Exhibit 99.3



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|LOGO |                                     | Four Oaks Place
|     | 1300 Post Oak Boulevard, Suite 1000
|     | Houston, Texas 77056               
|     | Telephone:                          |                 | (713) 850-9955        
|     | Facsimile:                          |                 | (713) 850-9966        
|     | Email:                              |                 | gcah@gaffney-cline.com







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|SOP/bgh/C1490.05/gcah.91.10 |  |  |  | May 21, 2010

Mr. Aquiles Rattia

Repsol YPF

Paseo de la
Castellana 278 28046, Madrid, Spain

Reserve Statement for Bloque 16, Area Bogi-Capiron and Tivacuno

as of September 30, 2009

Dear Mr. Rattia:

This
reserve statement has been prepared by Gaffney, Cline & Associates (GCA) at the request of Repsol YPF SA (RY) operator of and 55% interest participant in the Block 16, Area Bogi-Capiron and Tivacuno in the Oriente Basin of Ecuador. GCA has
conducted an independent audit examination as of September 30, 2009, of the crude oil reserves of Bloque 16, Area Bogi-Capiron and Tivacuno. On the basis of technical and other information made available to us concerning these property units,
we hereby provide the reserve statement given in the table below. Total Proved Reserves, net to RY interest, represent 0.5% of Repsol YPFs total Proved Reserves on a barrel oil equivalent (BOE) basis. Our study was completed on
January 12, 2010.

Statement of Remaining Hydrocarbon Volumes

Bloque 16, Area Bogi-Capiron and Tivacuno, Ecuador

as of September 30, 2009



|             |                |                           |                |                             
|------------ | -------------- | ------------------------- | -------------- | ----------------------------
|Reserves     |                | Gross (100%)Field Volumes |                | Reserves Net toRYs Interest
|             | Liquids(MMstb) |                           | Liquids(MMstb)
|Proved       |                |                           |                |                             
|Developed    |                | 24.4                      |                | 8.6                         
|Undeveloped  |                | 6.3                       |                | 2.2                         
|             |                |                           |                |                             
|Total Proved |                | 30.7                      |                | 10.8                        
|             |                |                           |                |                             

Hydrocarbon liquid volumes represent crude oil and
condensate estimated to be recovered during field separation, are reported in millions of stock tank barrels. Royalties payable to the State have been deducted from reported volumes.

The reserves audit commenced with two days of technical presentations and discussion at RYs office in Quito, Ecuador . In general,
GCA found the volume estimates, classification and categorization presented by RY to be reasonable although RY made some minor adjustments to acknowledge concerns raised by GCA. However, the present one year modificatory contracts for Bloque 16 and
Bogi-Capiron are only in force while new contract arrangements are being





UNITED KINGDOM     UNITED STATES     SINGAPORE     AUSTRALIA
    ARGENTINA     BRAZIL     KAZAKHSTAN     RUSSIA     UAE



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|SOP/bgh/C1490.05/gcah.91.10 | 

Repsol YPF

May 21, 2010

Page
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negotiated, GCA has considered a one year extension of the modificatory contracts (up to March 2011). Until such time as these negotiations are either completed or terminated, GCA only has
considered development work up to March 2011 and a contract expiry in January 2012 for all reserves volumes estimates. In the future these dates may change either by extending the modificatory contracts, or by signing final contracts which would
extend the expiration dates to December 31, 2018. Tables containing gross and net volumes by field are included in Appendix II.

This audit examination was based on reserve estimates and other information provided by RY to GCA through August 2009, and included such
tests, procedures and adjustments as were considered necessary. All questions that arose during the course of the audit process were resolved to our satisfaction. GCA believes that the assumptions, data, methods and procedures used in connection
with the preparation of this report are appropriate for the purpose served by the report.

The economic tests for the
September 30, 2009 Reserve volumes were based on a realized crude oil price of US$60.373/Bbl (NAPO oil price of 62.143 US$/Bbl), as advised by RY.

