Exhibit 99.5

REPSOL YPF

Audit Opinion of

Estimated Future Reserves Attributable to

Certain Properties in the Caribbean and South America

SEC Parameters



|                                               |  |                              |  | 
|---------------------------------------------- |  | ---------------------------- |  | 
|                                               |  | /s/ Herman G. Acuña          |  | 
|                                               |  | Herman G. Acuña, P.E.        |  | 
|                                               |  | TBPE License No. 92254       |  | 
|Managing Senior Vice President  International
|                                               |  |                             
|                                               |  | RYDER SCOTT COMPANY, L.P.    |  | 
|                                               |  | TBPE Firm License No. F-1580 |  | 

LOGO

RYDER SCOTT COMPANY    PETROLEUM CONSULTANTS



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LOGO

March 24, 2010

Repsol YPF

Mr. Aquiles Rattia Regalado

Director of Reserves Control

Paseo
de La Castellana, 278-280

28046 Madrid

España

Dear Mr. Rattia Regalado:

At your request, Ryder Scott Company has prepared an estimate of the proved reserves, future production and income
attributable to certain properties of Repsol YPF, as of September 30, 2009 and December 31, 2009, as applicable. The subject properties are located in the Caribbean and South America.

The reserves and income data were estimated based on the definitions and disclosure guidelines contained in the United States Securities
and Exchange Commission Title 17, Code of Federal Regulations, Modernization of Oil and Gas Reporting, Final Rule released January 14, 2009 in the Federal Register (SEC regulations). The conclusions of our third party studies, completed on
February 16, 2009, are discussed herein.

The conclusions discussed in this report are related to hydrocarbon prices. The
hydrocarbon prices used in the preparation of this report are based on the average prices during the 12-month period prior to the ending date of the period covered in this report, determined as unweighted arithmetic averages of the prices in effect
on the first-day-of-the-month for each month within such period, unless prices were defined by contractual arrangements as required by the SEC regulations. Actual future prices may vary significantly from the prices required by SEC regulations;
therefore, the conclusions of our third party study may differ significantly from the discussion below.

Repsol YPF has
elected to represent that Ryder Scott Company conducted these third party independent estimations; accordingly, Ryder Scott Company has prepared this report for inclusion as an exhibit to the relevant registration statement or other Commission
filings by Repsol YPF.

Scope of Third Party Independent Audit

At the request of Repsol YPF, Ryder Scott Company conducted an independent estimation of the reserves, future production and income
associated with certain assets in which Repsol YPF owns an interest. Ryder Scott Company was provided with both interpreted and uninterpreted data. Based on this information, Ryder Scott Company conducted the necessary studies to estimate and audit
the proved reserves to render the opinions expressed herein conforming with our understanding of the definition as set forth in the Securities and Exchange Commissions Regulations Part 210.4-10 (a). An abridged version of the SEC reserves
definitions from 210.4-10(a) entitled Petroleum Reserves Definitions is included as an attachment to this report. Furthermore, Repsol YPF has requested that we compare the proved reserves independently evaluated by us to the reserves
prepared by Repsol YPF according to the SEC regulations to fulfill the scope of the audit.



RYDER SCOTT COMPANY    PETROLEUM CONSULTANTS



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Repsol YPF

March 24, 2010

Page 2



During our investigations, no attempt was made to quantify or otherwise account for any
accumulated gas production imbalances that may exist. Repsol YPF does not include fuel gas in their estimation of net reserves; therefore, our conclusions herein are exclusive of these volumes.

While it may reasonably be anticipated that the future prices received for the sale of production and the operating costs and other costs
relating to such production may also increase or decrease from existing levels, such changes were, in accordance with rules adopted by the SEC, omitted from consideration in making this evaluation.

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. However, most of the parameters that define the reserves of a reservoir cannot be measured directly, and must be estimated indirectly through geologic and reservoir
engineering analysis and interpretations. Moreover, estimates of reserves may increase or decrease as a result of future operations, effects of regulation by governmental agencies or geopolitical risks. As a result, the estimates of oil and gas
reserves have an intrinsic uncertainty. The reserves included in this report are therefore estimates only and should not be construed as being exact quantities. They may or may not be actually recovered, and if recovered, the revenues therefrom and
the actual costs related thereto could be more or less than the estimated amounts.

