available
in Argentina, the Company used average realized gas prices during the year to determine its reserves. GCA audited and accepted the methodology and prices used by YPF in estimating the reserves in Argentina.

Future capital costs were derived from development program forecasts prepared by YPF for the fields. Recent historical operating expense data were utilized as
the basis for operating cost projections. GCA has found that YPF has projected sufficient capital investments and operating expenses to produce economically the projected volumes.

It is GCAs opinion that the estimates of total remaining recoverable hydrocarbon liquid and gas volumes at December 31, 2016, are, in the
aggregate, reasonable and the reserves categorization is appropriate and consistent with the definitions for reserves set out in 17-CFR Part 210 Rule 4-10(a) of
Regulation S-X of the United States Securities and Exchange Commission (as set out in Appendix VII). GCA concludes that the methodologies employed by YPF in the derivation of the volume estimates are
appropriate and that the quality of the data relied upon, the depth and thoroughness of the estimation process is adequate.

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

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.



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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 YPF in preparing estimates of reserves. 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

Reserves are estimated remaining
quantities of oil and gas and related substances anticipated to be economically producible, as of a given date, by application of development projects to known accumulations. In addition, there must exist, or there must be a reasonable expectation
that there will exist, the legal right to produce, or a revenue interest in, the production, installed means of delivering oil and gas or related substances to market, and all permits and financing required to implement the project.

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).

GCA has not undertaken a site
visit and inspection because it was not part of the scope of work. 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).



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Qualifications

In
performing this study, GCA is not aware that any conflict of interest has existed. As an independent consultancy, GCA is providing impartial technical, commercial, and strategic advice within the energy sector. GCAs remuneration was not in any
way contingent on the contents of this report.

In the preparation of this document, GCA has maintained, and continues to maintain, a strict independent
consultant-client relationship with the Client. Furthermore, the management and employees of GCA have no interest in any of the assets evaluated or related with the analysis performed, as part of this report.

Staff members who prepared this report hold appropriate professional and educational qualifications and have the necessary levels of experience and expertise
to perform the work. The technical qualification of the person primarily responsible for the preparation of the reserves estimates presented in this report are given in Appendix I.



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Notice

This report is
intended for inclusion in its entirety in YPFs filings (20-F, F-3) with the United States Securities and Exchange Commission (SEC) in accordance with the
disclosure requirements set forth in the SEC regulations. YPF S.A. will obtain GCAs prior written approval for any other use of any results, statements or opinions expressed to YPF S.A. in this report, which are attributed to GCA.



|                                  
|----------------------------------
|Yours sincerely,                  
|Gaffney, Cline & Associates       
|LOGO                              
|Project Manager                   
|Daniel Amitrano, Principal Advisor
|LOGO                              
|Reviewed by                       
|Rawdon Seager, Technical Director 

Appendices

Appendix I:
Statement of Qualifications

Appendix II: Statement of Gross Field (100%) Volumes per Basin

Appendix III: YPF Net Reserves per Basin

Appendix IV:
Hydrocarbon Prices

Appendix V: YPFs Participating Interest in each Area

Appendix VI: SEC Reserves Definitions

Appendix VII: Glossary



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Appendix I

Statement of Qualifications



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Statement of Qualifications

D. A. Amitrano

D. A. Amitrano is one of
GCAs Principal Advisors and was the primary responsible for preparation of the audit. Mr. Amitrano has over 27 years of diversified international industry experience mainly in reservoir-engineering, geology, reserves estimates, project
development, including, classification and reporting of reserves and resources. He is a member of the Society of Petroleum Engineers (SPE) and holds a BS Civil Engineering and Field Exploitation  Production Career and Reservoir Engineering
Course from Buenos Aires University, Argentina.



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Appendix II

Gross Field (100%) Volumes per Basin



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Statement of 100% Gross Field Volumes per Basin

YPF S.A. Certain Properties in Argentina

as of December 31, 2016

Liquid Hydrocarbon Volumes



|                |  |              |        |  |                 |  |     |          |  |  |        |  |  |  |        | 
|--------------- |  | ------------ | ------ |  | --------------- |  | --- | -------- |  |  | ------ |  |  |  | ------ | 
|                |  | Proved       |       
|Basin           |  | Developed    |        |  | UndevelopedMm3  |  |     | TotalMm3 | 
|                |  | ProducingMm3 |        |  | NonProducingMm3 |  |     |         
|Cuyana          |  |              | 2,411  |  |                 |  | 35  |          |  |  | 336    |  |  |  | 2,783  | 
|Golfo San Jorge |  |              | 19,862 |  |                 |  |    |          |  |  | 10,493 |  |  |  | 30,355 | 
|Neuquina        |  |              | 4,125  |  |                 |  | 194 |          |  |  | 1,866  |  |  |  | 6,185  | 
|Noroeste        |  |              | 1,521  |  |                 |  |    |          |  |  | 32     |  |  |  | 1,553  | 
|                |  |              |        |  |                 |  |     |          |  |  |        |  |  |  |        | 
|Total           |  |              | 27,919 |  |                 |  | 229 |          |  |  | 12,727 |  |  |  | 40,876 | 
|                |  |              |        |  |                 |  |     |          |  |  |        |  |  |  |        | 

Notes:



| | 1. | Hydrocarbon liquid volumes represent crude oil, condensate, gasoline and NGL estimated to be recovered during field separation and plant processing.
| | -- | ----------------------------------------------------------------------------------------------------------------------------------------------------



| | 2. | Totals may not exactly equal the sum of the individual entries because of rounding.
| | -- | -----------------------------------------------------------------------------------

