PRMS

Project No. D105

Prepared for GCA Clients, July 2007

Reserve Audit Processusing SPE Petroleum Resources Management System (PRMS)

D1052

Topics for Discussion

Brief comments on the revised “Standards” document and “auditing” Review of key features of the new SPE PRMS definitions

D1053

Standards Pertaining to the Estimating and Auditing of Oil and Gas Reserve Information

Although the standards have no legal or other force, they represent a generally-accepted set of guidelines for the conduct of Reserves Estimation and Auditing

The original version was published in 1977 and last updated in 2001 The current 2007 edition:

Includes modifications required to incorporate the latest PRMS Although it remains concerned with Reserves only at present

Clarifies the terms “auditors” and “auditing”, as well as “process review” Acknowledges the integration of geoscience with engineering in the preparation

of reliable reserves information

Companies may require their internal or external Reserves Estimators and Auditors to comply with these standards

Project No. D105

Part I: Reserve Audit Fundamentals

Prepared for GCA’s clients, July 2007

D1055

Reserves Audit - 1

“A Reserves Audit is the process of reviewing certain of the pertinent facts interpreted and assumptions made that have resulted in an estimate of reserves and/or Reserves Information prepared by others and the rendering of an opinion about: the appropriateness of the methodologies employed the adequacy and quality of the data relied upon the depth and thoroughness of the reserves estimation process the classification of reserves appropriate to the relevant definitions used the reasonableness of the estimated reserves quantities and/or the Reserves

Information The term “reasonableness” cannot be defined with precision but should

reflect a quantity and/or value difference of not more than plus or minus 10%, or the subject Reserves Information does not meet minimum recommended audit standards This tolerance can be applied to any level of reserves or Reserves Information

aggregation, depending upon the nature of the assignment, but is most often limited to Proved Reserves Information

A separate predetermined and disclosed tolerance may be appropriate for other reserves classifications”

D1056

Reserves Audit - 2

“Often a reserves audit includes a detailed review of certain critical assumptions and independent assessments with acceptance of other information less critical to the reserves estimation”

“A reserves audit should be of sufficient rigor to determine the appropriate reserves classification for all reserves in the property set evaluated and to clearly state the reserves classification system being utilized”

“In some cases, the auditing procedure may require independent estimates of Reserves Information for some or all properties”

D1057

Process Review

“A Process Review is the result of an investigation by a person who is qualified by experience and training equivalent to that of a Reserves Auditor to address the adequacy and effectiveness of an entity’s internal processes and controls relative to reserves estimation

These internal processes and controls most often include some form of an independent internal or external reserves audit system

The Process Review should not include an opinion relative to the reasonableness of the reserves quantities or Reserves Information and should be limited to the process and control system reviewed

The term process review includes reports that have also been termed “procedural audits” or “procedural reviews” in the industry

Although such reviews may provide value to the entity, an external or internal Process Review is not of sufficient rigor to establish appropriate classifications and quantities of reserves and should not be represented to the public as being equivalent to an audit of reserves”

D1058

Audit Methodology

The following list is intended to establish broad requirements for the conduct of a reserves or resources audit

A more comprehensive data list is available separately

The fundamental methodology for an audit is that the company prepares the estimates and that audit checks them

Therefore every number presented by the company must be traceable and supported by documented analysis

All work to be carried out consistent with the specific definitions and guidelines Whether they are regulatory (e.g. SEC) or industry (e.g. SPE PRMS)

Use the appropriate evaluation methodologies And compare with more than one approach

Be consistent across assets

Maintain a thorough audit trail

And always exercise informed professional judgment

D1059

Audit / Documentation Check List – 1

1) Development plan* in place and approved – internal, partner(s), government

2) Funding commitment

3) Market and/or production constraints

4) Methodology used - deterministic, probabilistic or scenario

5) Assessment method - volumetric or performance based / primary &

secondary

6) Proved area/volume tests applied

Vertical (LKH) – illustrate with logs, pressure plots and cross sections

Lateral – illustrate with maps

7) Reservoir drive - document assumptions and role of analogs

8) Producibility - evidence from well tests or other data

* Documentation should relate to specific project and decision to invest

D10510


9) License expiry

Typically, no reserve recognition outside current license term, unless specific

legal rights to extend (or precedence) exist

10) Improved Recovery increment issues

Describe method to be used

Successful pilot, actual implementation, commercial use in the area

11) Royalty treatment

Volumes taken in kind not included in Reserves

Royalty paid in cash:

Excluded; or

If included as Reserves, royalty treated as cost in economic limit test

D10511


12) Net Interest - economic interest or working interest?

