/ Free Tools Library

Engineering tools,
ready to use.

Practical Excel applications built from real field work — not textbook exercises. Download, open, and use. No registration required.

Free to download · Excel / .xlsx format · No macros required · More tools coming
● Free Production
Decline Curve Analysis
Arps DCA — exponential, hyperbolic, harmonic, and linear decline. Input production history, get b-factor, Di, and EUR automatically. Filter by well or field.
Exp / Hyp / Harm / Linear · EUR + reserves · Chart output
Download .xlsx
Coming soon
Coming soon Reservoir
Material Balance Calculator
P/Z plot and volumetric material balance for gas reservoirs. OGIP estimation with drive mechanism identification.
P/Z plot · OGIP · Drive mechanism
Not yet available
Coming soon
Coming soon Production
Gas Well Loading Diagnostic
Turner critical rate calculator with wellhead pressure input. Identifies wells at risk of liquid loading — candidate screening for CSSI or other deliquification methods.
Turner Qc · WHP input · CSSI screening
Not yet available
Coming soon
Coming soon Unconventional
CBM OGIP Calculator
Coalbed methane gas-in-place calculation using Langmuir isotherm. Input VL, PL, gas content, coal density and thickness — get OGIP and sorption-scale recovery factor.
Langmuir isotherm · OGIP · RFsc
Not yet available
Coming soon
Coming soon Production
CSSI Candidate Screener
Systematic well candidate selection for Capillary String Surfactant Injection. Score wells against critical rate, production trend, and reservoir drive criteria.
Scoring matrix · Drive mechanism · Ranking output
Not yet available
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More tools
in development
Suggest a tool via
info@rfourenergy.com
All tools are free to download and use. Built from real field experience — 25 years upstream engineering, published research. Files are provided as-is; verify results against your own data before use in decision-making. Questions or suggestions: info@rfourenergy.com
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