Natural
Gas



|                |  |               |        |  |                  |  |   |           |  |  |        |  |  |  |        | 
|--------------- |  | ------------- | ------ |  | ---------------- |  | - | --------- |  |  | ------ |  |  |  | ------ | 
|                |  | Proved        |       
|Area            |  | Developed     |        |  | UndevelopedMMm3  |  |   | TotalMMm3 | 
|                |  | ProducingMMm3 |        |  | NonProducingMMm3 |  |   |          
|Cuyana          |  |               | 27     |  |                  |  | 0 |           |  |  | 3      |  |  |  | 30     | 
|Golfo San Jorge |  |               | 4,277  |  |                  |  |  |           |  |  | 1,371  |  |  |  | 5,648  | 
|Neuquina        |  |               | 17,498 |  |                  |  | 7 |           |  |  | 9,789  |  |  |  | 27,294 | 
|Noroeste        |  |               | 12,703 |  |                  |  |  |           |  |  | 184    |  |  |  | 12,886 | 
|                |  |               |        |  |                  |  |   |           |  |  |        |  |  |  |        | 
|Total           |  |               | 34,504 |  |                  |  | 8 |           |  |  | 11,347 |  |  |  | 45,859 | 
|                |  |               |        |  |                  |  |   |           |  |  |        |  |  |  |        | 

Notes:



| | 1. | Natural gas volumes represent expected gas sales plus produced gas used for consumption.
| | -- | ----------------------------------------------------------------------------------------



| | 2. | Totals may not exactly equal the sum of the individual entries because of rounding.
| | -- | -----------------------------------------------------------------------------------



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Appendix III

YPF Net Reserves per Basin



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Statement of Reserves Net to YPF per Basin

Certain Properties in Argentina

as of December 31, 2016

Liquid Hydrocarbon Volumes



|                |  |              |        |  |                 |  |     |          |  |  |        |  |  |  |        | 
|--------------- |  | ------------ | ------ |  | --------------- |  | --- | -------- |  |  | ------ |  |  |  | ------ | 
|                |  | Proved       |       
|Basin           |  | Developed    |        |  | UndevelopedMm3  |  |     | TotalMm3 | 
|                |  | ProducingMm3 |        |  | NonProducingMm3 |  |     |         
|Cuyana          |  |              | 2,411  |  |                 |  | 35  |          |  |  | 336    |  |  |  | 2,783  | 
|Golfo San Jorge |  |              | 19,331 |  |                 |  |    |          |  |  | 10,391 |  |  |  | 29,722 | 
|Neuquina        |  |              | 3,758  |  |                 |  | 194 |          |  |  | 1,855  |  |  |  | 5,807  | 
|Noroeste        |  |              | 552    |  |                 |  |    |          |  |  | 17     |  |  |  | 569    | 
|                |  |              |        |  |                 |  |     |          |  |  |        |  |  |  |        | 
|Total           |  |              | 26,052 |  |                 |  | 229 |          |  |  | 12,599 |  |  |  | 38,881 | 
|                |  |              |        |  |                 |  |     |          |  |  |        |  |  |  |        | 

Notes:



| | 1. | YPF Net Reserves represent YPFs working interest volumes and therefore include volumes related to royalties payable to the relevant Argentine provinces, which according to historical treatment and reporting in
YPFs 20-F filings with the SEC, are treated as financial obligations.
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| | 2. | Hydrocarbon liquid volumes represent crude oil, condensate, gasoline and NGL estimated to be recovered during field separation and plant processing.
| | -- | ----------------------------------------------------------------------------------------------------------------------------------------------------



| | 3. | Totals may not exactly equal the sum of the individual entries because of rounding.
| | -- | -----------------------------------------------------------------------------------



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Statement of YPF Net Reserves per Basin

Certain Properties in Argentina

as of December 31, 2016

Natural Gas



|                |  |               |        |  |                  |  |   |           |  |  |       |  |  |  |        | 
|--------------- |  | ------------- | ------ |  | ---------------- |  | - | --------- |  |  | ----- |  |  |  | ------ | 
|                |  | Proved        |       
|Area            |  | Developed     |        |  | UndevelopedMMm3  |  |   | TotalMMm3 | 
|                |  | ProducingMMm3 |        |  | NonProducingMMm3 |  |   |          
|Cuyana          |  |               | 27     |  |                  |  | 0 |           |  |  | 3     |  |  |  | 30     | 
|Golfo San Jorge |  |               | 4,267  |  |                  |  |  |           |  |  | 1,371 |  |  |  | 5,638  | 
|Neuquina        |  |               | 11,664 |  |                  |  | 7 |           |  |  | 5,572 |  |  |  | 17,243 | 
|Noroeste        |  |               | 4,519  |  |                  |  |  |           |  |  | 97    |  |  |  | 4,616  | 
|                |  |               |        |  |                  |  |   |           |  |  |       |  |  |  |        | 
|Total           |  |               | 20,477 |  |                  |  | 8 |           |  |  | 7,043 |  |  |  | 27,528 | 
|                |  |               |        |  |                  |  |   |           |  |  |       |  |  |  |        | 

Notes:



| | 1. | YPF Net Reserves represent YPFs working interest volumes and therefore include volumes related to royalties payable to the relevant Argentine provinces, which according to historical treatment and reporting in
YPFs 20-F filings with the SEC, are treated as financial obligations.
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| | 2. | Natural gas volumes represent expected gas sales plus produced gas used for consumption.
| | -- | ----------------------------------------------------------------------------------------



| | 3. | Totals may not exactly equal the sum of the individual entries because of rounding.
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Appendix IV

