1. A Review & Classification of Petroleum Resource Base in Thailand Anon Punnahitanon Petroleum Engineer Mineral Fuel Division Department of Mineral Resources

2. Objectives Reclassify Petroleum Resources & Reserves into the Same Classification System Estimate Petroleum Resource Base Outlook on the Petroleum Industry of the Country Review Current Petroleum Resource Classification System Currently used in DMR

3. Outline Resource Classification System Reserve Definition Resource Evaluation Reserve Development Resource Base @ end 2001 Resource Lifecycle & Reserve Growth Projection

4. Resource Classification System

5. Resources (Recoverable Resources) Petroleum which are anticipated to be commercially recovered from known accumulations from a given date forward Resources (Recoverable Resources) Petroleum which are anticipated to be commercially recovered from known accumulations from a given date forward Undiscovered Resources Total estimated quantities to be recovered from accumulations that remainto be discovered Undiscovered Resources Total estimated quantities to be recovered from accumulations that remainto be discovered Reserves Aticipated to be commercially recovered from known accumulations from a given date forward Potential Resources Not commercially producible at present Hypothetical Mapped prospects Speculative Not yet been mapped Discovered Resources Total discovered deliverable quantities based on in place volume and recovery factor Discovered Resources Total discovered deliverable quantities based on in place volume and recovery factor

6. Reserves Petroleum which are anticipated to be commercially recovered from known accumulations from a given date forward Proved Reserves Estimated with reasonable certainty to be commercially recovered Unproved Reserves Less certain to be recovered than proved reserves Developed Reserves Expected to be recovered form existing wells Undeveloped Reserves Expected to be recovered with additional capital investment Probable reserves More likely than not to be recovered Possible reserves Less likely than likely to be recovered

7. Reserve Definitions

8. Reserves Economic Conditions Operating Methods Government Regulations Historical prices/costs Reserves Contributing Factors

9. Reserves Deterministic vs. Probabilistic

10. Probabilistic Estimation Probability Value 90 th percentile 10 th percentile Mean Cum. Probability Value 90 th percentile 10 th percentile Mean, P50 Proved ? Probable ? Possible ?

11. Probabilistic Estimation (Cont’d) Probability Value Mode Which one is the most confident ? 90 th percentile 10 th percentile Geometric Mean Median

12. If statistical method is to be used, each reserve category should be assessed on different basis to reflect its inherent different level of confidence in data from which it is derived. Probabilistic estimate is very useful to form an uncertainty range of and estimation. Its implication is “what the safe side of the estimate and what the outrageous one are” Criteria in assessing level of confidence is qualitatively spelled out in SPE/WPC definitions. Applying Statistics in Reserves Estimation

13. Because of potential differences in uncertainty, caution should be exercised when aggregating different reserve classification Caution

14. Resource / Reserve Assessment

15. Petroleum Provinces Northern Intermontane Central Plain Northeastern Gulf of Thailand The Andaman Sea

16. Estimated Undiscovered Resources

17. Estimated Discovered Resources Potential Recoveries Ultimate Recovery 924 1,02537.3 Oil (MMBBLS) Condensate (MMBBLS) Natural Gas (BCF)

18. Total Resource Base

19. Thailand Petroleum Proved Reserves 1979-2001

20. UR * Field Growth or Reserve Growth An Increase in Ultimate Recovery (Proved Reserves + Cumulative Production) Annual Field Growth (AFG) Cumulative Field Growth (CFG) UR AFG n = UR n-1 CFG n = UR 1 n n UR * 2...*

21. 0 20 40 60 80 100 120 Ultimate Recovery Potential % Proved+ProductionUnproved PotentialUndiscovered Resources Petroleum Resource Lifecycle

22. Natural Gas Reserve Cumulative Growth

23. Crude Oil Reserve Cumulative Growth

24. 68% 36.9 TCF 18.2 TCF 32% Natural Gas Resource Outlook 2002 2022 ? 55.1 TCF Unproved Reserves Undiscovered Resources + Potential Recovery

25. Crude Oil Resource Outlook 72% 913 MMBBLS 352 MMBBLS 28% 2002 2023 ? 1,276 MMBBLS

26. Oil Condensate Gas Oil Condensate Gas Thailand Petroleum Proved Reserves1979-2001 17 Years

27. Estimated Petroleum Resource Base for Oil, Condensate and Natural Gas are 1,276 MMBBLS, 1,288 MMBBLS, and 55 TCF, Respectively DMR’s Current Classification System is Reviewed Total Reserves are 924 MMBBLS Oil, 1025 MMBBLS Condensate, and 37.3 TCF Natural Gas Summary

28. Petroleum Industry has Past Mature Stage with Total Ultimate Recovery for Oil and Natural Gas 72% and 68 % of Total Resource Base Summary (Cont’d) Projection of Reserve Growth for Oil and Gas shows that total Reserves will sustain the Growth for the Next 20 Years