The conclusion reported herein are limited
to the period prior to expiration of current contracts providing the legal right to produce or a revenue interest in such production unless evidence indicates that contract renewal is reasonably certain. Furthermore, properties in the different
countries may be subjected to significantly varying contractual fiscal terms that affect the net revenue to Repsol YPF for the production of these volumes. The prices and economic return received for these net volumes can vary significantly based on
the terms of these contracts. Therefore, when applicable, Ryder Scott reviewed the fiscal terms of such contracts and discussed with Repsol YPF the net economic benefit attributed to such operations for the determination of the net hydrocarbon
volumes and income thereof. Ryder Scott has not conducted an exhaustive audit or verification of such contractual information. Neither our review of such contractual information or our acceptance of Repsol YPFs representations regarding such
contractual information should be construed as a legal or accounting opinion on this matter.

Ryder Scott did not evaluate
country and geopolitical risks in the countries where Repsol YPF operates or has interests. Repsol YPFs operations may be subject to various levels of governmental controls and regulations. These controls and regulations may include matters
relating to land tenure, drilling, production practices, environmental protection, marketing and pricing policies, royalties, various taxes and levies including income tax, and foreign trade and investment and are subject to change from time to
time. Such changes in governmental regulations and policies may cause volumes of reserves actually recovered and amounts of income actually received to differ significantly from the estimated quantities.

The conclusions presented herein were based upon a detailed study of the properties in which Repsol YPF owns an interest; however, we
have not made any field examination of the properties. No consideration was given in this report to potential environmental liabilities that may exist nor were any costs included for potential liability to restore and clean up damages, if any,
caused by past operating practices.



RYDER SCOTT COMPANY    PETROLEUM CONSULTANTS



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Repsol YPF

March 24, 2010

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The properties reviewed by Ryder Scott Company are located in the Caribbean and South
America and do not represent the entire asset portfolio from Repsol YPF.

Repsol YPF has indicated that the proved net
reserves attributable to the properties that we reviewed account for approximately 26 percent of their total proved net remaining hydrocarbon reserves as of December 31, 2009.

Data, Methods and Procedures

In performing our estimates, we have relied upon data furnished by Repsol YPF with respect to property interests owned, production and
well tests from examined wells, historical costs of operation and development, product prices, geological structural and isochore maps, well logs, core analyses, and pressure measurements, etc. In general, the reserve estimates for the properties
that we reviewed are based on data available through September 30, 2009 and December 31, 2009.

These data were
accepted as authentic and sufficient for determining the reserves unless, during the course of our examination, a matter of question came to our attention in which case the data were not accepted until all questions were satisfactorily resolved.

As prescribed by the Society of Petroleum Engineers in Paragraph 2.2(f) of the Standards Pertaining to the Estimating and
Auditing of Oil and Gas Reserves Information a reserves audit is defined as the process of reviewing certain of the pertinent facts interpreted and assumptions made that have resulted in an estimate of reserves prepared by others and the
rendering of an opinion about (1) the appropriateness of the methodologies employed, (2) the adequacy and quality of the data relied upon, (3) the depth and thoroughness of the reserves estimation process, (4) the classification
of reserves appropriate to the relevant definitions used, and (5) the reasonableness of the estimated reserve quantities.

The reserves included herein were estimated using generally accepted petroleum engineering and evaluation principles for the estimation
of future reserves. In general, these reserves were estimated by performance methods, volumetric or material balance methods; however, other methods were used in certain cases where characteristics of the data, in our opinion, indicated such other
methods were more appropriate. We consider the assumptions, data, methods and procedures used in this report appropriate, and we have used all such methods and procedures that we consider necessary and appropriate for the purpose hereof.

