----

**UNITEDSTATESSECURITIES AND EXCHANGE COMMISSION**Washington, D.C. 20549***————————————————————*******Form 20-F****/A**(Amendment No. 1)

| (Mark One) |
|------------|

|      |   | REGISTRATION STATEMENT PURSUANT TO SECTION 12(b)        or (g) OF THE SECURITIES EXCHANGE ACT OF 1934                                                              |
|------|--------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| OR   |
| **** |   | **ANNUAL REPORT        PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES        EXCHANGE ACT OF 1934         For the fiscal year ended December 31, 200****9**     |
| OR   |
|      |   | TRANSITION REPORT PURSUANT        TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF        1934        For the transition period from _____ to _____        |
| OR   |
|      |   | SHELL COMPANY REPORT        PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES        EXCHANGE ACT OF 1934        Date of event requiring this shell company report |

**Commission file number:1-14090*****——————————*********Eni SpA**(Exact name ofRegistrant as specified in its charter) **Republic of Italy**(Jurisdiction ofincorporation or organization) **1, piazzaleEnrico Mattei - 00144 Roma - Italy**(Address of principal executive offices)**Alessandro BerniniEni SpA1, piazza Ezio Vanoni20097 San Donato Milanese (Milano) - ItalyTel +39 02 52041730 - Fax +39 02 52041765**(Name, Telephone, Email and/or Facsimile number and Addressof Company Contact Person)***————————————————————*****Securitiesregistered or to be registered pursuant to Section 12(b) of theAct.

| Title of each class                                      |    | Name of each exchange on        which registered                                                                                                                                            |
|----------------------------------------------------------|--------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| **Shares        American Depositary Shares**             |    | **New York Stock Exchange*        New York Stock Exchange**                                                                                                                                 |
| (Which represent the right to receive two        Shares) |    | * Not for        trading, but only in connection with the registration of        American Depositary Shares, pursuant to the requirements        of the Securities and Exchange Commission. |

Securities registered or to beregistered pursuant to Section 12(g) of the Act:**None**Securities for which there is a reporting obligation pursuantto Section 15(d) of the Act:**None**

Indicate the number of outstanding shares ofeach of the issuer’s classes of capital or common stock asof the close of the period covered by the annual report.                                        **Ordinary sharesof euro 1.00 each**                                                                                                                                                                **4,005,358,876**

| Indicate by check mark if        the registrant is a well-known seasoned issuer, as        defined in Rule 405 of the Securities Act. |
|---------------------------------------------------------------------------------------------------------------------------------------|

| Yes  |  |     |  No  |  |
|-----------|--|--------------------|----------------|--|

|          If this report is an annual or transition report,        indicate by check mark if the registrant is not required        to file reports pursuant to Section 13 or 15(d) of the        Securities Exchange Act of 1934. |
|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|

| Yes  |  |     |  No  |  |
|-----------|--|--------------------|----------------|--|

| Note - Checking the box        above will not relieve any registrant required to file        reports pursuant to Section 13 or 15(d) of the Securities        Exchange Act of 1934 from their obligations under those        Sections.        Indicate by check mark whether the registrant (1) has        filed all reports required to be filed by Section 13 or        15(d) of the Securities Exchange Act of 1934 during the        preceding 12 months (or for such shorter period that the        registrant was required to file such reports), and (2)        has been subject to such filing requirements for the past        90 days. |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|

| Yes  |  |     |  No  |  |
|-----------|--|--------------------|----------------|--|

|          Indicate by check mark whether the registrant (1) has        filed all reports required to be filed by Section 13 or        15(d) of the Securities Exchange Act of 1934 during the        preceding 12 months (or for such shorter period that the        registrant was required to file such reports), and (2)        has been subject to such filing requirements for the past        90 days. |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|

| Yes  |  |     |  No  |  |
|-----------|--|--------------------|----------------|--|

|          Indicate by check mark whether the registrant have        submitted electronically and posted on their corporate        Web sites, if any, every Interactive Data File required        to be submitted and posted pursuant to Rule 405 of        Regulation S-T (§ 232.405 of this chapter) during the        preceding 12 months (or for such shorter period that the        registrant was required to submit and post such files).* |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|

| Yes  |  |     |  No  |  |
|-----------|--|--------------------|----------------|--|

| * This requirement does        not apply to the registrants until their fiscal year        ending December 31, 2011.         Indicate by check mark if the registrant is a large        accelerated filer, an accelerated filer, or a non        accelerated filer. See definition of "accelerated        filer and large accelerated filer" in Rule 12b-2 of        the Exchange Act. (Check one): |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|

| Large accelerated filer |  | Accelerated filer |  | Non-accelerated filer |  |
|-------------------------|--|-------------------|--|-----------------------|--|

|          Indicate by check mark which basis of accounting the        registrant has used to prepare the financial statements        included in this filing: |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------|

| U.S. GAAP |  | International Financial        Reporting Standards as issued by the International        Accounting Standards Board |  | Other |  |
|-----------|--|---------------------------------------------------------------------------------------------------------------------|--|-------|--|

|          If "Other" has been checked in response to the        previous question, indicate by check mark which financial        statement item the registrant has elected to follow. |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|

| Item        17 |  |     |  Item        18 |  |
|----------------|--|--------------------|----------------------|--|

|          If this is an annual report, indicate by check mark        whether the registrant is a shell company (as defined in        Rule 12b-2 of the Exchange Act). |
|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------|

| Yes  |  |     |  No  |  |
|-----------|--|--------------------|----------------|--|

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**EXPLANATORY NOTE**

Eni SpA is filing this Amendment No. 1 to its Annual Report onForm 20-F for the year ended December 31, 2009, as filed with theU.S. Securities and Exchange Commission on April 26, 2010("Original Form 20-F") in order to include revisedthird party reports that were prepared by enginnering firms whohave audited certain of our reserves estimates. 

Accordingly, this Amendment amends Item 19 of the OriginalForm 20-F to provide the amended third party reports appearing onpage E-[3] to E-[28] of this Amendment.

This Amendment should be read in conjunction with the OriginalForm 20-F, which continues to speak as of the date that theOriginal Form 20-F was filed. Except as specifically noted above,this Amendment does not modify or update any disclosures in theOriginal Form 20-F. Accordingly, this Amendment does not reflectevents occurring after the filing of the Original Form 20-F ormodify or update any disclosures that may have been affected bysubsequent events, including the results of operations, financialcondition, cash flows or any forward-looking statements made inthe Original Form 20-F.