13) Flare & Fuel

14) Economic limit test

Annual production forecast

Defined costs and prices

"as of assessment date“ for SEC

License expiry/quota issues incorporated

Abandonment cost accruals incorporated

15) Developed/Undeveloped split

Developed includes behind pipe or other volumes requiring capital investment,

at a minority fraction (say 10% - 20%) of a new well cost

Project No. D105

Part II: Reserve and Resources definitions PRMS 2007

Prepared for GCA’s clients, July 2007

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Resources Classification

Reserves Discovered, recoverable, commercial,

remaining Proved, Probable, Possible 1P, 2P, 3P (now formalized)

Contingent Resources Discovered, potentially recoverable,

not yet commercial, remaining 1C, 2C, 3C (new terms)

Equivalent to Low, Best and High Estimates

Prospective Resources Undiscovered, potentially

recoverable, potentially commercial, remaining

Low, Best and High Estimates Unrecoverable

Discovered or undiscovered, not recoverable

Cla

ssif

icat

ion

Categorization

D10514

Discovery Status

“A discovery is one petroleum accumulation, or several petroleum accumulations collectively, for which one or several exploratory wells have established through testing, sampling, and/or logging the existence of a significant quantity of potentially moveable hydrocarbons” The PRMS intentionally does not require a flow test in order to establish a

discovery In some instances it may nevertheless be considered that logging alone would

not be considered sufficient to identify a discovery since some indication of fluid type and producibility will normally be required to comply with the following requirement:

“In this context, “significant” implies that there is evidence of a sufficient quantity of petroleum to justify estimating the in-place volume demonstrated by the well(s) and for evaluating the potential for economic recovery”

D10515

Determination of Commerciality

“Discovered recoverable volumes (Contingent Resources) may be considered commercially producible, and thus Reserves, if the entity claiming commerciality has demonstrated firm intention to proceed with development and such intention is based upon all of the following criteria: Evidence to support a reasonable timetable for development A reasonable assessment of the future economics of such development

projects meeting defined investment and operating criteria A reasonable expectation that there will be a market for all or at least the

expected sales quantities of production required to justify development Evidence that the necessary production and transportation facilities are

available or can be made available Evidence that legal, contractual, environmental and other social and economic

concerns will allow for the actual implementation of the recovery project being evaluated”

With some minor differences, these criteria were typically applied to Proved reserves under prior guidelines

Distinction between “economic” and “commercial”

D10516

Economics and “ELT”

“While each organization may define specific investment criteria, a project is generally considered to be “economic” if its “best estimate” case has a positive net present value under the organization’s standard discount rate, or if at least has a positive undiscounted cash flow”

“Economic limit is defined as the production rate beyond which the net operating cash flows from a project, which may be an individual well, lease, or entire field, are negative, a point in time that defines the project’s economic life

Operating costs should ... exclude depreciation, abandonment and reclamation costs, and income tax, as well as any overhead above that required to operate the subject property itself

Operating costs may be reduced, and thus project life extended, by various cost-reduction and revenue-enhancement approaches, such as sharing of production facilities, pooling maintenance contracts, or marketing of associated non-hydrocarbons”

D10517

Project-Based Classification

The Reservoir assessment determines the petroleum initially in place, and fluid and rock properties that affect petroleum recovery

The Project is applied to a specific reservoir volume to generate production and cash flow schedule

One project may develop many reservoirs or many projects may develop one reservoir The Property incorporates contractual rights and obligations, and fiscal terms, defining

the entitlement share of investments, production and revenue One property may encompass many reservoirs or one reservoir may span many

properties

D10518

Project Maturity - Reserves

On Production The development project is currently

producing and selling petroleum to market

Approved for Development All necessary approvals have been

obtained, capital funds have been committed, and implementation of the development project is under way

