Exhibit 23.6

ATP OIL & GAS CORPORATION

Estimated

Future Reserves and Income

Attributable to Certain

Leasehold and Royalty Interests

SEC Parameters

As of

December 31, 2009



|                          |  |  |  |                               
|------------------------- |  |  |  | ------------------------------
|/s/ Eric T. Nelson        |  |  |  | /s/ John E. Hamlin            
|Eric T. Nelson, P.E.      |  |  |  | John E. Hamlin, P.E.          
|TBPE License No. 102286   |  |  |  | TBPE License No. 65319        
|Senior Petroleum Engineer |  |  |  | Managing Senior Vice President

RYDER SCOTT COMPANY, L.P.

TBPE Firm Registration No. F-1580



|       |  |       
|------ |  | ------
|[SEAL] |  | [SEAL]

RYDER SCOTT
COMPANY     PETROLEUM CONSULTANTS



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|     |                                         |      |                           |  |                          | 
|---- | --------------------------------------- | ---- | ------------------------- |  | ------------------------ | 
|LOGO |                                         | LOGO |                           |  |                          | 
|     | TBPE REGISTERED ENGINEERING FIRM
F-1580 |      | FAX (713) 651-0849       
|     | 1100 LOUISIANA         SUITE 3800       |      | HOUSTON, TEXAS 77002-5218 |  | TELEPHONE (713) 651-9191

February 3, 2010

ATP Oil & Gas Corporation

4600 Post Oak Place, Suite 200

Houston, TX 77027

Gentlemen:

At your request, we
have prepared an estimate of the proved reserves, future production, and income attributable to certain leasehold and royalty interests of ATP Oil & Gas Corporation (ATP) as of December 31, 2009. The subject properties are located in
the federal waters offshore Louisiana and Texas and in the state waters offshore Louisiana. The reserves and income data were estimated based on the definitions and disclosure guidelines contained in the United States Securities and Exchange
Commission Title 17, Code of Federal Regulations, Modernization of Oil and Gas Reporting, Final Rule released January 14, 2009 in the Federal Register (SEC regulations). The results of our third party study, completed on February 3, 2010,
are presented herein. Based on information provided by ATP, the proved reserves summarized in this report represent approximately two percent of the total net proved reserves on a gas equivalent, MMCFE, basis (using 6.0 MCF/BBL for hydrocarbon
liquids).

The estimated reserves and future net income amounts presented in this report, as of December 31, 2009, are
related to hydrocarbon prices. The hydrocarbon prices used in the preparation of this report are based on the average prices during the 12-month period prior to the ending date of the period covered in this report, determined as unweighted
arithmetic averages of the prices in effect on the first-day-of-the-month for each month within such period, unless prices were defined by contractual arrangements as required by the SEC regulations. Actual future prices may vary significantly from
the prices required by SEC regulations; therefore, volumes of reserves actually recovered and the amounts of income actually received may differ significantly from the estimated quantities presented in this report. The results of this study are
summarized below.

SEC PARAMETERS

Estimated Net Reserves and Income Data

Certain Leasehold and Royalty Interests of

ATP Oil & Gas Corporation

As of December 31, 2009



|                         |  |           |            |               |   |             |  |   |            |  |   |           
|------------------------ |  | --------- | ---------- | ------------- | - | ----------- |  | - | ---------- |  | - | ----------
|                         |  | Proved   
|                         |  | Developed |            | Undeveloped   |   | TotalProved
|                         |  | Producing |            | Non-Producing |   |            
|Net Remaining Reserves   |  |           |            |               |   |             |  |   |            |  |   |           
|Oil/Condensate  Barrels |  |           | 492,107    |               |   | 287,006     |  |   | 183,271    |  |   | 962,384   
|Gas  MMCF               |  |           | 5,391      |               |   | 3,073       |  |   | 649        |  |   | 9,113     
|                         |  |           |            |              
|Income Data              |  |           |            |               |   |             |  |   |            |  |   |           
|Future Gross Revenue     |  | $         | 49,755,933 |               | $ | 30,219,956  |  | $ | 13,802,836 |  | $ | 93,778,725
|Deductions               |  |           | 35,689,462 |               |   | 27,924,316  |  |   | 11,188,315 |  |   | 74,802,093
|                         |  |           |            |               |   |             |  |   |            |  |   |           
|Future Net Income (FNI)  |  | $         | 14,066,471 |               | $ | 2,295,640   |  | $ | 2,614,521  |  | $ | 18,976,632
|                         |  |           |            |              
|Discounted FNI @ 10%     |  | $         | 18,033,673 |               | $ | 2,119,005   |  | $ | 1,706,000  |  | $ | 21,858,678