##### **TABLE OFCONTENTS**

**PART I**Omissis

**PART II**Omissis

**PART III**

**Item 17. FINANCIAL STATEMENTS**Not applicable.

**Item 18. FINANCIAL STATEMENTS**Omissis

 

**Item 19. EXHIBITS**

1. By-laws of Eni SpA*8. List of subsidiaries*11. Code of Ethics*

Certifications:

12.1. Certification pursuant to Rule13a-14(a) of the Securities Exchange Act

12.2. Certification pursuant to Rule13a-14(a) of the Securities Exchange Act

13.1. Certification furnished pursuant to Rule 13a-14(b) ofthe Securities Exchange Act (such certificate is not deemed filedfor purpose of Section 18 of the Exchange Act and notincorporated by reference with any filing under the SecuritiesAct)*

13.2. Certification furnished pursuant to Rule 13a-14(b) ofthe Securities Exchange Act (such certificate is not deemed filedfor purpose of Section 18 of the Exchange Act and notincorporated by reference with any filing under the SecuritiesAct)*

15.a(i) Consent of DeGolyer and MacNaughton*15.a(ii) Consent of Ryder Scott Co*15.a(iii) Report of DeGolyer and MacNaughton15.a(iv) Report of Ryder Scott Co15.a(v) Report of DeGolyer and MacNaughton

16.f Agreement letter of PwC*

________________

(*) Previously filed as an exhibit to theOriginal Form 20-F.

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**SIGNATURES**

The registrant hereby certifies that it meets all of therequirements for filing on Form 20-F and that it has duly causedand authorized the undersigned to sign this Amendment No. 1 tothis annual report on its behalf.

Date: April 7, 2011

 

 

 

 

 

 

 

| Eni SpA                           |
|-----------------------------------|
|                              |
| /s/ANTONIO CRISTODORO             |
|                                   |
|                              |
| Antonio Cristodoro                |
| Title: Deputy Corporate Secretary |

 

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Certifications as separate documents filedas exhibits

**EXHIBIT 12.1**

**Certification**

 

I, Paolo Scaroni, certify that:

|   | 1. |   | I have        reviewed this annual report on Form 20-F/A of Eni SpA;        and |
|--------|----|--------|---------------------------------------------------------------------------------|

|   | 2. |   | Based on my knowledge, this        report does not contain any untrue statement of a        material fact or omit to state a material fact necessary        to make the statements made, in light of the        circumstances under which such statements were made, not        misleading with respect to the period covered by this        report. |
|--------|----|--------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|

Date: April 7, 2011

| /s/PAOLO SCARONI                                    |
|-----------------------------------------------------|
|                                                     |
| Paolo Scaroni        Title: Chief Executive Officer |

 

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**EXHIBIT 12.2**

**Certification**

 

I, Alessandro Bernini, certify that:

|   | 1. |   | I have reviewed this annual        report on Form 20-F/A of Eni SpA; and |
|--------|----|--------|--------------------------------------------------------------------------|

|   | 2. |   | Based on my knowledge, this        report does not contain any untrue statement of a        material fact or omit to state a material fact necessary        to make the statements made, in light of the        circumstances under which such statements were made, not        misleading with respect to the period covered by this        report. |
|--------|----|--------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|

Date: April 7, 2011

 

| /s/ALESSANDRO BERNINI                                    |
|----------------------------------------------------------|
|                                                          |
| Alessandro Bernini        Title: Chief Financial Officer |

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**EXHIBIT 15.a(iii)**

 

 

DeGolyer And MacNaughton5001 Spring Valley RoadSuite 800 EastDallas, Texas 75244

 

 

 

 

 

 

This is a digital representation of a DeGolyerand MacNaughton report.

 

This file is intended to be a manifestation ofcertain data in the subject report and as such are subject to thesame conditions thereof. The information and data contained inthis file may be subject to misinterpretation; therefore, thesigned and bound copy of this report should be considered theonly authoritative source of such information.

 

 

 

 

 

 

 

 

 

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DeGolyer And MacNaughton5001 Spring Valley RoadSuite 800 EastDallas, Texas 75244

 

February 26, 2010

 

 

 

 

 

 

> 
Eni S.p.A.                E&P Division                Ms. Manuela Feudaroli                Vice President, Reserves                Via Emilia 1                20097 San Donato Milanese                Milano, Italy

 

Dear Ms. Feudaroli:

 

Pursuant to your request, we have conducted an                independent evaluation, on the date of this                letter report, to serve as a reserves audit of                the net proved crude oil, natural gas liquids                (NGL), and natural gas reserves, as of December                31, 2009, of certain properties in Europe, North                Africa, and West Africa owned by Eni S.p.A.                (Eni). Eni has represented that these properties                account for 21 percent, on a net equivalent                barrel basis, of Eni's net proved reserves as of                December 31, 2009, and that Eni's net proved                reserves estimates have been prepared in                accordance with the reserves definitions of Rules                4-10(a) (1)-(32) of Regulation S-X of the                Securities and Exchange Commission (SEC) of the                United States. We have reviewed information                provided to us by Eni that it represents to be                Eni's estimates of the net reserves, as of                December 31, 2009, for the same properties as                those which we have independently evaluated.

Reserves included herein are expressed as net                reserves as represented by Eni. Gross reserves                are defined as the total estimated petroleum to                be produced from these properties after December                31, 2009. Net reserves are defined as that                portion of the gross reserves attributable to the                interests owned by Eni after deducting interests                owned by others.

Estimates of oil, NGL, and natural gas should                be regarded only as estimates that may change as                further production history and additional                information become available. Not only are such                reserves estimates based on that information                which is

 

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| DeGolyer        And MacNaughton | 2 |
|---------------------------------|---|

 

> 
 

currently available, but such estimates are                also subject to the uncertainties inherent in the                application of judgmental factors in interpreting                such information.

Data used in this audit were obtained from                reviews with Eni personnel, Eni files, from                records on file with the appropriate regulatory                agencies, and from public sources. In the                preparation of this report we have relied,                without independent verification, upon such                information furnished by Eni with respect to                property interests, production from such                properties, current costs of operation and                development, current prices for production,                agreements relating to current and future                operations and sale of production, and various                other information and data that were accepted as                represented. A field examination of the                properties was not considered necessary for the                purposes of this report.

 

**Methodology and Procedures**

Our estimates of reserves were prepared by the                use of standard geological and engineering                methods generally accepted by the petroleum                industry as presented in the publication of the                Society of Petroleum Engineers entitled                "Standards Pertaining to the Estimating and                Auditing of Oil and Gas Reserves Information                (Revision as of February 19, 2007)." The                method or combination of methods used in the                analysis of each reservoir was tempered by                experience with similar reservoirs, stage of                development, quality and completeness of basic                data, and production history.

When applicable, the volumetric method was                used to estimate the original oil in place (OOIP)                and the original gas in place (OGIP). Structure                and isopach maps were constructed to estimate                reservoir volume. Electrical logs, radioactivity                logs, core analyses, and other available data                were used to prepare these maps as well as to                estimate representative values for porosity and                water saturation. When adequate data were                available and when circumstances justified,                material balance and other engineering methods                were used to estimate OOIP or OGIP.