Hydrocarbon Prices



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Hydrocarbon Prices



|                                   |  |                                      |       |  |                   |  |      |              |  |  |       | 
|---------------------------------- |  | ------------------------------------ | ----- |  | ----------------- |  | ---- | ------------ |  |  | ----- | 
|Area                               |  | Crude OilCondensateGasoline(US$/Bbl) |       |  | NaturalGasUS$/Mcf |  |      | NGL(US$/Bbl) | 
|Acambuco                           |  |                                      | 62.97 |  |                   |  | 4.98 |              |  |  |      | 
|Aguaragüe                          |  |                                      | 62.97 |  |                   |  | 4.80 |              |  |  |      | 
|Ramos (PPE and YYE)                |  |                                      | 62.97 |  |                   |  | 4.80 |              |  |  |      | 
|San Antonio Sur                    |  |                                      | 62.97 |  |                   |  | 4.78 |              |  |  |      | 
|Lindero Atravesado                 |  |                                      | 65.13 |  |                   |  | 8.11 |              |  |  |      | 
|Manantiales Behr Norte             |  |                                      | 53.58 |  |                   |  | 5.40 |              |  |  |      | 
|Manantiales Behr Sur               |  |                                      | 53.58 |  |                   |  | 5.40 |              |  |  |      | 
|Restinga Alí                       |  |                                      | 53.58 |  |                   |  |     |              |  |  |      | 
|Río Mayo                           |  |                                      | 53.58 |  |                   |  |     |              |  |  |      | 
|Zona CentralBella Vista Este      |  |                                      | 53.58 |  |                   |  |     |              |  |  |      | 
|Sarmiento No Operada               |  |                                      | 53.58 |  |                   |  |     |              |  |  |      | 
|Barrancas                          |  |                                      | 54.68 |  |                   |  | 6.23 |              |  |  | 21.56 | 
|Cajón de los Caballos              |  |                                      |      |  |                   |  |     |              |  |  |      | 
|Cerro Fortunoso                    |  |                                      | 51.38 |  |                   |  |     |              |  |  |      | 
|El Manzano                         |  |                                      | 51.38 |  |                   |  |     |              |  |  |      | 
|Estructura Cruz de Piedra-Lunlunta |  |                                      | 54.68 |  |                   |  | 6.23 |              |  |  |      | 
|L.Carrizal                         |  |                                      | 54.68 |  |                   |  | 6.23 |              |  |  |      | 
|LV-Cañada Dura                     |  |                                      |      |  |                   |  |     |              |  |  |      | 
|Llancanelo R                       |  |                                      |      |  |                   |  |     |              |  |  |      | 
|Mesa Verde                         |  |                                      | 54.68 |  |                   |  |     |              |  |  |      | 
|Ugarteche                          |  |                                      | 54.68 |  |                   |  |     |              |  |  |      | 
|Altiplanicie del Payún             |  |                                      |      |  |                   |  |     |              |  |  |      | 
|Cerro Liupuca                      |  |                                      | 64.00 |  |                   |  |     |              |  |  |      | 
|Cerro Negro                        |  |                                      | 64.00 |  |                   |  |     |              |  |  |      | 
|Aguada de la Arena                 |  |                                      | 65.13 |  |                   |  | 7.35 |              |  |  |      | 
|La Ribera Bloque I                 |  |                                      |      |  |                   |  |     |              |  |  |      | 
|La Ribera Bloque II                |  |                                      |      |  |                   |  |     |              |  |  |      | 
|Las Tacanas                        |  |                                      |      |  |                   |  |     |              |  |  |      | 
|Pampa de las Yeguas Bloque I       |  |                                      | 65.13 |  |                   |  | 7.49 |              |  |  | 21.56 | 
|Aguada ToledoSierra Barrosa       |  |                                      | 65.13 |  |                   |  | 5.39 |              |  |  | 21.56 | 
|Río Neuquén                        |  |                                      | 64.55 |  |                   |  | 8.26 |              |  |  |      | 
|Barranca de los Loros              |  |                                      | 65.55 |  |                   |  |     |              |  |  |      | 
|Don Ruiz                           |  |                                      | 65.13 |  |                   |  |     |              |  |  |      | 
|Las Manadas                        |  |                                      | 65.55 |  |                   |  |     |              |  |  |      | 
|Loma Amarilla                      |  |                                      | 65.55 |  |                   |  |     |              |  |  |      | 
|Loma del Molle                     |  |                                      |      |  |                   |  |     |              |  |  |      | 
|Los Caldenes                       |  |                                      | 65.55 |  |                   |  | 2.68 |              |  |  |      | 
|Volcán Auca Mahuida                |  |                                      | 65.55 |  |                   |  |     |              |  |  |      | 
|Barranca Baya                      |  |                                      | 55.08 |  |                   |  | 5.23 |              |  |  |      | 
|Seco León                          |  |                                      | 55.08 |  |                   |  | 5.44 |              |  |  |      | 
|Barranca Yankowsky                 |  |                                      |      |  |                   |  |     |              |  |  |      | 
|Cañadón Yatel                      |  |                                      | 55.08 |  |                   |  | 5.23 |              |  |  |      | 
|Lomas del Cuy                      |  |                                      | 55.08 |  |                   |  | 5.23 |              |  |  |      | 
|Los Monos                          |  |                                      | 55.08 |  |                   |  |     |              |  |  |      | 
|Los Perales                        |  |                                      | 55.08 |  |                   |  | 5.23 |              |  |  |      | 
|Ojo de Agua                        |  |                                      |      |  |                   |  |     |              |  |  |      | 



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Appendix V

YPFs Participating Interest in Each Area



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| |  | 



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YPFs Participant Interest in each Area



|                             |  |        |     |  
|---------------------------- |  | ------ | --- | -
|Area                         |  | WI (%) |    
|MANANTIALES BEHR             |  |        | 100 | %
|RESTINGA ALI                 |  |        | 100 | %
|RIO MAYO                     |  |        | 100 | %
|SARMIENTO                    |  |        | 100 | %
|ZONA CENTRAL-BELLA V.ESTE    |  |        | 50  | %
|ACAMBUCO                     |  |        | 23  | %
|AGUARAGUE                    |  |        | 53  | %
|LINDERO ATRAVESADO           |  |        | 38  | %
|RAMOS (PLUSPETROL ENERGY)    |  |        | 23  | %
|RAMOS YPF (YPF + ASTRA)      |  |        | 28  | %
|SAN ANTONIO SUR              |  |        | 53  | %
|BARRANCAS                    |  |        | 100 | %
|CERRO FORTUNOSO              |  |        | 100 | %
|EST.CRUZ PIEDRA-LUNLUNTA     |  |        | 100 | %
|EL MANZANO 100%              |  |        | 100 | %
|EL MANZANO 60%               |  |        | 60  | %
|L.CARRIZAL                   |  |        | 100 | %
|MESA VERDE                   |  |        | 100 | %
|UGARTECHE                    |  |        | 100 | %
|CERRO LIUPUCA                |  |        | 100 | %
|CERRO NEGRO                  |  |        | 100 | %
|AGUADA DE LA ARENA           |  |        | 80  | %
|PAMPA DE LAS YEGUAS BLOQUE I |  |        | 50  | %
|AGUADA TOLEDO-SIERRA BARROSA |  |        | 100 | %
|RÍO NEUQUÉN                  |  |        | 33  | %
|BARRANCA DE LOS LOROS        |  |        | 100 | %
|DON RUIZ                     |  |        | 100 | %
|LOMA AMARILLA                |  |        | 100 | %
|LOS CALDENES                 |  |        | 100 | %
|LAS MANADAS                  |  |        | 100 | %
|VOLCAN AUCA MAHUIDA          |  |        | 100 | %
|BARRANCA BAYA                |  |        | 100 | %
|CAÑADON YATEL                |  |        | 100 | %
|LOMAS DEL CUY                |  |        | 100 | %
|LOS MONOS                    |  |        | 100 | %
|LOS PERALES                  |  |        | 100 | %
|SECO LEON                    |  |        | 100 | %
|CAJON DE LOS CABALLOS        |  |        | 60  | %
|LV-CAÑADA DURA               |  |        | 70  | %
|LLANCANELO R                 |  |        | 100 | %
|ALTIPLANICIE DEL PAYUN       |  |        | 100 | %
|CERRO PARTIDO*               |  |        | 0   | %
|LA RIBERA BLOQUE I           |  |        | 100 | %
|LA RIBERA BLOQUE II          |  |        | 100 | %
|LAS TACANAS                  |  |        | 50  | %
|MATA MORA*                   |  |        | 0   | %
|LOMA DEL MOLLE               |  |        | 50  | %
|BARRANCA YANKOWSKY           |  |        | 98  | %
|CERRO AVISPA*                |  |        | 0   | %

