Well 15/9-F-11 (North Sea) — Multi-Track Display
Hover canvas to read depth & curve values
Ready-to-run script based on Andy McDonald's petrophysical plotting workflow.
Analyzed Interval
200.0 m
Net Gas Pay
24.5 m
Avg Reservoir Porosity
22.4 %
Shale Baseline (GR)
105 API
Track & Shading Key
Track 1: Gamma Ray (GR) — 0 to 150 API. Low indicates clean sand; high indicates shale.
Track 2: Deep Resistivity (ILD) — 0.2 to 2000 ohm.m (Logarithmic scale). Identifies hydrocarbons.
Track 3: Gas Crossover Shading — Activated when NPHI < RHOB (compatible limestone scale).
Track 4: Lithology — Yellow (Clean Sand), Grey (Shale), Amber (Gas-bearing Reservoir).
Neutron-Density Compatible Scale
To visually identify gas, RHOB (Bulk Density: 1.95 to 2.95 g/cm³) and NPHI (Neutron Porosity: 0.45 to -0.15 v/v) are plotted on an inverted dual-axis scale. Because gas contains low hydrogen index, neutron porosity drops while bulk density decreases, creating a distinct crossover.
Linear Shale Volume (Vsh)
Vsh = (GR - GR_clean) / (GR_shale - GR_clean)
When Vsh is below the user-selected cutoff and resistivity exceeds 15 ohm.m with crossover, the interval is characterized as permeable hydrocarbon reservoir.