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

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

Outline Resource Classification System Reserve Definition Resource Evaluation Reserve Development Resource end 2001 Resource Lifecycle & Reserve Growth Projection

Resource Classification System

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

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

Reserve Definitions

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

Reserves Deterministic vs. Probabilistic

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 ?

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

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

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

Resource / Reserve Assessment

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

Estimated Undiscovered Resources

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

Total Resource Base

Thailand Petroleum Proved Reserves

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...*

Ultimate Recovery Potential % Proved+ProductionUnproved PotentialUndiscovered Resources Petroleum Resource Lifecycle

Natural Gas Reserve Cumulative Growth

Crude Oil Reserve Cumulative Growth

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

Crude Oil Resource Outlook 72% 913 MMBBLS 352 MMBBLS 28% ? 1,276 MMBBLS

Oil Condensate Gas Oil Condensate Gas Thailand Petroleum Proved Reserves Years

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

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