A Review & Classificationof

Petroleum Resource Base in Thailand

Anon PunnahitanonPetroleum EngineerMineral Fuel DivisionDepartment of Mineral Resources

Objectives

Reclassify Petroleum Resources & Reserves into the Same Classification SystemEstimate 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 DevelopmentResource Base @ end 2001Resource 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 ResourcesTotal estimated quantities to be recovered from accumulations that remainto be discovered

Undiscovered ResourcesTotal estimated quantities to be recovered from accumulations that remainto be discovered

ReservesAticipated to be commercially recovered from known accumulations from a given date forward

Potential ResourcesNot commercially producible at present

HypotheticalMapped prospects

SpeculativeNot yet been mapped

Discovered ResourcesTotal discovered deliverable quantitiesbased on in place volume and recovery factor

Discovered ResourcesTotal discovered deliverable quantitiesbased on in place volume and recovery factor

ReservesPetroleum which are anticipated to be commercially recovered from known accumulations from a given date forward

Proved ReservesEstimated with reasonable certainty to be commercially recovered

Unproved ReservesLess certain to be recovered than proved reserves

Developed ReservesExpected to be recovered form existing wells

Undeveloped ReservesExpected to be recoveredwith additional capital investment

Probable reservesMore likely than notto be recovered

Possible reservesLess likely than likely to be recovered

Reserve Definitions

ReservesReserves

Economic Conditions

Operating Methods

Government Regulations

Historical prices/costs

Reserves Contributing Factors

ReservesDeterministic vs.

Probabilistic

Probabilistic Estimation

Probability

Value

90 th percentile10 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 percentile10 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 exercisedwhen aggregating different reserve classification

Caution

Resource / Reserve Assessment

Petroleum Provinces

Northern Intermontane

Central Plain

Northeastern

Gulf of Thailand

The Andaman Sea

Gas (TCF) Oil (MMBBL) Condensate (MMBBL)

Basins

Low High Low High Low High Onshore Tertiary

0.2 0.5 120.0 260.0 - -

Pre-Tertiary 3.5 11.0 - - 1.0 5.0

Gulf of Thailand

11.0 33.0 110 350 225.0 600.0

Andaman Sea

2.5 7.5 30.0 100.0 30.0 100.0

Total 17.2 52.0 260.0 710.0 256.0 705.0

Estimated Undiscovered Resources

Oil (MMBBL)

Condensate (MMBBL)

Natural Gas (BCF)

Gulf of Thailand 92.42 7.29 633.77 Onshore NA NA NA

Estimated Discovered Resources

Possible Reserves 253.4 321.0 7,617.8

Probable Reserves 156.9 245.1 9,654.4

Proved Reserves 325.0 262.4 13,301.6

Cumulative Production 188.6 196.5 6,739.5

Potential Recoveries

Ultimate Recovery

924 1,025 37.3

Oil (MMBBLS)

Condensate(MMBBLS)

Natural Gas(BCF)

Oil (MMBBL)

Condensate (MMBBL)

Natural Gas (BCF)

Undiscovered Resources 260 256 17,200.0 Potential Recovery 92.4 7.3 633.8 Possible Reserves 253.4 321.0 7,617.8 Probable Reserves 156.9 245.1 9,654.4 Proved Reserves 325.0 262.4 13,301.6 Cumulative Production 188.6 196.5 6,739.5 Total 1,276.3 1,288.3 55,147.1

Total Resource Base

0

50

100

150

200

250

300

350

1979

1980

1981

1982

1983

1984

1985

1986

1987

1988

1989

1990

1991

1992

1993

1994

1995

1996

1997

1998

1999

2000

2001

MM

BB

Ls

-

2,000

4,000

6,000

8,000

10,000

12,000

14,000

16,000

BC

F

Oil Condensate Gas

0

50

100

150

200

250

300

350

1979

1980

1981

1982

1983

1984

1985

1986

1987

1988

1989

1990

1991

1992

1993

1994

1995

1996

1997

1998

1999

2000

2001

MM

BB

Ls

-

2,000

4,000

6,000

8,000

10,000

12,000

14,000

16,000

BC

F

Oil Condensate Gas

Thailand Petroleum Proved Reserves 1979-2001

UR *

Field Growth or Reserve Growth

An Increase in Ultimate Recovery (Proved Reserves + Cumulative Production)

Annual Field Growth (AFG)

Cumulative Field Growth (CFG)

URAFGn =

UR n-1

CFGn = UR 1 n

n

UR *2 ...*

0

20

40

60

80

100

120U

ltim

ate

Rec

over

y P

oten

tial

%

Proved + Production Unproved Potential Undiscovered Resources

Petroleum Resource Lifecycle

y = 71.106Ln (x) - 167.75

20

40

60

80

100

120

0 10 20 30 40 50

Year

Cu

mu

lati

ve G

row

th F

acto

r

y = 71.106Ln (x) - 167.75

20

40

60

80

100

120

0 10 20 30 40 50

Year

Cu

mu

lati

ve G

row

th F

acto

rNatural Gas Reserve Cumulative Growth

y = 23.268Ln(x) - 47.113

5

10

15

20

25

30

35

40

45

0 10 20 30 40 50Year

Cu

mu

lati

ve G

row

th F

acto

r

y = 23.268Ln(x) - 47.113

5

10

15

20

25

30

35

40

45

0 10 20 30 40 50

Cu

mu

lati

ve G

row

th F

acto

rCrude Oil Reserve Cumulative Growth

68%

36.9 TCF

18.2TCF32%

Natural Gas Resource Outlook

2002 2022

?

55.1 TCF

Unproved Reserves

Undiscovered Resources+ Potential Recovery

Crude Oil Resource Outlook

72%

913 MMBBLS

352MMBBLS28%

2002 2023

?1,276 MMBBLS

10

20

30

40

50

60

1976 1978 1980 1982 1984 1986 1988 1990 1992 1994 1996 1998 2000 2002 2004

10

20

30

40

50

60

1976 1978 1980 1982 1984 1986 1988 1990 1992 1994 1996 1998 2000 2002 2004

Oil

Condensate

Gas

Oil

Condensate

Gas

Thailand Petroleum Proved Reserves 1979-2001

17 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