Notes:

The
YPFs interest participation in the mentioned areas below, were transferred during 2016 to the following companies:



| | 1. | Working Interest in Palmar Largo was transferred to HIGH LUCK GROUP LTD SUC ARG
| | -- | -------------------------------------------------------------------------------



| | 2. | The YPFs participation in Corralera, Cerro Partido, Mata Mora and Cerro Avispa areas were transferred to GAS Y PETROLEO DEL NEUQUEN S.A.
| | -- | -----------------------------------------------------------------------------------------------------------------------------------------



| |  | 
| |  | 
| |  | 



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Appendix VI

SEC Reserves Definitions



18



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U.S. SECURITIES AND EXCHANGE COMMISSION (SEC)

MODERNIZATION OF OIL AND GAS REPORTING1

Oil and Gas Reserves Definitions and Reporting

(a)    Definitions

(1)
Acquisition of properties. Costs incurred to purchase, lease or otherwise acquire a property, including costs of lease bonuses and options to purchase or lease properties, the portion of costs applicable to minerals when land including
mineral rights is purchased in fee, brokers fees, recording fees, legal costs, and other costs incurred in acquiring properties.

(2) Analogous
reservoir. Analogous reservoirs, as used in resources assessments, have similar rock and fluid properties, reservoir conditions (depth, temperature, and pressure) and drive mechanisms, but are typically at a more advanced stage of development
than the reservoir of interest and thus may provide concepts to assist in the interpretation of more limited data and estimation of recovery. When used to support proved reserves, an analogous reservoir refers to a reservoir that shares
the following characteristics with the reservoir of interest:



| | (i) | Same geological formation (but not necessarily in pressure communication with the reservoir of interest);
| | --- | ---------------------------------------------------------------------------------------------------------



| | (ii) | Same environment of deposition;
| | ---- | -------------------------------



| | (iii) | Similar geological structure; and
| | ----- | ---------------------------------



| | (iv) | Same drive mechanism.
| | ---- | ---------------------

Instruction to paragraph (a)(2): Reservoir properties must, in
the aggregate, be no more favorable in the analog than in the reservoir of interest.

(3) Bitumen. Bitumen, sometimes referred to as natural
bitumen, is petroleum in a solid or semi-solid state in natural deposits with a viscosity greater than 10,000 centipoise measured at original temperature in the deposit and atmospheric pressure, on a gas free basis. In its natural state it usually
contains sulfur, metals, and other non-hydrocarbons.

(4) Condensate. Condensate is a mixture of
hydrocarbons that exists in the gaseous phase at original reservoir temperature and pressure, but that, when produced, is in the liquid phase at surface pressure and temperature.

(5) Deterministic estimate. The method of estimating reserves or resources is called deterministic when a single value for each parameter (from the
geoscience, engineering, or economic data) in the reserves calculation is used in the reserves estimation procedure.

(6) Developed oil and gas
reserves. Developed oil and gas reserves are reserves of any category that can be expected to be recovered:



| | (i) | Through existing wells with existing equipment and operating methods or in which the cost of the required equipment is relatively minor compared to the cost of a new well; and
| | --- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------



| | (ii) | Through installed extraction equipment and infrastructure operational at the time of the reserves estimate if the extraction is by means not involving a well.
| | ---- | --------------------------------------------------------------------------------------------------------------------------------------------------------------

(7) Development costs.Costs incurred to obtain access to proved reserves and to provide facilities for extracting, treating, gathering and storing the
oil and gas. More specifically, development costs, including depreciation and applicable operating costs of support equipment and facilities and other costs of development activities, are costs incurred to:



|1 | Extracted from 17 CFR Parts 210, 211, 229, and 249 [Release Nos. 33-8995; 34-59192; FR-78; File No.
S7-15-08] RIN 3235-AK00].
|- | -----------------------------------------------------------------------------------------------------------------------------



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| | (i) | Gain access to and prepare well locations for drilling, including surveying well locations for the purpose of determining specific development drilling sites, clearing ground, draining, road building, and relocating
public roads, gas lines, and power lines, to the extent necessary in developing the proved reserves.
| | --- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------



| | (ii) | Drill and equip development wells, development-type stratigraphic test wells, and service wells, including the costs of platforms and of well equipment such as casing, tubing, pumping equipment, and the wellhead
assembly.
| | ---- | -----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------



| | (iii) | Acquire, construct, and install production facilities such as lease flow lines, separators, treaters, heaters, manifolds, measuring devices, and production storage tanks, natural gas cycling and processing plants, and
central utility and waste disposal systems.
| | ----- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------



| | (iv) | Provide improved recovery systems.
| | ---- | ----------------------------------

(8) Development project. A development project is the means by
which petroleum resources are brought to the status of economically producible. As examples, the development of a single reservoir or field, an incremental development in a producing field, or the integrated development of a group of several fields
and associated facilities with a common ownership may constitute a development project.

