the ccop guidelines for risk assessment of petroleum prospects · 1 coordinating committee for...

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Coordinating Committee for GeoscienceProgrammes in East and Southeast Asia (CCOP)

The CCOP Guidelines for Risk The CCOP Guidelines for Risk Assessment of Petroleum Assessment of Petroleum

ProspectsProspects

Simplicio P. Caluyong


Contents!REP Project

!Why Risking Guidelines?

!Probability concept

!Risking procedure

!Play & Prospect definition

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REP Project, 1996REP Project, 1996--20022002-- backgroundbackground

“A step from resource base understanding to evaluating economics and risks”

" Outputs:– Conducted a series of workshops and

seminars dealing with resource management and using GeoX as the main software

– Formed a technical working group composed mostly of national coordinators for the REP projects

Contents

! REP Project

! Why Risking Guidelines?

! Probability concept

! Risking procedure

! Play & Prospect definition


" Formation of 2 working groups with one group given the tasked of compiling the Guidelines for Risk Assessment

" The compilation were based on data and information passed on during previous NORAD-funded activities in the CCOP such as– OGRM (1989-1991)– WGRA (1992-1994)– REP 1 (1996)

Contents

! REP Project



! Risking procedure


REP Project, 1996REP Project, 1996--20022002-- backgroundbackground

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– Published the following:# The CCOP Petroleum

Resource Classification System, March 1999

#The CCOP Guidelines for Risk Assessment of Petroleum Prospects, July 2000

Contents

! REP Project



! Risking procedure



" As a reference guideline for Member Countries that do not practice resource risk assessment

" As a reference material for Member Countries who wants to update their existing risk assessment guidelines

" Reduces the subjectivity of risking

Contents

! REP Project



! Risking procedure


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" Estimate the probability of discovery prior to drilling of a mapped prospect– Keep in mind that risk is associated

with the volumetric calculations! The Probability of discovery is the chance of finding at least the minimum volume

" Calculate the undiscovered resources in an area during play assessment

Contents

! REP Project



! Risking procedure



Basic requirementsBasic requirements"Resource classification

system"Clear definitions of play and

prospects"Understanding of the

petroleum system

Contents

! REP Project



! Risking procedure


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Probability vs risk scale

Probability = 1 - RiskContents

! REP Project



! Risking procedure



" Probability of one of several mutually exclusive events:

Either Outcome A, or outcome B then:

P = PA + PB

Contents

! REP Project



! Risking procedure


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"Throwing of dices:What is the probability of getting

either 1 or 2, when throwing a die only once?

P1or2 = P1 + P2 = 1/6 + 1/6 = 2/6 = 0.33

Contents

! REP Project



! Risking procedure



"Probability of simultaneous occurrence of several independent events:

Both outcome A, outcome B and outcome C, then:

P = PA x PB x PC

Contents

! REP Project



! Risking procedure


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"“Either one or another event, or both events”The “risk” approach: 1-P = (1- PA) x

(1– PB)Quantity considerations:

P = PA + PB – (PA x PB)

Contents

! REP Project



! Risking procedure



" Assuming 2 types of source rocks at different strat levels (A & B), where: Probability of effective source rock (PA) = 0.5Probability of effective source rock (PB) = 0.2

What is the probability of an effective source rock in the area?

1- P = (1 – PA) x (1 – PB) or 1- P = (1-0.5) x (1-0.2)

Contents

! REP Project



! Risking procedure


A

B

P = 1- (0.5 x 0.8) = 0.6

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Probability CategoriesProbability Categories"Stochastic probabilities

– Measured values– Success rates, etc

"Objective probabilities– Logical arguments– Analogue events, etc

"Subjective probabilities– Beliefs– “guts feeling”, etc

Contents

! REP Project



! Risking procedure



GeochronologicalGeochronological Risk Risk AssessmentAssessment

This principle is mainly applied to avoid double risking

Contents

! REP Project



! Risking procedure


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Contents

! REP Project



! Risking procedure



Database must be also be assessed with respect to the prospect under evaluation

Database consists of geological, geochemical and geophysical data

Interpretation and compilation in most cases by interpolation and extrapolation to establish a model for the geological factors

Contents

! REP Project



! Risking procedure


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The geolo gical factor is n ot kn ow n to exist within th e tren d. Con ditions are verified by un am bigu ou s well an d seismic contro l.