Our forecasts of future production rates are based on historical performance from wells now on production. Test data and other related
information were used to estimate the anticipated initial production rates for those wells or locations that are not currently producing. If no production decline trend has been established, future production rates were held constant, or adjusted
for the effects of curtailment where appropriate, until a decline in ability to produce was anticipated. An estimated rate of decline was then applied to depletion of the reserves. If a decline trend has been established, this trend was used as the
basis for estimating future production rates. For reserves not yet on production, sales were estimated to commence at an anticipated date furnished by Repsol YPF. The future production rates from wells now on production may be more or less than
estimated because of changes in market demand or allowables set by regulatory bodies. Wells or locations that are not currently producing may start producing earlier or later than anticipated in our estimates.

To estimate economically recoverable oil and gas reserves and related future net cash flows, we consider many factors and assumptions
including, but not limited to, the use of reservoir parameters derived from geological, geophysical and engineering data which cannot be measured directly,



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Repsol YPF

March 24, 2010

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economic criteria based on current costs and SEC pricing requirements, and forecasts of future production rates. Under the SEC regulations 210.4-10(a)(22)(v) and (26), proved reserves must be
demonstrated to be economically producible based on existing economic conditions including the prices and costs at which economic producibility from a reservoir is to be determined as of the effective date of the report.

As previously stated, the hydrocarbon prices used herein are based on the average prices during the 12-month period prior to the ending
date of the period covered in this report, determined as the unweighted arithmetic averages of the prices in effect on the first-day-of-the-month for each month within such period, unless prices were defined by contractual arrangements. For
hydrocarbon products sold under contract, the contract prices including fixed and determinable escalations, exclusive of inflation adjustments, were used until expiration of the contract. Upon contract expiration, the prices were adjusted to the
12-month unweighted arithmetic average as previously described.

Repsol YPF has informed us that the operating costs for the
assets in this report are based on the operating expense reports of Repsol YPF and include only those costs directly applicable to the leases or wells. The operating costs include a portion of general and administrative costs allocated directly to
the assets. When applicable for operated properties, the operating costs include an appropriate level of corporate general administrative and overhead costs. No deduction was made for loan repayments, interest expenses, or exploration and
development prepayments that were not charged directly to the assets. Development costs were furnished to us by Repsol YPF and are based on authorizations for expenditure for the proposed work or actual costs for similar projects. The estimated net
cost of abandonment after salvage was included for properties where abandonment costs net of salvage was significant. Ryder Scott reviewed such factual data for its reasonableness; however, we have not conducted an independent verification of the
data supplied by Repsol YPF.

Summary of Ryder Scott Company Conclusions

In our opinion, Repsol YPFs estimates of future reserves for the reviewed properties were prepared in accordance with generally
accepted petroleum engineering and evaluation principles for the estimation of future reserves and we found no bias in the utilization and analysis of data in estimates for these properties.

In our opinion, the information relating to estimated proved reserves prepared by Repsol YPFs have been prepared in accordance with
Extractive Industries, Oil and Gas (Topic 932) of the Financial Accounting Standards Boards and Rules 4-10 (a) of regulation S-X and rules 302(b) and 1201, 1202, 1203(a) of regulation S-K of the SEC.

Ryder Scott found both positive and negative differences between the proved reserves estimated by us and by Repsol YPF. The overall
proved reserves for the reviewed properties as estimated by Repsol YPF are, in the aggregate, not materially different than those prepared by Ryder Scott Company with a tolerance equal or less than seven percent (7%).

Standards of Independence and Professional Qualification

Ryder Scott is an independent petroleum engineering consulting firm that has been providing petroleum consulting services throughout the
world for over seventy years. Ryder Scott is employee owned and maintains offices in Houston, Texas; Denver, Colorado; and Calgary, Alberta, Canada. We have over eighty engineers and geoscientists on our permanent staff. By virtue of the size of our
firm and the large number of clients for which we provide services, no single client or job represents a



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Repsol YPF

March 24, 2010

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material portion of our annual revenue. We do not serve as officers or directors of any publicly traded oil and gas company and are separate and independent from the operating and investment
decision-making process of our clients. This allows us to bring the highest level of independence and objectivity to each engagement for our services.

Ryder Scott actively participates in industry related professional societies and organizes an annual public forum focused on the subject
of reserves evaluations and SEC regulations. Many of our staff have authored or co-authored technical papers on the subject of reserves related topics. We encourage our staff to maintain and enhance their professional skills by actively
participating in ongoing continuing education.