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

It is GCAs opinion that the estimates of total remaining recoverable hydrocarbon liquid volumes as of September 30, 2009, are,
in the aggregate, reasonable and have been prepared in accordance with the definitions for Proved reserves set out in Rule 4-10 of Regulation S-X of the United States Securities and Exchange Commission, attached in Appendix III.

This assessment has been conducted within the context of GCAs understanding of RYs petroleum property rights as represented
by RY management as well as the effects of petroleum legislation, taxation and other regulations that currently pertain to the property. GCA is not aware of any potential regulation amendments which could affect the ability to recover the estimated
reserves. GCA is not in a position to attest to property title, financial interest relationships or encumbrances thereon for any part of the appraised properties or interests.

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 reserve engineering and resource assessment 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 reserves or resources prepared by other parties may differ, perhaps materially, from those contained within this report. The accuracy of any Reserve or 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, Reserve and 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.









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|SOP/bgh/C1490.05/gcah.91.10 | 

Repsol YPF

May 21, 2010

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For this assignment, GCA served as independent Reserve auditors. The firmss
officers and employees have no direct or indirect interest holdings in the property units evaluated. GCAs remuneration was not in any way contingent on reported reserve estimates.

Finally, please note that GCA reserves the right to approve, in advance, the use and context of the use of any results, statements or
opinions expressed in this report. Such approval shall include, but not be confined to, statements or references in documents of a public or semi-public nature such as loan agreements, prospectuses, reserve statements, press releases etc. This
report has been prepared for RY and should not be used for purposes other than those for which it is intended.



Very truly yours,GAFFNEY, CLINE & ASSOCIATES, INC./s/ David K. MorganDavid K. Morgan
Senior Technical Manager




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|Attachments |  |      |  |                            
|            |  |     
|Appendices  |  | I:   |  | Statement of Qualifications
|            |  | II:  |  | Technical Explanations     
|            |  | III: |  | Reserve Definitions (SEC)  









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APPENDICES









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APPENDIX I:

Statement of Qualifications









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Statement of Qualifications

One of GCAs Senior Technical Managers was responsible for overseeing the preparation of the audit. This manager has over 40 years of diversified
international industry experience mainly in reservoir-engineering, geology, reserves estimates, project development, economics and training in the assessment, classification and reporting of reserves and resources. Over the past 5 years he has been
responsible for project review and oversight of GCAs Houston office as it pertains to exploration and production activities including the reserves audits conducted on behalf of Repsol YPF. He is a member of the Society of Petroleum Engineers
(SPE) and holds a petroleum engineering degree from Marietta College.









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APPENDIX II:

Gross and Net Volume Tables









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Reserves Statement as of September 30, 2009

Bloque 16, Bogi Capiron y Tivacuno (100%WI)



|             |  |       |  |      
|------------ |  | ----- |  | -----
|             |  | PDP   |  | PUD  
|AMO          |  |       |  | 2444 
|DAIMI        |  |       |  | 150  
|IRO          |  |       |  | 2295 
|GINTA        |  |       |  | 196  
|WATI         |  |       |  |      
|             |  |       |  |      
|Subtotal     |  | 19252 |  | 5085 
|             |  |       |  |      
|BOGI         |  |       |  | 532  
|CAPIRON      |  |       |  | 528  
|             |  |       |  |      
|Subtotal     |  | 1741  |  | 1061 
|             |  |       |  |      
|TIVACUNO     |  | 3444  |  | 119  
|             |  |       |  |      
|Total        |  | 24436 |  | 6264 
|             |  |       |  |      
|             |  |      
|             |  | PDP   |  | 1P   
|B16          |  | 19252 |  | 24336
|BOGI-CAPIRON |  | 1741  |  | 2802 
|TIVACUNO     |  | 3444  |  | 3562 
|             |  |       |  |      
|Total        |  | 24436 |  | 30701
|             |  |       |  |      