|                                                                                                         
|---------------------------------------------------------------------------------------------------------
|1200, 530 8TH AVENUE, S.W. CALGARY, ALBERTA T2P 3S8         TEL (403) 262-2799
        FAX (403) 262-2790
|621 17TH STREET, SUITE 1550 DENVER, COLORADO 80293-1501 TEL (303) 623-9147         FAX (303) 623-4258    



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ATP Oil & Gas Corporation

February 3, 2010

Page 2



Liquid hydrocarbons are expressed in standard 42 gallon barrels. All gas volumes are
reported on an as sold basis expressed in millions of cubic feet (MMCF) at the official temperature and pressure bases of the areas in which the gas reserves are located.

The estimates of the reserves, future production, and income attributable to properties in this report were prepared using the economic software package PHDWin Petroleum Economic Evaluation Software, a
copyrighted program of TRC Consultants L.C. The program was used solely at the request of ATP. Ryder Scott has found this program to be generally acceptable, but notes that certain summaries and calculations may vary due to rounding and may not
exactly match the sum of the properties being summarized. Furthermore, one line economic summaries may vary slightly from the more detailed cash flow projections of the same properties, also due to rounding. The rounding differences are not
material.

The future gross revenue is after the deduction of production taxes, if any. The deductions comprise the normal
direct costs of operating the wells, ad valorem taxes, recompletion costs, development costs, and certain abandonment costs net of salvage. Certain gas, oil and condensate processing and handling fees, including compression fees where applicable,
are included as other costs. The future net income is before the deduction of state and federal income taxes and general administrative overhead, and has not been adjusted for outstanding loans that may exist nor does it include any
adjustment for cash on hand or undistributed income.

Liquid hydrocarbon reserves account for approximately 62 percent of the
total future gross revenue from proved reserves and gas reserves account for the remaining 38 percent of total future gross revenue from proved reserves.

The discounted future net income shown above was calculated using a discount rate of 10 percent per annum compounded monthly. Future net income was discounted at four other discount rates, which were also
compounded monthly. These results are shown in summary form as follows.



|                      |  |                                                     
|--------------------- |  | ----------------------------------------------------
|                      |  | Discounted Future Net Income As of December 31, 2009
|                     
|Discount Rate Percent |  | Total Proved                                        
|                     
|                      | 
|5                     |  | $20,714,678                                         
|15                    |  | $22,575,565                                         
|20                    |  | $22,983,516                                         
|30                    |  | $23,186,992                                         

The results
shown above are presented for your information and should not be construed as our estimate of fair market value.

Reserves Included in
This Report

The proved reserves included herein conform to the definitions as set forth in the Securities and Exchange
Commissions Regulations Part 210.4-10 (a). An abridged version of the SEC reserves definitions from 210.4-10(a) entitled Petroleum Reserves Definitions is included as an attachment to this report.



RYDER SCOTT COMPANY    PETROLEUM CONSULTANTS



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ATP Oil & Gas Corporation

February 3, 2010

Page 3



The various reserve status categories are defined in the attachment to this report
entitled Petroleum Reserves Definitions. The developed non-producing reserves included herein consist of the behind pipe category.

No attempt was made to quantify or otherwise account for any accumulated gas production imbalances that may exist. The gas volumes included herein do not attribute gas consumed in operations as reserves.

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

Proved oil and gas reserves are those quantities of oil and gas, which, by analysis of geoscience and engineering data, can be estimated
with reasonable certainty to be economically producible from a given date forward. Moreover, estimates of reserves may increase or decrease as a result of future operations, effects of regulation by governmental agencies or geopolitical risks. As a
result, the estimates of oil and gas reserves have an intrinsic uncertainty. The reserves included in this report are therefore estimates only and should not be construed as being exact quantities. They may or may not be actually recovered, and if
recovered, the revenues therefrom and the actual costs related thereto could be more or less than the estimated amounts.

