Contents
xix
Interpretation
89
Outliers
89
Long or Short Tails at Both Ends
90
Symmetry
90
Plateaus
90
The Beaverhill Lake Play
91
Plays from Worldwide Basins
91
Pool-Size Distribution of a Basin
100
Justifi cations for Using a Lognormal Distribution
102
Evidence from the Q–Q Plots
102
Approximation of a Lognormal Distribution to
Geological Random Variables
102
Advantages of Using a Lognormal Distribution
103
Estimation Error Resulting from Lognormal
Distribution Approximation
105
5 Evaluating Conceptual Plays
106
Geological Factors
106
Exploration Risk
106
Methods for Estimating Marginal Probability
107
Play-Level Geological Factor
108
Prospect-Level Geological Factor
111
Marginal Probability Distribution
112
Dependence in Prospect-Level Geological Factors
114
The East Coast Play
115
Pool-Size Distribution
116
The Monte Carlo Method
116
The Lognormal Approximation
119
Examples
120
The Beaverhill Lake Play
120
The East Coast Play
124
Estimating Resources
127
Number-of-Prospects Distribution
127
Number-of-Pools Distribution
127
Play Resource Distribution
131
Pool-Size-by-Rank
133
Generation of Reservoir Parameters
135
Constructing Probability Distributions
136