Estimates of ultimate recovery were obtained                after applying recovery factors to OOIP or OGIP.                These recovery factors were based on                consideration of the type of energy inherent in                the reservoirs, analyses of the petroleum, the                structural positions of the properties, and the                production histories. When applicable, material                balance and other engineering methods were used                to estimate recovery factors. An analysis

 

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| DeGolyer        And MacNaughton | 3 |
|---------------------------------|---|

 

> 
of reservoir performance, including production                rate, reservoir pressure, and gas-oil ratio                behavior, was used in the estimation of reserves.

For depletion-type reservoirs or those whose                performance disclosed a reliable decline in                producing-rate trends or other diagnostic                characteristics, reserves were estimated by the                application of appropriate decline curves or                other performance relationships. In the analyses                of production-decline curves, reserves were                estimated only to the limits of economic                production or to the limit of production licenses                as appropriate.

 

**Definition of********Reserves**

Petroleum reserves included in this report are                classified as proved. Reserves classifications                used for our estimates of proved reserves are in                accordance with the reserves definitions of Rules                4-10(a) (1)-(32) of Regulation S-X of the SEC.                Eni has represented that its estimates of proved                reserves are in accordance with the reserves                definitions of Rules 4-10(a) (1)-(32) of                Regulation S-X of the SEC. Reserves are judged to                be economically producible in future years from                known reservoirs under existing economic and                operating conditions and assuming continuation of                current regulatory practices using conventional                production methods and equipment. In the analyses                of production-decline curves, reserves were                estimated only to the limit of economic rates of                production under existing economic and operating                conditions using prices and costs consistent with                the effective date of this report, including                consideration of changes in existing prices                provided only by contractual arrangements but not                including escalations based upon future                conditions. The petroleum reserves are classified                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

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| DeGolyer        And MacNaughton | 4 |
|---------------------------------|---|

 

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

 

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| DeGolyer        And MacNaughton | 5 |
|---------------------------------|---|

 

> 
(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.

*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.

*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

 

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| DeGolyer        And MacNaughton | 6 |
|---------------------------------|---|

 

> 
 

technique is contemplated, unless such                        techniques have been proved effective by                        actual projects in the same reservoir or                        an analogous reservoir, as defined in                        [section 210.4-10 (a) Definitions], or by                        other evidence using reliable technology                        establishing reasonable certainty.

 

**Primary Economic Assumptions**

The following economic assumptions were used for            estimating existing and future prices and costs:

*Oil and NGL Prices*

Eni has represented that the oil and                        NGL prices were based on a 12-month                        average price (reference price),                        calculated as the unweighted arithmetic                        average of the first-day-of-the-month                        price for each month within the 12-month                        period prior to the end of the reporting                        period, unless prices are defined by                        contractual arrangements. A dated Brent                        oil price of U.S.$59.91 per barrel was                        the resulting reference price. Eni                        supplied appropriate differentials by                        field to the relevant reference prices                        and the prices were held constant                        thereafter.

*Natural Gas Prices*

Eni has represented that the natural                        gas prices were based on a reference                        price, calculated as the unweighted                        arithmetic average of the                        first-day-of-the-month price for each                        month within the 12-month period prior to                        the end of the reporting period, unless                        prices are defined by contractual                        arrangements. A significant quantity of                        the gas sold by Eni is subject to                        contract prices, and the range of such                        prices is varied. Where appropriate, Eni                        supplied appropriate differentials by                        field to the relevant reference prices                        and the prices were held constant                        thereafter.

 

 

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| DeGolyer        And MacNaughton | 7 |
|---------------------------------|---|

 

> 
*Operating Expenses and Capital Costs*

Operating expenses and capital costs,                        based on information provided by Eni,                        were used in estimating future costs                        required to operate the properties. In                        certain cases, future costs, either                        higher or lower than existing costs, may                        have been used because of anticipated                        changes in operating conditions. These                        costs were not escalated for inflation.

While the oil and gas industry may be subject                to regulatory changes from time to time that                could affect an industry participant's ability to                recover its oil and gas reserves, we are not                aware of any such governmental actions which                would restrict the recovery of the December 31,                2009, estimated oil and gas volumes. The reserves                estimated in this report can be produced under                current regulatory guidelines.

Eni has represented that its estimated net                proved reserves attributable to the reviewed                properties in Europe, North Africa, and West                Africa are based on the definitions of proved                reserves of the SEC. Eni represents that its                estimates of the net proved reserves attributable                to these properties, which represent 21 percent                of Eni's reserves on a net equivalent basis, are                as follows, expressed in millions of barrels                (MMbbl), billions of cubic feet (Bcf), and                millions of barrels of oil equivalent (MMboe):

|                                                                                                                             |   | **Estimated by Eni         Net Proved Reserves as of        December 31, 2009** |
|----------------------------------------------------------------------------------------------------------------------------------|--------|---------------------------------------------------------------------------------|
|                                                                                                                             |   |                                                                                 |
|                                                                                                                             |   | **Oil and        NGL        (MMbbl)**                                           |   | **Natural        Gas        (Bcf)** |   | **Oil        Equivalent        (MMboe)** |
|                                                                                                                             |   |                                                                                 |   |  |   |  |
| **Properties reviewed        by DeGolyer and MacNaughton**                                                                       |   |                                                                            |   |   |   |   |
| Total Proved                                                                                                                     |   | 952                                                                             |   | 2,470 |   | 1,383 |
|                                                                                                                             |   |                                                                            |   |   |   |   |
| Note: Gas        is converted to oil equivalent using a factor of 5,742        cubic feet of gas per 1 barrel of oil equivalent. |

> 
 

In comparing the detailed net proved reserves                estimates prepared by us and by Eni, we have                found differences, both positive and negative. It                is our opinion that the net proved reserves                estimates prepared by Eni on the properties                reviewed by us and referred to above, when                compared on the basis of net equivalent barrels,                in aggregate, do not differ materially from those                prepared by us, with tolerance of 5 percent or                less.

 

 

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| DeGolyer        And MacNaughton | 8 |
|---------------------------------|---|

 

 

 

> 
DeGolyer and MacNaughton is an independent                petroleum engineering consulting firm that has                been providing petroleum consulting services                throughout the world for over 70 years. DeGolyer                and MacNaughton does not have any financial                interest, including stock ownership, in Eni. Our                fees were not contingent on the results of our                evaluation. This letter report has been prepared                at the request of Eni. DeGolyer and MacNaughton                has used all assumptions, data, procedures, and                methods that it considers necessary and                appropriate to prepare this report.