(9) Development well. A well drilled within the proved
area of an oil or gas reservoir to the depth of a stratigraphic horizon known to be productive.

(10) Economically producible. The term
economically producible, as it relates to a resource, means a resource which generates revenue that exceeds, or is reasonably expected to exceed, the costs of the operation. The value of the products that generate revenue shall be determined at the
terminal point of oil and gas producing activities as defined in paragraph (a)(16) of this section.

(11) Estimated ultimate recovery (EUR).
Estimated ultimate recovery is the sum of reserves remaining as of a given date and cumulative production as of that date.

(12) Exploration costs.
Costs incurred in identifying areas that may warrant examination and in examining specific areas that are considered to have prospects of containing oil and gas reserves, including costs of drilling exploratory wells and exploratory-type
stratigraphic test wells. Exploration costs may be incurred both before acquiring the related property (sometimes referred to in pail as prospecting costs) and after acquiring the property. Principal types of exploration costs, which include
depreciation and applicable operating costs of support equipment and facilities and other costs of exploration activities, are:



| | (i) | Costs of topographical, geographical and geophysical studies, rights of access to properties to conduct those studies, and salaries and other expenses of geologists, geophysical crews, and others conducting those
studies. Collectively, these are sometimes referred to as geological and geophysical or G&G costs.
| | --- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------



| | (ii) | Costs of carrying and retaining undeveloped properties, such as delay rentals, ad valorem taxes on properties, legal costs for title defense, and the maintenance of land and lease records.
| | ---- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------



| | (iii) | Dry hole contributions and bottom hole contributions.
| | ----- | -----------------------------------------------------



| | (iv) | Costs of drilling and equipping exploratory wells.
| | ---- | --------------------------------------------------



| | (v) | Costs of drilling exploratory-type stratigraphic test wells.
| | --- | ------------------------------------------------------------



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(13) Exploratory well. An exploratory well is a well drilled to find a new field or to find a new reservoir in a
field previously found to be productive of oil or gas in another reservoir. Generally, an exploratory well is any well that is not a development well, an extension well, a service well, or a stratigraphic test well as those items are defined in this
section.

(14) Extension well. An extension well is a well drilled to extend the limits of a known reservoir.

(15) Field. An area consisting of a single reservoir or multiple reservoirs all grouped on or related to the same individual geological structural
feature and/or stratigraphic condition. There may be two or more reservoirs in a field which are separated vertically by intervening impervious strata, or laterally by local geologic barriers, or by both. Reservoirs that are associated by being in
overlapping or adjacent fields may be treated as a single or common operational field. The geological terms structural feature and stratigraphic condition are intended to identify localized geological features as opposed to
the broader terms of basins, trends, provinces, plays, areas-of-interest, etc.

(16) Oil and gas producing activities.



| | (i) | Oil and gas producing activities include:
| | --- | -----------------------------------------



| | (A) | The search for crude oil, including condensate and natural gas liquids, or natural gas (oil and gas) in their natural states and original locations;
| | --- | ------------------------------------------------------------------------------------------------------------------------------------------------------



| | (B) | The acquisition of property rights or properties for the purpose of further exploration or for the purpose of removing the oil or gas from such properties;
| | --- | -----------------------------------------------------------------------------------------------------------------------------------------------------------



| | (C) | The construction, drilling, and production activities necessary to retrieve oil and gas from their natural reservoirs, including the acquisition, construction, installation, and maintenance of field gathering and
storage systems, such as:
| | --- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------



| | (1) | Lifting the oil and gas to the surface; and
| | --- | -------------------------------------------



| | (2) | Gathering, treating, and field processing (as in the case of processing gas to extract liquid hydrocarbons); and
| | --- | ----------------------------------------------------------------------------------------------------------------



| | (D) | Extraction of saleable hydrocarbons, in the solid, liquid, or gaseous state, from oil sands, shale, coalbeds, or other nonrenewable natural resources which are intended to be upgraded into synthetic oil or gas, and
activities undertaken with a view to such extraction.
| | --- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

Instruction 1 to paragraph (a)(16)(i): The oil and gas
production function shall be regarded as ending at a terminal point, which is the outlet valve on the lease or field storage tank. If unusual physical or operational circumstances exist, it may be appropriate to regard the terminal point
for the production function as:



| | a. | The first point at which oil, gas, or gas liquids, natural or synthetic, are delivered to a main pipeline, a common carrier, a refinery, or a marine terminal; and
| | -- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------



| | b. | In the case of natural resources that are intended to be upgraded into synthetic oil or gas, if those natural resources are delivered to a purchaser prior to upgrading, the first point at which the natural resources are
delivered to a main pipeline, a common carrier, a refinery, a marine terminal, or a facility which upgrades such natural resources into synthetic oil or gas.
| | -- | -----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

Instruction 2 to paragraph (a)(16)(i): For purposes of this paragraph (a)(16), the term saleable hydrocarbons means hydrocarbons
that are saleable in the state in which the hydrocarbons are delivered.



| | (ii) | Oil and gas producing activities do not include:
| | ---- | ------------------------------------------------



| | (A) | Transporting, refining, or marketing oil and gas;
| | --- | -------------------------------------------------



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| | (B) | Processing of produced oil, gas or natural resources that can be upgraded into synthetic oil or gas by a registrant that does not have the legal right to produce or a revenue interest in such production;
| | --- | -----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------



| | (C) | Activities relating to the production of natural resources other than oil, gas, or natural resources from which synthetic oil and gas can be extracted; or
| | --- | ----------------------------------------------------------------------------------------------------------------------------------------------------------



| | (D) | Production of geothermal steam.
| | --- | -------------------------------



|(17) | Possible reserves. Possible reserves are those additional reserves that are less certain to be recovered than probable reserves.
|---- | --------------------------------------------------------------------------------------------------------------------------------



| | (i) | When deterministic methods are used, the total quantities ultimately recovered from a project have a low probability of exceeding proved plus probable plus possible reserves. When probabilistic methods are used, there
should be at least a 10% probability that the total quantities ultimately recovered will equal or exceed the proved plus probable plus possible reserves estimates.
| | --- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------