Prior to becoming an officer of the Company, Ryder Scott requires that staff
engineers and geoscientists have received professional accreditation in the form of a registered or certified professional engineers license or a registered or certified professional geoscientists license, or the equivalent thereof, from
an appropriate governmental authority or a recognized self-regulating professional organization.

We are independent petroleum
engineers with respect to Repsol YPF Neither we nor any of our employees have any interest in the subject properties and neither the employment to do this work nor the compensation is contingent on our estimates of reserves for the properties which
were reviewed.

The conclusions presented in this report are the result of technical analysis conducted by teams of
geoscientists and engineers. The professional qualifications of the undersigned, the technical person primarily responsible for overseeing this project, is included as an attachment to this letter.

Terms of Usage

This
report was prepared for the exclusive use and sole benefit of Repsol YPF Company and may not be put to other use without our prior written consent for such use. The data and work papers used in the preparation of this report are available for
examination by authorized parties in our offices. Please contact us if we can be of further service.



Very truly yours,RYDER SCOTT COMPANY, L. P.TBPE Firm Registration No. F-1580/s/ Herman G. AcuñaHerman G. Acuña, P.E.TBPE License No. 92254Managing Senior Vice PresidentInternational


LOGO



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Professional Qualifications

Herman G. Acuña

The conclusions presented in the report issued on March 24, 2010 for Repsol YPF for assets located in Bolivia, Trinidad &
Tobago, and Venezuela are the result of technical analysis conducted by teams of geoscientists and engineers from Ryder Scott Company, L.P. Herman G. Acuña was the primary technical person responsible for overseeing the independent estimation
of the reserves, future production and income to render the audit conclusions of that report.

Mr. Acuña, an
employee of Ryder Scott Company L.P. (Ryder Scott) since 1997, is a Managing Senior International Vice President and serves as an Engineering Group Coordinator responsible for coordinating and supervising staff and consulting engineers of the
company in ongoing reservoir evaluation studies worldwide. Before joining Ryder Scott, Mr. Acuña served in a number of engineering positions with Exxon. For more information regarding Mr. Acuñas geographic and job
specific experience, please refer to the Ryder Scott Company website at www.ryderscott.com.

Mr. Acuña
earned a Bachelor (Cum Laude) and a Masters (Magna Cum Laude) of Science degree in Petroleum Engineering from The University of Tulsa in 1987 and 1989 respectively. He is a registered Professional Engineer in the State of Texas, a member of the
Association of International Petroleum Negotiators (AIPN) and the Society of Petroleum Engineers (SPE).

In addition to
gaining experience and competency through prior work experience, the Texas Board of Professional Engineers requires a minimum of fifteen hours of continuing education annually, including at least one hour in the area of professional ethics, which
Mr. Acuña fulfills. As part of his 2009 continuing education hours, Mr. Acuña attended over 34 hours of formalized training and conferences including 10 hours dedicated to the subject of the definitions and disclosure
guidelines contained in the United States Securities and Exchange Commission Title 17, Code of Federal Regulations, Modernization of Oil and Gas Reporting, Final Rule released January 14, 2009 in the Federal Register. In 2009,
Mr. Acuña taught various company reserves evaluation schools in Argentina, Bolivia, China, Spain, U.S.A and Venezuela. Mr. Acuña has participated in various capacities in reserves conferences such as being a panelist a the
2008 Trinidad and Tobagos Petroleum Conference, delivering the reserves evaluation seminar during IAPG convention in Mendoza, Argentina in 2006 and chairing the first Reserves Evaluation Conference in the Middle East in Dubai, U.A.E in 2006.

Based on his educational background, professional training and 20 years of practical experience in petroleum engineering and
the estimation and evaluation of petroleum reserves, Mr. Acuña has attained the professional qualifications as a Reserves Estimator and Reserves Auditor set forth in Article III of the Standards Pertaining to the Estimating and
Auditing of Oil and Gas Reserves Information promulgated by the Society of Petroleum Engineers as of February 19, 2007.