ATPs operations may be subject to various levels of governmental controls and regulations. These controls and regulations may include matters relating to land tenure, drilling, production practices, environmental protection, marketing
and pricing policies, royalties, and various taxes and levies including income tax, and are subject to change from time to time. Such changes in governmental regulations and policies may cause volumes of reserves actually recovered and amounts of
income actually received to differ significantly from the estimated quantities.

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

Estimates
of Reserves

The reserves for the properties included herein were estimated by performance methods or the volumetric
method. In general, reserves attributable to producing wells and/or reservoirs were estimated by performance methods such as decline curve analysis and/or material balance which utilized extrapolations of historical production and pressure data
available through October, 2009 in those cases where such data were considered to be definitive. In certain cases, producing reserves were estimated by the volumetric method where there were inadequate historical performance data to establish a
definitive trend and where the use of production performance data as a basis for the reserve estimates was considered to be inappropriate. Reserves attributable to proved non-producing and undeveloped reserves included herein were primarily
estimated by the volumetric method which utilized all pertinent well and seismic data available through October, 2009. We utilized all methods and procedures that we deemed necessary to estimate ATPs proved reserves, and we affirm that those
methods and procedures were appropriate for this purpose.



RYDER SCOTT COMPANY    PETROLEUM CONSULTANTS



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ATP Oil & Gas Corporation

February 3, 2010

Page 4



To estimate economically recoverable oil and gas reserves and related future net cash
flows, we consider many factors and assumptions including, but not limited to, the use of reservoir parameters derived from geological, geophysical and engineering data which cannot be measured directly, economic criteria based on current costs and
SEC pricing requirements, and forecasts of future production rates. Under the SEC regulations 210.4-10(a)(22)(v) and (26), proved reserves must be demonstrated to be economically producible based on existing economic conditions including the prices
and costs at which economic producibility from a reservoir is to be determined as of the effective date of the report. ATP has informed us that they have furnished us all of the accounts, records, geological and engineering data, and reports and
other data required for this investigation. In preparing our forecast of future production and income, we have relied upon data furnished by ATP with respect to property interests owned, production and well tests from examined wells, normal direct
costs of operating the wells or leases, other costs such as transportation and/or processing fees, recompletion and development costs, abandonment costs after salvage, product prices based on the SEC regulations, geological structural and isochore
maps, well logs, core analyses, and pressure measurements. Ryder Scott reviewed such factual data for its reasonableness; however, we have not conducted an independent verification of the data supplied by ATP.

Future Production Rates

Our forecasts of future production rates are based on historical performance from wells now on production. Test data and other related information were used to estimate the anticipated initial production rates for those wells or locations
that are not currently producing. If no production decline trend has been established, future production rates were held constant, or adjusted for the effects of curtailment where appropriate, until a decline in ability to produce was anticipated.
An estimated rate of decline was then applied to depletion of the reserves. If a decline trend has been established, this trend was used as the basis for estimating future production rates. For reserves not yet on production, sales were estimated to
commence at an anticipated date furnished by ATP.

The future production rates from wells now on production may be more or
less than estimated because of changes in market demand or allowables set by regulatory bodies. Wells or locations that are not currently producing may start producing earlier or later than anticipated in our estimates.

Hydrocarbon Prices

As previously stated, the hydrocarbon prices used herein are based on the average prices during the 12-month period prior to the ending date of the period covered in this report, determined as the unweighted arithmetic averages of the
prices in effect on the first-day-of-the-month for each month within such period. Product prices which were actually used for each property reflect adjustment for gravity, quality, local conditions, and/or distance from market.

The effects of derivative instruments designated as price hedges of oil and gas quantities are not reflected in our individual property
evaluations.

Costs

Operating costs for the leases and wells in this report are based on the operating expense reports of ATP and include only those costs directly applicable to the leases or wells. The operating costs
include a portion of general and administrative costs allocated directly to the leases and wells.



RYDER SCOTT COMPANY    PETROLEUM CONSULTANTS



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ATP Oil & Gas Corporation

February 3, 2010

Page 5



When applicable for operated properties, the operating costs include an appropriate level of corporate general administrative and overhead costs. The operating costs for non-operated properties
include the COPAS overhead costs that are allocated directly to the leases and wells under terms of operating agreements. Certain gas, oil and condensate processing and handling fees, including compression fees where applicable, are included as
other costs. No deduction was made for loan repayments, interest expenses, or exploration and development prepayments that were not charged directly to the leases or wells.