 

|   | Submitted,                              |
|--------|-----------------------------------------|
|   |                                    |
|   | /s/ DEGOLYER AND MACNAUGHTON            |
|   |                                    |
|   | DeGOLYER and MacNAUGHTON                |
|   | Texas Registered Engineering Firm F-716 |

> 

|   | /s/ LLOYD W. CADE, P.E.  |
|--------|--------------------------|
|   |                     |
|   | Lloyd W. Cade, P.E.      |
|   | Senior Vice President    |
|   | DeGolyer and MacNaughton |

 

 

 

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| DeGolyer        And MacNaughton |   |
|---------------------------------|--------|

 

 

**CERTIFICATE of QUALIFICATION**

> 
I, Lloyd W. Cade Petroleum Engineer with DeGolyer            and MacNaughton, 5001 Spring Valley Road, Suite 800            East, Dallas, Texas, 75244 U.S.A., hereby certify:
1.  That I am a                    Senior Vice President with DeGolyer and                    MacNaughton, which company did prepare the                    letter report addressed to Eni dated February                    26, 2010, and that I, as Senior Vice                    President, was responsible for the                    preparation of this report.   2.  That I attended                    Kansas State University, and that I graduated                    with a Bachelor of Science degree in                    Mechanical Engineering in the year 1982; that                    I am a Registered Professional Engineer in                    the State of Texas; that I am a member of the                    International Society of Petroleum Engineers;                    and that I have approximately twenty-seven                    (27) years of experience in oil and gas                    reservoir studies and reserves evaluations.
 

 

 

SIGNED: February 26, 2010

 

 

 

|   | /s/ LLOYD W. CADE, P.E.  |
|--------|--------------------------|
|   |                     |
|   | Lloyd W. Cade, P.E.      |
|   | Senior Vice President    |
|   | DeGolyer and MacNaughton |

 

 

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**EXHIBIT 15.a(iv)**

 

**Eni S.p.A.**

 

 

 

**Estimated**

**Future Reserves and Income**

**Attributable to Certain Leasehold**

**and Royalty Interests**

 

 

 

 

**SEC Parameters**

 

**As of**

**December 31, 2009**

/s/HERMAN G. ACUÑA.

Herman G. Acuña, P.E.TBPE License No. 92254Managing Senior International Vice President

**RYDER SCOTT COMPANY, L.P.**TBPE Firm Registration No. F-1580

[SEAL]

 

 

RYDER SCOTT COMPANY      PETROLEUMCONSULTANTS

 

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February 23, 2010

 

Eni S.p.A.E&P DivisionMs. Manuela FeudaroliVice President ReservesVia Emilia 120097 San Donato MilaneseMilano, Italy

Dear Ms. Feudaroli:

At the request of Eni S.p.A. (Eni), Ryder Scott Company (RyderScott) has conducted a reserves audit of the estimates of theproved reserves as prepared by Eni’s engineering andgeological staff based on the definitions and disclosureguidelines of the United States Securities and ExchangeCommission (SEC) contained in Title 17, Code of FederalRegulations, Modernization of Oil and Gas Reporting, Final Rulereleased January 14, 2009 in the Federal Register (SECregulations). Our third party reserves audit, completed onJanuary 25, 2010 and presented herein, was prepared for publicdisclosure by Eni in filings made with the SEC in accordance withthe disclosure requirements set forth in the SEC regulations. Enihas indicated that the proved net reserves attributable to theproperties that we reviewed account for 6.5 percent of theirtotal proved net remaining hydrocarbon reserves. The subjectproperties are located in the following geographic locations:

> - North Africa
- North America
- South America and Caribbean

As prescribed by the Society of Petroleum Engineers inParagraph 2.2(f) of the Standards Pertaining to the Estimatingand Auditing of Oil and Gas Reserves Information (SPE auditingstandards), a reserves audit is defined as "the process ofreviewing certain of the pertinent facts interpreted andassumptions made that have resulted in an estimate of reservesprepared by others and the rendering of an opinion about (1) theappropriateness of the methodologies employed; (2) the adequacyand quality of the data relied upon; (3) the depth andthoroughness of the reserves estimation process; (4) theclassification of reserves appropriate to the relevantdefinitions used; and (5) the reasonableness of the estimatedreserve quantities."

Based on our review, including the data, technical processesand interpretations presented by Eni, it is our opinion that theoverall procedures and methodologies utilized by Eni in preparingtheir estimates of the proved reserves as of December 31, 2009comply with the current SEC regulations and that the overallproved reserves for the reviewed properties as estimated by Eniare, in the aggregate, reasonable within 5 percent of RyderScott’s estimates which is less than the established audittolerance guidelines of 10 percent as set forth in the SPEauditing standards.

The conclusions discussed in this report, as of December 31,2009, are related to hydrocarbon prices. The hydrocarbon pricesused in the preparation of this report are based on the averageprices during the 12-month period prior to the ending date of theperiod covered in this report, determined as the unweightedarithmetic averages of the prices in effect on thefirst-day-of-the-month for each month

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within such period, unless prices were defined by contractualarrangements, as required by the SEC regulations. Actual futureprices may vary significantly from the prices required by SECregulations; therefore, volumes of reserves actually recoveredmay differ significantly from the estimated quantities audited byRyder Scott. 

***Reserves Included in This Report***

The proved reserves included herein conform to the definitionas set forth in the Securities and Exchange Commission’sRegulations Part 210.4-10(a). An abridged version of the SECreserves definitions from 210.4-10(a) entitled "PetroleumReserves Definitions" is included as an attachment to thisreport. The various proved reserve status categories are definedunder the attachment entitled "Petroleum ReservesDefinitions" in this report. 

No attempt was made to quantify or otherwise account for anyaccumulated gas production imbalances that may exist. The auditedproved**gas volumes includedgas consumed in operations as reserves. Non-hydrocarbon or inertgas volumes have been excluded from the reserves reported herein.

Reserves are those estimated remaining quantities of petroleumthat are anticipated to be economically producible, as of a givendate, from known accumulations under defined conditions. Allreserve estimates involve an assessment of the uncertaintyrelating the likelihood that the actual remaining quantitiesrecovered will be greater or less than the estimated quantitiesdetermined as of the date the estimate is made. The uncertaintydepends chiefly on the amount of reliable geologic andengineering data available at the time of the estimate and theinterpretation of these data. The relative degree of uncertaintymay be conveyed by placing reserves into one of two principalclassifications, either proved or unproved. Unproved reserves areless certain to be recovered than proved reserves, and may befurther sub-classified as probable and possible reserves todenote progressively increasing uncertainty in theirrecoverability. At Eni’s request, this report addresses onlythe proved reserves attributable to the properties evaluatedherein.

Proved oil and gas reserves are those quantities of oil andgas which, by analysis of geoscience and engineering data, can beestimated with reasonable certainty to be economically produciblefrom a given date forward. The proved reserves included hereinwere estimated using deterministic methods. If deterministicmethods are used, the SEC has defined reasonable certainty forproved reserves as a "high degree of confidence that thequantities will be recovered." 

