CPG Risk Assessment & Mitigation 2

Question 1

Which statistical method is most appropriate for quantifying the probability of a petroleum system being active when data are sparse?

Accepted Answer

Bayesian inference using analog data

Answer

Bayesian inference allows geologists to update prior probabilities from analog basins with sparse site-specific data to estimate petroleum system risk.

Question 2

What does a 'probability of success' (Ps) value of 0.12 indicate for an exploration prospect?

Accepted Answer

A 12% chance that all geologic risk factors are simultaneously satisfied

Answer

Ps represents the joint probability that all required geologic elements (trap, reservoir, seal, source, migration) are simultaneously present and effective.

Question 3

In risked resource estimation, which of the following best defines the 'chance of geological success' (CGoS)?

Accepted Answer

Probability that the prospect contains a producible accumulation given drilling

Answer

CGoS is the probability that a drilled prospect contains a producible hydrocarbon accumulation, encompassing all geologic risk components.

Question 4

A geologist estimates reservoir presence risk at 0.7, trap integrity risk at 0.8, seal risk at 0.6, and source/charge risk at 0.75. What is the approximate Ps?

Accepted Answer

0.25

Answer

Ps = 0.7 × 0.8 × 0.6 × 0.75 = 0.252, approximately 0.25, as risk factors multiply when independent.

Question 5

Which scenario best illustrates a 'common risk segment' (CRS) in prospect portfolio analysis?

Accepted Answer

Multiple prospects that would all fail if the regional source rock is immature

Answer

A CRS groups prospects sharing a risk element that, if absent, causes all prospects in the group to fail simultaneously, affecting portfolio diversification.

(CPG) Certified Petroleum Geologist Practice Test

(CPG) Certified Petroleum Geologist Practice Test

CPG Risk Assessment & Mitigation 2