Development costs were furnished to us by ATP and are based on authorizations for expenditure for the proposed work or actual costs
for similar projects. The estimated net cost of abandonment after salvage was included for properties where abandonment costs net of salvage was significant. The estimates of the net abandonment costs furnished by ATP were accepted without
independent verification.

Because of the direct relationship between volumes of proved undeveloped reserves and
development plans, we include in the proved undeveloped category only reserves assigned to undeveloped locations that we have been assured will definitely be drilled. ATP has assured us of their intent and ability to proceed with the development
activities included in this report, and that they are not aware of any legal, regulatory or political obstacles that would significantly alter their plans.

Current costs used by ATP were held constant throughout the life of the properties.

Standards of Independence and Professional Qualification

Ryder Scott is an independent petroleum
engineering consulting firm that has been providing petroleum consulting services throughout the world for over seventy years. Ryder Scott is employee owned and maintains offices in Houston, Texas; Denver, Colorado; and Calgary, Alberta, Canada. We
have over eighty engineers and geoscientists on our permanent staff. By virtue of the size of our firm and the large number of clients for which we provide services, no single client or job represents a material portion of our annual revenue. We do
not serve as officers or directors of any publicly traded oil and gas company and are separate and independent from the operating and investment decision-making process of our clients. This allows us to bring the highest level of independence and
objectivity to each engagement for our services.

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

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

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



RYDER SCOTT COMPANY    PETROLEUM CONSULTANTS



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ATP Oil & Gas Corporation

February 3, 2010

Page 6



The professional qualifications of the undersigned, the technical person primarily
responsible for reviewing and approving the reserves information discussed in this report are included as an attachment to this letter.

Terms of Usage

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



Very truly yours,RYDER SCOTT COMPANY, L.P. TBPE Firm Registration No. F-1580/s/ Eric T. NelsonEric T. Nelson, P.E.TBPE License No. 102286

[SEAL]Senior Petroleum Engineer/s/ John E. HamlinJohn E. Hamlin, P.E.TBPE License No. 65319

[SEAL]Managing Senior Vice President


ETN/sm



RYDER SCOTT COMPANY    PETROLEUM CONSULTANTS



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Professional Qualifications of Primary Technical Person

The conclusions presented in this report are the result of technical analysis conducted by teams of geoscientists and engineers from Ryder Scott Company,
L.P. Mr. John E. Hamlin was the primary technical person responsible for overseeing the estimate of the reserves, future production, and income presented herein.

Mr. Hamlin, an employee of Ryder Scott Company L.P. (Ryder Scott) since 1979, is a Managing Senior Vice President and also serves as an Engineering Group Supervisor responsible for coordinating and
supervising staff and consulting engineers of the company in ongoing reservoir evaluation studies worldwide. Before joining Ryder Scott, Mr. Hamlin served in a number of engineering positions with Phillips Petroleum Corporation. For more
information regarding Mr. Hamlins geographic and job specific experience, please refer to the Ryder Scott Company website at http://www.ryderscott.com/Experience/Employees.php.

Mr. Hamlin earned a Bachelor of Science degree in Petroleum Engineering from the University of Texas at Austin in 1975 and is a registered Professional
Engineer in the State of Texas. He is also a member of the Society of Petroleum Engineers.

In addition to gaining experience and competency
through prior work experience, the Texas Board of Professional Engineers requires a minimum of 15 hours of continuing education annually, including at least one hour in the area of professional ethics, which Mr. Hamlin fulfills. As part of his
2009 continuing education hours, Mr. Hamlin attended an internally presented 9 hours of formalized training as well as a day long public forum relating to the definitions and disclosure guidelines contained in the United States Securities and
Exchange Commission Title 17, Code of Federal Regulations, Modernization of Oil and Gas Reporting, Final Rule released January 14, 2009 in the Federal Register. Mr. Hamlin attended an additional 24 hours of formalized in-house training as
well as an additional 4 hours of formalized external training during 2009 covering such topics as the SPE/WPC/AAPG/SPEE Petroleum Resources Management System, reservoir engineering, geoscience and petroleum economics evaluation methods, procedures
and software and ethics for consultants.