Proved**reserve estimateswill generally be revised only as additional geologic orengineering data become available or as economic conditionschange. For proved reserves, the SEC states that "as changesdue to increased availability of geoscience (geological,geophysical, and geochemical), engineering, and economic data aremade to the estimated ultimate recovery (EUR) with time,reasonably certain EUR is much more likely to increase or remainconstant than to decrease." Moreover, estimates of provedreserves may be revised as a result of future operations, effectsof regulation by governmental agencies or geopolitical oreconomic risks. Therefore, the proved reserves included in thisreport are estimates only and should not be construed as beingexact quantities, and if recovered, the revenues therefrom, andthe actual costs related thereto, could be more or less than theestimated amounts.

The proved reserves reported herein are limited to the periodprior to expiration of current contracts providing the legalrights to produce, or a revenue interest in such production,unless evidence indicates that contract renewal is reasonablycertain. Furthermore, properties in the different countries maybe subjected to significantly varying contractual fiscal termsthat affect the net revenue to Eni for the production of thesevolumes. The prices and economic return received for these net 

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volumes can vary significantly based on the terms of thesecontracts. Therefore, when applicable, Ryder Scott reviewed thefiscal terms of such contracts and discussed with Eni the neteconomic benefit attributed to such operations for thedetermination of the net hydrocarbon volumes and income thereof.Ryder Scott has not conducted an exhaustive audit or verificationof such contractual information. Neither our review of suchcontractual information nor our acceptance of Eni’srepresentations regarding such contractual information should beconstrued as a legal opinion on this matter.

Ryder Scott did not evaluate the country and geopoliticalrisks in the countries where Eni operates or has interests.Eni’s operations may be subject to various levels ofgovernmental controls and regulations. These controls andregulations may include, but may not be limited to, mattersrelating to land tenure and leasing, the legal rights to producehydrocarbons including the granting, extension or termination ofproduction sharing contracts, the fiscal terms of variousproduction sharing contracts, drilling and production practices,environmental protection, marketing and pricing policies,royalties, various taxes and levies including income tax, andforeign trade and investment and are subject to change from timeto time. Such changes in governmental regulations and policiesmay cause volumes of proved reserves actually recovered andamounts of proved income actually received to differsignificantly from the estimated quantities.

The estimates of proved reserves audited herein were basedupon a detailed study of the properties in which Eni owns aninterest; however, we have not made any field examination of theproperties. No consideration was given in this report topotential environmental liabilities that may exist nor were anycosts included for potential liabilities to restore and clean updamages, if any, caused by past operating practices.

***Audit Data, Methodology, Procedure and Assumptions***

The estimation of reserves involves two distinctdeterminations. The first determination results in the estimationof the quantities of recoverable oil and gas and the seconddetermination results in the estimation of the uncertaintyassociated with those estimated quantities in accordance with thedefinitions set forth by the Securities and ExchangeCommission’s Regulations Part 210.4-10(a). The process ofestimating the quantities of recoverable oil and gas reservesrelies on the use of certain generally accepted analyticalprocedures. These analytical procedures fall into three broadcategories or methods: (1) performance-based methods; (2)volumetric-based methods; and (3) analogy. These methods may beused singularly or in combination by the reserve evaluator in theprocess of estimating the quantities of reserves. Reserveevaluators must select the method or combination of methods whichin their professional judgment is most appropriate given thenature and amount of reliable geoscience and engineering dataavailable at the time of the estimate, the established oranticipated performance characteristics of the reservoir beingevaluated and the stage of development or producing maturity ofthe property.

In many cases, the analysis of the available geoscience andengineering data and the subsequent interpretation of this datamay indicate a range of possible outcomes in an estimate,irrespective of the method selected by the evaluator. When arange in the quantity of reserves is identified, the evaluatormust determine the uncertainty associated with the incrementalquantities of the reserves. If the reserve quantities areestimated using the deterministic incremental approach, theuncertainty for each discrete incremental quantity of thereserves is addressed by the reserve category assigned by theevaluator. Therefore, it is the categorization of reservequantities as proved, probable and/or possible that addresses theinherent uncertainty in the estimated quantities reported. Forproved reserves, uncertainty is defined by the SEC as reasonablecertainty wherein the "quantities actually recovered aremuch more likely than not to be achieved." The SEC statesthat "probable reserves are those additional reserves thatare less certain to be recovered than proved reserves but 

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which, together with proved reserves, are as likely as not tobe recovered." The SEC states that "possible reservesare those additional reserves that are less certain to berecovered than probable reserves and the total quantitiesultimately recovered from a project have a low probability ofexceeding proved plus probable plus possible reserves." Allquantities of reserves within the same reserve category must meetthe SEC definitions as noted above.

Estimates of reserves quantities and their associated reservecategories may be revised in the future as additional geoscienceor engineering data become available. Furthermore, estimates ofreserves quantities and their associated reserve categories mayalso be revised due to other factors such as changes in economicconditions, results of future operations, effects of regulationby governmental agencies or geopolitical or economic risks aspreviously noted herein.

The proved reserves for the properties included herein wereestimated by performance methods, analogy methods, the volumetricmethod, or a combination of performance and volumetric methods.These performance methods include, but may not be limited to,decline curve analysis and analogy which utilized extrapolationsof historical production and pressure data available throughDecember, 2009 in those cases where such data were considered tobe definitive. The data utilized in this analysis were suppliedto Ryder Scott by Eni and were considered sufficient for thepurpose thereof. The volumetric method was used where there wereinadequate historical performance data to establish a definitivetrend and where the use of production performance data as a basisfor the reserve estimates was considered to be inappropriate. Thevolumetric analysis utilized pertinent well and seismic datasupplied to Ryder Scott by Eni that were available throughDecember, 2009. The data utilized from the well and seismic dataincorporated into our volumetric analysis were consideredsufficient for the purpose thereof.

To estimate economically recoverable proved oil and gasreserves and related future net cash flows, we consider manyfactors and assumptions including, but not limited to, the use ofreservoir parameters derived from geological, geophysical andengineering data that cannot be measured directly, economiccriteria based on current costs and SEC pricing requirements, andforecasts of future production rates. Under the SEC regulations210.4-10(a)(22)(v) and (26), proved reserves must be anticipatedto be economically producible from a given date forward based onexisting economic conditions including the prices and costs atwhich economic producibility from a reservoir is to bedetermined. While it may reasonably be anticipated that thefuture prices received for the sale of production and theoperating costs and other costs relating to such production mayincrease or decrease from those under existing economicconditions, such changes were, in accordance with rules adoptedby the SEC, omitted from consideration in making this evaluation.