Justified for Development Implementation of the development

project is justified on the basis of reasonable forecast commercial conditions at the time of reporting, and there are reasonable expectations that all necessary approvals/contracts will be obtained

D10519

Project Maturity – Contingent Resources

Development Pending A discovered accumulation where

project activities are ongoing to justify commercial development in the foreseeable future

Development Unclarified or on Hold A discovered accumulation where

project activities are on hold and/or where justification as a commercial development may be subject to significant delay

Development Not Viable A discovered accumulation for which

there are no current plans to develop or to acquire additional data at the time due to limited production potential

D10520

Project Maturity – Prospective Resources

Prospect A project associated with a potential

accumulation that is sufficiently well defined to represent a viable drilling target

Lead A project associated with a potential

accumulation that is currently poorly defined and requires more data acquisition and/or evaluation in order to be classified as a prospect

Play A project associated with a

prospective trend of potential prospects, but which requires more data acquisition and/or evaluation in order to define specific leads or prospects

D10521

Project Maturity Linked to Decision Gates(can be quantified if desired)

Chance of discovery

Chance of commerciality

D10522

Volume Categorization

The PRMS recognizes three distinct approaches to volume categorization

Deterministic incremental (“risk-based”) Proved, Probable, Possible There are no “incremental” categories for

CR or PR, so by inference this is expected to be applied to Reserves only

Deterministic scenario (“cumulative”) 1P, 2P, 3P 1C, 2C, 3C Low, Best, High Estimates

Probabilistic P90, P50, P10

The PRMS notes these approaches in the order given above

Although the probabilistic method may be applied to any volume, it is also indicated that this is most often applied to volumetric calculations in the early phases of an exploitation and development project

And although not mentioned, it is also typically applicable for Prospective Resources

D10523

Proved Reserves Comparison

SPE/WPC 1997 SPE PRMS 2007 Comments

Proved reserves are those quantities of petroleum which, by analysis of geological and engineering data, can be estimated with reasonable certainty to be commercially recoverable, from a given date forward, from known reservoirs and under current economic conditions, operating methods, and government regulations

If deterministic methods are used, the term reasonable certainty is intended to express a high degree of confidence that the quantities will be recovered

If probabilistic methods are used, there should be at least a 90% probability that the quantities actually recovered will equal or exceed the estimate

Proved Reserves are those quantities of petroleum, which by analysis of geoscience and engineering data, can be estimated with reasonable certainty to be commercially recoverable, from a given date forward, from known reservoirs and under defined economic conditions, operating methods, and government regulations

If deterministic methods are used, the term reasonable certainty is intended to express a high degree of confidence that the quantities will be recovered

If probabilistic methods are used, there should be at least a 90% probability that the quantities actually recovered will equal or exceed the estimate

Very similar definitions, with the key difference being the use of “defined” economic conditions

Still requires “reasonable certainty”

D10524

Probable Reserves Comparison


Probable reserves are those unproved reserves which analysis of geological and engineering data suggests are more likely than not to be recoverable

In this context, when probabilistic methods are used, there should be at least a 50% probability that the quantities actually recovered will equal or exceed the sum of estimated proved plus probable reserves

Probable Reserves are those additional Reserves which analysis of geoscience and engineering data indicate are less likely to be recovered than Proved Reserves but more certain to be recovered than Possible Reserves.

It is equally likely that actual remaining quantities recovered will be greater than or less than the sum of the estimated Proved plus Probable Reserves (2P)

In this context, when probabilistic methods are used, there should be at least a 50% probability that the actual quantities recovered will equal or exceed the 2P estimate

Removed mathematical inconsistency in the definitions of Probable and 2P

D10525

Possible Reserves Comparison


Possible reserves are those unproved reserves which analysis of geological and engineering data suggests are less likely to be recoverable than probable reserves

In this context, when probabilistic methods are used, there should be at least a 10% probability that the quantities actually recovered will equal or exceed the sum of estimated proved plus probable plus possible reserves

Possible Reserves are those additional reserves which analysis of geoscience and engineering data indicate are less likely to be recoverable than Probable Reserves