| | (ii) | Possible reserves may be assigned to areas of a reservoir adjacent to probable reserves where data control and interpretations of available data are progressively less certain. Frequently, this will be in areas where
geoscience and engineering data are unable to define clearly the area and vertical limits of commercial production from the reservoir by a defined project.
| | ---- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------



| | (iii) | Possible reserves also include incremental quantities associated with a greater percentage recovery of the hydrocarbons in place than the recovery quantities assumed for probable reserves.
| | ----- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------



| | (iv) | The proved plus probable and proved plus probable plus possible reserves estimates must be based on reasonable alternative technical and commercial interpretations within the reservoir or subject project that are
clearly documented, including comparisons to results in successful similar projects.
| | ---- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------



| | (v) | Possible reserves may be assigned where geoscience and engineering data identify directly adjacent portions of a reservoir within the same accumulation that may be separated from proved areas by faults with displacement
less than formation thickness or other geological discontinuities and that have not been penetrated by a wellbore, and the registrant believes that such adjacent portions are in communication with the known (proved) reservoir. Possible reserves may
be assigned to areas that are structurally higher or lower than the proved area if these areas are in communication with the proved reservoir.
| | --- | -----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------



| | (vi) | Pursuant to paragraph (a)(22)(iii) of this section, where direct observation has defined a highest known oil (HKO) elevation and the potential exists for an associated gas cap, proved oil reserves should be assigned in
the structurally higher portions of the reservoir above the HKO only if the higher contact can be established with reasonable certainty through reliable technology. Portions of the reservoir that do not meet this reasonable certainty criterion may
be assigned as probable and possible oil or gas based on reservoir fluid properties and pressure gradient interpretations.
| | ---- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

(18)    Probable reserves. Probable reserves are those additional reserves that are less certain to be recovered than proved
reserves but which, together with proved reserves, are as likely as not to be recovered.



| | (i) | When deterministic methods are used, it is as likely as not that actual remaining quantities recovered will exceed the sum of estimated proved plus probable reserves. When probabilistic methods are used, there should be
at least a 50% probability that the actual quantities recovered will equal or exceed the proved plus probable reserves estimates.
| | --- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------



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| | (ii) | Probable reserves may be assigned to areas of a reservoir adjacent to proved reserves where data control or interpretations of available data are less certain, even if the interpreted reservoir continuity of structure
or productivity does not meet the reasonable certainty criterion. Probable reserves may be assigned to areas that are structurally higher than the proved area if these areas are in communication with the proved reservoir.
| | ---- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------



| | (iii) | Probable reserves estimates also include potential incremental quantities associated with a greater percentage recovery of the hydrocarbons in place than assumed for proved reserves.
| | ----- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------



| | (iv) | See also guidelines in paragraphs (a)(17)(iv) and (a)(17)(vi) of this section.
| | ---- | ------------------------------------------------------------------------------

(19) Probabilistic
estimate. The method of estimation of reserves or resources is called probabilistic when the full range of values that could reasonably occur for each unknown parameter (from the geoscience and engineering data) is used to generate a full range
of possible outcomes and their associated probabilities of occurrence.



|(20) | Production costs.
|---- | -----------------



| | (i) | Costs incurred to operate and maintain wells and related equipment and facilities, including depreciation and applicable operating costs of support equipment and facilities and other costs of operating and maintaining
those wells and related equipment and facilities, they become part of the cost of oil and gas produced. Examples of production costs (sometimes called lifting costs) are:
| | --- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------



| | (A) | Costs of labor to operate the wells and related equipment and facilities.
| | --- | -------------------------------------------------------------------------



| | (B) | Repairs and maintenance.
| | --- | ------------------------



| | (C) | Materials, supplies, arid fuel consumed and supplies utilized in operating the wells and related equipment and facilities.
| | --- | --------------------------------------------------------------------------------------------------------------------------



| | (D) | Property taxes and insurance applicable to proved properties and wells and related equipment and facilities.
| | --- | ------------------------------------------------------------------------------------------------------------



| | (E) | Severance taxes.
| | --- | ----------------



| | (ii) | Some support equipment or facilities may serve two or more oil and gas producing activities and may also serve transportation, refining, and marketing activities. To the extent that the support equipment and facilities
are used in oil and gas producing activities, their depreciation and applicable operating costs become exploration, development or production costs, as appropriate. Depreciation, depletion, and amortization of capitalized acquisition, exploration,
and development costs are not production costs but also become part of the cost of oil and gas produced along with production (lifting) costs identified above.
| | ---- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------



|(21) | Proved area. The part of a property to which proved reserves have been specifically attributed.
|---- | -----------------------------------------------------------------------------------------------

(22)
Proved oil and gas reserves. Proved oil and gas reserves are those quantities of oil and gas, which, by analysis of geoscience and engineering data, can be estimated with reasonable certainty to be economically produciblefrom a given
date forward, from known reservoirs, and under existing economic conditions, operating methods, and government regulationsprior to the time at which contracts providing the right to operate expire, unless evidence indicates that renewal is
reasonably certain, regardless of whether deterministic or probabilistic methods are used for the estimation. The project to extract the hydrocarbons must have commenced or the operator must be reasonably certain that it will commence the project
within a reasonable time.



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| | (i) | The area of the reservoir considered as proved includes:
| | --- | --------------------------------------------------------



| | (A) | The area identified by drilling and limited by fluid contacts, if any, and
| | --- | --------------------------------------------------------------------------



| | (B) | Adjacent undrilled portions of the reservoir that can, with reasonable certainty, be judged to be continuous with it and to contain economically producible oil or gas on the basis of available geoscience and engineering
data.
| | --- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------



| | (ii) | In the absence of data on fluid contacts, proved quantities in a reservoir are limited by the lowest known hydrocarbons (LKH) as seen in a well penetration unless geoscience, engineering, or performance data and
reliable technology establishes a lower contact with reasonable certainty.
| | ---- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------



| | (iii) | Where direct observation from well penetrations has defined a highest known oil (HKO) elevation and the potential exists for an associated gas cap, proved oil reserves may be assigned in the structurally higher portions
of the reservoir only if geoscience, engineering, or performance data and reliable technology establish the higher contact with reasonable certainty.
| | ----- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------



| | (iv) | Reserves which can be produced economically through application of improved recovery techniques (including, but not limited to, fluid injection) are included in the proved classification when:
| | ---- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------



| | (A) | Successful testing by a pilot project in an area of the reservoir with properties no more favorable than in the reservoir as a whole, the operation of an installed program in the reservoir or an analogous reservoir, or
other evidence using reliable technology establishes the reasonable certainty of the engineering analysis on which the project or program was based; and
| | --- | -----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------



| | (B) | The project has been approved for development by all necessary parties and entities, including governmental entities.
| | --- | ---------------------------------------------------------------------------------------------------------------------



| | (v) | Existing economic conditions include prices and costs at which economic producibility from a reservoir is to be determined. The price shall be the average price during the
12-month period prior to the ending date of the period covered by the report, determined as an unweighted arithmetic average of the first-day-of-the-month price for each month within such period, unless prices are defined by contractual arrangements, excluding escalations based upon future
conditions.
| | --- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

(23) Proved properties. Properties with proved reserves.