Eni has informed us that they have furnished us all of thematerial accounts, records, geological and engineering data, andreports and other data required for this investigation. Inpreparing our forecast of future proved production and income, wehave relied upon data furnished by Eni with respect to propertyinterests owned, production and well tests from examined wells,normal direct costs of operating the wells or leases, other costssuch as transportation and/or processing fees, ad valorem andproduction taxes, recompletion and development costs, abandonmentcosts after salvage, product prices based on the SEC regulations,adjustments or differentials to product prices, geologicalstructural and isochore maps, well logs, core analyses, andpressure measurements. Ryder Scott reviewed such factual data forits reasonableness; however, we have not conducted an independentverification of the data furnished by Eni. We consider thefactual data used in this report appropriate and sufficient forthe purpose of our investigations.

In summary, we consider the assumptions, data, methods andanalytical procedures used in this report appropriate for thepurpose hereof, and we have used all such methods and proceduresthat we consider necessary and appropriate to conduct the auditof reserves of the properties described 

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herein. The proved reserves discussed herein were determinedin conformance with the United States Securities and ExchangeCommission (SEC) Modernization of Oil and Gas Reporting; FinalRule, including all references to Regulation S-X and RegulationS-K, referred to herein collectively as the "SECRegulations." In our opinion, the proved reserves reviewedin this report comply with the definitions, guidelines anddisclosure requirements as required by the SEC regulations.

***Future Production Rates***

For wells currently on production, our forecasts of futureproduction rates are based on historical performance data. If noproduction decline trend has been established, future productionrates were held constant, or adjusted for the effects ofcurtailment where appropriate, until a decline in ability toproduce was anticipated. An estimated rate of decline was thenapplied to depletion of the reserves. If a decline trend has beenestablished, this trend was used as the basis for estimatingfuture production rates.

Test data and other related information were used to estimatethe anticipated initial production rates for those wells orlocations that are not currently producing. For reserves not yeton production, sales were estimated to commence at an anticipateddate furnished by Eni. Wells or locations that are not currentlyproducing may start producing earlier or later than anticipatedin our estimates due to unforeseen factors causing a change inthe timing to initiate production. Such factors may includedelays due to weather, the availability of rigs, the sequence ofdrilling, completing and/or recompleting wells and/or constraintsset by regulatory bodies. 

The future production rates from wells currently on productionor wells or locations that are not currently producing may bemore or less than estimated because of changes including, but notlimited to, reservoir performance, operating conditions relatedto surface facilities, compression and artificial lift, pipelinecapacity and/or operating conditions, producing market demandand/or allowables or other constraints set by regulatory bodies.

***Hydrocarbon Prices***

The hydrocarbon prices used herein are based on SEC priceparameters using the average prices during the 12-month periodprior to the ending date of the period covered in this report,determined as the unweighted arithmetic averages of the prices ineffect on the first-day-of-the-month for each month within suchperiod, unless prices were defined by contractual arrangements.For hydrocarbon products sold under contract, the contractprices, including fixed and determinable escalations, exclusiveof inflation adjustments, were used until expiration of thecontract. Upon contract expiration, the prices were adjusted tothe 12-month unweighted arithmetic average as previouslydescribed.

Eni furnished us with the above mentioned average prices ineffect on December 31, 2009. These initial SEC hydrocarbon priceswere determined using the 12-month average first-day-of-the-monthbenchmark prices appropriate to the geographic area where thehydrocarbons are sold. In certain geographic areas, the pricereference and benchmark prices may be defined by contractualarrangements. The average Dated Brent of $59.908/Bbl and WTI of$61.138 average oil prices were used by Eni. Eni also indicatedthat they provided us with the gas prices outside the UnitedStates of America based on their gas sales agreements. Gas pricesin the United States of America were referenced back to the HenryHub unweighted average of $3.871/MMBTU. 

The product prices that were actually used to determine thefuture gross revenue for each property reflect adjustments to thebenchmark prices for gravity, quality, local conditions and/ordistance from market, referred to herein as"differentials." The differentials used in thepreparation of 

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this report were furnished to us by Eni. The differentialsfurnished to us were accepted as factual data and reviewed by usfor their reasonableness; however, we have not conducted anindependent verification of the data used by Eni to determinethese differentials.

***Costs***

Operating costs used in our evaluation were based on theoperating expense reports of Eni and include only those costsdirectly applicable to the evaluated assets. The operating costsinclude a portion of general and administrative costs allocateddirectly to the leases and wells. The operating costs furnishedto us were accepted as factual data and reviewed by us for theirreasonableness; however, we have not conducted an independentverification of the operating cost data used by Eni. No deductionwas made for loan repayments, interest expenses, or explorationand development prepayments that were not charged directly to theassets.

Development costs were furnished to us by Eni and are based onauthorizations for expenditure for the proposed work or actualcosts for similar projects. The development costs furnished to uswere accepted as factual data and reviewed by us for theirreasonableness; however, we have not conducted an independentverification of these costs. The estimated net cost ofabandonment after salvage was included for properties whereabandonment costs net of salvage were significant. The estimatesof the net abandonment costs furnished by Eni were acceptedwithout independent verification.****

The proved developed and undeveloped reserves in this reporthave been incorporated herein in accordance with Eni’s plansto develop these reserves as of December 31, 2009. Theimplementation of Eni’s development plans as presented to usand incorporated herein is subject to the approval processadopted by Eni’s management. As the result of our inquiresduring the course of preparing this report, Eni has informed usthat the development activities included herein have beensubjected to and received the internal approvals required byEni’s management at the appropriate local, regional and/orcorporate level. In addition to the internal approvals as noted,certain development activities may still be subject to specificpartner AFE processes, Joint Operating Agreement (JOA)requirements or other administrative approvals external to Eni.Additionally, Eni has informed us that they are not aware of anylegal, regulatory, political or economic obstacles that wouldsignificantly alter their plans. 

Current costs used by Eni were held constant throughout thelife of the properties.

***Standards of Independence and Professional Qualification***

Ryder Scott is an independent petroleum engineering consultingfirm that has been providing petroleum consulting servicesthroughout the world for over seventy years. Ryder Scott isemployee-owned and maintains offices in Houston, Texas; Denver,Colorado; and Calgary, Alberta, Canada. We have over eightyengineers and geoscientists on our permanent staff. By virtue ofthe size of our firm and the large number of clients for which weprovide services, no single client or job represents a materialportion of our annual revenue. We do not serve as officers ordirectors of any publicly-traded oil and gas company and areseparate and independent from the operating and investmentdecision-making process of our clients. This allows us to bringthe highest level of independence and objectivity to eachengagement for our services.

Ryder Scott actively participates in industry-relatedprofessional societies and organizes an annual public forumfocused on the subject of reserves evaluations and SECregulations. Many of our staff have authored or co-authoredtechnical papers on the subject of reserves related topics. We 

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encourage our staff to maintain and enhance their professionalskills by actively participating in ongoing continuing education.