Reserves Statement as of September 30, 2009

Bloque 16, Bogi Capiron y Tivacuno (RY 55% WI net of Royalties)



|             |  |      |  |      
|------------ |  | ---- |  | -----
|             |  | PDP  |  | PUD  
|AMO          |  |      |  | 852  
|DAIMI        |  |      |  | 52   
|IRO          |  |      |  | 800  
|GINTA        |  |      |  | 68   
|WATI         |  |      |  |      
|             |  |      |  |      
|Subtotal     |  | 6543 |  | 1772 
|             |  |      |  |      
|BOGI         |  |      |  | 199  
|CAPIRON      |  |      |  | 197  
|             |  |      |  |      
|Subtotal     |  | 589  |  | 396  
|             |  |      |  |      
|TIVACUNO     |  | 1471 |  | 54   
|             |  |      |  |      
|Total        |  | 8603 |  | 2222 
|             |  |      |  |      
|             |  |     
|             |  | PDP  |  | 1P   
|B16          |  | 6543 |  | 8315 
|BOGI-CAPIRON |  | 589  |  | 985  
|TIVACUNO     |  | 1471 |  | 1526 
|             |  |      |  |      
|Total        |  | 8603 |  | 10825
|             |  |      |  |      









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APPENDIX III:

Reserves Definitions

(SEC)









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SEC DEFINITIONS FOR OIL AND GAS RESERVES

Proved Oil and Gas Reserves

Proved oil and gas reserves are the estimated quantities of crude oil, natural gas and natural gas liquids which geological and
engineering data demonstrate with reasonable certainty to be recoverable in future years from known reservoirs under existing economic and operating conditions, i.e., prices and costs as of the date the estimate is made. Prices include consideration
of changes in existing prices provided only by contractual arrangements, but not on escalations based upon future conditions.



|(i) | Reservoirs are considered proved if economic producibility is supported by either actual production or conclusive formation tests. The area of a reservoir considered
proved includes (A) that portion delineated by drilling and defined by gas-oil and/or oil-water contacts, if any; and (B) the immediately adjoining portions not yet drilled, but which can be reasonably judged as economically productive on
the basis of available geological and engineering data. In the absence of information on fluid contacts, the lowest known structural occurrence of hydrocarbons controls the lower proved limit of the reservoir.
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|(ii) | Reserves which can be produced economically through application of improved recovery techniques (such as fluid injection) are included in the proved
classification when successful testing by a pilot project, or the operation of an installed program in the reservoir, provides support for the engineering analysis on which the project or program was based.
|---- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------



|(iii) | Estimates of proved reserves do not include the following: (A) oil that may become available from know reservoirs, but is classified separately as indicated
additional reserves; (B) crude oil, natural gas and natural gas liquids, the recovery of which is subject to reasonable doubt because of uncertainty as to geology, reservoir characteristics, or economic factors: (C) crude oil,
natural gas, and natural gas liquids that may occur in undrilled prospects; and (D) crude oil, natural gas and natural gas liquids that may be recovered from oil shales, coal, gilsonite and other such sources.
|----- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

Proved Developed Oil and Gas Reserves

Proved developed oil and gas reserves that can be expected to be recovered through existing wells with existing equipment and operating
methods. Additional oil and gas expected to be obtained through the application of fluid injection or other improved recovery techniques for supplementing the natural forces and mechanisms of primary recovery should be included as proved
developed reserves only after testing by a pilot project or after the operation of an installed program has confirmed through production response that increased recovery will be achieved.

Proved Undeveloped Reserves

Proved undeveloped oil and gas reserves are reserves 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. Reserves or undrilled acreage shall be limited to those drilling units offsetting productive units that are reasonably certain of production when drilled. Proved
reserves for other undrilled units can be claimed only where it can be demonstrated with certainty that there is continuity of production from the existing productive formation. Under no circumstances should estimates for proved 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 tests in the area and in the same reservoir.