(24) Reasonable certainty. If deterministic methods are used, reasonable certainty means a high degree of confidence that the quantities will be
recovered. If probabilistic methods are used, there should be at least a 90% probability that the quantities actually recovered will equal or exceed the estimate. A high degree of confidence exists if the quantity is much more likely to be achieved
than not, and, as changes due to increased availability of geoscience (geological, geophysical, and geochemical), engineering, and economic data are made to estimated ultimate recovery (EUR) with time, reasonably certain EUR is much more likely to
increase or remain constant than to decrease.

(25) Reliable technology. Reliable technology is a grouping of one or more technologies (including
computational methods) that has been field tested and has been demonstrated to provide reasonably certain results with consistency and repeatability in the formation being evaluated or in an analogous formation.





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(26) Reserves. Reserves are estimated remaining quantities of oil and gas and related substances anticipated to be
economically producible, as of a given date, by application of development projects to known accumulations. In addition, there must exist, or there must be a reasonable expectation that there will exist, the legal right to produce or a revenue
interest in the production, installed means of delivering oil and gas or related substances to market, and all permits and financing required to implement the project.

Note to paragraph (a)(26): Reserves should not be assigned to adjacent reservoirs isolated by major, potentially sealing, faults until
those reservoirs are penetrated and evaluated as economically producible. Reserves should not be assigned to areas that are clearly separated from a known accumulation by a non-productive reservoir
(i.e., absence of reservoir, structurally low reservoir, or negative test results). Such areas may contain prospective resources (i.e., potentially recoverable resources from undiscovered accumulations).

(27) Reservoir. A porous and permeable underground formation containing a natural accumulation of producible oil and/or gas that is confined by
impermeable rock or water barriers and is individual and separate from other reservoirs.

(28) Resources. Resources are quantities of oil and gas
estimated to exist in naturally occurring accumulations. A portion of the resources may be estimated to be recoverable, and another portion may be considered to be unrecoverable. Resources include both discovered and undiscovered accumulations.

(29) Service well. A well drilled or completed for the purpose of supporting production in an existing field. Specific purposes of service wells
include gas injection, water injection, steam injection, air injection, salt-water disposal, water supply for injection, observation, or injection for in-situ combustion.

(30) Stratigraphic test well. A stratigraphic test well is a drilling effort, geologically directed, to obtain information pertaining to a specific
geologic condition. Such wells customarily are drilled without the intent of being completed for hydrocarbon production. The classification also includes tests identified as core tests and all types of expendable holes related to hydrocarbon
exploration. Stratigraphic tests are classified as exploratory type if not drilled in a known area or development type if drilled in a known area.

(31) Undeveloped oil and gas reserves. Undeveloped oil and gas reserves are reserves of any category that are expected to be recovered from new wells
on undrilled acreage, or from existing wells where a relatively major expenditure is required for recompletion.



| | (i) | Reserves on undrilled acreage shall be limited to those directly offsetting development spacing areas that are reasonably certain of production when drilled, unless evidence using reliable technology exists that
establishes reasonable certainty of economic producibility at greater distances.
| | --- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------



| | (ii) | Undrilled locations can be classified as having undeveloped reserves only if a development plan has been adopted indicating that they are scheduled to be drilled within five years, unless the specific circumstances,
justify a longer time.
| | ---- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------



| | (iii) | Under no circumstances shall estimates for undeveloped reserves be attributable to any acreage for which an application of fluid injection or other improved recovery technique is contemplated, unless such techniques
have been proved effective by actual projects in the same reservoir or an analogous reservoir, as defined in paragraph (a)(2) of this section, or by other evidence using reliable technology establishing reasonable certainty.
| | ----- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

(32) Unproved properties. Properties with no proved reserves.



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Appendix VII

Glossary



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|-------------------------------------------------------- |  | ----
|Glossary  Standard Oil Industry Terms and Abbreviations |  | LOGO



%

Percentage1H05

First half (6 months) of 2005 (example)2Q06

Second quarter (3 months) of 2006 (example)2D

Two dimensional3D

Three dimensional4D

Four dimensional1P

Proved Reserves2P

Proved plus Probable Reserves3P

Proved plus Probable plus Possible ReservesABEX

Abandonment ExpenditureACQ

Annual Contract QuantityoAPI

Degrees API (American Petroleum Institute)AAPG

American Association of Petroleum GeologistsAVO

Amplitude versus OffsetA$

Australian DollarsB

Billion (109)Bbl

Barrels/Bbl

per barrelBBbl

Billion BarrelsBHA

Bottom Hole AssemblyBHC

Bottom Hole CompensatedBscf or Bcf

Billion standard cubic feetBscfd or Bcfd

Billion standard cubic feet per dayBm3

Billion cubic metresbcpd

Barrels of condensate per dayBHP

Bottom Hole Pressureblpd

Barrels of liquid per day


bpd

Barrels per dayboe

Barrels of oil equivalent @ xxx mcf/Bblboepd

Barrels of oil equivalent per day @ xxx mcf/BblBOP

Blow Out Preventerbopd

Barrels oil per daybwpd

Barrels of water per dayBS&W

Bottom sediment and waterBTU

British Thermal Unitsbwpd

Barrels water per dayCBM

Coal Bed MethaneCO2

Carbon DioxideCAPEX

Capital ExpenditureCCGT

Combined Cycle Gas Turbinecm

centimetresCMM

Coal Mine MethaneCNG

Compressed Natural GasCp

Centipoise (a measure of viscosity)CSG

Coal Seam GasCT

Corporation TaxD1BM

Design 1 Build ManyDCQ

Daily Contract QuantityDeg C

Degrees CelsiusDeg F

Degrees FahrenheitDHI

Direct Hydrocarbon IndicatorDLIS

Digital Log Interchange StandardDST

Drill Stem TestDWT

Dead-weight tonE&A

Exploration & Appraisal






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|-------------------------------------------------------- |  | ----
|Glossary  Standard Oil Industry Terms and Abbreviations |  | LOGO