Based on his educational background, professional training and more than 33 years of practical
experience in the estimation and evaluation of petroleum reserves, Mr. Hamlin has attained the professional qualifications as a Reserves Estimator and Reserves Auditor set forth in Article III of the Standards Pertaining to the Estimating
and Auditing of Oil and Gas Reserves Information promulgated by the Society of Petroleum Engineers as of February 19, 2007.



RYDER SCOTT COMPANY    PETROLEUM CONSULTANTS



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PETROLEUM RESERVES DEFINITIONS

As Adapted From:

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

UNITED STATES SECURITIES AND EXCHANGE COMMISSION (SEC)

PREAMBLE

On January 14, 2009, the United States Securities and Exchange Commission (the Commission) published the Modernization of Oil and Gas Reporting; Final Rule in the Federal Register of National Archives and
Records Administration (NARA). The Modernization of Oil and Gas Reporting; Final Rule includes revisions and additions to the definition section in Rule 4-10 of Regulation S-X, revisions and additions to the oil and gas reporting
requirements in Regulation S-K, and amends and codifies Industry Guide 2 in Regulation S-K. The Modernization of Oil and Gas Reporting; Final Rule, including all references to Regulation S-X and Regulation S-K, shall be referred to
herein collectively as the SEC Regulations. The SEC Regulations take effect with all filings made with the United States Securities and Exchange Commission as of December 31, 2009, or after January 1, 2010. Reference should be
made to the full text under Title 17, Code of Federal Regulations, Regulation S-X Part 210, Rule 4-10 (a) for the complete definitions, as the following definitions, descriptions and explanations rely wholly or in part on excerpts from the
original document (direct passages excerpted from the aforementioned SEC document are denoted in italics herein).

Reserves
are those quantities of petroleum which are anticipated to be commercially recovered from known accumulations from a given date forward under defined conditions. All reserve estimates involve some degree of uncertainty. The uncertainty depends
chiefly on the amount of reliable geologic and engineering data available at the time of the estimate and the interpretation of these data. The relative degree of uncertainty may be conveyed by placing reserves into one of two principal
classifications, either proved or unproved. Unproved reserves are less certain to be recovered than proved reserves and may be further sub-classified as probable and possible reserves to denote progressively increasing uncertainty in their
recoverability. Under the SEC Regulations as of December 31, 2009, or after January 1, 2010, a company may optionally disclose estimated quantities of probable or possible oil and gas reserves in documents publicly filed with the
Commission. The SEC Regulations continue to prohibit disclosure of estimates of oil and gas resources other than reserves and any estimated values of such resources in any document publicly filed with the Commission unless such information is
required to be disclosed in the document by foreign or state law as noted in §229.102 (5).

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

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



RYDER SCOTT COMPANY    PETROLEUM CONSULTANTS



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PETROLEUM RESERVES DEFINITIONS

Page 2



RESERVES (SEC DEFINITIONS)

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

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

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

PROVED
RESERVES (SEC DEFINITIONS)

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

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

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

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

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

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

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



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RESERVES DEFINITIONS

Page 3



(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.

[Remainder of this page is
left blank intentionally]



RYDER SCOTT COMPANY    PETROLEUM CONSULTANTS



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RESERVES STATUS DEFINITIONS AND GUIDELINES

Page 1



RESERVES STATUS DEFINITIONS AND GUIDELINES

As Adapted From:

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

UNITED STATES SECURITIES AND EXCHANGE COMMISSION (SEC)

and

PETROLEUM RESOURCES MANAGEMENT SYSTEM (SPE-PRMS)

Sponsored and Approved
by:

SOCIETY OF PETROLEUM ENGINEERS (SPE),

WORLD PETROLEUM COUNCIL (WPC)

AMERICAN ASSOCIATION
OF PETROLEUM GEOLOGISTS (AAPG)

SOCIETY OF PETROLEUM EVALUATION ENGINEERS (SPEE)

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

DEVELOPED RESERVES (SEC DEFINITIONS)

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

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

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

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

Developed Producing (SPE-PRMS
Definitions)

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

Developed
Producing Reserves

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

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

Developed Non-Producing

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



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RESERVES DEFINITIONS

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Shut-In

Shut-in Reserves are expected to be recovered from:

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

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

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

Behind-Pipe

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

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

UNDEVELOPED RESERVES (SEC DEFINITIONS)

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

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

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

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

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



RYDER SCOTT COMPANY    PETROLEUM CONSULTANTS