Shale Volume & Net Pay Calculator: Vshale Methods, Cutoff Sensitivity & Thomas-Stieber Analysis
Four Vshale methods, a 5×5 cutoff sensitivity heat map, and Thomas-Stieber shale distribution analysis, all from your GR and porosity logs.
TAGLINE
Four Vshale methods, a 5×5 cutoff sensitivity heat map, and Thomas-Stieber shale distribution analysis — all from your GR and porosity logs.
WHO IT'S FOR
Petrophysicists and formation evaluation engineers performing shale volume and net pay determination for reservoir characterisation or field development planning.
WHAT IT DOES
Calculates Vshale by four standard methods simultaneously, automatically flags net pay vs. your adjustable cutoffs, generates a colour-coded sensitivity heat map showing how net pay % changes across a 5×5 Vsh×Sw cutoff matrix, and classifies shale distribution type using the Thomas-Stieber method.
TABS INCLUDED (7)
• Instructions • Log Data Input — depth, GR, RHOB, NPHI, RT, PHIE, Sw, Net Pay flag • Vshale Calculation — Linear GR, Larionov-T, Larionov-O, Clavier — all four computed per depth • Net Pay Analysis — Pay/Marginal/Non-Pay flags with adjustable cutoffs • Cutoff Sensitivity — 5×5 heat map (Vsh≤0.30–0.70 × Sw≤0.40–0.80), base case highlighted • Vsh Method Crossplot — Vshale by method, sample by sample (the depth plot is on the Vshale Calculation tab) • Summary Dashboard — gross, net pay and marginal footage, NTG
KEY FEATURES
• Cutoff sensitivity: each cell shows net pay % for that Vsh/Sw combination — colour-coded green/orange/red • Thomas-Stieber: structural / dispersed / laminated / clean classification from the Thomas-Stieber geometry of total porosity against Vsh, with adjustable endpoints • Larionov-Tertiary is the default Vsh method; it gives the lowest Vsh of the four, so it is the most optimistic for net pay • Net pay from live Vsh, PHIE and Sw cutoffs in light-blue input cells — change one and every flag and total updates
TECHNICAL SPECS
• Excel 2016+ compatible • 1,100+ formulas across 7 tabs • 25-sample log dataset pre-loaded • MDT professional color scheme
ABOUT RESERVOIR RISK SOLUTIONS
Built by petroleum engineers for petroleum engineers. All workbooks require only Microsoft Excel (2016+) — no plugins, no subscriptions. www.reservoir-risk-solutions.com
What you get
- Instant workbook access after payment in your Excel Library
- Formula-driven worksheet designed for petroleum workflows
- No recurring fees and no plugin requirements
Licence
Single-user licence: the purchaser may use and modify this workbook for their own work, including work for their employer and clients. It may not be resold, shared publicly or redistributed as a template. Results are engineering estimates for screening and must be checked by a qualified professional before they are relied on.
FAQ
Is this a one-time purchase?
Yes. Each workbook is sold as a one-time purchase with no recurring subscription.
How do I access purchased files?
After checkout, your file appears in Excel Library under your account for download.
Do these templates require macros or plugins?
No. Templates are designed for Excel 2016+ and do not require VBA macros or external add-ins.
