Por-Perm Crossplot Interpreter: Rock Typing, RQI, FZI & Lorenz Plot

Core plug data to rock types: least-squares k–φ transform, RQI/FZI rock typing, Winland R35 and Pittman R25, five permeability transforms compared against core, and Lorenz, Dykstra-Parsons and Gini heterogeneity.

Formation evaluation engineers, petrophysicists, and reservoir engineers who analyse core plug data and need to characterise reservoir quality, classify rock types, and build audit-ready permeability transforms.

Loads your core porosity–permeability data, fits the power-law k–φ transform by least squares (type over it to impose your own), and generates five crossplots from the live data: the Por-Perm scatter by fluid zone with the fitted trend and RQI contours, the RQI vs φz diagnostic (Amaefule et al. 1993) with FZI lines, the Lorenz flow-capacity plot, the Winland R35 pore-throat map, and a Transform QC plot of predicted vs core k for five methods. Classifies rock types by RQI cutoffs and flow units by FZI, compares power-law, Timur, Kozeny-Carman, class-based Winland and multi-regression permeability (best method per sample and lowest log RMSE overall), and measures heterogeneity with the Lorenz coefficient, Dykstra-Parsons V and the Gini coefficient. Adds a Stratigraphic Modified Lorenz Plot and a depth plot.

• Instructions & Legend • Core Data Input — core plug data entry, RQI cutoffs, Swi • Por-Perm Crossplot — Gas/Oil/Water scatter, least-squares power-law trend and R², RQI contour lines • RQI & Rock Typing — RT1–RT4 classification by RQI cutoffs, class summary • FZI & Flow Units — FZI = RQI/φz, hydraulic flow unit table • Winland Pore Throat — Winland R35 and Pittman R25, pore class, Winland R35 map with iso-R35 lines • Permeability Transforms — power-law, Timur, Kozeny-Carman, class-based Winland, multi-regression; best method; log RMSE and bias • Reservoir Heterogeneity — Lorenz coefficient, Dykstra-Parsons V, Gini coefficient • RQI vs φz Crossplot — log-log with FZI iso-lines by flow unit • Lorenz & SMLP — flow capacity vs storage capacity curve and Stratigraphic Modified Lorenz Plot • Transform QC & Depth Plots — predicted vs core k for five methods with 1:1 line; permeability depth plot • Multi-Crossplot Panel — por-perm by facies and by Vshale class, bubble chart sized by R35, k vs Vshale

k = a × φ^b (a, b by least squares on ln k vs ln φ); RQI = 0.0314√(k/φ); FZI = RQI/[φ/(1−φ)]; Winland: log R35 = 0.732 + 0.588·log k − 0.864·log φ (φ in %); Pittman: log R25 = 0.204 + 0.531·log k − 0.350·log φ; Timur with porosity in %; Lorenz coefficient from samples sorted by decreasing k/φ

• Excel 2016+ compatible — no plugins required • 6,000+ formulas, fully transparent • 40-sample dataset included (Gas/Oil/Water zones) • MDT professional color scheme throughout

Built by petroleum engineers for petroleum engineers. All workbooks require only Microsoft Excel (2016+) — no plugins, no subscriptions. www.reservoir-risk-solutions.com