Core PHI vs. Log PHI, by Supplier
Compares real lab-measured core porosity against EACH available porosity supplier (the project's own computed PHI curve, plus any third-party CPI vendor curve), one supplier at a time, as a binned density heatmap -- the companion Core-Log Porosity Crossplot card groups the SAME underlying matches by formation instead of by supplier, and shows raw points rather than a heatmap. Pick a supplier chip to see its own agreement pattern against core; the summary table below ranks all suppliers by accuracy.
What "accuracy" means here: Only wells with a computed PHI curve (nsta.derived_curve_parquet) qualify -- 1,488 of 2,352 core-bearing wells project-wide (63%), the rest never had enough NPHI/RHOB log coverage to compute PHI at all. Same coverage gap as the Core-Log Porosity Crossplot card, since both read the same underlying match.
Last run: 2026-08-09 20:19:47 UTC
Core PHI vs. Log PHI, by Supplier
Smoothed density surface of every core sample matched against the selected supplier's porosity curve, over core PHI (X) vs. supplier PHI (Y) -- built from the FULL matched population, not a randomly-capped subsample. Darker/more opaque regions mean more samples land at that core/supplier PHI combination. The dashed line is perfect agreement (1:1); the solid amber line is a Deming regression fit through the actual population -- unlike an ordinary least-squares fit, it accounts for measurement error in BOTH core and supplier PHI (neither is an error-free reference), so it's the honest "what this supplier actually does" line to compare against the 1:1 ideal. Hover the chart for the exact core/supplier PHI at the cursor; see the summary table (right) for each supplier's overall bias/RMSE against core.
How this result was generated
(lab porosity_1)"] log["Well's Own Computed PHI Curve
(derived_curve_parquet)"] ext["External CPI Vendor Curve
(if the well has one)"] match["Nearest-Depth Match (0.5 m)"] bin["Bin into a 1%-Porosity Grid,
Per Supplier"] heat["Heatmap: Core PHI vs.
Selected Supplier's PHI"] core --> match log --> match ext --> match match --> bin --> heat
Hover a step for a plain-language explanation.