The total quantities ultimately recovered from the project have a low probability to exceed the sum of Proved plus Probable plus Possible (3P), which is equivalent to the high estimate scenario

When probabilistic methods are used, there should be at least a 10% probability that the actual quantities recovered will equal or exceed the 3P estimate

Essentially identical definitions

D10526

Contingent Resources Comparison

SPE/WPC/AAPG 2000 SPE PRMS 2007 Comments

Contingent Resources are those quantities of petroleum which are estimated, on a given date, to be potentially recoverable from known accumulations, but which are not currently considered to be commercially recoverable

Contingent Resources are those quantities of petroleum estimated, as of a given date, to be potentially recoverable from known accumulations, but the applied project(s) are not yet considered mature enough for commercial development due to one or more contingencies


D10527

Prospective Resources Comparison

SPE/WPC/AAPG 2000 SPE PRMS 2007 Comments

Prospective Resources are those quantities of petroleum which are estimated, on a given date, to be potentially recoverable from undiscovered accumulations

Prospective Resources are those quantities of petroleum estimated, as of a given date, to be potentially recoverable from undiscovered accumulations by application of future development projects


D10528

Some Important Observations

Brief observations on the following topics will be made Economics Project Financing Aggregation Best Estimate Transition from CR to Reserves Lease Fuel Risk Service Agreements Contract Extension Developed and Undeveloped

D10529

Economics

“The economic evaluation underlying the investment decision is based on the entity’s reasonable forecast of future conditions, including costs and prices, which will exist during the life of the project (forecast case)

Such forecasts are based on projected changes to current conditions SPE defines current conditions as the average of those existing during the

previous 12 months Alternative economic scenarios are considered in the decision process and,

in some cases, to supplement reporting requirements Evaluators may examine a case in which current conditions are held constant

(no inflation or deflation) throughout the project life (constant case)”

Companies (and consultants) need to define a consistent set of “forecast case” parameters such as oil and gas prices (and differentials), cost inflation, perhaps exchange rates, and discount rates to be used for reserve evaluation purposes Companies reporting to the SEC will of course continue to use constant prices

and cost cases as of the reporting date

D10530

Project Financing

“While SPE guidelines do not require that project financing be confirmed prior to classifying projects as Reserves, this may be another external requirement

In many cases, loans are conditional upon the same criteria as above; that is, the project must be economic based on Proved Reserves only

In general, if there is not a reasonable expectation that loans or other forms of financing (e.g., farm-outs) can be arranged such that the development will be initiated within a reasonable timeframe, then the project should be classified as Contingent Resources

If financing is reasonably expected but not yet confirmed, the project may be classified as Reserves, but no Proved Reserves may be reported as above”

D10531

Aggregation

“Petroleum quantities classified as Reserves, Contingent Resources, or Prospective Resources should not be aggregated with each other without due consideration of the significant differences in the criteria associated with their classification [emphasis added]

In particular, there may be a significant risk that accumulations containing Contingent Resources and/or Prospective Resources will not achieve commercial production”

GCA does not believe that it is appropriate to report the aggregation of different resource classes (such as Prospective or Contingent Resources with Reserves) under any circumstances Such classes should always be reported separately, with no totaling between

classes Also, unless undertaken as part of an integrated portfolio analysis

incorporating “chance of success”, Prospective Resources for individual prospects should not be aggregated

D10532

Best Estimate

“The best estimate ... is generally considered to represent the sum of Proved and Probable estimates (2P) when using the deterministic scenario or the probabilistic assessment methods

It should be noted that under the deterministic incremental (risk-based) approach, discrete estimates are made for each category, and they should not be aggregated without due consideration of their associated risk.”