Prior to becoming an officer of the Company, Ryder Scottrequires that staff engineers and geoscientists have receivedprofessional accreditation in the form of a registered orcertified professional engineer’s license or a registered orcertified professional geoscientist’s license, or theequivalent thereof, from an appropriate governmental authority ora recognized self-regulating professional organization.

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

The results of this study, presented herein, are based ontechnical analysis conducted by teams of geoscientists andengineers from Ryder Scott. The professional qualifications ofthe undersigned, the technical person primarily responsible foroverseeing, reviewing and approving the evaluation of thereserves information discussed in this report, are included as anattachment to this letter.

**Terms of Usage**

The results of our third party study, presented in report formherein, were prepared in accordance with the disclosurerequirements set forth in the SEC regulations and intended forpublic disclosure as an exhibit in filings made with the SEC byEni. 

We have provided Eni with a digital version of the originalsigned copy of this report letter. In the event there are anydifferences between the digital version included in filings madeby Eni and the original signed report letter, the original signedreport letter shall control and supersede the digital version.

The data and work papers used in the preparation of thisreport are available for examination by authorized parties in ouroffices. 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. ACUÑA                            |
|   |                                                |
|   | Herman G. Acuña, P.E.                          |
|   | TBPE License No. 92254                              |
|   | Managing Senior Vice        President-International |

 

 

| HGA/sm | [SEAL] |
|--------|--------|

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**Professional QualificationsHerman G. Acuña**

The conclusions presented in the report issued on February 23,2010 for Eni S.p.A are the result of technical analysis conductedby teams of geoscientists and engineers from Ryder Scott Company,L.P. Herman G. Acuña was the primary technical personresponsible for overseeing the independent estimation of thereserves, future production and income to render the auditconclusions of that report.

Mr. Acuña, an employee of Ryder Scott Company L.P. (RyderScott) since 1997, is a Managing Senior International VicePresident and serves as an Engineering Group Coordinatorresponsible for coordinating and supervising staff and consultingengineers of the company in ongoing reservoir evaluation studiesworldwide. Before joining Ryder Scott, Mr. Acuña served in anumber of engineering positions with Exxon. For more informationregarding Mr. Acuña’s geographic and job specificexperience, please refer to the Ryder Scott Company website at www.ryderscott.com/Experience/Employees.

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

In addition to gaining experience and competency through priorwork experience, the Texas Board of Professional Engineersrequires a minimum of fifteen hours of continuing educationannually, including at least one hour in the area of professionalethics, which Mr. Acuña fulfills. As part of his 2009 continuingeducation hours, Mr. Acuña attended over 34 hours of formalizedtraining and conferences including 10 hours dedicated to thesubject of the definitions and disclosure guidelines contained inthe United States Securities and Exchange Commission Title 17,Code of Federal Regulations, Modernization of Oil and GasReporting, Final Rule released January 14, 2009 in the FederalRegister. In 2009, Mr. Acuña taught various company reservesevaluation schools in Argentina, Bolivia, China, Spain, U.S.A andVenezuela. Mr. Acuña has participated in various capacities inreserves conferences such as being a panelist a the 2008 Trinidadand Tobago’s Petroleum Conference, delivering the reservesevaluation seminar during IAPG convention in Mendoza, Argentinain 2006 and chairing the first Reserves Evaluation Conference inthe Middle East in Dubai, U.A.E in 2006. 

Based on his educational background, professional training and20 years of practical experience in petroleum engineering and theestimation and evaluation of petroleum reserves, Mr. Acuña hasattained the professional qualifications as a Reserves Estimatorand Reserves Auditor set forth in Article III of the"Standards Pertaining to the Estimating and Auditing of Oiland Gas Reserves Information" promulgated by the Society ofPetroleum 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 EXCHANGECOMMISSION (SEC)**

 

 

***PREAMBLE***

On January 14, 2009, the United States Securities and ExchangeCommission (SEC) published the "Modernization of Oil and GasReporting; Final Rule" in the Federal Register of NationalArchives and Records Administration (NARA). The"Modernization of Oil and Gas Reporting; Final Rule"includes revisions and additions to the definition section inRule 4-10 of Regulation S-X, revisions and additions to the oiland gas reporting requirements in Regulation S-K, and amends andcodifies 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 "SECRegulations". The SEC Regulations take effect for allfilings made with the United States Securities and ExchangeCommission as of December 31, 2009, or after January 1, 2010.Reference should be made to the full text under Title 17, Code ofFederal Regulations, Regulation S-X Part 210, Rule 4-10(a) forthe complete definitions, as the following definitions,descriptions and explanations rely wholly or in part on excerptsfrom the original document (direct passages excerpted from theaforementioned SEC document are denoted in italics herein).

Reserves are those estimated remaining quantities of petroleumwhich are anticipated to be economically producible, as of agiven date, from known accumulations under defined conditions.All reserve estimates involve some degree of uncertainty. Theuncertainty depends chiefly on the amount of reliable geologicand engineering data available at the time of the estimate andthe interpretation of these data. The relative degree ofuncertainty may be conveyed by placing reserves into one of twoprincipal classifications, either proved or unproved. Unprovedreserves are less certain to be recovered than proved reservesand may be further sub-classified as probable and possiblereserves to denote progressively increasing uncertainty in theirrecoverability. Under the SEC Regulations as of December 31,2009, or after January 1, 2010, a company may optionally discloseestimated quantities of probable or possible oil and gas reservesin documents publicly filed with the Commission. The SECRegulations continue to prohibit disclosure of estimates of oiland gas resources other than reserves and any estimated values ofsuch resources in any document publicly filed with the Commissionunless such information is required to be disclosed in thedocument by foreign or state law as noted in §229.1202Instruction to Item 1202.

Reserves estimates will generally be revised as additionalgeologic or engineering data become available or as economicconditions change.

Reserves may be attributed to either natural energy orimproved recovery methods. Improved recovery methods include allmethods for supplementing natural energy or altering naturalforces in the reservoir to increase ultimate recovery. Examplesof such methods are pressure maintenance, natural gas cycling,waterflooding, thermal methods, chemical flooding, and the use ofmiscible and immiscible displacement fluids. Other improvedrecovery methods may be developed in the future as petroleumtechnology continues to evolve.

 

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PETROLEUM RESERVES DEFINITIONSPage 2

 

 

Reserves may be attributed to either conventional orunconventional petroleum accumulations. Petroleum accumulationsare considered as either conventional or unconventional based onthe nature of their in-place characteristics, extraction methodapplied, or degree of processing prior to sale. Examples ofunconventional petroleum accumulations include coalbed orcoalseam methane (CBM/CSM), basin-centered gas, shale gas, gashydrates, natural bitumen and oil shale deposits. Theseunconventional accumulations may require specialized extractiontechnology and/or significant processing prior to sale. Reserves do not include quantities of petroleum being held ininventory. 