E&P

Exploration and ProductionEBIT

Earnings before Interest and TaxEBITDA

Earnings before interest, tax, depreciation and amortisationECS

Elemental Capture SpectroscopyEI

Entitlement InterestEIA

Environmental Impact AssessmentELT

Economic Limit TestEMV

Expected Monetary ValueEOR

Enhanced Oil RecoveryEUR

Estimated Ultimate RecoveryFDP

Field Development PlanFEED

Front End Engineering and DesignFPSO

Floating Production Storage and OffloadingFSO

Floating Storage and OffloadingFWL

Free Water Levelft

Foot/feetFx

Foreign Exchange Rateg

gramg/cc

grams per cubic centimetregal

gallongal/d

gallons per dayG&A

General and Administrative costsGBP

Pounds SterlingGCoS

Geological Chance of SuccessGDT

Gas Down toGIIP

Gas Initially In PlaceGJ

Gigajoules (one billion Joules)GOC

Gas Oil ContactGOR

Gas Oil Ratio


GRV

Gross Rock VolumesGTL

Gas to LiquidsGWC

Gas water contactHDT

Hydrocarbons Down toHSE

Health, Safety and EnvironmentHSFO

High Sulphur Fuel OilHUT

Hydrocarbons up toH2S

Hydrogen SulphideIOR

Improved Oil RecoveryIPP

Independent Power ProducerIRR

Internal Rate of ReturnJ

Joule (Metric measurement of energy) I kilojoule = 0.9478 BTU)k

PermeabilityKB

Kelly BushingKJ

Kilojoules (one Thousand Joules)kl

Kilolitreskm

Kilometreskm2

Square kilometreskPa

Thousands of Pascals (measurement of pressure)KW

KilowattKWh

Kilowatt hourLAS

Log ASCII StandardLKG

Lowest Known GasLKH

Lowest Known HydrocarbonsLKO

Lowest Known OilLNG

Liquefied Natural GasLoF

Life of FieldLPG

Liquefied Petroleum GasLTI

Lost Time Injury






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|-------------------------------------------------------- |  | ----
|Glossary  Standard Oil Industry Terms and Abbreviations |  | LOGO



LWD

Logging while drillingm

MetresM

Thousandm3

Cubic metresMcf or Mscf

Thousand standard cubic feetMCM

Management Committee MeetingMMcf or MMscf

Million standard cubic feetm3/d

Cubic metres per daymD

Measure of Permeability in millidarciesMD

Measured DepthMDT

Modular Dynamic TesterMean

Arithmetic average of a set of numbersMedian

Middle value in a set of valuesMFT

Multi Formation Testermg/l

milligrams per litreMJ

Megajoules (One Million Joules)Mm3

Thousand Cubic metresMm3/d

Thousand Cubic metres per dayMM

MillionMMm3

Million Cubic metresMMm3/d

Million Cubic metres per dayMMBbl

Millions of barrelsMMBTU

Millions of British Thermal UnitsMode

Value that exists most frequently in a set of values = most likelyMscfd

Thousand standard cubic feet per dayMMscfd

Million standard cubic feet per dayMW

Megawatt


MWD

Measuring While DrillingMWh

Megawatt hourmya

Million years agoNGL

Natural Gas LiquidsN2

NitrogenNTG

Net/Gross RatioNPV

Net Present ValueOBM

Oil Based MudOCM

Operating Committee MeetingODT

Oil-Down-ToOGIP

Original Gas in PlaceOIIP

Oil Initially In PlaceOOIP

Original Oil in PlaceOPEX

Operating ExpenditureOWC

Oil Water Contactp.a.

Per annumPa

Pascals (metric measurement of pressure)P&A

Plugged and AbandonedPDP

Proved Developed ProducingPhie

effective porosityPI

Productivity IndexPIIP

Petroleum Initially In PlacePJ

Petajoules (1015Joules)PSDM

Post Stack Depth Migrationpsi

Pounds per square inchpsia

Pounds per square inch absolutepsig

Pounds per square inch gaugePUD

Proved UndevelopedPVT

Pressure, Volume and Temperature






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|Glossary  Standard Oil Industry Terms and Abbreviations |  | LOGO



P10

10% ProbabilityP50

50% ProbabilityP90

90% ProbabilityRF

Recovery factorRFT

Repeat Formation TesterRT

Rotary TableR/P

Reserve to ProductionRw

Resistivity of waterSCAL

Special core analysiscf or scf

Standard Cubic Feetcfd or scfd

Standard Cubic Feet per dayscf/ton

Standard cubic foot per tonSL

Straight line (for depreciation)so

Oil SaturationSPM

Single Point MooringSPE

Society of Petroleum EngineersSPEE

Society of Petroleum Evaluation EngineersSPS

Subsea Production SystemSS

Subseastb

Stock tank barrelSTOIIP

Stock tank oil initially in placeSwi

irreducible water saturationsw

Water SaturationT

TonnesTD

Total DepthTe

Tonnes equivalentTHP

Tubing Head PressureTJ

Terajoules (1012Joules)Tscf or Tcf

Trillion standard cubic feet


TCM

Technical Committee MeetingTOC

Total Organic CarbonTOP

Take or PayTpd

Tonnes per dayTVD

True Vertical DepthTVDss

True Vertical Depth SubseaUFR

Umbilical Flow Lines and RisersUSGS

United States Geological SurveyUS$

United States dollarVLCC

Very Large Crude CarrierVsh

shale volumeVSP

Vertical Seismic ProfilingWC

Water CutWI

Working InterestWPC

World Petroleum CouncilWTI

West Texas Intermediatewt%

Weight percent






30