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PETROLEUM RESERVES DEFINITIONS

As Adapted From:

RULE 4-10(a) of REGULATION S-X PART 210

UNITED STATES SECURITIES AND EXCHANGE COMMISSION (SEC)

and

PETROLEUM RESOURCES MANAGEMENT SYSTEM (SPE-PRMS)

Sponsored and Approved by:

SOCIETY OF PETROLEUM ENGINEERS (SPE),

WORLD PETROLEUM COUNCIL (WPC)

AMERICAN ASSOCIATION OF PETROLEUM GEOLOGISTS (AAPG)

SOCIETY OF PETROLEUM EVALUATION ENGINEERS (SPEE)

PREAMBLE

Reserves are those quantities of petroleum which are anticipated to be commercially recovered from known accumulations from a given date
forward under defined conditions. All reserve estimates involve some degree of uncertainty. The uncertainty depends chiefly on the amount of reliable geologic and engineering data available at the time of the estimate and the interpretation of these
data. The relative degree of uncertainty may be conveyed by placing reserves into one of two principal classifications, either proved or unproved. Unproved reserves are less certain to be recovered than proved reserves and may be further
sub-classified as probable and possible reserves to denote progressively increasing uncertainty in their recoverability.

Estimation of reserves is done under conditions of uncertainty. The method of estimation is called deterministic if a single best
estimate of reserves is made based on known geological, engineering, and economic data. The method of estimation is called probabilistic when the known geological, engineering, and economic data are used to generate a range of estimates and their
associated probabilities. Identifying reserves as proved, probable, and possible has been the most frequent classification method and gives an indication of the probability of recovery. Because of the differences in uncertainty, caution should be
exercised when aggregating reserves of different classifications.

Reserves estimates will generally be revised as additional
geologic or engineering data becomes available or as economic conditions change.

Reserves may be attributed to either natural
energy or improved recovery methods. Improved recovery methods include all methods for supplementing natural energy or altering natural forces in the reservoir to increase ultimate recovery. Examples of such methods are pressure maintenance,
cycling, waterflooding, thermal methods, chemical flooding, and the use of miscible and immiscible displacement fluids. Other improved recovery methods may be developed in the future as petroleum technology continues to evolve.

Reserves may be attributed to either conventional or unconventional petroleum accumulations under the SPE-PRMS. Petroleum accumulations
are considered as either conventional or unconventional based on the nature of their in-place characteristics, extraction method applied, or degree of processing prior to sale. Examples of unconventional petroleum accumulations include coalbed or
coalseam methane (CBM/CSM), basin-centered gas, shale gas, gas hydrates, natural bitumen and oil shale deposits. These



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PETROLEUM RESERVES DEFINITIONS

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unconventional accumulations may require specialized extraction technology and/or significant processing prior to sale. Both the SPE-PRMS and SEC reserve classification systems acknowledge
unconventional petroleum accumulations as reserves regardless of their in-place characteristics, the extraction method applied, or the degree of processing required. Saleable hydrocarbons based on the final product resulting from oil and gas
producing activities must be disclosed in SEC filings made as of December 31, 2009 or after January 1, 2010 as noted in 210.4-10 (a) (16).

RESERVES (SEC/SPE-PRMS DEFINITIONS)

Reserves are defined similarly in both the Securities and Exchange Commission Regulation S-X §229.4-10(a) and the SPE-PRMS.

Reserves (SEC Definitions)

Securities and Exchange Commission Regulation S-X §229.4-10(a) (26) defines reserves as follows:

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 (SPE-PRMS Definitions)

The SPE-PRMS Section 1.1 and Table 1 define reserves as follows:

Reserves.Reserves are those quantities of petroleum anticipated to be commercially recoverable by application of development projects
to known accumulations from a given date forward under defined conditions. Reserves must satisfy four criteria: they must be discovered, recoverable, commercial and remaining based on the development project(s) applied. Reserves are further
subdivided in accordance with the level of certainty associated with the estimates and may be sub-classified based on project maturity and/or characterized by their development and production status.

