58
Statistical Methods for Estimating Petroleum Resources
The play resource distribution is the superpopulation distribution
and contains the uncertainties explained in the previous chapter. The
next two sections describe the remaining play potential.
Play Potential Distribution
Expected Play Potential
Play potential is defi ned as undiscovered resources that can be estimated from the play resource distribution depending on the matched
pool ranks. Summation of the means of all undiscovered pools yields
the expected value of the remaining potential distribution and is called
the expected play potential. The remaining potential is governed by the
individual pool sizes and the assigned pool ranks, both of which are
determined by the geological play defi nition used and the quality of
the database of the discovered pools. If the discovered sizes are incorrectly estimated, appreciated, or depreciated, or if the rankings are
altered, then the expected value of the remaining potential will change.
Provided that the geology of a play is well understood and documented,
the expected value should provide a reasonable and reliable estimate
of the potential of the play.
A
B
50
10
100
500 1000
5000 1000
In-Place Play Resource, 10 9 m 3
100
90
80
70
60
50
40
30
20
10
0
Cumulative Frequency Greater Than, %
Figure 3.15. (A, B) Potential distribution (A) and play resource distribution
(B) for Beaverhill Lake play.