0.2

0.1

0.2

0.1

Co ndition is virtually to absolu tely im possible. Data con trol and quality is excellent

T he mod el is un likely and very q uestion ab le. Unfavo urab le m odels are very likely to certainT he mod el is un likely and hig hly q uestion ab le. Unfavo urab le m odels are very likely to certain

Similar geolo gical factor may exist within th e tren d. Valid co ncep ts, bu t uncon vin cin g data o nly hints at po ssible presence of th e feature.

0.4

0.3

0.4

0.3

Co ndition is p ossib le o r data con trol and quality is po or to fair. L ess favorable in terp retation

Unfavo rable mo dels are mo re likely than applied m od el

T he mod el is qu estionable and u nfavorab le m od els are likely to very likely

0.6

0.5

T he mod el is mo re likely than all o th er unfavo urab le m odels

L ikely m od el, ho wever, u nfavou rable are also likely

Similar geolo gical factor su ccessfully tested b y wells in th e trend . Lateral co ntinuity is p rob ab le as in dicated b y con vin cin g well an d seismic contro l

0.8

0.7

Co ndition is p ro bable or d ata con trol and quality is fair. F avo urable in terp retation

Similar geolo gical factor is kn ow n to exist within th e tren d. Lateral con tin uity is pro bable as ind icated by co nvincing w ell and seism ic con trol

0.6

0.5

0.8 Co ndition is p ro bable. Data con trol and quality is go od. Most likely interp retation0.7

T he mod el is very likely. Only m in or ch an ce that u nfavo urable m odels can b e app lied .T he mod el is likely to very likely. Unfavo urab le m odels can b e app lied

Only po ssible mo delm applicable for th e con cerned area. Unfavo urab le m odels are T he mod el is very likely to absolu tely certain. Unfavou rable m odels can b e app lied

Id entical geolo gical factor to th ose fou nd in fields and disco veries in immed iate vicinity. Co ndition s are verified by un am bigu ou s well an d seismic contro l

1

0.9

Co ndition is virtually to absolu tely certain. Data q uality an d con trol is excellent

1

0.9

Analogue or Theoritical Models

Prov en Geological Models

PP General Scale

Contents

! REP Project



! Risking procedure



"Model with direct data Probability– Favorable 0.7 – 0.9– Unfavorable 0.1 – 0.3

"Model with indirect data– Encouraging 0.5 – 0.7– Questionable 0.3 – 0.5

(Otis and Schneiderman, 1977)

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Conditional ProbabilitiesConditional Probabilities" Bayes Theorem“ Interdependency

between prospects means that the result of the drilling of any one prospect (discovery or otherwise) will impact on the probability of making a discovery in all of the other prospects”

Contents

! REP Project



! Risking procedure



Play ProbabilitiesPlay ProbabilitiesDefined as a group of prospects within a geographically delimited area, where a set of mutually related geological factors must be present concurrently in order to permit the discovery of hydrocarbons

Contents

! REP Project



! Risking procedure


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Contents

! REP Project



! Risking procedure


Schematic diagram of a Petroleum System


SummarySummary" It is important for Governments to determine

the total petroleum risked resources " Ranking of basins as well plays and

prospects within the basin is an important tool for government to determine appropriate strategies for exploration, licensing and investment promotion

" A risking guideline helps reduce subjectivity in risking and provides a consistency in the calculation of the resources

" Member Countries can advantage of the guidelines published by CCOP

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Maturity map with drainage areas and migration paths

Contents

! REP Project



! Risking procedure



Examples of trap mechanism

Contents

! REP Project



! Risking procedure


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Probability of an Effective Probability of an Effective ChargeCharge

Factors to be evaluated

-quality and maturity of the potential source rocks

--what type of hydrocarbon are generated-- volume of mature source rock within the drainage area-- points in time for onset and end of oil migration-- points in time for onset and end of gas migration-- mapping of drainage area and migration routes,

-- mapping of “fill-spill” relationship


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Thank you!

http://www.ccop.or.th/projects/PPM.html

the ccop guidelines for risk assessment of petroleum prospects · 1 coordinating committee for...

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