Estimating Mature Plays
49
single pool tends to be. Hence the magnitude of the fi rst few large pools
among the N pools tends to be greater.
Plays from the Western Canada Sedimentary Basin—the Beaverhill
Lake (estimation of this play was based on data that contain commercial pools only), Bashaw, and Zama plays—reveal an interesting pattern. Values of σ
2 were estimated from pool-size data. Figure 3.12B
displays the sizes of the largest 10 pools for three plays, which have σ
2
values of 6.6, 3.0, and 1.0 respectively. Note that the estimated variance
value of 6.6 for the Beaverhill Lake play was obtained from the data set
consisting of commercial pools only. These 10 pools include discovered and undiscovered pools of the plays. The sizes in the Beaverhill
Lake play (indicated by dots) decrease more rapidly than those of the
Bashaw reef play (indicated by crosses) and those of the Zama play
Figure 3.12. (A, B) Median pool-size-by-rank. (A) With population parameters
of μ = 0.25 and N = 60 for σ
2 = 6.0 (dots) and σ
2 = 0.5 (open dots), and (B) for the
Beaverhill Lake play (dots) with μ ˆ = 0.25, σ ˆ
2 = 6.6, and N ˆ = 60; the Bashaw play
(crosses) with μ ˆ =− 0.91, σ ˆ
2 = 3.0, and N ˆ = 80; and the Zama play (triangles) with
μ ˆ = − 1.5, σ ˆ
2 = 1.0, and N ˆ = 160.
49
single pool tends to be. Hence the magnitude of the fi rst few large pools
among the N pools tends to be greater.
Plays from the Western Canada Sedimentary Basin—the Beaverhill
Lake (estimation of this play was based on data that contain commercial pools only), Bashaw, and Zama plays—reveal an interesting pattern. Values of σ
2 were estimated from pool-size data. Figure 3.12B
displays the sizes of the largest 10 pools for three plays, which have σ
2
values of 6.6, 3.0, and 1.0 respectively. Note that the estimated variance
value of 6.6 for the Beaverhill Lake play was obtained from the data set
consisting of commercial pools only. These 10 pools include discovered and undiscovered pools of the plays. The sizes in the Beaverhill
Lake play (indicated by dots) decrease more rapidly than those of the
Bashaw reef play (indicated by crosses) and those of the Zama play
Figure 3.12. (A, B) Median pool-size-by-rank. (A) With population parameters
of μ = 0.25 and N = 60 for σ
2 = 6.0 (dots) and σ
2 = 0.5 (open dots), and (B) for the
Beaverhill Lake play (dots) with μ ˆ = 0.25, σ ˆ
2 = 6.6, and N ˆ = 60; the Bashaw play
(crosses) with μ ˆ =− 0.91, σ ˆ
2 = 3.0, and N ˆ = 80; and the Zama play (triangles) with
μ ˆ = − 1.5, σ ˆ
2 = 1.0, and N ˆ = 160.