PROVED AND UNPROVED RESERVES (SEC/SPE-PRMS DEFINITIONS)

Both the Securities and Exchange Commission Regulation S-X §229.4-10(a) and the SPE-PRMS Section 2.2.2 and Table 3 define
proved, probable and possible reserves. In general, the SEC and SPE-PRMS definitions are similar; however, it should be noted that there are certain differences between the two reserve classification systems and, as such, reserves classified as
proved and/or probable and possible under one system may differ from those classified under the other system. These nuances include, but are not limited to, the application of prices and discounting used in the determination of discounted future net
income, the commercial criteria used for the determination of economic producibility and the degree of certainty necessary for receiving project financing or negotiating the extension of existing contracts beyond their expiration date. The
definitions also differ regarding the nature of the specific circumstances associated with undrilled locations that, as part of an adopted development plan, will not be drilled within five years from the initial date of their inclusion as volumes
reported as reserves, as well as in the assignment of reserves to unpenetrated fault blocks which are adjacent to known reservoirs but are separated by major, potentially sealing, faults. The user of this report should refer to the report or audit
letter for additional discussion of these issues, where applicable.



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PETROLEUM RESERVES DEFINITIONS

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UNITED STATES SECURITIES AND EXCHANGE COMMISSION (SEC) RESERVES DEFINITIONS

On January 14, 2009, the United States Securities and Exchange Commission (the Commission) published the
Modernization of Oil and Gas Reporting; Final Rule in the Federal Register of National Archives and Records Administration (NARA). The Modernization of Oil and Gas Reporting; Final Rule includes revisions and additions to the
definition section in Rule 4-10 of Regulation S-X, revisions and additions to the oil and gas reporting requirements in Regulation S-K, and amends and codifies Industry Guide 2 in Regulation S-K. The Modernization of Oil and Gas Reporting;
Final Rule, including all references to Regulation S-X and Regulation S-K, shall be referred to herein collectively as the SEC Regulations. The SEC Regulations take effect with all filings made with the United States Securities and
Exchange Commission as of December 31, 2009, or after January 1, 2010.

Reference should be made to the full text
under Title 17, Code of Federal Regulations, Regulation S-X Part 210, Rule 4-10 (a) for the complete definitions, as the following definitions, descriptions and explanations rely wholly or in part on excerpts from the original document (direct
passages excerpted from the aforementioned SEC document are denoted in italics herein).

PROVED RESERVES (SEC DEFINITIONS)

Securities and Exchange Commission Regulation S-X §229.4-10(a) (22) defines proved oil and gas reserves
as follows:

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.

(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



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(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.

SPE-PRMS RESERVES DEFINITIONS

In March 2007, the Society of Petroleum Engineers (SPE), World Petroleum Council (WPC), American Association of Petroleum Geologists
(AAPG), and Society of Petroleum Evaluation Engineers (SPEE) jointly approved the Petroleum Resources Management System (SPE-PRMS). The SPE-PRMS consolidates, builds on, and replaces guidance previously contained in the 2000
Petroleum Resources Classification and Definitions and the 2001 Guidelines for the Evaluation of Petroleum Reserves and Resources publications.

The intent of the SPE, WPC, AAPG and SPEE in approving additional classifications beyond proved reserves is to facilitate consistency
among professionals using such terms. In presenting these definitions, none of these organizations are recommending public disclosure of reserves classified as unproved. Public disclosure of the quantities classified as unproved reserves is left to
the discretion of the countries or companies involved and should not be construed as replacing guidelines for public disclosures under the guidelines established by regulatory and/or other governmental agencies.

Reference should be made to the full SPE-PRMS for the complete definitions and guidelines as the following definitions, descriptions and
explanations rely wholly or in part on excerpts from the SPE-PRMS document (direct passages excerpted from the SPE-PRMS document are denoted in italics herein).

UNPROVED RESERVES (SPE-PRMS DEFINITIONS)

The SPE-PRMS Section 2.2.2 and Appendix A define unproved oil and gas reserves as follows:

Unproved oil and gas reserves.Unproved Reserves are based on geoscience and/or engineering data similar to that used in
estimates of Proved Reserves, but technical or other uncertainties preclude such reserves being classified as Proved. Unproved Reserves may be further categorized as Probable Reserves or Possible Reserves. Based on additional data and updated
interpretations that indicate increased certainty, portions of Possible and Probable Reserves may be re-categorized as Probable and Proved Reserves.