GCA concurs that “generally” the best estimate is represented by the most likely case (termed 2P or P50 by definition), if such as been evaluated

However, there are other circumstances to consider: Using the deterministic incremental approach, it is not necessarily the case

that the sum of Proved plus Probable will necessarily represent the best estimate

It is therefore recommended that reports include the individual reserves categories and not their aggregation

The “best estimate’ of a well-established decline curve may actually be representative of Proved reserves, rather than 2P

D10533

Transition from CR to Reserves

“Without new technical information, there should be no change in the distribution of technically recoverable volumes and their categorization boundaries when conditions are satisfied sufficiently to reclassify a project from Contingent Resources to Reserves ”

This implies that 1C becomes 1P, 2C becomes 2P, and 3C becomes 3P While in principle this is reasonable, there are two implications, especially for

the Low Estimate: If this were to apply in all cases, the 1C estimate would have to be made

including all constraints (other than commercial ones) that apply for Proved reserves, such as complying with LKH

Alternatively, if the 1C estimate did not comply with the Proved volume constraints, it would need to be revised before moving to Proved

D10534

Lease Fuel

“For consistency, lease fuel should be treated as shrinkage and is not included in sales quantities or resource estimates

However, some regulatory guidelines may allow lease fuel to be included in Reserves estimates where it replaces alternative sources of fuel and/or power that would be purchased in their absence

Where claimed as Reserves, such fuel quantities should be reported separately from sales, and their value must be included as an operating expense

Flared gas and oil and other losses are always treated as shrinkage and are not included in either product sales or Reserves”

The recommendation is therefore to exclude fuel from Reserves However, it is not clear why the value should be included as an operating

expense, as long as the value is not included in sales There is no “cost” associated with this volume

D10535

Risked-Service Agreements

“Risked-Service Contracts (RSCs) are similar to PSCs, but in this case, the producers are paid in cash rather than in production

As with PSCs, the Reserves claimed are based on the parties’ net economic interest”

The requirement is therefore to assess net volumes based on net economic interest (entitlement), rather than working interest, which some companies have used

D10536

Contract Extension

“Reserves should not be claimed for those volumes that will be produced beyond the ending date of the current agreement unless there is reasonable expectation that an extension, a renewal, or a new contract will be granted

Such reasonable expectation may be based on the historical treatment of similar agreements by the license-issuing jurisdiction

Otherwise, forecast production beyond the contract term should be classified as Contingent Resources with an associated reduced chance of commercialization

Moreover, it may not be reasonable to assume that the fiscal terms in a negotiated extension will be similar to existing terms

Similar logic should be applied where gas sales agreements are required to ensure adequate markets

Reserves should not be claimed for those quantities that will be produced beyond those specified in the current agreement or reasonably forecast to be included in future agreements

In either of the above cases, where the risk of cessation of rights to produce or inability to secure gas contracts is not considered significant, evaluators may choose to incorporate the uncertainty by categorizing quantities to be recovered beyond the current contract as Probable or Possible Reserves”

It is important to keep in mind that the requirement for reporting of Proved reserves is still one of “reasonable certainty”, so if that condition is not met, then no Proved Reserves can be reported after the termination of the contract term

If the “reasonable expectation” criterion can be met, then Probable and/or Possible Reserves can be assigned

Consideration applies to terms as well as “will it happen?”

D10537

Developed and Undeveloped Reserves

“Reserves ... may be allocated to the following subdivisions based on the funding and operational status of wells and associated facilities within the reservoir development plan” “Developed Reserves are expected quantities to be recovered from existing

wells and facilities” “Undeveloped Reserves are quantities expected to be recovered through future

investments”

Thus these subdivisions are applied to all Reserves categories, not just Proved

Regarding the distinction between PDNP and PUD, the PRMS says: “Undeveloped Reserves [are] ... where a relatively large expenditure (e.g. when

compared to the cost of drilling a new well) is required to (a) recomplete an existing well or (b) install production or transportation facilities for primary or improved recovery projects

This is useful, but there is no quantitative guidance given

D10538

Unconventional Resources

D10539

Conclusions

The PRMS is a major contribution to international oil and gas resources management and one that many companies will adopt

There is clear recognition of the different ways that reserves and resources can be estimated and these are all embraced within the system

Certain changes in procedures will probably be required to ensure that the differences with the prior definitions are recognized and incorporated into resource reporting Nothing will change with respect to reporting Proved reserves to the SEC

Contingent Resources should become better understood and more acceptable as a valid resource category and not just “not reserves”

The revised “Standards” document should remain a valuable guidebook in the practical and ethical application of reserves estimation and auditing procedures

Project No. D105

Prepared for GCA Clients, July 2007

Reserve Audit Processusing SPE Petroleum Resources Management System (PRMS)

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