104
Statistical Methods for Estimating Petroleum Resources
The Pareto model may provide estimates about the small pools but
requires that pool size exhibit a constant ratio of two adjacent size
classes. Drew et al. (1980) empirically estimated that the ratio was
about two for the Permian Basin. Chen (1993) plotted log density versus
Figure 4.27. (A–D) Cumulative greater-than plots showing various geological
random variables. Pool area of Cardium sandstone (A), porosity of Lower
Mannville sandstone (B), net pay of Lower Mannville sandstone (C), and net pay
of Devonian clastics (D) from the Western Canada Sedimentary Basin can be
approximated by the family of a lognormal distribution.
Statistical Methods for Estimating Petroleum Resources
The Pareto model may provide estimates about the small pools but
requires that pool size exhibit a constant ratio of two adjacent size
classes. Drew et al. (1980) empirically estimated that the ratio was
about two for the Permian Basin. Chen (1993) plotted log density versus
Figure 4.27. (A–D) Cumulative greater-than plots showing various geological
random variables. Pool area of Cardium sandstone (A), porosity of Lower
Mannville sandstone (B), net pay of Lower Mannville sandstone (C), and net pay
of Devonian clastics (D) from the Western Canada Sedimentary Basin can be
approximated by the family of a lognormal distribution.