PROBABLE RESERVES (SPE-PRMS DEFINITIONS)

The SPE-PRMS Section 2.2.2 and Table 3 define probable oil and gas reserves as follows:

Probable oil and gas reserves.Probable Reserves are those additional reserves which analysis of geoscience and engineering data
indicate are less likely to be recovered than Proved Reserves but more certain to be recovered than Possible Reserves. It is equally likely that actual remaining quantities recovered will be greater than or less than the sum of the estimated Proved
plus Probable reserves (2P). In this context, when probabilistic methods are used, there should be at least a 50% probability that the actual quantities recovered will equal or exceed the 2P estimate.



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Probable Reserves may be assigned to areas of a reservoir adjacent to Proved where
data control or interpretations of available data are less certain. The interpreted reservoir continuity may not meet the reasonable certainty criteria. Probable estimates also include incremental recoveries associated with project recovery
efficiencies beyond that assumed for Proved.

POSSIBLE RESERVES (SPE-PRMS DEFINITIONS)

The SPE-PRMS Section 2.2.2 and Table 3 define possible oil and gas reserves as follows:

Possible oil and gas reserves.Possible Reserves are those additional reserves which analysis of geoscience and engineering data
indicate are less likely to be recoverable than Probable Reserves. The total quantities ultimately recovered from the project have a low probability to exceed the sum of Proved plus Probable plus Possible (3P), which is equivalent to the high
estimate scenario. When probabilistic methods are used, there should be at least a 10% probability that the actual quantities recovered will equal or exceed the 3P estimate.

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 may be in areas where geoscience and engineering data are unable to clearly define the area and vertical reservoir limits of commercial production from the reservoir by a defined
project. Possible estimates also include incremental quantities associated with project recovery efficiencies beyond that assumed for Probable.

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RESERVES STATUS DEFINITIONS AND GUIDELINES

As Adapted From:

RULE 4-10(a) of REGULATION S-X PART 210

UNITED STATES SECURITIES AND EXCHANGE COMMISSION (SEC)

and

PETROLEUM RESOURCES MANAGEMENT SYSTEM (SPE-PRMS)

Sponsored and Approved by:

SOCIETY OF PETROLEUM ENGINEERS (SPE),

WORLD PETROLEUM COUNCIL (WPC)

AMERICAN ASSOCIATION OF PETROLEUM GEOLOGISTS (AAPG)

SOCIETY OF PETROLEUM EVALUATION ENGINEERS (SPEE)

Reserves status categories define the development and producing status of wells and reservoirs.

DEVELOPED RESERVES (SEC DEFINITIONS)

Securities and Exchange Commission Regulation S-X §229.4-10(a) (6) defines developed oil and gas reserves as follows:

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.

Developed Producing (SPE-PRMS
Definitions)

While not a requirement for disclosure under the SEC regulations, developed oil and gas reserves may be
further sub-classified according to the guidance contained in the SPE-PRMS as Producing or Non-Producing.

Developed
Producing Reserves

Developed Producing Reserves are expected to be recovered from completion intervals that are
open and producing at the time of the estimate.

Improved recovery reserves are considered producing only after the
improved recovery project is in operation.

Developed Non-Producing

Developed Non-Producing Reserves include shut-in and behind-pipe reserves.



RYDER SCOTT COMPANY    PETROLEUM CONSULTANTS



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PETROLEUM RESERVES STATUS DEFINITIONS AND GUIDELINES

Page 2



Shut-In

Shut-in Reserves are expected to be recovered from:

(1) completion intervals which are open at the time of the estimate but which have not yet started producing;

(2) wells which were shut-in for market conditions or pipeline connections; or

(3) wells not capable of production for mechanical reasons.

Behind-Pipe

Behind-pipe Reserves are expected to be recovered from zones in existing wells which will require additional completion work or future
re-completion prior to start of production.

In all cases, production can be initiated or restored with relatively low
expenditure compared to the cost of drilling a new well.

UNDEVELOPED RESERVES (SEC DEFINITIONS)

Securities and Exchange Commission Regulation S-X §229.4-10(a) (31) defines undeveloped oil and gas reserves as follows:

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.



RYDER SCOTT COMPANY    PETROLEUM CONSULTANTS