Because of the differences in uncertainty, caution should beexercised when aggregating quantities of petroleum from differentreserves categories.****

**RESERVES (SEC DEFINITIONS)**

Securities and Exchange Commission Regulation S-X§210.4-10(a)(26) defines reserves as follows:

***Reserves.****Reserves are estimated remainingquantities of oil and gas and related substances anticipated tobe economically producible, as of a given date, by application ofdevelopment projects to known accumulations. In addition, theremust exist, or there must be a reasonable expectation that therewill exist, the legal right to produce or a revenue interest inthe production, installed means of delivering oil and gas orrelated substances to market, and all permits and financingrequired to implement the project.*

*Note to paragraph (a)(26):**Reserves shouldnot be assigned to adjacent reservoirs isolated by major,potentially sealing, faults until those reservoirs are penetratedand evaluated as economically producible. Reserves should not beassigned to areas that are clearly separated from a knownaccumulation by a non-productive reservoir (**i.e.**,absence of reservoir, structurally low reservoir, or negativetest results). Such areas may contain prospective resources (**i.e.**,potentially recoverable resources from undiscoveredaccumulations).*

**PROVED RESERVES (SEC DEFINITIONS)**

Securities and Exchange Commission Regulation S-X§210.4-10(a)(22) defines proved oil and gas reserves as follows:

***Proved oil and gas reserves.****Proved oil andgas reserves are those quantities of oil and gas, which, byanalysis of geoscience and engineering data, can be estimatedwith reasonable certainty to be economically producible—froma given date forward, from known reservoirs, and under existingeconomic conditions, operating methods, and governmentregulations—prior to the time at which contracts providingthe right to operate expire, unless evidence indicates thatrenewal is reasonably certain, regardless of whetherdeterministic or probabilistic methods are used for theestimation. The project to extract the hydrocarbons must havecommenced or the operator must be reasonably certain that it willcommence 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*

 

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PETROLEUM RESERVES DEFINITIONSPage 3

> 
 

*(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.*

**PROVED RESERVES (SEC DEFINITIONS) CONTINUED**

> 
*(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.*

 

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**RESERVES STATUS DEFINITIONS AND GUIDELINES**

**As Adapted From:RULE 4-10(a) of REGULATION S-X PART 210UNITED 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 andproducing status of wells and reservoirs. Reference should bemade to Title 17, Code of Federal Regulations, Regulation S-XPart 210, Rule 4-10(a) and the SPE-PRMS as the following reservesstatus definitions are based on excerpts from the originaldocuments (direct passages excerpted from the aforementioned SECand SPE-PRMS documents are denoted in italics herein).****

**DEVELOPED RESERVES (SEC DEFINITIONS)**

Securities and Exchange Commission Regulation S-X§210.4-10(a)(6) defines developed oil and gas reserves asfollows:

> 
*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 SECregulations, developed oil and gas reserves may be furthersub-classified according to the guidance contained in theSPE-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.*

 

RYDER SCOTT COMPANY      PETROLEUMCONSULTANTS

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RESERVES STATUS DEFINITIONS AND GUIDELINESPage 2

 

 

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

***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§210.4-10(a)(31) defines undeveloped oil and gas reserves asfollows:

> 
*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.*

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*(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.*

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*(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.*

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*(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      PETROLEUMCONSULTANTS

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**EXHIBIT 15.a(v)**

 

DeGolyer And MacNaughton5001 Spring Valley RoadSuite 800 EastDallas, Texas 75244

 

November 6, 2009

 

 

> 
Mr. Lorenzo Acquati        Reserves Guidelines Coordinator        Eni E&P Division        Via Emilia, 1        20097 San Donato Milanese (MI)        ITALY

Dear Mr. Acquati:

Pursuant to your request, DeGolyer and MacNaughton has        reviewed the document entitled "Eni S.p.A.        Exploration and Production Division: Division Directive        for Evaluation, Classification, and Reporting of        Petroleum Reserves and Contingent Resources; November 4,        2009." The document was provided electronically to        DeGolyer and MacNaughton on November 5, 2009.

The document is represented as being based on research        of the requirements (2008 Release) of the United States        Securities and Exchange Commission (SEC) and the        Petroleum Resources Management System (PRMS) approved in        March 2007 by the Society of Petroleum Engineers, the        World Petroleum Council, the American Association of        Petroleum Geologists, and the Society of Petroleum        Evaluation Engineers, as they apply to reserves and        contingent resources classification, categorization,        estimating, and reporting. It is observed that,        throughout the document, language directly from SEC        regulations, as well as PRMS, has been used. Where        specific language from SEC rules or PRMS did not apply,        typical industry standards have been utilized. It should        be noted that the SEC has not commented on the PRMS and        has not endorsed any specific methodology for determining        reserves, nor has the SEC made any references to        estimating contingent resources.

> 
In our opinion, the referenced document presents        guidelines for preparing estimates of proved, probable,        and possible reserves that, if followed, would result in        reporting reserves as specified in Rules 4-10(a)(1)-(32)        of Regulation S-X and Rule 302(b) of Regulation S-K of        the SEC and paragraphs 10-13 and 15 of the Statement of        Financial Accounting Standards No. 69 (November 1982) of        the

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> 
Financial Accounting Standards Board (FASB). This        opinion is based on our review of the document and our        understanding of how the guidelines will be applied from        discussions with Eni. The document addresses situations        where SEC rules are less specific in a reasonable manner        and provides guidance that is aligned with SEC standards        and general industry practice.

Due to the recent implementation of the 2008 release        of the SEC rules, there are a number of issues that are        due for additional commentary and clarification by the        SEC and its staff. However, that additional information        is not yet available and may not be until well into the        next calendar year. As such, the comments herein        regarding compliance are applicable to prevailing        conditions, interpretations, and public commentary at the        date of this document. Thus, any such interpretations and        implementation opinions are, particularly at this        juncture in the application of the new SEC rules, subject        to review and reconsideration pending any future public        comments from the SEC staff.

It is also our opinion, that the referenced document        presents guidelines for preparing estimates of contingent        resources that, if followed, would result in volumes in        accordance with the PRMS published and approved in 2007.        This opinion is based on our review of the document and        our understanding of how the guidelines will be applied        from discussions with Eni.

To the extent that the document requires        determinations of an accounting or legal nature, DeGolyer        and MacNaughton is necessarily unable to express an        opinion.

 

 

|   | Submitted,                              |
|--------|-----------------------------------------|
|   |                                    |
|   | /s/ DEGOLYER AND MACNAUGHTON            |
|   |                                    |
|   | DeGOLYER and MacNAUGHTON                |
|   | Texas Registered Engineering Firm F-716 |

 

 

 

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